Making Gears in the Home Shop - Automatically Part 5 - Measuring and Correcting the Teeth
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- เผยแพร่เมื่อ 8 ก.พ. 2025
- In part 5 of our series on automating the gear making process, we build a device to measure the gears we have made so far, improve the process and make some new gears.
www.teknic.com...
Harmonic Analyzer: • Albert Michelson's Har...
Gear formulas and definitions: www.sdp-si.com/...
You're a true scientist by the way you chase down anomalies until you find the cause. While watching the videos I noticed a few times what I thought might be the cause of unexpected results and you always got there by your testing methods. Thanks for the series...good job!
Thanks so much for the kind words.
I just finished watching this series. Awesome job I really like how you keep the whole system rather uncomplicated. Thanks for posting and look forward to seeing more of your work!
I expect to be making more gears after the holidays. Thanks for stopping by.
Hi Paul,
I just finished watching the whole series. Great project and interesting and informative videos. I'm anxiously waiting for the Harmonic Analyzer series. As an interesting aside, our career paths are remarkably similar. Amateur radio in high school (K3KQR), EE in collage doing all sorts of analog and digital design, moving into IC design and finally into computers. Many small microcomputer projects later on, both hardware and software design. Now I have my hobby area at home with a pretty complete electronics design and development capability and for a basement hobby, I have a Bridgeport mill and a Colchester lathe. Both mill and lathe are upgraded with VFDs, digital readouts and all kinds of homebrew enhancements. Best wishes to you... Karl
Hi, Karl,
Thanks for the kind words. It does sound like we were cut from the same cloth. I have enjoyed the electronics side of my hobbies as well. A few years ago I designed and built a 6 meter FM base and mobile and it's about the only ham radio activity I still pursue. Pretty much all my hobby time is in the machine shop these days. You should make a few videos about your adventures. I'm sure you would have a good audience.
Great job working out the problems. I am sure the complicated machine you are going to build will work just right.
Thanks, Harold. Nice job on your Tapmatic, too. I wish I had one when I was making my mini-pallet.
Thanks for sharing. Nice set of videos. Very nice table mover set up and I really like its removable design with endless possibilities.
P. S. I'm almost scared to ask but how much did it cost to build your wonderful automation dive?
Thanks, Sam. Yes, I can knock it down and set it up in a short time. The hardest part is getting the drive for the rotary table in line, square and tensioned correctly.
I did not keep a detailed budget for the project, but the biggest part of the cost was the Clearpath motors at about $250 each. Their prices are available on their web site. Looking through my receipts, I spent $120 on pulleys and belts and $230 on electronics, connectors Microcontrollers, etc. but in both cases, I bought at least two of each part. It would be cheaper if you got only what you needed. I think the rest of the parts were found around the shop.
Watched the whole series--- Great build ----- Thanks for sharing
Thanks, Tom. I hope to get started on the remainder of the project soon.
Enjoyed the series. You might be able to stack more than one blank on the mandrel if you need to cut more than one of the same gear.
Thanks, Donald. Yes, one of a series of 20 gears all have the same tooth count and I am thinking about how I could cut them all at once. The problem is that each must have a cam attached. Originally I thought I could make the cam and gear in one piece but now I am leaning towards making all the cams at once and all the gears at once and using adhesive to hold each pair together. The timing will be tricky but do-able. The other 30 or so gears all have different tooth counts and will be made individually.
Paul, I am amazed at the clear technical thought, combined with the craftsmanship you have displayed. May you live long and prosper.
May I enquire what your background is/was? Engineer? High level technician? You are a real polymath, I think.
Thanks, Greg. Yes, I am an electrical engineer. I fell in love with ham radio while still in grade school and that led to a career in engineering and wireless communication product design. Machine shop work came along later as a hobby.
Hi Paul,
Thank you for the clear and technically complete videos on making gears.l am new at machining. I have a manual lathe and small milling machine. TH-cam is a wonderful way to learn. I have a rotary table and would like to purchase an adjustable tail stock, would you tell me the make,model and where I can purchase one like your?
With great appreciation,
Bob
Nice videos, need is the mother of invention. I'd still be slaving away turning the crank on the dividing head. Looking forward to your project that uses all those gears. Also looking forward to seeing you kick the table over on a universal Kearney Trecker and move the dividing head and table at the same time so as to cut helical gears:)
Thanks for the kind words, Wayne. I will probably be starting on the harmonic analyzer project after the holidays. I wouldn't recommend you hold your breath for the helical gears thing, though :-)
Hi Paul, did you get your gearcutting sorted out? I would recommend measuring them over wires to make sure your pitch diameters are right, but at the same time there is usually a lot of forgiveness in a gear train and they will still work, even when less than perfect. Both Marc Lecuyer and Keith Rucker have some good videos on gear cutting. Can't wait for you to get back on the analyser project.
Thanks for the tips. I follow Keith Rucker regularly but have not seen Marc's channel. I will check him out. Thanks for stopping by.
Not that it probably matters after half a year, but the measurement discrepancy of 2 thou you are having @ 27:25 is probably due to the fact that you are measuring the "height" across the valley of the cut tooth.
By just rotating the measuring stick, its resting on both sides of the valley not on the true perimeter.
If you rotated the gear blank so the measuring of the teeth height was the true perimeter, you would probably get the correct 71 thou.
In fact this seems what you are doing in the end, and hitting the correct measurement.
Nothing wrong with the cutting only in the initial measurement as far as I can see.
The discrepancy does not matter on small gears but on large wide teeth you would have a significant measurement error if done this way.
btw I'm no expert gear cutter.
That's a good observation. I suppose it would make a couple of thousands difference if I got on the exact top of the adjacent tooth. I will check that out when I start making the gears that will be used in the harmonic analyzer. Thanks for stopping by.
That was my thought, also.
In addition to this observation, I'm thinking the test probe is not reaching the bottom of the valley unless it is a true wedge point or at least a small radius. This could add a bit of error in measurement, though likely less than the above comments. Basically the same type of error, but coming from the valley.
Hi there, I have not watched all your maths about these gears, but I did notice that in a screen shot you showed all the nomclementure for gear teeth and the illustration showed MODULE. Perhaps your gear cutters are Diametral Pitch ones which are totally different. Just a thought. Good quality cutters usually have etched on them what the tooth depth should be, but that is on D.P Cutters, I do not own any Module ones.
Hi, Dave,
Yes, the cutters in the series with the label "module" are for metric gears and mine are labeled as such. My problems were associated with learning how to use them. Things are sorted out now and soon I will start making the many gears I need for the harmonic analyzer. Thanks for stopping by.
Congrats on sleuthing out the gremlins on tooth cutting. I am also thinking that the .002" error that you saw with your test gear might have been due to the fact that you were measuring from the edge of one tooth to the edge of the other (the chord) of the arc and not to the top of the arc what was machined away?? Looking forward to seeing videos of your off road project. Will you be bringing it to the Pageant of Steam this year?
All the Best- Fred
Thanks, Fred. Yes, I expect to have it ready for the Pageant. I wanted to bring it to the JD show in July as well but we will be out of town all but the first day. Hope to see you at the steam show.
Nice job. enjoyed watching.
Thanks, Randy. I have been keeping up to date with your vids, too. I was hoping to attend the bash this year, but unfortunately it's not going to happen. Maybe I'll see you next year.
Thats a nice set up thanks for sharing Im just a beginner at this sure having fun learning a lot from all you guys all the best from John in Texas
Thanks, John. I'm learning too from the many experienced machinists making videos.. Ain't you-tube great?
John R Pannell to
you can buy hollow ground screw driver bits of all sizes for your index tool
Thanks for the tip.
Hi Paul. This is exact what I want to do with my mill. Every other video I've seen shows a tabletop or mini mill. I contacted Teknic about their Clearpath servos a while back and they just weren't helpful! Told me I was looking at a 1kw or better servo for a full size mill - mine is a Lagun FTV4, a bit bigger than what you have so I thought about using my CnC (Cheap n Nasty) barely more than a desktop Grizzley knee mill. Struggled (because of monologue issues that have been beaten to death by commentators who don't understand...) thru your series and it confirmed that I could do it on either mill! Would you comment on the size of the servos you used? I have several proof of concept ideas I'm working on and they need to be Arduino powered to make them affordable and it's something I'm struggling to get into, sigh.
Hi Scott Burrous,
I am an engineer with Teknic and, after reading your post, I would like to apologize on behalf of Teknic if you feel your experience with us has been less then stellar.
Without knowing the details of the conversation, I can’t say where the miscommunication may have occurred, but hopefully I can help clear things up. When sizing a motor replacement, there is some pertinent data we will need in order to help you choose the right motor:
• Peak torque requirements
• Continuous torque requirements
• RPM range
• Voltage input (VDC or VAC depending on the ClearPath model)
• Duty cycles
This is a subset of the data we require, but it is enough to ensure Teknic engineers are recommending appropriate models for your application.
Without the above information, it is difficult to say exactly what motor is appropriate. If we don't have all the required design details, we will likely provide a conservative general recommendation to help ensure that you will get at least reasonable performance. Teknic offers a 90-day evaluation period so if it turns out the motor is greatly oversize, you can return it for a different model.
If you have any other questions or concerns, please feel free to contact us at support@teknic.com.
Best regards,
Mark D.
nice!!! good Job.
Can you use standard plain cutters and develop the tooth profile from software and a table?
Yes, I guess you could, but you would need a very slim cutter that could reach to the root of the tooth. You would also need control of the y axis which I do not presently have.
Why do they call it a module? Has no relation to any definition of module I can think of.
Very Nice, but I think You'll find that the true depth is now a thou or two deeper than spec, because you are measuring from a TANGENT to the diameter, NOT the actual diameter. The tangent is the line drawn across the top of adjacent teeth. Effectively, you have "chopped off" a tiny portion of the diameter.
You are right and other commenters have noticed that as well. I need to turn the gear a bit to get on the top of the adjacent tooth. Thanks.
I'm not that experienced but can follow along. I used the link you provided to the board but As I cannot locate the easypic4 development board on MikroE's site, what is a reasonable substitute please. I don't understand comments on your manner of video narration! I enjoy following along but so far cannot emulate the construction as the easypic4 does not seem available. Perhaps as there is no support for microsoft xp? One can only guess why it is unavailable just a few months after your tutorial. Thank you for your time and patience. This seems like a good way to move into gear making.
I support the work of 'Clickspring' who is doing everything by hand. Also; In the case of making gears consider viewing Buchanan's site:
www.my-time-machines.net/my_current_project3.htm
I appreciate your skill and learning about both techniques.
Thanks for your comments and kind words. Yes, the easypic4 is not a current product. It has been in my shop for years and I have used it for many projects. I looked at the newer v7 on the MikroE site, and the board layout has clearly changed since the older v4. Looking at the specs, though, the v7 does still support the 16F877A which is the processor that I use and it seems to have identical port headers to connect to external circuits. The main function of these development boards is to make it easy to connect to external circuits and to see what is going on while the software is running. I don't see any reason why the v7 would not do the job for you. The compiler that goes with the board is the Mikrobasic pro for pic. I have downloaded several versions of it over the years and each time I found that the baseline version is free. That is not always obvious from the web site, though. They want to sell you the full featured version. The free version has worked just fine for any of the programs I have written including the current one for gears. Good luck with your project.
Wet your paper and stick it to the material being machined. This is SAFER and easier.
God idea. I had seen other you tube machinists do it by holding in the fingers and in fact, I was a bit nervous holding the bit of paper so close to the cutter. Your way is better. Thanks for stopping by.
That was one of the reasons most of us had roll your own cigarette papers in our tool box, Zig-Zag were 3 thou. if I remember correct.
inch ? laughable