Hey everyone- it’s a very popular comment that the leg on a coaxial indicator is in fact adjustable. All I can tell you is, the instructions for mine say not to touch that bolt. Like many of you, I tried anyway and found it to be so tight that it couldn’t be removed without risk of damage. Likely Loctited in place. Maybe other brands of this are different, but that is how mine is.
Yeah probably because adjusting it introduces more cosine error. I think mine was just cheap and not loctited. I do wonder why the one side has that bevel if not for that
Very nice video, Quinn. The instructions of my centering indicator states to "adjust rocker friction joint to make the feeler contact with the workpiece". So you should not touch the bolt because it is set loose enough to be able to adjust the joint but tight enough to stay in place during the measurement. Adjusting the joint though still feels like you are forcing something you should not do on a precision measuring instrument.
Correct, that Bolt and nut is factory adjusted for a tight Friction slip. Just like the the Tip on a test indicator, you can push it past it's measurement range, and get the friction slip to adjust. It does have an mechanical Adjustment limit. in one direction it will stop close straight up and down. in the other Direction it should go almost a full 45 degrees. Just needs a bit of constant force to get it to start to slip. look at the angle that is cut on on it, that will clue you in to which direction it can be adjusted. So don't try to force it the wrong way if it's already against it's mechanical limit. Yes, it is a friction adjustment... Push on it...
LOL "...the instructions for mine say not to touch that bolt. Like many of you, I tried anyway..." Oh, really? I wonder why they would say that? That can't be right, and why doesn't the leg just adjust like other indicators?... RTFM in case of emergency ONLY!
I am a journeyman machinist. I worked in the field for 25 years, then taught machine tool technology at our local technical school the last 12 years before retirement. I love your videos. They are informative, entertaining, and well made. Thank you for calling the drill a drill, and not a drill bit-that always bothers me that people don’t know the difference. Even when precision requires a hole be indicated, I always used an edge finder to get close. It saves a lot of time with the indicator. You can easily get within .001” of the center using the 3 point hit method. If you have an edge finder with a .200” end, it will work on holes as small as .250”. Just take a hit at approximately 10:30 on the inside of the hole, and zero your x and y read outs. Move in the x direction and take a hit at 1:30. Move in the y direction, and take a hit at 4:30. Divide your readout values by 2, and move to that location. If you were careful with your edge finding techniques, you will be within .001” of the center. For many applications, that may be close enough. If not, you can now very easily and quickly sweep the bore with your indicator to make it more precise. Thanks for taking the time to make these valuable videos.
Worth to point out that microns have a limited use in metric countries, outside few industries. In general mechanic and manufacturing we use millimiters with 2 decimal places.
Recently, I was doing an operation training on an ID grinding machine. We were using micron to 1 decimal! Most cases, on a CNC machine (lathes, mills), I use microns. For example, to set and caliber a measuring arm/head like Renishaw. Frankly, I don't think there's a limit to the decimals. Only machines have limitations due to manufacturing and price.
Another wonderfully instructional video. Two points about the coaxial indicator. 1. While it may or may not be recommended, the indicating arm can absolutely be adjusted in or out similar to a test indicator. Theres just enough friction at the joint to move the arm and it will hold it's place. You can hold the indicator body while you move it or install the white plastic ring that the unit ships with to keep it from moving. 2. While the ability to use the coax indicator under power is novel, I've found that it's much faster to just swing the spindle by hand from side to side. Then you just split the difference in readings similar to the test indicator. I use coax indicators nearly every day and these techniques have never given me problems. Just my two cents. Thanks for making all your amazing content!!
Just wanted to say how much I like your fresh perspective on machining. You notice and comment on things that are perplexing to novices that many other TH-camrs gloss over without realizing it. As an example, during your explanation of a boring head you mentioned that the tool is a single point tool and only then did I understand what I had been doing wrong for years with poor results, I had been trying to cut with the edges of the boring bars.
Quinn: first, let me say that I really appreciate a young lady like you showing an interest in the machine shop profession. You’re articulate, pleasant and well-disciplined speaking voice shows your confidence and willingness to share your knowledge about the subject matter of your illustrations. I am a retired journeyman tool and die maker with just under 50 years of experience at 19+ manufacturing and vocational institutions of employment, both full-time and part-time. I am presently the lead machine shop instructor at engineering college in my community. I plan on referring my class to some of your videos. I enjoy critiquing them. I wish there was some way that I could speak with you for 15 minutes to help you with the subtle imperfections in your videos. As a small suggestion please show the thousands of an inch like this .005 and not 5 thou. Also, you are drill Chuck may be Jacobs, but it is an Albech design chuck or quick change drill Chuck. Thank you. Please keep up the good work. Rick
The moment you climbed onto your workbench to read the dial indicator, was hilarious!!!!! ; )) Fantastic entertainment while learning something. Sat here drinking coffee while eating chocolate ..................... and watching Quinn : ) TURK
I really enjoy your videos and I always learn stuff from watching them. From what I understand, the indicator body doesn't need to be in line with the spindle. This is because you are rotating the spindle to take the measurement, thus the circle the indicator tip is moving will always be centered on the center line of the spindle since it's the spindle that is rotating. So you don't need to hold the indicator body in a collet or any other precision mechanism. That's why things like the InDicol holder you can clamp on the quill is so handy. Also, a trap I ran into, the quill lock actually will always push the spindle over a few thou, so if you find a center with it locked, then make sure any operations you do also have it locked. Or if you are planning to drill with the quill, then do the indicating without the quill locked.
Hey I've been watching your channel for a little bit and I feel like I've watched you really come into your own style and format. Thank you for making videos that are both excellent and unique to you.
Relatively new to machining and didn't realise that you could move the leg on a DTI! Mine was quite stiff to start with but some penetrating oil freed it up. Always something to learn on your channel.
Ditto. I"ve only been using them for 2 years, and I guess I've been lucky that I always managed to make it work anyway. Setup should be easier now that my ignorance has been slightly diminished. Thanks Blondi
I got a coaxial indicator a few days ago. Wow what a difference it makes. I use it in the lathe to indicate in my tailstock and drills in the toolpost. Such a time saver. Maybe not super precise because it was an amazon special but plenty accurate enough for me!
Good treatment of a nessesary subject. Lots of old machinests watching and enjoying your channel so there will be plenty of good feedback. One is about that bolt on the coax. Use a soldering iron to heat up and then undo that bolt. I set the drag on that pivot to do the same as the tip on a dial test guage so I can carefully change the angle without a spanner. This opens up a wonderful range of options. Do not use the units of measurement on the gauge as actual, they are accurate comparators, but suffer greatly from cosine error as units of measurement. One method you didn't show but I've seen you use is the pointer end of the edge finder, easy to a couple of thou.. Keep up the great vids, you are fun.
Old school :) I was taught to use a sticky pointer. Which was a piece of plasticine with a pin stuck in it. It worked like a wobbler. I have a wobbler now. I’m lusting after one of those fancy concentric things :) Funny you published this now as I was doing this exact thing today repairing a machine vice.
Okay, my inner teenager was amused a couple times in this video, I confess. I will also volunteer that I had no idea how maddeningly complex it was to find or locate a hole with a vertical mill. To be both amused and gobsmacked at the same time was very difficult for my gray cells. I will now both console and reward myself with a cookie, both because I need more training at holding two somewhat opposed feelings in my head at the same time and also because I like cookies. Thank you.
Thanks for showing how the coaxial indicator works. My preferred method is an edge finder with a 0.2" machined end on one end and a pointed end on the other. These are available in different sizes, but I usually use the 3/8" body and it fits perfectly into a 3/8" R8 collet or Jacobs chuck and are short for small mills. They are used dynamically at a medium-high RPM (around 1000 is recommended). Simply adjust X and Y until the end just kicks out (0.2" end) or is at minimum if using the pointed end for a center punch. I think Mr. Pete has a video on how to make one, but Amazon has a Mitutoyo for around $20 as I write this. Since I have a DRO, I use the 1/2X (or 1/2Y) function for the 1st axis. I then set the X (or Y) axis to zero. I then do the same thing for the other axis. The problem with the normal edge finder is it can leave marks on the edge if it is soft material, such as aluminum. If that is important, I find the electronic edge finders useful if you are machining metal or other conductive material. These are used statically and cost a bit more. Amazon has a Fowler for about $50 as I write this. They usually have a 1/2" body and are not usually produced with a pointed tip. The DRO method can also be used, but creep up slowly so that the tool is not permanently bent (they can take a small amount of flex). Of course, for non-conductive soft plastics, use a thin sheet of paper between the dynamic edge finder and the work.
I absolutely love your videos. This one in particular I found very helpful. I am a journeywoman machinist and have been working in the trade for almost 7 years now. I have acquired and purchased many tools. One of which is a coaxial indicator. One issue I struggle with is my set ups and I am always looking for ways to improve. I have never run the indicator under power but this is definitely how I will be doing moving forward. It is a much faster way. You do an amazing job with these videos. Your explanations are so easy to understand and very entertaining! I wish I would have discovered your channel sooner.
That was really fantastic. I'm just a hobbyist with a PM25, but I think there may be a feature on your coaxial indicator that you might have skipped past. This little thing has helped me in the past anyway, especially if I'm restricted in Z travel but need to indicate a bigger hole than the small rod would usually work for. The coaxial does have a friction type adjustment (mine does anyway, and looks exacty like yours) like the needle of a test indicator, but you just need to loosen the Philips screw and nut at the lower fulcrum, readjust slightly for a bigger circle, then retighten. I know there are arguments for days on the forums about how the rod length and angle effect the actual reading on the dial, but zero or little needle movement is good enough for any of my projects regardless if I did something to desensitize the actual tool measurement in a slight way. Maybe you are aware of this adjustment, but just wanted to put it out there in case another person might not have known. Thanks for the video!
Ahhh the co-ax . . . bought mine some 25-30 years ago when there were few options/ manufacturers of said indicators. $ 329 is one reason to question my sanity. unlike many other professions, it'll cost ya . my "everyday" starrett top box holds the gold, the gerschner holds the jewels, including the co-ax. (and THAT'S why i don't loan out tools, TOM!!) Keep up the great service and continue to teach. you are the best source for knowledge outside of the handbook . . . i'm retired, and after 45 years, and i've seen the 180 of that
The resolution of the coax indicator diminishes with longer probes. I put a 4 slot encoder disk and optical sensor on the coax indicator and triggered a strobe light with it. It visually separates the two axis' of error indication. it it good fun to try it. Use a two color LED and some better electronics for even more fun.
There is one more dirt cheap method, laser. Those $5 doller laser pointer using watch battery, you can put it in the chuck and it will give you good indication. The only problem is, sometimes the red dot is too big, you can make a cover with paper/rubber/leather. Center it on you lathe/mill and use the smallest needle you can find to punch a hole on that cover. Depending how small the hole is, how accurate it will be. Loose your vice little bit, move the parts instead of the axis, press dro zero, It will reduce your tuning to seconds, but it only work on punch marks, not for holes already excisted.
I bought an indicator from SHARS that has half of the dial shaded in yellow. This works great when using a mirror. The indicator is jeweled with a reasonable cost.
Those coaxial indicators can actually be adjusted for different sized holes with any tip by loosening the Phillips screw near the fulcrum and moving the mounting end
Thanks Quinn! When I bought my edge finder it had cone end on it. I assumed that was for finding the center of a hole, though I’ve never tried it. Is it?
Quinn , I have wondered how to use a coax indicator properly , I will be trying this method out on Monday morning , Just by chance If some one cut you off , say on your way to the space ship factory would you roll down your car window and call them a WOOD WORKER .?????? Thank you for taking the time to make this video Pete M
Hi Blondi, my center finder has a friction mounted feeler much like the pupitas indicators. Does yours not have that!? It helps much with the range of the feelers. Thanks for the video, as always very nice to watch!
You can see that Quinn's does also have the friction "pivot" to allow adjustment for different diameter holes. It only moves to one side though unlike DTIs. Sometimes the pivot screw may be very tight and make you think it doesn't move.
Well I hate to say it but I had to stop and think about " Oh Behave " then every time and yes there is a lot of them good one. Always good to watch your vids.
I'll tell you a little trick I've used in the shop for year for picking up existing holes when you only need to be within a thou or two. Use an edge finder. Drop down in the hole, eyeball it to center of the hole. In "X" axis move until the edge finder kicks, zero your DRO then move the the opposite wall and when the EF kicks, look at the dimension, divide it by two and move back to that dimension and zero. Repeat for the "Y" axis and you will be centered.
Good suggestions. Luckily for me I seldom have to get too accurate. Retired doing home projects. I have both the coaxial indicator and dial test indicator, but my "go to" are a set of various sizes turn ground and polished pins (that fit in R8 collets) with one end turned on the lathe to a (long) tapered point then ground with tool post grinder for the finish. Most of the time I can see enough for a good enough fit. Sort of like your #2 center. I got a laugh from a few of your comments, reminded me of This Old Tony's channel. Thanks for the video!
I'm not sure this is as much an issue with jobber-length drills, but I can tell you for sure that extra long drillbits untwist a little during use, expanding slightly, and that's part of why they drill oversize. I found this out drilling a deep hole with a jobber drill and then running an extra long in there and having it bind. (Hence the existence of aircraft extension drills, I guess.)
Question, I can understand why you would want to find dead center of punch mark, @28:13 when your finding the center of the already machined hole, why would you want to unless you was going to enlarge it or cut a thread but wouldn't you have done that already while it was attached in its correct position ?
Awesome video - thank you (new to your channel - great work). I suspect another reason for the twist drill drilling slightly oversize is the torsional stress during operation tends to make the helical flutes unwind. This is probably less a factor than just being sharpened asymmetrically (or bent) as you said.
Hi Quinn. At 8:55 you mentioned someone saved a rotary table position in a DRO. I did not know that was a feature in a DRO. I searched without much luck. Could you briefly explain how that's done? (I have a Fagor 2-axis 20i. There's a video on saving on a 40i that involves a usb dongle but not on mine.) Thanks.
I love your channel, and i admit I'm new to your channel and machining as well. I have a clausing 12 inch lathe 5900 series. You are an inspiration and I love how you come out at the end with great results on your projects. And i also love your humor, (because of this video Beavis and Butthead popped into my head lmao!) i love it! Keep up the amazing content and thank you for sharing your skills!
Quinn, Like your vids. You have a very pleasant voice for narration. Re adjusting the coaxial, if you hold the rocker against the body with your thumb, you can pivot the "rod" holder around the screw some what in the manner of a DTI.
I want to align on a punch mark but my question is how do I get my brother to hold still so I can find the center of the mark I made where I punched him
@@somebodyelse6673 -I had already punched him ,I was just trying to find the center ,anyway I think I`ll try the super glue method or maybe loctite 601
Actually, since you have both a coaxial indicator and the mitutoyo indicator, you should consider using both! First, use the coaxial since it is the easiest. But, the coaxial is not the most precise! However, since the coaxial can locate the spindle center well within the range of the mitutoyo, finish locating the center with the more precise mitutoyo. That way, you get the best of both indicators with very little compromise. It is important to understand that coaxial indicators only work if the machine is large enough. The space inside some machines can be to small to use something as large as a coaxial indicator. That is why traditional dial indicators will always have greater versatile.
I have used a variation of the first method to center on a bullet mold in order to rework it. First you machine a cone . With that cone in the spindle , and the part in the vise, you come down until you are as close as possible , vertically and laterally. Then you loosen the vise , go further down until the vise doesn't wiggle any more , and tighten the bolts. ( the big disavantage is you will have to align the vise after you are done )
I may be a bit too old since I am retired I have more time than money. The wiggler you mentioned and demonstrated has another method that I like even better. If you take the pointed wiggler (for a punch mark) and place it in the punch mark with the machine off, then lift the quill and turn on the machine, it will swing around since it is off center. So, stabilize the wiggler as you mentioned and get it very close, place the wiggler in the punch mark and turn the machine on and lift, now leave the machine on and stabilize the pointer and adjust your X or Y then lower the quill into the mark again then lift. Repeat until there is no run out of the wiggler when you lift it from the mark. I do the same thing with the ball wiggler when I have a hole that is smaller than the ball. There you go. Another method. I use this so often that my drill has a wiggler and so does my mill. I am quite fast at this method and a lot less set up and fussiness of the tools I can't afford any way. lol Fortunately, I don't need 3/10ths of accuracy for my projects.
The beauty about purchasing a coaxial indicator is that you can use it with a known flat plate held down to your milling table and it will make a quick job of tramming your mill head to the table.
Working in machine shop environments ranging from automotive to pharmaceutical the best thing to do when trimming the head on a Bridgeport/clone or anything else is to bring the indicator down on a part of known height (gage blocks work best. Zero the indicator sweep 180° and see where you are to the block. Adjust as required. Doing this eliminates a number of variables. If you really want to use a piece of known height where the sides are dead nuts (at least anything you could measure in a home shop*) beg, borrow or steal an inner or outer race from a ball or roller bearing**. Unfortunately BPs are terrible for developing sagging at the ends. They also tend to develop wear patterns in which they wear mostly in the center. After all they are NOT a jog borer. Also if most of the work is done in the center of the tables the table will wind up with a hollow area over time. Plus if tee nuts are over tightened or the nuts on strap clamps are reffed on too much it is possible to distort the table in that area. When using strap clamps the best thing is to have a nut and washer on the stud that you run the stud into the tee nut and tighten the nut within reason to lock the stud. *Robin Rinzetti excluded **I know people call steel balls ball bearings. They aren't. When combined with the inner and outer race plus the gage. That's a ball bearing. Pet peeve of mine.
I thought the pointy end of an edge finder was for centering on holes. I haven't actually ever tried this, even though I have an edge finder with a pointy end. Does that trick not actually work, or am I mistaken about what the pointy end is for?
I never miss any of your videos - they’re explained so thoroughly and at a level that suits me. I’ve learnt loads! I wondered whether you are planning a video on milling slots - I’m having trouble! Mike (Lincoln, UK)
One big one that you missed, that doesn't intuitively sound like it could work, but does, and is often overlooked, is the lowly edge finder. Although they are designed to work with only straight and square edges, they work just as well for rounded features, like holes, slots, and bosses (yes, outside, too!), and can approach the accuracy of the test or coax indicator. It's much quicker and much more versatile than many of the other solutions. I use it with the 1/2 feature on my DRO usually, and don't even need to compensate for the edge finder's diameter at all - any diameter in any feature that it fits into will work. One would think that if you're off-center in either axis to start, it can't find the opposing (rounded and/or straight) edges of the hole accurately, but it somehow does - every time! I usually set my zero center at each axis in turn and then double-check for zero to verify repeatability. Never had an error yet. Try it yourself if you find it hard to believe. Do the edge finder method first and then double-check with your other tool of choice without moving your position. You'll be pleasantly surprised, save tons of time, and maybe even drop those older traditional methods for good. The first time you precisely locate the middle of that elusive round-ended slot, or the axis of that stubborn dowel pin you can't remove from the blind hole, in under a minute, with one simple tool, I think you'll be hooked. Another bonus tip - There seems to be a misconception that an edge finder needs to run true to be accurate. Not so! This is the beauty and genius behind it! The edge finder will shift on axis of the quill at concentricity no matter where it's rotational axis is (within reason, of course), which is important to remember if you were thinking about using the cylindrical tool (drill, transfer punch, etc.) method to locate holes. Set your edge finder intentionally off center with a shim of paper or whatever and try it. It will still work just as well. I have used them with old worn-out drill chucks with no loss of accuracy. Edge finders are usually good to 0.0005" if in good shape and used carefully, and can be dependent on your ability to interpret the "shift point" closely. If you want more accuracy than that, I would use the edge finder to get close and then switch over to a test indicator for the last few tenths. Or, get one of those "chair" style edge finders if you want to be even closer. I have never used a coax indicator, but they seem more trouble than they're worth, with the clearance issues especially. I have a small mill without power knee and cranking it up and down to make space is tedious when I can simply insert a two inch tool into my spindle. I'm sure it's much the same problem with the Z-axis on the column. Keep up the good work and the insightful advice. BTW, these are trade secrets, so please don't tell anyone ;)
When finding the hole with an indicator you don't have to worry about looking at the back side of the dial as long as the hole is perfectly round. After finding the center on the x axis, move the y axis to get the same dial reading. If the three readings are exactly the same, the fourth must also be identical.
Great video! I just wanted to point out that the coaxial indicator can be adjusted on the shiny screw joint in between the leg fixture and the body tilt to fit a wider range of hole sizes. And also that the scale of the dial does vary with the lengths and angle of the leg pins (or whatever the shiny rods touching the part is called). This can easily be tested by putting a shim stock or something with a known dimension in between the part and the pin to see. Another useful way to find a hole is to use a live or dead center in the spindle. Keep up the great work!
Still a big fan of my optical centre and edge finder,just line up the graticules and off you go. Very quick,easy and accurate. There is the Haimer and the Renishaw probe on the Haas but the optical still a favourite.
Wouldnt it be possible to machine a plug gauge on your lathe, with the shank sized for a relevant collet and the "plug end" machined to a transition fit for the hole your trying to align 🤔?
My preferred way to pick up a bore is to use a 3d indicator like a Haimer or Tschorn. Not a cheap option but they are also great for replacing edge finders.
I had a Blake co-ax indicator and the leg moved where ever you wanted. But for me an even better option was a vertical dial test indicator. Unlike your horizontal indicator with mirrors, the dial sits straight up so you can easily read it as you rotate around the hole. I have even heard of shops that don't allow their employees to use co-axial indicators as they can introduce too many errors.
Still taking digs at us woodworkers I see! : ) No mercy for us dual trade people. Might be good to mention backlash when using the indicators for those people that don't have a dro, just as a reminder. Thanks for mentioning the wiggler. Best method I have used for picking up scribed lines. Another great video! Thanks!
Tucker Southard: yeah wired that. But, with lathe based time travel. I no longer believe in coincidence. The truth will out when your sat in you ToT tea shirt sipping a cuppa from your blondihacks mug Whatching a Clickspring vid. Free will is not covered in the machinists handbook. (Metric fist shake)
I prefer using a dial indicator with a holder like an Indicol that allows you to face the dial up so you can see it while spinning. I've never used a coaxial indicator that I liked, they all felt cheaply made and imprecise. I think there is a reason the big names (Starrett, Mitutoyo, Brown & Sharpe) don't make them. To speed up centering, I usually start with a pin and eyeball it, then go in with the dial indicator. One thing that help with sweeping in a hole with a dial indicator is once you get one axis in, the zero reading will be the same (or very close) in the second axis, so you can just zero the dial, turn it 90º and then just move the second axis until the dial reads zero again. This should get you within a few thousandths, assuming your hole is within a few thou of round. One other way of locating on a center punch is using the pointed end of an edge finder using the same method you would for a hole.
A good tutorial, there is one other method that works particularly well on holes or cylinders that have diameters larger than 1" say like 6". Use a cylindrical edge finder and the DRO. If you are unfamiliar with this type of edge finder they work much like the wand type demonstrated near the end of this video but they do not tend to flail around. By using a method similar to the dial indicator, with the DRO and a calculator a center can be found in a minute or two. The diameter is only limited by the travel of the Y or X of the mill bed.
Here’s a project to try for you. Couple of cents laser diode, add a coin battery and magnet/clip to the spindle. Persistence of vision gives you a circle and you adjust diameter by changing height. The eye seems to be decently accurate at judging equiv gaps ...
Boy do I owe you. I own the "cadillac" option, and never entirely understand the fine details of it. You really filled in a few things I needed to know. AND, how you showed how to dial it in while running slowly and adjusting it with the axis's correctly. This settles it..... I have to STOP, marrying beautiful woman who are great cooks. I need to mary a beautiful woman, that is also a machinist, (better than me) and we can HIRE, a cook. I've been entirely doing this wrong. Actually, while I'm thinking about it, we should get married. LOL. Blessings, keep up the great videos.
i have the same coax indicator as you do and mine gives me a 0.100 error in comparison with the dial indicator, i was wondering why i was not getting my center, after doing a few comparison tests i found out the coax indicator is off. do you have an idea what can cause it? does it need to be calibrated
Now it is 2023, mid February, and I cannot find that device. SPI makes a lot of wonderful stuff, and I was curious. I wonder why you provided no link? Is it because the thing has been superseded by something else? I'm fine using any of the methods you demonstrated, until I need real 1 tenth or better. It takes so much time, sometimes.
The really interesting thing about a coax indicator is that if you mount them eccentrically, they still work. So they automatically correct for any runout in your collet or chuck. If you get a cheap one they often have a minimum amount of wobble. If you just minimize that you are good. Mine will never get exactly down to no wobble in the dial. I don't think it's worth paying extra for a good one unless it has a shorter footprint.
This is a bit off topic but it relates to punch marks. I found that I can use a punch to drill incredibly accurate hole patterns. The trick is to put a sharp object in the quill and bring it down to make a mark. The quill mustn't rotate. Move the table an accurate amount using gage blocks or something accurate to a tenth or better. Bring the quill down and make a mark. After they are all done use a small flexible drill that will follow the mark. Drill the hole on all of them and go back and make them the size you need. I find I can get most of them to within a tenth and the worst might be two tenths. Measuring the accuracy is a chore. I usually put pins in two holes and measure the outside distance and compare with the others.
Another way is to use the pointed end of an edge finder and a 1/2" precision bushing that is just able to slide over the edge finder body with no slop. Load the edge finder in the chuck point end down with the bushing in the middle. Stick the point in the punch mark, and move your x and y axis till you can slide the bushing down to meet the part surface. If it won't go all the way down, it's not lined up yet.
Blondie, thank you for your channel. It has been 50 years since I took machine shop in high school, and spent a summer working for research tool and die for a summer. I just bought my first lathe, a 7"X14" and will make a machinest hammer and then a meat tenderizing hammer like the one I made in high school. I have five daughters and a son. All of them would like to have the meat hammer they grew up with. So I plan to make four more, maybe five. I am trying to decide if I should buy a mill with a tilt head, tilt column or one like your PM-25? I have been looking hard for about a month and see no hobby projects that require the tilt column, or tilt head. The tilt seems to introduce unnecessary error?
Hmmmmm, new to the channel but👍 What I usualy do is machine a cone of sutable size in the mini lathe then chuck it in the mini mill which has a built in z axis readout then manipulate the axis(es) to get maximum z value. That was good enough for me but I am a hobby machinest
Hey Blondihacks how's your day going? My dad and I just got back from doing two days on the Appalachian Trail. It's nice to be back in my home state of Ohio however.
Very informative, thank you. I saw a video some time ago where a laser pointer was used to align the quill to the hole. I don't know if it was a commercially available tool or a homemade device. It got me to thinking why there aren't more machining measuring tools that use laser technology. DRO,s for instance.
It is critical with the co-axial indicator that the body of the indicator does not wobble as the mill spindle rotates, since this wobble shows up as needle movement on the dial. I noticed that yours was wobbling slightly. So it would be interesting to check the centring accuracy of the coaxial indicator with a dial indicator.
Hey everyone- it’s a very popular comment that the leg on a coaxial indicator is in fact adjustable. All I can tell you is, the instructions for mine say not to touch that bolt. Like many of you, I tried anyway and found it to be so tight that it couldn’t be removed without risk of damage. Likely Loctited in place. Maybe other brands of this are different, but that is how mine is.
Yeah probably because adjusting it introduces more cosine error. I think mine was just cheap and not loctited. I do wonder why the one side has that bevel if not for that
Very nice video, Quinn. The instructions of my centering indicator states to "adjust rocker friction joint to make the feeler contact with the workpiece". So you should not touch the bolt because it is set loose enough to be able to adjust the joint but tight enough to stay in place during the measurement. Adjusting the joint though still feels like you are forcing something you should not do on a precision measuring instrument.
Correct, that Bolt and nut is factory adjusted for a tight Friction slip. Just like the the Tip on a test indicator, you can push it past it's measurement range, and get the friction slip to adjust. It does have an mechanical Adjustment limit.
in one direction it will stop close straight up and down. in the other Direction it should go almost a full 45 degrees.
Just needs a bit of constant force to get it to start to slip. look at the angle that is cut on on it, that will clue you in to which direction it can be adjusted. So don't try to force it the wrong way if it's already against it's mechanical limit.
Yes, it is a friction adjustment... Push on it...
LOL "...the instructions for mine say not to touch that bolt. Like many of you, I tried anyway..." Oh, really? I wonder why they would say that? That can't be right, and why doesn't the leg just adjust like other indicators?... RTFM in case of emergency ONLY!
With respect: that’s strange. I’m not home, or I’d send you a pic of mine.
Just wanted to say that I really appreciate the on screen metric conversions, coming from outside the US, so thanks for that!
I am a journeyman machinist. I worked in the field for 25 years, then taught machine tool technology at our local technical school the last 12 years before retirement. I love your videos. They are informative, entertaining, and well made.
Thank you for calling the drill a drill, and not a drill bit-that always bothers me that people don’t know the difference.
Even when precision requires a hole be indicated, I always used an edge finder to get close. It saves a lot of time with the indicator. You can easily get within .001” of the center using the 3 point hit method. If you have an edge finder with a .200” end, it will work on holes as small as .250”. Just take a hit at approximately 10:30 on the inside of the hole, and zero your x and y read outs. Move in the x direction and take a hit at 1:30. Move in the y direction, and take a hit at 4:30. Divide your readout values by 2, and move to that location.
If you were careful with your edge finding techniques, you will be within .001” of the center. For many applications, that may be close enough. If not, you can now very easily and quickly sweep the bore with your indicator to make it more precise.
Thanks for taking the time to make these valuable videos.
Thank you for a thoughtful and informative comment! 😄
oh nice, I don't know if you've been doing this for a while but thanks for showing metric conversations on screen!
Worth to point out that microns have a limited use in metric countries, outside few industries. In general mechanic and manufacturing we use millimiters with 2 decimal places.
Recently, I was doing an operation training on an ID grinding machine. We were using micron to 1 decimal!
Most cases, on a CNC machine (lathes, mills), I use microns. For example, to set and caliber a measuring arm/head like Renishaw.
Frankly, I don't think there's a limit to the decimals. Only machines have limitations due to manufacturing and price.
Great tips, and well explained. This is the first time I have understood how a 'wiggler' works!
Then there's the Red Wiggler, the Cadillac of centre finders.
Another wonderfully instructional video. Two points about the coaxial indicator.
1. While it may or may not be recommended, the indicating arm can absolutely be adjusted in or out similar to a test indicator. Theres just enough friction at the joint to move the arm and it will hold it's place. You can hold the indicator body while you move it or install the white plastic ring that the unit ships with to keep it from moving.
2. While the ability to use the coax indicator under power is novel, I've found that it's much faster to just swing the spindle by hand from side to side. Then you just split the difference in readings similar to the test indicator. I use coax indicators nearly every day and these techniques have never given me problems.
Just my two cents. Thanks for making all your amazing content!!
Thank you for the metric conversions! Helps the rest of the world percive what your actually talking about when you say a thou or a tenth.
Just wanted to say how much I like your fresh perspective on machining. You notice and comment on things that are perplexing to novices that many other TH-camrs gloss over without realizing it. As an example, during your explanation of a boring head you mentioned that the tool is a single point tool and only then did I understand what I had been doing wrong for years with poor results, I had been trying to cut with the edges of the boring bars.
That’s great! Glad I could help! 😀
Quinn: first, let me say that I really appreciate a young lady like you showing an interest in the machine shop profession.
You’re articulate, pleasant and well-disciplined speaking voice shows your confidence and willingness to share your knowledge about the subject matter of your illustrations.
I am a retired journeyman tool and die maker with just under 50 years of experience at 19+ manufacturing and vocational institutions of employment, both full-time and part-time. I am presently the lead machine shop instructor at engineering college in my community. I plan on referring my class to some of your videos. I enjoy critiquing them. I wish there was some way that I could speak with you for 15 minutes to help you with the subtle imperfections in your videos. As a small suggestion please show the thousands of an inch like this .005 and not 5 thou. Also, you are drill Chuck may be Jacobs, but it is an Albech design chuck or quick change drill Chuck.
Thank you. Please keep up the good work. Rick
More handy dandy Blondihacks tips.
Yay!
Thanks, and Woof to Sprocket (a Confuse a Cat technique, just in case boredom abounds).
Very informative. You are a good teacher and crafts woman.
The moment you climbed onto your workbench to read the dial indicator, was hilarious!!!!! ; ))
Fantastic entertainment while learning something.
Sat here drinking coffee while eating chocolate ..................... and watching Quinn : )
TURK
Another excellent video Quinn. I don't think I've ever seen anyone go over that many procedures in one video.
I really enjoy your videos and I always learn stuff from watching them. From what I understand, the indicator body doesn't need to be in line with the spindle. This is because you are rotating the spindle to take the measurement, thus the circle the indicator tip is moving will always be centered on the center line of the spindle since it's the spindle that is rotating. So you don't need to hold the indicator body in a collet or any other precision mechanism. That's why things like the InDicol holder you can clamp on the quill is so handy. Also, a trap I ran into, the quill lock actually will always push the spindle over a few thou, so if you find a center with it locked, then make sure any operations you do also have it locked. Or if you are planning to drill with the quill, then do the indicating without the quill locked.
Yup! The indicator doesn’t need to be mounted in a collet, as long as it is attached to the rotating part of the spindle.
Hey I've been watching your channel for a little bit and I feel like I've watched you really come into your own style and format. Thank you for making videos that are both excellent and unique to you.
Relatively new to machining and didn't realise that you could move the leg on a DTI! Mine was quite stiff to start with but some penetrating oil freed it up. Always something to learn on your channel.
Ditto. I"ve only been using them for 2 years, and I guess I've been lucky that I always managed to make it work anyway. Setup should be easier now that my ignorance has been slightly diminished. Thanks Blondi
I got a coaxial indicator a few days ago. Wow what a difference it makes. I use it in the lathe to indicate in my tailstock and drills in the toolpost. Such a time saver. Maybe not super precise because it was an amazon special but plenty accurate enough for me!
Good treatment of a nessesary subject.
Lots of old machinests watching and enjoying your channel so there will be plenty of good feedback.
One is about that bolt on the coax.
Use a soldering iron to heat up and then undo that bolt.
I set the drag on that pivot to do the same as the tip on a dial test guage so I can carefully change the angle without a spanner.
This opens up a wonderful range of options.
Do not use the units of measurement on the gauge as actual, they are accurate comparators, but suffer greatly from cosine error as units of measurement.
One method you didn't show but I've seen you use is the pointer end of the edge finder, easy to a couple of thou..
Keep up the great vids, you are fun.
Old school :) I was taught to use a sticky pointer.
Which was a piece of plasticine with a pin stuck in it. It worked like a wobbler.
I have a wobbler now.
I’m lusting after one of those fancy concentric things :)
Funny you published this now as I was doing this exact thing today repairing a machine vice.
Okay, my inner teenager was amused a couple times in this video, I confess. I will also volunteer that I had no idea how maddeningly complex it was to find or locate a hole with a vertical mill. To be both amused and gobsmacked at the same time was very difficult for my gray cells. I will now both console and reward myself with a cookie, both because I need more training at holding two somewhat opposed feelings in my head at the same time and also because I like cookies. Thank you.
Thanks for showing how the coaxial indicator works. My preferred method is an edge finder with a 0.2" machined end on one end and a pointed end on the other. These are available in different sizes, but I usually use the 3/8" body and it fits perfectly into a 3/8" R8 collet or Jacobs chuck and are short for small mills. They are used dynamically at a medium-high RPM (around 1000 is recommended). Simply adjust X and Y until the end just kicks out (0.2" end) or is at minimum if using the pointed end for a center punch. I think Mr. Pete has a video on how to make one, but Amazon has a Mitutoyo for around $20 as I write this.
Since I have a DRO, I use the 1/2X (or 1/2Y) function for the 1st axis. I then set the X (or Y) axis to zero. I then do the same thing for the other axis.
The problem with the normal edge finder is it can leave marks on the edge if it is soft material, such as aluminum. If that is important, I find the electronic edge finders useful if you are machining metal or other conductive material. These are used statically and cost a bit more. Amazon has a Fowler for about $50 as I write this. They usually have a 1/2" body and are not usually produced with a pointed tip. The DRO method can also be used, but creep up slowly so that the tool is not permanently bent (they can take a small amount of flex).
Of course, for non-conductive soft plastics, use a thin sheet of paper between the dynamic edge finder and the work.
I absolutely love your videos. This one in particular I found very helpful. I am a journeywoman machinist and have been working in the trade for almost 7 years now. I have acquired and purchased many tools. One of which is a coaxial indicator. One issue I struggle with is my set ups and I am always looking for ways to improve. I have never run the indicator under power but this is definitely how I will be doing moving forward. It is a much faster way. You do an amazing job with these videos. Your explanations are so easy to understand and very entertaining! I wish I would have discovered your channel sooner.
That was really fantastic. I'm just a hobbyist with a PM25, but I think there may be a feature on your coaxial indicator that you might have skipped past. This little thing has helped me in the past anyway, especially if I'm restricted in Z travel but need to indicate a bigger hole than the small rod would usually work for. The coaxial does have a friction type adjustment (mine does anyway, and looks exacty like yours) like the needle of a test indicator, but you just need to loosen the Philips screw and nut at the lower fulcrum, readjust slightly for a bigger circle, then retighten. I know there are arguments for days on the forums about how the rod length and angle effect the actual reading on the dial, but zero or little needle movement is good enough for any of my projects regardless if I did something to desensitize the actual tool measurement in a slight way. Maybe you are aware of this adjustment, but just wanted to put it out there in case another person might not have known. Thanks for the video!
Quinn, I think this video is one of maybe 2 0r 3 that didn't have an imperal fist shake! well done !
Ahhh the co-ax . . . bought mine some 25-30 years ago when there were few options/ manufacturers of said indicators. $ 329 is one reason to question my sanity. unlike many other professions, it'll cost ya . my "everyday" starrett top box holds the gold, the gerschner holds the jewels, including the co-ax. (and THAT'S why i don't loan out tools, TOM!!) Keep up the great service and continue to teach. you are the best source for knowledge outside of the handbook . . . i'm retired, and after 45 years, and i've seen the 180 of that
Can also be used to center the tail stock on your lathe. Just purchased one tonight and can't wait till this tool comes in.
The resolution of the coax indicator diminishes with longer probes. I put a 4 slot encoder disk and optical sensor on the coax indicator and triggered a strobe light with it. It visually separates the two axis' of error indication. it it good fun to try it. Use a two color LED and some better electronics for even more fun.
Ok, so this I'd love to see a video on. Coaxial DRO?
I totally want to see a how-to video on this!
So happy to hear the word "ostensibly" used. One of my favorites (I have many)
There is one more dirt cheap method, laser. Those $5 doller laser pointer using watch battery, you can put it in the chuck and it will give you good indication. The only problem is, sometimes the red dot is too big, you can make a cover with paper/rubber/leather. Center it on you lathe/mill and use the smallest needle you can find to punch a hole on that cover. Depending how small the hole is, how accurate it will be. Loose your vice little bit, move the parts instead of the axis, press dro zero, It will reduce your tuning to seconds, but it only work on punch marks, not for holes already excisted.
I bought an indicator from SHARS that has half of the dial shaded in yellow. This works great when using a mirror. The indicator is jeweled with a reasonable cost.
Those coaxial indicators can actually be adjusted for different sized holes with any tip by loosening the Phillips screw near the fulcrum and moving the mounting end
Not according to the instructions on this one. 🤷♀️
@@Blondihacks mine either but that hasn't stopped me ;)
You can even pull the bolt out and flip the mount around to give even more range in the other direction
Thanks Quinn! When I bought my edge finder it had cone end on it. I assumed that was for finding the center of a hole, though I’ve never tried it. Is it?
Yah, I didn’t talk about that tool, but I have talked about it in other videos.
Yes, that is what it is for. It is quicker and more accurate than most of the methods shown, if the hole it bigger and about 1/4".
Did I type Gwen?! I meant Quinn! 😎
Quinn , I have wondered how to use a coax indicator properly , I will be trying this method out on Monday morning , Just by chance If some one cut you off , say on your way to the space ship factory would you roll down your car window and call them a WOOD WORKER .?????? Thank you for taking the time to make this video Pete M
Hi Blondi, my center finder has a friction mounted feeler much like the pupitas indicators. Does yours not have that!? It helps much with the range of the feelers. Thanks for the video, as always very nice to watch!
You can see that Quinn's does also have the friction "pivot" to allow adjustment for different diameter holes. It only moves to one side though unlike DTIs. Sometimes the pivot screw may be very tight and make you think it doesn't move.
Yup. Mine is like this too. I can adjust for different sized bores.
Well I hate to say it but I had to stop and think about " Oh Behave " then every time and yes there is a lot of them good one. Always good to watch your vids.
Another great video! Thanks. I use an edge finder for most holes. Works for this mope. 😆 great stuff!
I'll tell you a little trick I've used in the shop for year for picking up existing holes when you only need to be within a thou or two. Use an edge finder. Drop down in the hole, eyeball it to center of the hole. In "X" axis move until the edge finder kicks, zero your DRO then move the the opposite wall and when the EF kicks, look at the dimension, divide it by two and move back to that dimension and zero. Repeat for the "Y" axis and you will be centered.
That's basically what the 3D Tasters do.
Good suggestions. Luckily for me I seldom have to get too accurate. Retired doing home projects. I have both the coaxial indicator and dial test indicator, but my "go to" are a set of various sizes turn ground and polished pins (that fit in R8 collets) with one end turned on the lathe to a (long) tapered point then ground with tool post grinder for the finish. Most of the time I can see enough for a good enough fit. Sort of like your #2 center. I got a laugh from a few of your comments, reminded me of This Old Tony's channel. Thanks for the video!
I'm not sure this is as much an issue with jobber-length drills, but I can tell you for sure that extra long drillbits untwist a little during use, expanding slightly, and that's part of why they drill oversize. I found this out drilling a deep hole with a jobber drill and then running an extra long in there and having it bind. (Hence the existence of aircraft extension drills, I guess.)
Question, I can understand why you would want to find dead center of punch mark, @28:13 when your finding the center of the already machined hole, why would you want to unless you was going to enlarge it or cut a thread but wouldn't you have done that already while it was attached in its correct position ?
I absolutely love your videos!! Your very knowledgeable and patient to explain technical and practical techniques. Thank u ❤👍👍👍👍👍👍👍👍
Awesome video - thank you (new to your channel - great work). I suspect another reason for the twist drill drilling slightly oversize is the torsional stress during operation tends to make the helical flutes unwind. This is probably less a factor than just being sharpened asymmetrically (or bent) as you said.
Hi Quinn. At 8:55 you mentioned someone saved a rotary table position in a DRO. I did not know that was a feature in a DRO. I searched without much luck. Could you briefly explain how that's done? (I have a Fagor 2-axis 20i. There's a video on saving on a 40i that involves a usb dongle but not on mine.) Thanks.
Excellent information! Thank for share.
I love your channel, and i admit I'm new to your channel and machining as well. I have a clausing 12 inch lathe 5900 series. You are an inspiration and I love how you come out at the end with great results on your projects. And i also love your humor, (because of this video Beavis and Butthead popped into my head lmao!) i love it! Keep up the amazing content and thank you for sharing your skills!
That Phase II is adorable! I must find myself one. I find my 8 and 12 inch a little too cumbersom at times.
Cheers!
Quinn,
Like your vids. You have a very pleasant voice for narration.
Re adjusting the coaxial, if you hold the rocker against the body with your thumb,
you can pivot the "rod" holder around the screw some what in the manner of a DTI.
I want to align on a punch mark but my question is how do I get my brother to hold still so I can find the center of the mark I made where I punched him
@@somebodyelse6673 Top face ? I didn`t know he had another one , soooo then I can punch another ?
@@somebodyelse6673 -I had already punched him ,I was just trying to find the center ,anyway I think I`ll try the super glue method or maybe loctite 601
Actually, since you have both a coaxial indicator and the mitutoyo indicator,
you should consider using both!
First, use the coaxial since it is the easiest. But, the coaxial is not the most precise!
However, since the coaxial can locate the spindle center well within the range of the
mitutoyo, finish locating the center with the more precise mitutoyo. That way,
you get the best of both indicators with very little compromise.
It is important to understand that coaxial indicators only work if the machine
is large enough. The space inside some machines can be to small to use
something as large as a coaxial indicator. That is why traditional dial indicators
will always have greater versatile.
I like the climbing in the back to read the dial... looks like fun!!!!
I have used a variation of the first method to center on a bullet mold in order to rework it. First you machine a cone . With that cone in the spindle , and the part in the vise, you come down until you are as close as possible , vertically and laterally. Then you loosen the vise , go further down until the vise doesn't wiggle any more , and tighten the bolts. ( the big disavantage is you will have to align the vise after you are done )
I may be a bit too old since I am retired I have more time than money. The wiggler you mentioned and demonstrated has another method that I like even better. If you take the pointed wiggler (for a punch mark) and place it in the punch mark with the machine off, then lift the quill and turn on the machine, it will swing around since it is off center. So, stabilize the wiggler as you mentioned and get it very close, place the wiggler in the punch mark and turn the machine on and lift, now leave the machine on and stabilize the pointer and adjust your X or Y then lower the quill into the mark again then lift. Repeat until there is no run out of the wiggler when you lift it from the mark. I do the same thing with the ball wiggler when I have a hole that is smaller than the ball. There you go. Another method. I use this so often that my drill has a wiggler and so does my mill. I am quite fast at this method and a lot less set up and fussiness of the tools I can't afford any way. lol Fortunately, I don't need 3/10ths of accuracy for my projects.
The beauty about purchasing a coaxial indicator is that you can use it with a known flat plate held down to your milling table and it will make a quick job of tramming your mill head to the table.
Working in machine shop environments ranging from automotive to pharmaceutical the best thing to do when trimming the head on a Bridgeport/clone or anything else is to bring the indicator down on a part of known height (gage blocks work best. Zero the indicator sweep 180° and see where you are to the block. Adjust as required. Doing this eliminates a number of variables. If you really want to use a piece of known height where the sides are dead nuts (at least anything you could measure in a home shop*) beg, borrow or steal an inner or outer race from a ball or roller bearing**. Unfortunately BPs are terrible for developing sagging at the ends. They also tend to develop wear patterns in which they wear mostly in the center. After all they are NOT a jog borer. Also if most of the work is done in the center of the tables the table will wind up with a hollow area over time. Plus if tee nuts are over tightened or the nuts on strap clamps are reffed on too much it is possible to distort the table in that area. When using strap clamps the best thing is to have a nut and washer on the stud that you run the stud into the tee nut and tighten the nut within reason to lock the stud.
*Robin Rinzetti excluded
**I know people call steel balls ball bearings. They aren't. When combined with the inner and outer race plus the gage. That's a ball bearing. Pet peeve of mine.
Another great video, thanks for all the effort Quinn👍👍👌🤩
I thought the pointy end of an edge finder was for centering on holes. I haven't actually ever tried this, even though I have an edge finder with a pointy end.
Does that trick not actually work, or am I mistaken about what the pointy end is for?
You can use it for that, yes
Thoroughly enjoyed this tutorial. You make a great tutor, and hope to see more of these shop clips.
I never miss any of your videos - they’re explained so thoroughly and at a level that suits me. I’ve learnt loads!
I wondered whether you are planning a video on milling slots - I’m having trouble!
Mike (Lincoln, UK)
One big one that you missed, that doesn't intuitively sound like it could work, but does, and is often overlooked, is the lowly edge finder. Although they are designed to work with only straight and square edges, they work just as well for rounded features, like holes, slots, and bosses (yes, outside, too!), and can approach the accuracy of the test or coax indicator.
It's much quicker and much more versatile than many of the other solutions.
I use it with the 1/2 feature on my DRO usually, and don't even need to compensate for the edge finder's diameter at all - any diameter in any feature that it fits into will work.
One would think that if you're off-center in either axis to start, it can't find the opposing (rounded and/or straight) edges of the hole accurately, but it somehow does - every time!
I usually set my zero center at each axis in turn and then double-check for zero to verify repeatability.
Never had an error yet.
Try it yourself if you find it hard to believe. Do the edge finder method first and then double-check with your other tool of choice without moving your position.
You'll be pleasantly surprised, save tons of time, and maybe even drop those older traditional methods for good. The first time you precisely locate the middle of that elusive round-ended slot, or the axis of that stubborn dowel pin you can't remove from the blind hole, in under a minute, with one simple tool, I think you'll be hooked.
Another bonus tip - There seems to be a misconception that an edge finder needs to run true to be accurate.
Not so! This is the beauty and genius behind it!
The edge finder will shift on axis of the quill at concentricity no matter where it's rotational axis is (within reason, of course), which is important to remember if you were thinking about using the cylindrical tool (drill, transfer punch, etc.) method to locate holes.
Set your edge finder intentionally off center with a shim of paper or whatever and try it. It will still work just as well.
I have used them with old worn-out drill chucks with no loss of accuracy.
Edge finders are usually good to 0.0005" if in good shape and used carefully, and can be dependent on your ability to interpret the "shift point" closely.
If you want more accuracy than that, I would use the edge finder to get close and then switch over to a test indicator for the last few tenths.
Or, get one of those "chair" style edge finders if you want to be even closer.
I have never used a coax indicator, but they seem more trouble than they're worth, with the clearance issues especially. I have a small mill without power knee and cranking it up and down to make space is tedious when I can simply insert a two inch tool into my spindle. I'm sure it's much the same problem with the Z-axis on the column.
Keep up the good work and the insightful advice.
BTW, these are trade secrets, so please don't tell anyone ;)
Your coax indicator does have a friction adjust at the rocker pivot just like the test indicator, so you can adjust the circle the leg describes.
When finding the hole with an indicator you don't have to worry about looking at the back side of the dial as long as the hole is perfectly round. After finding the center on the x axis, move the y axis to get the same dial reading. If the three readings are exactly the same, the fourth must also be identical.
Good point! 😁
Great video! I just wanted to point out that the coaxial indicator can be adjusted on the shiny screw joint in between the leg fixture and the body tilt to fit a wider range of hole sizes. And also that the scale of the dial does vary with the lengths and angle of the leg pins (or whatever the shiny rods touching the part is called). This can easily be tested by putting a shim stock or something with a known dimension in between the part and the pin to see. Another useful way to find a hole is to use a live or dead center in the spindle. Keep up the great work!
Still a big fan of my optical centre and edge finder,just line up the graticules and off you go. Very quick,easy and accurate. There is the Haimer and the Renishaw probe on the Haas but the optical still a favourite.
Wouldnt it be possible to machine a plug gauge on your lathe, with the shank sized for a relevant collet and the "plug end" machined to a transition fit for the hole your trying to align 🤔?
My preferred way to pick up a bore is to use a 3d indicator like a Haimer or Tschorn. Not a cheap option but they are also great for replacing edge finders.
Another awesome video!
(Sorry, I don't know what "awesome" equals in metric.)
Wunderbar. Magnifique. Simply spiffing.
The only tool I own is a screwdriver but I love watching all your videos including This Old Tony
I had a Blake co-ax indicator and the leg moved where ever you wanted. But for me an even better option was a vertical dial test indicator. Unlike your horizontal indicator with mirrors, the dial sits straight up so you can easily read it as you rotate around the hole. I have even heard of shops that don't allow their employees to use co-axial indicators as they can introduce too many errors.
What about the other pointed end of the centre finder you showed previously? Wouldn’t that do too?
Still taking digs at us woodworkers I see! : ) No mercy for us dual trade people. Might be good to mention backlash when using the indicators for those people that don't have a dro, just as a reminder. Thanks for mentioning the wiggler. Best method I have used for picking up scribed lines. Another great video! Thanks!
Stars aligned or a bit of scheduling?
Blondihacks first and less than a hour later This old Tony!
Did you notice that TOT also needed to align a bore to his spindle? I thought that was a neat coincidence.
Tucker Southard: yeah wired that. But, with lathe based time travel. I no longer believe in coincidence. The truth will out when your sat in you ToT tea shirt sipping a cuppa from your blondihacks mug Whatching a Clickspring vid. Free will is not covered in the machinists handbook. (Metric fist shake)
Once again, a clear and interesting explanation by on outstanding teacher. Thanks!
How makes the cool looking indicator in the red box. I’m new to your channel and always looking for better ways of doing things.
I use a taper pin in my watchmakers staking set the stakes are precision ground for that purpose.
Great video. Ive ordered my coaxial but i do have a digitzing probe already but i dont know to set it up in my cnc software yet.
I am always losing my holes around the shop, can’t remember where I put them.
A strange quirk of quantum physics... A hole will always appear directly behind the very small object you are about to drop on the floor
Luckily ACME sells them in bulk!
I alphabetize all of mine, starting with A...
I prefer using a dial indicator with a holder like an Indicol that allows you to face the dial up so you can see it while spinning. I've never used a coaxial indicator that I liked, they all felt cheaply made and imprecise. I think there is a reason the big names (Starrett, Mitutoyo, Brown & Sharpe) don't make them. To speed up centering, I usually start with a pin and eyeball it, then go in with the dial indicator.
One thing that help with sweeping in a hole with a dial indicator is once you get one axis in, the zero reading will be the same (or very close) in the second axis, so you can just zero the dial, turn it 90º and then just move the second axis until the dial reads zero again. This should get you within a few thousandths, assuming your hole is within a few thou of round.
One other way of locating on a center punch is using the pointed end of an edge finder using the same method you would for a hole.
A good tutorial, there is one other method that works particularly well on holes or
cylinders that have diameters larger than 1" say like 6". Use a cylindrical edge
finder and the DRO. If you are unfamiliar with this type of edge finder they work
much like the wand type demonstrated near the end of this video but they do not
tend to flail around. By using a method similar to the dial indicator, with the DRO
and a calculator a center can be found in a minute or two. The diameter is only
limited by the travel of the Y or X of the mill bed.
Here’s a project to try for you. Couple of cents laser diode, add a coin battery and magnet/clip to the spindle. Persistence of vision gives you a circle and you adjust diameter by changing height. The eye seems to be decently accurate at judging equiv gaps ...
Boy do I owe you. I own the "cadillac" option, and never entirely understand the fine details of it. You really filled in a few things I needed to know. AND, how you showed how to dial it in while running slowly and adjusting it with the axis's correctly. This settles it..... I have to STOP, marrying beautiful woman who are great cooks. I need to mary a beautiful woman, that is also a machinist, (better than me) and we can HIRE, a cook. I've been entirely doing this wrong. Actually, while I'm thinking about it, we should get married. LOL. Blessings, keep up the great videos.
Perfect didactic, keep doing your great job!
i have the same coax indicator as you do and mine gives me a 0.100 error in comparison with the dial indicator, i was wondering why i was not getting my center, after doing a few comparison tests i found out the coax indicator is off. do you have an idea what can cause it? does it need to be calibrated
Now it is 2023, mid February, and I cannot find that device. SPI makes a lot of wonderful stuff, and I was curious. I wonder why you provided no link? Is it because the thing has been superseded by something else? I'm fine using any of the methods you demonstrated, until I need real 1 tenth or better. It takes so much time, sometimes.
Metric conversions are the best!!!
i sometimes use a wiggler to find either punch marks or layout lines. like you said depends on how accurate i want it.
The really interesting thing about a coax indicator is that if you mount them eccentrically, they still work. So they automatically correct for any runout in your collet or chuck. If you get a cheap one they often have a minimum amount of wobble. If you just minimize that you are good. Mine will never get exactly down to no wobble in the dial. I don't think it's worth paying extra for a good one unless it has a shorter footprint.
This is a bit off topic but it relates to punch marks. I found that I can use a punch to drill incredibly accurate hole patterns. The trick is to put a sharp object in the quill and bring it down to make a mark. The quill mustn't rotate. Move the table an accurate amount using gage blocks or something accurate to a tenth or better. Bring the quill down and make a mark. After they are all done use a small flexible drill that will follow the mark. Drill the hole on all of them and go back and make them the size you need. I find I can get most of them to within a tenth and the worst might be two tenths. Measuring the accuracy is a chore. I usually put pins in two holes and measure the outside distance and compare with the others.
Another way is to use the pointed end of an edge finder and a 1/2" precision bushing that is just able to slide over the edge finder body with no slop. Load the edge finder in the chuck point end down with the bushing in the middle. Stick the point in the punch mark, and move your x and y axis till you can slide the bushing down to meet the part surface. If it won't go all the way down, it's not lined up yet.
Is there a reason to use this over something like a Haimer? And their method of locating bores
Someday try out a Centering Scope. They rock for centering on marks.
Excellent as always.
That mirror trick works better when you have a double mirror setup, at 90degrees from each other, maybe that could be an additional inspection tool?
what about locating the center point of a half circle? Any solutions for that?
Useful and learned. Take care.
Blondie, thank you for your channel. It has been 50 years since I took machine shop in high school, and spent a summer working for research tool and die for a summer. I just bought my first lathe, a 7"X14" and will make a machinest hammer and then a meat tenderizing hammer like the one I made in high school. I have five daughters and a son. All of them would like to have the meat hammer they grew up with. So I plan to make four more, maybe five. I am trying to decide if I should buy a mill with a tilt head, tilt column or one like your PM-25? I have been looking hard for about a month and see no hobby projects that require the tilt column, or tilt head. The tilt seems to introduce unnecessary error?
Hmmmmm, new to the channel but👍
What I usualy do is machine a cone of sutable size in the mini lathe then chuck it in the mini mill which has a built in z axis readout then manipulate the axis(es) to get maximum z value. That was good enough for me but I am a hobby machinest
Hey Blondihacks how's your day going? My dad and I just got back from doing two days on the Appalachian Trail. It's nice to be back in my home state of Ohio however.
I will not behave, I will cackle like a 12 year old.
The cultural reference in these jokes is relevant to my interests (generation, I guess?)
Same, I only frequent all these machinist videos for the double entendres'
thanks Quinn. enjoyed this a lot
Very informative, thank you. I saw a video some time ago where a laser pointer was used to align the quill to the hole. I don't know if it was a commercially available tool or a homemade device. It got me to thinking why there aren't more machining measuring tools that use laser technology. DRO,s for instance.
lasercenteredgefinder.com.
This laser center finder works great for picking up points, scribed lines and edges
It is critical with the co-axial indicator that the body of the indicator does not wobble as the mill spindle rotates, since this wobble shows up as needle movement on the dial. I noticed that yours was wobbling slightly. So it would be interesting to check the centring accuracy of the coaxial indicator with a dial indicator.