Bronze Acme Nut for Lead Screw Part 1
ฝัง
- เผยแพร่เมื่อ 28 ก.ย. 2024
- We begin the machine work for the new bronze acme thread nut for the new lead screw I machined that will be used on the American Pacemaker lathe. We'll take some old bronze square stock and go to the 4 jaw chuck to machine them. Also we'll use our big FlexArm for power tapping the 3/4-5 left hand acme threads.
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Hey, nice to see you here, John!
And I agree with you by the way.
24:05 That sounds like when I try to open the bathroom door slowly at night.
Thanks for the in depth walk through all of this. I know you're slowing yourself down by bringing us along, but it's appreciated. I have some brass to drill some holes in at home, and the reminder about brass wanting to grab probably saved me a nasty surprise with a drill press. I'll probably hand drill it to make sure it doesn't grab.
It sounds like the refrigerator door when taking a sneaky snack in the middle of night.
Hand drilling is even worse than drill press and can break your arm if you’re not careful.
Hone a small neutral flat on both cutting edges of drills to remove the “hook” and stop drills from grabbing.
Oh, I mean arm power only, no motor.
I'd go for a "Loosen Lows, Tighten Highs" T-shirt
Clever use of the centres for dialing that nut in. Respect!
I just love videos. I love watching them on Saturday afternoons just relaxing
Adam eye-balls it and says 'probably 10 thousandths' then measures it at 11 thousandths :)) a master at work
I like how when Adam is centering a workpiece, he gets within two or three thou and says, "That's close enough," then keeps going to get it zeroed exactly. "Close enough" just isn't close enough. When it comes to machine work, perfectionism isn't a bug, it's a feature!
I was thinking the same thing! 😂 like man that guy is good!
I don't know, Adam...... You better get your eyeball recalibrated...... You were off by a thousandth or two! 😉
GreT to see you working between the two shops.
Great convenience.
Good work on the bronze parts too.👍
Since I am new to machining, I really like videos like this where you show all the steps for indicating an irregular shaped piece in a 4-jaw chuck. Great video! Thank you!
Want to see off-center machining, head over to CEE AUS, The piece he machined was 6" thick & 8-10" long. Bet that was an off center load.
cool trick indicating with the dead center!
Fun watching the new shop full then empty then full. :}
I am sure I echo all your followers in wishing you a very fast recovery. Get well soon.
all the years I've been Machining, using that dead center and indicator to Center up that hole I've never seen before.. the way I was taught to do it on an offset hole like that in between Jaws was to just use a plain 60° dead center ( or whatever degree Center you have as long as they're mating ) open up the Jaws on the Chuck, use your tail stock and quill to pinpoint and press your work up against the back of the chuck then bring your jaws down to meet your work evenly ..once it's tight, remove your tail stock and dead center that should put you right on the money.. that's the way I was taught.. I wish I had a shop because I'd get up and go down into the shop and test it to see which one's better.. thanks for the tip Adam.. another useful tool for the Arsenal..
Using the live and dead center method is more accurate, Just lining up a center will always be at least a few thousandths out no matter how carefully you try to line it up, the few thousands out really doesn’t matter in this instance but it’s nice to know how to get it dead nuts when needed.
I use the tail stock like that but i wouldn't say it gets dead nuts on, it's a good way to get it close though.. i done that trick yesterday but it's just a burnt out 5/8" thick disc that needs to be bored so a piece of 2" round can be welded in ready for the next opp so a couple of thou out doesn't matter at this stage
Sir, you are an artist.
Glad you are well Adam
I was getting quite excited to view the cutting of lefthand thread on the lathe. The tap was an alternative method. Nice relaxed video.
Learned something. Centering the square stocks center drill hole with a 4 jaw. Thanks!
At 29:00 when you were manually tapping the hole my dog was really concerned with the squeaking. He must have thought something was in pain.
amazing how much the heat swell from the taping affects Bronze can affect the size.
Россия смотрит !!! Ваша работа завораживает !!! Мира и добра !
Tapping bronze by hand would make a great coyote call 😬
You could put it in the freezer for a few minutes then run the tap through again too if if was still too tight...
That's a good idea but there would be more clearance grains to be had by heating the tap in boiling water or hot oil if even more clearance was needed
That tapping was amazing to watch. I do not understand the geometry of that tap but interesting, just the same.
He explained it a few videos ago. The first section cuts the threads and the second section cuts the shape of the threads
First section is cutting same pitch 60°V Threads to get some material away, second Section cuts the actual Acme Thread
A good trick to drilling bronze or plastic is by honing a small radius on the corner of your drill.
Putting flats at the cutting edge to make a neutral cutting edge is the normal way to brass off a bit, people who do lots of yellow metal often have 2 sets of drills but for most people, it's just take it easy with a bit sharpened for steel and don't step drill
An old tool maker taught me that trick..... To put a small flats on the leading lips of the drill point...... Because brass and bronze will grab the drill and try to draw it in (possibly break it) if the drill point is dead Sharp.
I suspect the need for running the tap through a second time, by hand. Is probably due to heat expansion. I'm not a materials guy but I think Bronze expands more due to heat than tool steel. Please, anyone, let me know if this is incorrect.
This is the first of your videos I've seen, won't be the last.
In my experience, making tons and tons of nuts for propellershafts, if you run the tap in dry, it'll fit the first time... Bronze doesn't want to be cut, so if you lube it, you're helping the material win and not the tool 😉 sharp tools and no lube is the way to go 👍
So the oil allows the tap to slide and not to sheer?
Well this is an interesting comment lol. Now I'm confused as hell! 🤣
@@iamkilroiyo that's my experience 👍
Спасибо за видео, Адам! Вот это я понимаю, оснащение. Нам бы такой инструмент. А то режем внутреннюю трапецию резцом!
Удачи в работе!
I have to buy a new one of these for my little Atlas, so it'll be interesting in seeing how one would go about making one.
Monster tap
I love your show Adam~!
On your acme rod you made - did you cut a slot down it to clear dirt and metal ? Might help on tight fits. A hole expands when hot, so it might have been hot and cut threads, when it cooled it was tight. That is my educated guess. Good catch.
Hate tapping acme thread, got parts I convert on rebuild at work to acme xand tapping through steel is such a pain for how big threads are. Can hear your power tap not liking brass too much, be interested to see how it works on steel. I end up using lathe to spin workpiece n have tap held n tap wrench on carrige with live center in tail of tap to be able to get done
He's power tapped steel before and it works perfectly, Brass is just awful to tap. Lol
Screeches like a banshee.
Some great tips in this video for all machinists from the hobbyist to trade. But Adam, shame on you for throwing Abbey under the bus with the recording mishap. Could've blamed running out of battery for that, just saying.
I am very much enjoying your videos mate.
Have you thought about remaking lead screws and nuts for the Monarch to fix the threading issue you had earlier? Renewing the Monarch parts would be a interesting series.
...I'm pretty sure that making the necessary new parts for the Monarch lathe, would be beyond the capacity of the machines in Adam's shop.
To restore the accuracy that the Monarch lathe had when it was new, it would be necessary to send the Monarch lathe back to the manufacturer.
I'm not sure there is anything wrong with the monarch, other than the halfnut, which he could do himself.
As many commenters pointed out, he didn't do some things on the monarch that he did on the PM, almost as if he wanted his old lathe to fail.
@@an2thea514...YOU CAN BET THAT THE LEAD SCREW ON THE MONARCH IS WORN TOO- I SEEM TO RECALL THAT ADAM MENTIONED THAT HE MONARCH WAS MADE IN 1943- YOU CAN'T POSSIBLY EXPECT A MACHINE THAT OLD TO BE AS ACCURATE AS WHEN IT WAS NEW-(!)
ANYWAY, IT'S ADAM'S BUSINESS WHICH MACHINE HE USES.
Probably nothing wrong with the Monarch parts. He was pushing his luck on the first screw by not using lubricant or a follower rest. The part may have slightly slipped in the chuck.
@@daleburrell6273 Why are you shouting so much? Did your Caps get locked?
Yes, his lead screw needs to be worn, but he has both a threading dial and a great mix of materials, so it's not as worn as you might think. Hard steel against Bronze, do you know what will get worn first?
I think that I missed something in this setup...
Adam located a thread drill hole center, but I didn't see him do this (maybe I dozed off). He used this center to locate the hole center in the lathe 4 jaw chuck using the dead center trick. I like this method. It is much better than trying to use a test indicator in the tiny center hole. How did he register the square stock flat in the 4 jaw chuck. Did he use a parallel behind the stock or seat it against the chuck face? How will he pick up perpendicularity to the tapped bore to turn the stem? It seems to me that the stem shank must be perpendicular to the thread to prevent screw binding. The square stock will all be machined away so it isn't required for final part registration. I think that I would have marked a registration surface from the original square stock since the part can be flipped 180 degrees and the square stock parallelism isn't validated. I am wondering if he could turn a registration bar to the thread minor diameter and indicate from the lathe cross slide to ensure that he turns the stem perpendicular to the tapped hole.
Is my concern or question valid? Is the stock material flat adequate for registration?
Was just about to ask the same.
Your concern is valid. And if this had all been made out of tool steel it would probably had become an issue. But Brass is rather forgiving. If it isn't dead nuts on the perpendicularity either the forces of the machine will make it conform or the clearance will eat it up (he could wiggle the lead screw a bit). Obviously if the stock had been outright questionable on the flats it would have been a different matter.
yeah I'm not sure the whole is square to the block unless he just didn't show indicating it in that direction
I was thinking about this also. The axis of round part of the nut (the spigot?), which has yet to be turned, needs to be square to the long axis of the threaded hole. One way to insure this would have been to face the whole side of the block when he bored the hole. Doing so would pretty much guarantee a reference surface that is square to the hole. Or another way to say it, the hole would be normal to that surface. The other sides don't really matter.* Then when he sets it up on the lathe he can indicate along that surface to insure it is parallel to the ways of the lathe before turning. He did face the ends but aren't as big a reference surface.
*The other alignment that is important is having the axis of the spigot in the same plane as the axis of the threaded hole (coplanar.) It may not make much difference but whatever the difference is it will be most noticeable when the nut is closes to the bearings. One way to insure they are coplanar would be to have turned the spigot first then do the drilling, boring, and threading features with the spigot mounted in a V-block on the mill. Another would be if the hole is centered along the short axis of the nut when he marked it on the mill and then centered it on the lathe to within a TIR of 0.0005" he can indicate it off the sides he used to center it on the mill. (Hope that makes sense! )
Maybe Adam has another trick up his sleeve. I am sure this is not the first time Adam has made a leadscrew and nut. In any case... I am very interested to see how it turns (no pun intended) out.
Outstanding
Did the acme tap made a smaller thread because the material heat expanded while tapping and the thread collapsed afterwards or why didn't it fit?
Those Acme threads are a bear aren't they!
I'm thankful that Atlas has tiny 1/2" Acme.
looks like a protopipe
I think the smaller thread may have heated up/expanded the bronze so that the second stage was actually cutting less material due to a very slightly bigger, heat expanded , hole. Does this seem feasible as to why the hand tap had to be done?
Brass is rather flexible. The outward pressure from the tab should be enough to cause it. The hole was pretty big for the wall thickness, and it's not a fine pitch thread by any means. If it was like 4x4" stock the problem would probably have been a lot less pronounced.
Curious why you didn't just do the boring and champhering on a drill press. Wouldn't that save you a fair bit of set-up time?
Drills make pretty crummy holes, usually somewhere near where you actually want them. Reamers are a little better; at least the holes get rounder and straighter. Lathes make really nice holes, the right size, in the right place, straight, smooth, perpendicular, very round.
Drill press is the wrong machine for this job for many reasons. This is a one in a century replacement screw and nut so setup time is not as important as getting it right.
@@ydonl he was at the edge of vibration, this hole would have been more accurate in the mill
@@ellieprice363 A Mill is just as accurate as a Lathe, not a Drill Press
I've had several sinus procedures done so I feel your pain.
What bronze are you using for the nut? Looks a bit like yellow brass to me.
I’m quite inexperienced, but it seems unusual for a tap to need to be run twice. And it seems especially strange that it would generate so many chips for having already run through once. But hey, stuff is weird.
That is a keen observation! .... And well worth thinking about.... (To be honest with you I was wondering the same thing 🤨)
I believe what we were seeing was a combination of the elasticity of the material...... And the heat Factor. You heard the squeaking and rubbing as the tap was going through, and you can bet that was generating some serious heat from the friction. And that heat might have been just enough to expand the "plasticity" of the bronze material slightly. When the tap was finished..... the heat was finished..... and the bronze shrunk back down a couple of thousands in diameter.
Then, when Adam ran the tap through manually the second time..... There was not as much material to remove (as the first time)...... And there was almost no heat generated -- so the plasticity of the material did not come into play..... And the tap cut "hard solid" material.
This "plasticity" Factor would not come so much into play if he were tapping steel (which is much denser than non-ferrous metals like brass, bronze, or aluminum).
Well anyway..... That's my take on it. I'm not sure if it's accurate, but it makes sense to me.
To use a ridiculous example, for instance, let's pretend that he was tapping a marshmallow. Now can you picture that a marshmallow -- once the tap has passed through it -- would shrink back down again. The tapped hole would probably almost close up completely (marshmallows being very "plastic" in their flexibility). It's kind of the same principle: non-ferrous metals are more "plastic" in their elasticity then ferrous metals (metals containing iron).
Looks great Adam! I have a small bench lathe, I noticed you had a fine adjustment screw on yours to help adjust to the actual center of the work.
How can I find a tool holder that has that option? Any help there would be appreciated.
Hello to Abby, God bless you folks. Stay safe and take care!🙏🎚🇲🇾🇲🇾🇲🇾
Maybe i missed something, but what was the point of moving off the mill after creating the first center, then do the rest of the drilling on the lathe? Seems like it created needless work centering the work piece again, when it was already centered on the mill.
I think he needed to bore the hole to the dimension for the tap, and probably didn't have a drill/reamer the right diameter. That's just my guess.
He needed a .570 hole, a 9/16ths drill is only .562. Either way it had to be bored in the lathe to the right dimension. It also gave him a reason to show how to use a dead center and a live center to indicate a spotting hole on the face of a rectangular part.
I would have used a boring head on my milling machine, but maybe he does not have one yet for his new shop.
@@keiththomas8796 Quicker on the lathe... even with the dialing in.
Left-handed acme thread?
👍
Adam, why did didn't the acme thread tool cut threads the first time?
The bronze or brass will swell when you are tapping with a deep cutting ACME tap using a flex-arm. He tapped his part in one (non stop) thought the part. This makes heat fast and the hole got bigger so after it cooled down the swelling went down (the tapped hole was tight)
and he ran the tap back though by hand taking a little bit of cut to make it perfect.
All could have been avoided if he would have just tapped just a little bit then backup tap a little bit backup. Repeatedly until the hole was tapped but this could also made it easier to have backlash.
It turned out perfectly ok the way Abom did it.
Randy, appreciate the explanation.
@@ronnydowdy7432 The problem is, you can't back up a 2 stage Acme thread tap. It HAS to be done in one pass, straight through.
@@beezul thanks for the information
29:00 I suspect that the power tap generated a good amount of heat expansion in the bronze and the tight spots on the lead screw occurred when the bronze cooled and shrank. Running the tap through a second time by hand on a room temperature part cleared out the few thousandths of shrinkage due to the part cooling.
Yes I'm sure that's likely.
@@jonka1 I don't think so. The thermal coefficent of expansion for typical bronzes is about 17-20 X 10^-6 (millionths) per degree Celsius. On a part that size it would melt before it expanded "a few thousandths."
I don't think it was only heat expansion. On the next video, notice the pattern on the bottom of the radius. It is convex across the surface. The tap forced the material out. It didn't go back on the ends hence why the tap would start but got tight. An indicator would prove this. Interesting to see. I don't think steel would be so easily distorted.
Oh Adam..... That use of the Dead center for indicating the bronze center hole in the jaws.....that blew me away! I've never seen that done before..... But it's brilliant!!! 😉
And don't worry about sounding 'nasal' old buddy....... I think all of us would watch your videos even if you just used sign language -- they're that good!
Apparently I don't know what off camera means ...
Lol, the second drilling has better camera angles though. Maybe he was trying something out
Bronze always closes down after cutting, we used to allow +,002" on diameters to allow for this.
To keep a twist drill from hogging in brass and bronze put a small flat on the cutting edge no larger than 1/32" parallel to the center line of the drill.
This will make the cutting edge 0 degree rake and will stop the pulling.
That's exactly what an old tool maker taught me years ago!
This is Why i watch you Adam The skill and Professionalism and attention to detail cannot be taught from a book, It has to be hands on real work experience and you even admit when you fail... This is the definition of a master craftsman. God Bless you and Abbie. ❤🙏🏽👊🏽
I agree completely! Very well said!!!! 👍
I guess sometimes taps need a spring pass too :-) I expect the power tapping warmed up and expanded the bronze ever so slightly, making the threads on size for that temperature, but then when it cooled to natural temp it was slightly tight again.
Edit: Sorry - looks like lots of others commented the exact same thing.
Good stuff Adam! The lighting and video footage in the new shop looks amazing. :)
Love that Fex Arm. Done a fair amount of rigid tapping on my mill but that little bit of wiggle room and the hydro drive - seems like the bees knees.
Wait until you start learning your CNC lathe..... And find out that, with power driven cross drills in a couple of the turret stations, you can make this entire part in one operation!
Right now you're just curious about CNC..... But just wait and see what you can do -- Mr Manual Machinist, it will blow your mind. 🤗
When you stated that you were excited about trying out that giant acme tap I could picture your flex arm going, "Oh Jesus!".
Your video is always excellent. The scene of you loading the hydmech is great! Perfect lighting and focus. Sound is good, strong and clear. Never seen better on broadcast TV!
That dead center technique was really cool!
Wow! That hydraulic FlexArm is wicked powerful! Does such a great job too. Anyone know the diff in torque that it has vs. the electric one at the new shop? Great tool - now I want one LOL!
That pic sure as heck looks like the pipes I made in high school metal shop....41 years ago! :~)
Oh No Adam! your doing it all wrong! I have been watching the Pakistani truck channel lately. When they center something in the four jaw, they use a chunk of metal for a base and a bent wire stuck in that base. They bend the wire really really close to the workpiece and center it by eye! Then turn to the correct diameter using a pair of firm joint calipers and a tape measure. They don't even indicate Bro! 😁🤣 Edit: those Micro 100 Boring bars things are sweet. The next time I have a small job that could use a tool like that......
Wow! The trolls are out in force.
Que trabalho perfeito amigo Adam!!!
Grande abraço daqui do Brasil a todos aí!!!
Nice work! If it was me I would cut those radius features first, then turn the remainder in the lathe with a 4 jaw chuck. Gives you more to grip for the milling operation.
Adam got a nose job! Looking forward to the Avon79 review 😊
Damn tony and his time traveling lathe
Using the dead center to indicate off of was one of the coolest indicating tricks I have seen you do. Thanks for showing that!
I used that trick with the live center when I indicated the bronze nut I made for my lathe.
You can see the indicating tool I used to finish the indicating procedure in my Part 7 video.
The Precision Matthews machine looks exactly like the Colchester machines I used as a student. I guess you can’t improve on excellence. Our training workshop had machines made in the early 1970s.
Stavros
Any theories as to why it had to be tapped twice? My theory is that power tapping caused the brass to heat up & expand so after it cooled down it was undersized. This explains why the the lead screw was able to start but not go through the nut. The second tapping pass done by hand didn't create much heat so it was able to cut it to size when cold.
Nailed it. It's what happens with brass or bronze when tapping straight through and not stopping especially with ACME threads
Wow, just learned something new!! Thanks guys!!
That's gonna be a beautiful piece when complete. Too bad that the 1st acme rod went out of whack. Everything is coming together Adam. Can't wait to see that BIG lathe actually make chips...Great
Vids👏
Nice Adam. Why didn't you do all that on one of your mills? Amatuer asking 👴
I never saw that "dual center" centering trick before. Simple once you see it done, but still very slick. Nice!
I was very surprised to see how much tweaking you had to do to indicate & center the part just flipping it around 180 degrees in the 4-jaw chuck after drilling the first through-hole. That's a mini-lesson right there.
Oh yeah, and at long last, one of the charter members of Adam's vast tap handle collection finally makes an appearance. Bravo!
Double Boost (John Mills) uses a trick for quickly getting it very close, before indicating with the dead centre.
With the chuck jaws opened wide, he places the point of the tailstock mounted live centre in the drilled centre, pressing the workpiece against the face of the chuck, and brings the jaws in until they just touch the workpiece, leaving him close to centred.
I know...not workin here, cause of the big trough hole in his chuck.
That only works on larger parts unless you stick something behind it so it doesn't disappear up the head stock
@@markshort9098 You mean like a parallel?
@@BedsitBob yeah it's just something to cover the hole but then you either have to get it out or tape it in so it doesn't fly out, sometimes it's just easier to indicate in the whole way than stuff around trying to hold parallels and the part while winding the tail stock all at the same time
Matches up with our original sample when it’s Just a block with a hole 🤣
It must be frustrating having to compromise the accuracy of the piece to keep the sponsors happy. That's the only reason I can find not to tap the hole in the same setup as when you bored it.
Do you feel conflicted doing it this way, given you've built your reputation on following best practice?
This could have been a good candidate for thread milling on your cnc mill
probably a pretty expensive thread milling cutter i would bet.
Sounds like a good workout
Yeah, because threadmilling is a great thing to start doing for a beginner who just got his first CNC… 😂
@@bucknaked31 Im sorry? You ovbiiusly start on CNC cylinder head porting, of course!
Sorry your sniffer is stopped up! Glad you got it hoovered. Hope it comes back 100% right!
I've learned a lot about machining from you and others on the you-of-tubes. Making things helps me deal Combat Related PTSD (Creative Therapy), and then I sell whatever I make on Etsy (as per my Better Half's "request" (LoL)) The only problem I have being Medically Retired from the work force and not having the funds to stock up on materials such as Brass to keep making things. An I'm sure there are tools that would help as well, but it is what it is.
Please keep making great videos that I can learn from; and maybe I'll be able to practice what I'm learning one day.. Take Care and Stay Safe.
"Go Hard... Be Humble..."
man first look I thought you were making a proto pipe mod :)
Would have loved to have seen how you counter weight the chuck in order to increase speed.
Great video, Adam. Your explanation and instruction are great. I enjoy seeing you indicate a part. The threading is a nice piece of work with that two-stage tap. I am looking forward to seeing some CNC action as well. Thanks for sharing,
Squeal! LOL nice work Adam.
Adam, I've got an 1-3/4x4 2 stage tap for you to try.
Your Dad's shop keeps providing! Nice video Adam.
Muy buen trabajo maestro 👍
I love that technique for centering on a small hole. Definitely going to have to remember that one
Thanks for the tip.
That’s an ABOM size flex arm, so impressive how much torque that has!
Wow. this is wonderful. Talk about a "machinist's fit." I have watch Abom79 since SNS 2. This is the first one, that I remember, where Adam shows the indicating gauge up close at 22:50. Note that the needle is moving much less than one thousandth. Adam also guesses that he is out by 10 thousandth but it actually was 11 thousandth. This exemplifies why Adam is "Adam Booth Grand Master Machinist" and the rest of us are trying to be.
Your clock is broken!
So you're not supposed to reverse that acme tap out ??
No, because it is 2 stage tap there is too much risk of misalignment of the lower (first cut) section which could destroy the thread if you try to reverse it out.
@@grahamstretch6863 Thanks !
The sound of turning that tap by hand could be used to call coyotes
my guess with the tapping is that: the powertapping with the flex arm causes allot of heat and makes the brass expand, due to friction of the relatively highspeed tapping with the constant rpm from the flexarm, making the 2nd pass necessary because of shrinkage after the first tapping.
How many miles are your 2 shops apart?
Wow you couldn't afford to buy that piece of bronze today. You'd have to take a mortgage forsure. Just the short piece would-be $100 plus. Good thing ya saved dads shorts.
...is bronze more valuable than GOLD?!
I just bought a foot of 20mm brass round bar and it was 40 Australian dollars, I'd hate to think what those chunks cost these days.. i always clean everything before machining brass or other yellow metals and i save all the swarf to melt down one day
@@daleburrell6273 trumpet gold for sure.
I do somtimes acme nuts, but run to rigth. I do with tap with you.
Are modern bronze alloys the same? Looking at the wiki, there used to be quite a variation.
I guess anything different would be special order.
Ya gotta love it when a plan comes together Maestro.🙃
I know 'how' to operate a lathe and milling machine but I'm still little more than an amateur machinist even after almost 60 years a mechanic, I have to say I'm impressed with the way Adam used the dead center and live center to indicate the work!
Very cool trick!