How to drill a Bolt circle
ฝัง
- เผยแพร่เมื่อ 26 ก.ย. 2024
- Bolt circles are easy to do. You do not need a dividing head, rotary table, or a lathe. In this video I show you a metalworking technique and shortcuts to making bolt holes on a milling machine. I think you will appreciate this metal tips and tricks.
A lot of nay-sayers and eliteists here.
40+ years ago I was laying out a bolt circle for a PVDF pipe flange on a wet bench drain, and the company owner chastized me for "gold plating" it. At the time I was offended, and thought to myself "geez - he doesn't care at all about quality"
In later years, I was the business owner, and found myself on the other side of the same discussion. (fortunately the lesson wasn't lost on me and I explained to my employees WHY, which they did understand)
Some work just doesn't justify pulling out the rotary and spending 2 hours on a pipeflange or something similar where "Good enough IS Good enough" (better actually).
Once that pipe flange is bolted up, no one will know or care if those bolt holes are a few thou off. The machine will not operate any better, just cost more. They WILL care if the machine comes in over budget and everyone looses money on it. Many farm machines are the same story and are designed with loose tolerances where they can be tolerated for just this reason. I occasionally do repair work for local farmers, and they don't care if it's perfect to the tenth, they need it to work for a reasonable cost and fast as they often are on a hard deadline.
It's easy to be a perfectionist when someone else is paying the bills, and you have all the time in the world. This type of setup (and the radius trick in another video) Indeed has a place in industry, and it's a bigger place than most people seem to realize.
It seemed to me it was stated up front this is a technique for when it's NOT justified to spend 1/2hr breaking down the mill and setting up the rotary, but an awful lot of people seemed to have missed the point.
I think this video describes a better way to do good work "good enough" to make the customer happy and the shop money. That's what it's all about in the end.
Scott
Hi Scott,
I'm in agreeance with you. Unless the job requires precision then there is no need for it. I like to be a perfectionist from time to time, yet I know there is line drawn with individual customers and their needs as opposed to what I would do for myself or love jobs for family and friends. Though, there are some customers that appreciate the little bit of effort you put in which is reciprocal kindness 99% of the time, you know others just want the bare minimum - get in and get out. The bottom line is, you don't do anymore than you have to...
Good 'ole plain common sense, and a really excellent compromise between , cost VS adequacy and client satisfaction.
nifty1940 no one mentions pride in the job....do it once do it right.
on board there am part of as they call it downturn in the econemy shop.helper cnc
i have 40 + years automatics..manual i know the quick get it to the customer he coming now versus my supervisor straight cnc plastics sits down scetches out on computer goes to mill are how many tool changes he will need print out a program look up spindle speed material corner the owner show him his print all and all 4 hrs or more for a 20 min job
Holds true for every trade. I try and show the apprentices when its o.k. to be a wood butcher and when you have to split pencil lines. 🤣😂😁😀😎
As a home shop machinist / part timer there are projects, a lot of projects , that I didn't even start because of time constraints .
THANKS ! . This tip opens up another 10 - 20 minutes for a project .
Very clever. Might be a well known technique in the wizardly world of machining but to a none member of your club it is magic. Thank you.
Great tip Dale! This is really helpful for those new to machining, as well as those of us without a DRO, rotary table, etc., and perhaps will help people begin to think outside of the box to find a solution for a task they face. Since there are numerous ways to perform an operation and we all have our own unique perspective, then perhaps someone who was inspired this will come up with an innovation that may benefit us all. So keep up the good work planting seeds of knowledge and inspiration for they shall bear fruit.
Thanks for taking the time to write this comment. It is excellent😀😀😀😀😀
Man, you honor the flag behind you! It was this ingeniouty that made very good American products in the past, including very precise equipment.
First time on your chanel, I'm running a relatively primitive set up, so you've just saved my life 💪🔥
Or use the bolt circle table in Machinery's Handbook. Gives you the XY coordinates for all bolt circles from 3-12 holes based on a 1" circle. Multiply the XY coordinates by your bolt circle and then use your DRO or the graduations on your table. That's the right way. I'd be making holes before you were done with the layout.
I very much seeing methods like this. I have a mill but not a rotary table or a dividing head much less a CNC. I do not do this as a job it is just a hobby and i have many hobbies so money is an object, also skills like this can allow someone to make their own tools. I also do Blacksmithing and make many of my own tools. also it is always handy to have more than one way to accomplish the same task.
Great comment :-)
i grew up on a bridgeport as a tool and die/ plastic moldmaker without using digital readouts. they were just being developed like nc at the time.
there are so many ways to accomplish a task, indicators and jo blocks are your best friend.
math is the language and patience is the pervayor!
I have been a machinist for 40 years and it is always nice to learn something new. I subscribed by the way, didn't want to miss out on other tips and tricks. Even after being a machinist for as long as I have, I find the process fascinating to take a block of material and turn it into something useful. As I read the comments concerning the making of this part, I will agree, there is more than one way to skin a cat. Versatility is always going to get a machinist out of a jam. And if the tolerance for the part isn't that tight then there isn't any reason it can't be done without the rotary table and indexing. Thank you for the video.
Cheap and easy way to do bolt hose and if you do not have a mill use your press drill love your work.
It should be pointed out that this method will work with a drill press, which typically does not have precise XY positioning. Thanks Dale!
Great Point John :-)
My thoughts exactly!
@@StoversMotors Yes this is a very good drill press way to geter done
The method of drilling holes in a round block is easy enough, the problems come about when you need an exact tolerance, if you make 2 separate plates then bolt both them together it would be only luck if the holes line up.
Can you then use transfer punch to translate the hole pattern over to the other plate? I know one can, jsut not sure how good the tolerance of that may be.
Great educational video... I just finished laying out a 7 hole 5\8 diameter holes pattern on a 2 1\2 inch diameter circle in the method you described for my new 6 inch diameter flywheel on my vertical double acting oscillating steam engine... Really enjoyed the simplicity of doing things old school... Thanks again,Frank
Hi Frank. I like your comment. I did it for a friend of mine working on a steam engine for his kids. .
Brilliant video, someone like me who has not the same engineering experience that is extremely helpful. Please keep your videos coming. Geoff Lewis, Wales, UK.
Very nice !!! especially for guys who doesn't have DRO. Looks like many comments here add the way to how calcultate using trigonometry.
I feel sorry for them did not understand difference between this trick using no DRO and no trigo : just and ONLY very basic tools.
Thanks again for showing this trick as it is very useful for people having NO DRO and NO trigo diploms...
Sorry to say : there are nowadays CNC machines that will do this work like 1+1=2... here : this is not the point to using something someone simple might simply not have...uh ??? no CNC ??? no maths ??? no Digital read-out ??? uhhhh ???
Please continue the good work uploading good stuff like that !!!!! LOVELY !!! and USEFUL !!!!
Nice to know for those of us with only a drill press. Thanks Dale.
hey dale, thanks for showing us a practical method. I have a mill without a DRO . when I want to make a bolt circle for a part on a larger project, I dont want to get online or replace the vise or make a printout or go get my books. thanks for posting.
What a nice way to build our future in easy way to make holes
Hi Dale
Another nice one of those "so that's how it's done" videos.
Great simple solution to a complex problem for a rookie
Thanks for showing and sharing
Keep 'em rolling
aRM
This is amazing, especially for someone who is not a machinist. Thank you.
Real good Information thanks Dale for taking the time to show your awesome shortcut good enough is good enough
Can you explain how you set the compass to the right distance for marking the holes? I usually just calculate the coordinates of the holes from the center point. Then just crank over to each point and drill (even easier with a DRO). I think some DROs will even do bolt circles calculations for you.
I was going to ask about setting the dividers, too, but I got the answer in the comments. Luckily, my DRO has a bolt circle feature. :)
Thanks!!
Mike
COOL !!!
Thanks for sharing and please continue the good job !!!
Man This Is a real great idea 👍👍 from México
As a novice I enjoyed this video, just a pity about all the soapbox people commenting.
Thanks for taking the time and sharing.
+Captain G
Thanks For your comment and your support
I'm surprised at all the complaining in this comment section; guess some folks just are not happy people...
Appreciate the use of brains instead of gadgets as I am so prone to do. Thanks.
Thanks Im glad you liked it.
Thank you thats a great tip and another clever use of a v block.
Hey Dale Excellent video as usual. Gives a great tip, to the point and less than half an hour presentation. Thanks
+Newmachinist
Glad you liked it
Thanks very much for taking the time to show these time saving tips! I'm a hobby machinist, and I often don't have enough time to spend hours on setting up a rotary table for example. And I don't have a DRO. And I don't need mega precision, so these tricks come in very handy! :)
I'm glad you liked it.
Good video Dale, I can use this one on my drill press. You know I'm a fan of the KISS principle and this is really simple.
you are great man. thanks a lot from morocco ♥
Great video. I am going to practice this technique later. I use a scrap piece of brass to knock down and secure my work (~2" in diameter X 3" long) . The brass knocker fits in tighter places than a hammer, and the weight and softness of the brass doesn't seem to damage the work. Thank's for the video.
Did i miss something, i was waiting to learn how to use the math to makeca bolt circle, any one can drill the holes,the part that counts is the math to divide the circles.
Circumference divided by number of holes. Advertising major here
@@basik1dotcom But the dividers are chord lengths not arc lengths. Then it all depends how good your eyes are to center drill on the scribed lines.
Divide the number of holes into 360 yerimy
basik1dotcom
Yes.
Elementary my good man.
You would obviously know how many holes and what dia before starting. The straight line distance ( not curved on circumference) is the segment. To find segment length S
S = 2r x Sin (degrees)
----------
2.
Degrees is the angle between two holes, in this case 7 holes. 360/7 = 51.42857143 degrees.
Just found your channel while wondering down the wormhole and this and your radii cutting video hooked me! Thanks for the great information!
Always struggled with bolt patterns. Probably quite basic to machinists but this is magic to self-taught hobby metal carvers. Really enjoy your You Tubes, Dale. Usually learn something new even with those way over my head. Keep up the good work.
Bill
I'm glad you find my channel interesting and useful, thanks
Nice quick technique.
I must have completely missed the bit where you actually decided how far apart the holes are.
I thought 7 holes would be interesting, as I`ve been doing this sort of thing most of my life; but nothing
Deciding/working out where they should be is one thing, then rotating/drilling the piece by eye is another. The end result can't be 100% accurate surely??
As others have pointed out, good enough is not necessarily 100% accurate.
+ Paul J. Agreed. It's a pity Dale omitted to describe how he determined the very important chord length for scribing the centres of the other six holes once he'd centre-popped the first one. Especially since 360° is not exactly divisible by 7 (51.429°) Chord length = [2 × Sin {(360° ÷ 7) ÷ 2} × R = 2 × Sin 25.714° × (D ÷ 2)] = Sin 25.714° × D = 0.43388 × D. So it's also neccessary to know the diameter of the pitch circle, D.
Had there been 6 holes, the chord length would be Sin 30° × D = ½ × D (0.5 × D) = R.
He looked it up either in machinery’s handbook or on his phone.
Yeah, he conveniently skipped that step by saying, 'hopefully I've already calculated this out in advance'. Waste of a video, as the other stuff is obvious.
great tip Dale thanks for sharing.
Nice and clean. thanks
A friend years ago showed me a trick similar to your machining a circle trick for layout. If he new he would also be having to drill a center hole, he would do so with a hole saw, or comparable sized bit, then just barely kiss the surface with the saw blade itself.
Nice video. I print the circle and the bolt pattern on the printer (regular paper) and lay it over the work with Elmer's white glue. After the project is finished the glue will remove with water. Not high tech but simple and fast.
+acklan3
Great idea.
I was gonna suggest that. Nowadays everyone has a computer & printer.
So simple so good. Thanks
Machining can be simple. In some ways machining is easier with less tools.
Its tricks like this that make a real difference.
thanks
Gotta love the kiss theory.
Simple and efective😉😊👍👍
Thanks again for uploading this.
great video, really glad you had the BUDWEISER CAN in the video. Great ad
Thanks LOL
Good video. Thanks for making it easy to follow just like your other videos.
Great tips. Thank you for sharing
I never thought of this thanks for the v block lesson
Indicate or edge find center, then use Zeus book, trig, or an app on your phone I use an app called CNC bolt pattern it gives you the option of a graphic point or manual output ( 1 hole at a time ) angle of rotation etc.
as a toolmaker I am often asked to do unusual layouts to fairly tight tolerances, I hope that this helps.
Robert
I'm in the don't have a dividing head or rotary table circle, but have a vice and the same machine tools parallel bars etc, so this is very handy technique.
Thank you for sharing Dale :)
+David Stevens (davro)
Don't need all the cool machines to get simple things done. Keep up the great comments.
Love your videos. I learn a lot.
great trick! Im not a machinist by any means but I like to learn as much as possible. thanks
Learning is the joy of life
Another fine Guessing, almost accurate project by Dale.
In the UK we call those calipers odd-leg calipers, it's a little easier to pronounce. Enjoying the videos, reminds me of my apprentice days.
+Lee Turner
I'm Glade you like it
Great video Dale! I'm not sure what anyone had to thumbs down about?! Can't please everyone I guess.
+Dustin Masters
Thanks for your comment it's very appreciated :-)
Actually, indicate in on the center hole and set your table dials at zero.. Then look in your Machinery's Handbook. It has a formula that, If you know the diameter of your bolt circle, will allow you to compute X and Y settings for your mill table for various numbers of holes. If you can multiply and/or divide on a calculator you can do the math. If your lead screws are accurate, it will put your holes on within a thousandth or so.
and in a zeus handbook it works it out for you so all u do is just multiply,
Lawrence, right on,
Great little pocket data pad, use it all the time, one in the house and one in the shop, and cheap, about $15 cdn includes shipping from UK,
Edmund.........Alberta
Get a Zeus handbook. It has all you need to do bolt hole circles. If you have digital display or even the bog standard dials it works.
Exactly you can even use a dro calculating program online
No shit
how did you get the spacing right ? You left out aomething
There's a formula for cord or chord distance (can't remember the proper spelling). I used to lay out bolt circles on machined castings in a foundry machine shop. I've been away from that for a few years
@@ontariosfinest8971 there is a chord chart on line it gives a hole center to center based on number of holes and hole ciercle diameter
You would obviously know how many holes and what dia before starting. The straight line distance ( not curved on circumference) is the segment. To find segment length S
S = 2r x Sin (degrees)
----------
2.
Degrees is the angle between two holes, in this case 7 holes. 360/7 = 51.42857143 degrees.
Great method and easy for everyone. Myself being lucky enough to have a DRO I just find the center, input the number of holes and the radius into my DRO bolt circle function and it tells me where to go. I used to have to rely on people for telling me where to go. =(;-) Thanks for sharing.
DRO's or cheating lol 😀😄
Very well presented. Thank you
Hi Dale My First metal lathe grizzly G0602 will be here tomorrow Keep the tips coming
+John R Pannell
I love the smell of a new tool in the the shop. Graduations.
Just something I never thought of! One day you need to explain how you get the right calliper setting to mark 7 holes...or 5 or whatever.
HI,
Great video, how did you compute the distance between the 7 holes?
Thanks
Tony
Circumference of bolt circle divided by 7
@@leaettahyer9175 that doesn't work. You need to compute an object with 7 straight sides (septagon) then get the length of the straight side.
The easiest way to do that is with a CAD program or an online calculator.
Or, if you are old school, a good machinists handbook might have a table of multi sided objects and The length of their sides.
@@wizrom3046 You're more correct than you know, and yes a CAD program will calculate what I'm about to describe. There is some omitted detail here in the interest of saving time; dimensions for starters. This information was used to set his dividers. You have to be familiar with the concept of coordinate pairs (x,y). Each bolt hole center is located from a common datum point which is more than likely the center of the disc. The center of the disc and the center of the bolt hole forms the base of a triangle. Utilizing the Sine and Cosine, whichever the case may be to calculate the opposite or adjacent angles in that triangle you can calculate the distance between the hole centers; this is the dimension he used to set his dividers. If you know the holes are equally spaced you only need to do the calculation once. Once he had his dividers set, he simply went from one hole center to the other, 51.4 degrees apart resulting in 7 equally spaced holes.
@@ecmillerbud1 thanks! Nice comment. 👍
In the workshop I have a number of protractors, which are probably my go to method for achieving a result fast.
That's a great trick, thanks for sharing.
Nice video with good simple information. Your video title reads "Both" circles.
Was just gonna say the same thing...
Thank you this idea helps specially countries no dividing heDs/ rotary tables not available plus poor training but this idea helps
I have a number of interchangeable hardened and ground jaws with both horizontal and vertical Vs, of various widths, machined into their vertical faces. They work a treat and dispense with the need for a stop.
what a great tip thanks
+RPWLKR1
Thanks
Nice article thanks!. The proof of the pudding would be as follows, (to check accuracy). When setting up to drill, put a bed disc under the flange, (say around 4mm thick), and "tack" the pieces with superglue, and at each hole, drill through both pieces). When all holes are drilled, warm the parts to break the glue bond and then change the relationship between the holes in both pieces, by rotating one piece or the other by one hole. Only if they all match are you on a winner. This is particularly useful when using holes that do not work out to a whole number of degrees and using the setting out method you selected. I've just been through this as I had to make 6 flange plates, and do not have the luxury of a rotating table/chuck arrangement and used a method very similar to yours.
I call those things ODD legs those calipers lol ...so how did u get the hole distance apart ...I would have put a dot punch on the line then go round with ya calipers until u get back to the dot punch mark ..watt do u think.
Reminds me of my boss. Oh it's close enough... I do it old school and figure out the coordinates of each hole. Zero in middle of part and move X and Y to their points. Not hard to do figuring out the side lengths on a triangle. Come's out closer than "enough". Comes out right on the money! You left out a bunch of info in this vid. But you know that. Been a machinist for 45 years now, so I don't care about time. I care that it is right!
Great idea thanks
Great tip Dale, thanks
Thanks
Good one. Thank you for sharing this!
Thanks for watching
Very good tip
I have been a Machinist for 40yrs and I use a calculation sheet that was made by RCA many years ago and does all kinds of bolt circles in less than a minute . it gives you the X Y axis and Cord Length been using it since I was a Young Lad in the Trade.
I Love those calculators too, but sometimes I like to use the trial and error method :-)
Well, you did miss a critical part there with the hole spacing. If dead nuts accuracy isn't needed you can draw lines thru the piece splitting the center hole dividing it like a pie. This will get you pretty good accuracy on an even count of holes anyway. I start by placing a dot with a sharpie on the outer edges starting at 12 o'clock - 6 o'clock, then 3;00, 9:00 then split those lines for more holes if needed by measuring the distance between the lines on the outer edges between 12 and 3 then 6 and 9, and so on. This will give you an 8 hole circle. I use this method when cross drilling brake rotors. You can get very accurate with just a steel ruler to measure and also draw straight lines with
Thanks for the tip. Could you also show this done using the DRO?
I use the bolt circle calculator found online. Make the O.D. of your part larger than the finished part so that you can sit it on the parallels. Drill the center hole first and use the calculator to find where to drill your bolt circle holes. The center hole dose not have to be exactly centered because you will turn the od of your part in the lathe by putting it on a spud with a drilled and tapped hole and a bolt and washer. If you have a DRO on your mill it makes this process very easy. Remember once you drill the center hole do not move the part you are working on untill finished. This is the only way I do this and Ive done it hundreds of times.
Not having a rotary table nor a DRO myself, I like this idea! Thanks for sharing!
Is that a mill or a giraffe? :)
LOL
Elephant.
ShysterLawyer
Carson Lawrence
Yes?
I have cheap *iGaging* DROs on my mill, so I typically fire up my PC and use Excel to spit out a table of X/Y coordinates. Go back to the shop, locate my part's center while held in the vise and zero the DRO. Then just dial in my coords, lock down the table, and drill away. It's been pretty accurate for me, good to a few thou on each hole's location.
In woodworking, doing finger joints, a cut is made then a placed over a stationary physical indexing stop that fits into the cut to reference the next cut..... all that said can that ploy be used here which takes out indexing by eye?
Just saved me $700 on a quality rotary and chuck to perform the same process. Great video.
:-)
Indicate center, zero out, use machinery's handbook to go to XY coordinates with your digital readout,, it is more accurate and faster.
This is an interesting method. Quick and dirty definitely has it's place in an emergency, but if you are in a machine shop, the least you can do is dial indicate the reference dia ( I. D. , or O. D. ) trig out the X, and Y locations , dial in the hole locations and drill.
The consensus is it doesn't really matter, but whoever machined the opposite side of the flange more than likely dialed it in, or drilled with a fixture with drill bushings, so it'll definitely fit and seal better with an accurately drilled flange.
In the long run, doing it right takes the same amount of time as doing a "short cut", and you know it'll be right.
As I said originally, this short cut has it's place in machining / fabricating, and that is what you are teaching, and teaching well.
Even laying it out this way, you still need to figure out the chore between the holes on an evenly spaced bolt pattern, so your halfway to trig-ing out the hole locations anyway.
Good video.
Thanks Dale great Idea
The point of this method people is to show how you could have done this with a drill press as opposed to using your read out or dials X-Y with trig or hole position pattern in some read out heads. Simple and considering they are " BOLT " holes visual accuracy is fine. This is old school and it works.
Thank you!
I noticed that you have a digital readout. Most of them include a bolt circle feature that makes life easy and simple. That's all I've used for the last 20 years or so. I'm surprised you didn't mention this.
How did you measure it out🤔🤔🤔 that would've vey helpful👍
I did a follow video showing that detail. Please take a look at it .
Perfect idea for rc 👍🏾
Thanks 👍
I just want to point out to the scoffers, this is a "Tips n Tricks" channel not "advanced aerospace machining". Also, accurate enough, IS accurate enough.
J Plough you said it amigo, Jude 1:18 They said to you, “In the last times there will be scoffers who will follow their own ungodly desires.”
n & m Sandberg amen Brother!
VERY NICE ANSWER J PLOUGH !!!! LOVE IT !!!
Unfortunately, this method takes a lot more time to be far less accurate.
J Plough It may not be aerospace but remember there wasn’t enough time to do it right, but there was time to do it again. Or maybe the young bull old bull parable.
I like the invisible side shields on your safety glasses.
I usually just cheat by laying it out in a cad program to get the offsets from the center and drill the parts. It only takes a few minutes and you don't have to remove the vise. Of course I have a DRO but it could be done with dials. Keep up the good work, I enjoy your videos.
cool system i have none of those items. how do you center a rotary table? so you can offset it in 1 axxis to get a nice hole pattern of specific dimensions.
I like ur drilling machine
Dam. Seen this back when I first started to go to school for a machinist long time
good idea! thanks.
Thanks
I've made up a sleeve which screws into the back of the spindle and onto that bolts circular saw blades, 4 or 6 inch dia and any number of teeth. They give very accurate divisions on whatever is in the jaws of the lathe when I use a ratchet system with a pawl attached to the body of the lathe. A 24 tooth saw is the handiest giving 15 degrees with each click and marking is done with the the tool point. Its accurate but I wouldn't be building aircraft engine parts that way of course.