Cut any gear with just a slitting saw

[@LarryButler-kp3se]

Charleston Naval Shipyard had a precision gear machine that was programmed by 4 gears in the machine. 4 equations had to be satisfied to pick the 4 programming gears. I wrote a BASIC program to test every possible combination to solve the problems. I only had a Radio Shack Model 3 to run the program. It took 2 weeks to complete. 24/7. Each time it came up with a solution, it stored the data on its floppy disk and printed it out on one line of the printer. After completion, the results were sorted and printed out to create 7 volumes to use on the machine. Tests showed my effort gave results making custom gears much easier with no math. That was in 1975.

[@AndysMachines]

That's very interesting. I wonder could it do prime numbers of teeth? Perhaps if you had a prime number as one of the programming gears?

[@gyrogearloose1345]

Nice work Matey! Good to hear of the good old - new - days!

[@edwardhuff4727]

Minor nit: either it wasn't a TRS-80 Model III or it wasn't 1975. Wikipedia TRS-80 article.

[@abcdfgh4321]

This video taught me two things: first that I really like the gear math and this method of approximating a complex shape. Second, that gear cutters are so so cheap in comparison to making 200 cuts per gear

[@trevorvanbremen4718]

Tune in next week when Andy creates an additional identical gear with a rusty old worn hacksaw blade and a guy named Pythagoras

[@jimqossim2554]

Believe me, it will not worth the investment if what you need is just one or two gears of specific dimensions.

[@mechanician7735]

@@trevorvanbremen4718 I need at least 3 different sizes of gears. Module 1, DP16, and DP18 with at least two different pressure angles between them. Good quality US-made gear cutters are around going to be around $50-100 each, minimum. I can get sets of import gears from Asia for around $100 per set, but the quality is unknown. Some of the DP imports are marked for 14.5 degrees, which is what I need, but are really 20 degrees, which will eventually damage the original gears in my machines. On top of that, how many gears do I really need? At least a set of metric transposition gears for each machine, which is only 6 gears at the moment. But they're 127 and 100 tooth gears... Those would, indeed, be more labor intensive using his method, but still much cheaper. Buying the gear cutters in sets so I could do any tooth count of gear in the sizes I know I need now is going to be much more expensive, but cost at least somewhat less time. What happens if I need another size gear for any reason? Just one, or just a few... One of these days maybe I'll know the answers to those questions, but for right now, accumulating knowledge of the various ways of doing this is good. And I have slitting saws in an assortment of sizes... If you know what you need, the answer is simple. If you do not know what you really need, things are a lot less simple! ;) Bill

[@iguanapete3809]

@@jimqossim2554 works for me b/c I keep braking the same gear.

[@jonasstahl9826]

@@mechanician7735 I would rather upgrade the the Mill to CNC actual 2 axles would be enough Turntable and the feed. You have to setup each cut manual but the cutting itself is automatic.

[@williamstyers4264]

I am a retired master machinist. I worked many years in shops that made gears for textiles as well as printing equipment. I was curious when I saw this video about how you were going to create the involute profile of the gear tooth but was pleasantly surprised at how you did it. Very impressive.

[@AndysMachines]

Thanks very much! That's praise indeed!

[@taxicamel]

AGREED! It takes effort to go through the math to come up with a finished generated profile. There will also be those that think just go out and buy a gear cutter set ....which they certainly can do, but when there is only one gear to be done, and a guy has both time and an interest in figuring out a way machining "at home" and not ending up with shelves of cutters that will only be used once ......it is the journey that is far more interesting. Nice job and thanks for sharing the spreadsheet!!! .

[@DavidG2P]

I will not even get NEAR to do ANY of this ever in my life, yet I watched the entire video. Awesome work, and what a beauty of a perfect gear you have made! ⚙️👍

[@santopino2546]

Same here.

[@taxicamel]

Maybe this video will get you closer to doing this kind of work. This might have been one of the purposes of the video in the first place. .

[@richardsanborn7963]

hes theb most amazing problem solving machinist ive ever seen he could make anything with just 2 tools 1 actua;lly im really surprised hes not using his lathe

[@PhotogNT]

Same here, way above my pay grade.

[@davehiggins5903]

Amazing

[@HenryParkes-kp1yc]

Well, after 50 years in machine shop engineering - and I operate my own jobbing shop with gear cutting capabilities - I must say how much I enjoyed your video! Very well presented and educational!

[@AndysMachines]

Thanks! 😁

[@USA-freedom]

As a job shop machinist of 20 some years and a industrial maintenance mechanic who was the go to machinist at that plant for nearly 17 years I was quite impressed with this video. This is the type of project you might be given in a school shop for the student(s) to learn machine practice and theory. Although not practical in the real world the experience the math the adaptation of machine tools and the hands on machining would be priceless. Let me add you could have save yourself a few radius corner cuts by using an endmill with rounded corners. They can be shaped quite easily by hand to the end mill using a grinding wheel. One cut centered and done.

[@rallymax2]

My brain lit up when you showed that a slitting saw is the same as a hob edge. It makes so much sense now! And thank you for all the hard work in video editing and screen graphics.

[@AndysMachines]

Yes, It's just generating the curved tooth profile from successive straight cuts, the only difference is that a hob takes many more cuts per tooth.

[@deankay4434]

i love it when someone takes a new approach to a problem with the equipment they have, or tools not in house. Regards, Certified Automotive ASE Master tech since 1978 - Retired Thanks much for sharing, very nice!

[@dumbo800]

I get paid to hob, shape, and single-pass gears. I'm impressed far beyond my initial expectations for this video. Definitely subscribed!

[@ppa4345]

I won’t ever cut a gear, I don’t need to, but the beauty of this video gave me a lot of personal satisfaction, what an extraordinary expresión of human creativity and mental order. Congratulations !!!

[@neilbanks6845]

I was a gear manufacturer and designer many years ago. I was impressed with your gear knowledge and lovely to see your ingenuity in action. I don't think the quality would come anywhere near to that of a gear produced by specialist machines such as hobbers, planers and shapers and if you compare your time spent with subcontracting to a specialist I would sub out. However, that would take the fun and job satisfaction away. Enjoyed the video and the nostalgic trip.

[@hilariodecastro1755]

I'm a gear making machinist almost 45 years it's amazing

[@bobengelhardt856]

What an excellent video!! Not only that the content is interesting and most useful, but the presentation is very professional. All aspects - camera, lighting, sound, graphics (!) and especially the editing! The narration stands apart from all the others - as informative as it needs to be without dragging it out. Not off-the-cuff as most are, but scripted and as well spoken as a professional actor. The amount of time that went into this must be staggering. Thank you!

[@AndysMachines]

I'm glad you appreciate it, thanks!

[@WireWeHere]

Every once in a while there's a video with valuable educational knowledge. You gotta love the value available using trigonometry to better use and understand the trades. Electrician here. Well done video sir.

[@abcdef-uc1rj]

Very cool problem solving there! I'm blown away by how you simplified the process into easy to understand steps.

[@peterconnan5631]

A magnificent example of the adage that a professiinal expends money to save time while a hobbyist expends time to save money. Thank you very much!

[@MachinecoMachines]

I haven't even finished the video, and want to Thank You for the very clear, informative video. We were thinking to buy a simple hobber or gear shaper to do the same thing. Andy, your video nicely side steps our idea and at much less expense. BTW, in 1970, my very first job out of university, was salesman at new gear maker- International Gears. After NOT getting paid for 6 months, I quit to set up what became Machineco (used machine tools) and yes in the past, we had a few gear hobbers. ...and I gave a whole bunch of Likes to other comments too. Bravo on the clarity and production values. 🙂

[@AndysMachines]

Thanks for the kind words!

[@KW-ei3pi]

I've already commented on this video when I watched it months ago, but I just watched it again and I just had to thank you again for sharing your knowledge and skill, not just as a machinist, but also as a videographer. Just watching the videos is very entertaining, and enjoyable. I might make a gear or two in my hobby machine shop someday, but I learn so much from your videos about machining in general. The math is over my head, but with the spreadsheet, I might just pull it off. Thank you .... again, SO MUCH !!!

[@jameshamilton5849]

It's me, I'm the guy with a lathe, a mill, a dividing head, a few slitting saws, and no gear cutters. The lathe needs a few more gears (and a repair to a broken gear post) to be useful for threading or power feeding. This video is definitely going in the queue for reference later.

[@WizardVespian]

As an engineer, I appreciate the derivations. It’s useful to see how you think through these calculations.

[@taxicamel]

AGREED. Also, if people have a CAD program in their home shops, they could also use some modeling to "fine-tune" the cuts get the end result involute closer to spec. .

[@IrenESorius]

Impressive, informative and entertaining. I wish every lesson in school was like this. Cheers and thanks for your work and time Andy,, 🍻😎👍‍‍!

[@AndysMachines]

Thanks! I'm glad you appreciate it!

[@IrenESorius]

@@AndysMachines ❤️

[@troygay2784]

Brilliant! Thank you for this outstanding video. Camera work, lighting, narration all excellent.

[@texacajundiy]

this is the best gear cutter advertisement I've ever seen.

[@marknaglreiter9330]

Ingenuity is the key to success in creating something with only what's on hand. great job on this project.

[@glidercoach]

I'm very disappointed on how few views this has. This was a brilliant video. The graphics, animation and effort put into this was a lot of work. I appreciate it wholly!

[@48ford8n]

This is fantastic! It also adheres to the old saying about “good, fast, or cheap. It’s good and cheap but definitely not fast!

[@gyrogearloose1345]

Well . . . two out of three ain't at all bad! Cheers.

[@Mm-ik9uq]

I have seen this done with a fly cutter with a tool ground to match the gear profile, good use of tooling on hand..Excellent video

[@sumntingwhong]

Loving the fact that you explain the math involved!! Please keep it up. Thank you for the explanations.

[@riccello]

Great video! It teaches you to think and how to get the job done even if you don't have the right tool that someone else figured out for you. The world has lost that.

[@niskristensen7006]

Thanks for showing me what to do if you do not have the specific readymade tool, very creative thinking.

[@finecutpost]

Not only have you produced an excellent item the editing and music choices are 1st class. As I retired film editor I know how much work this must have been. 👍

[@AndysMachines]

Thanks for the comment! Yes, I do spend a lot of time on my videos, I think the average person browsing through KZbin doesn't realise how much effort goes into most of what they are watching. I tend to keep music to the minimum these days, as in the past I would always get a few comments saying whatever music I used was terrible! It's very subjective I guess.

[@blackdaan]

the way you edited it.. and car you took on the details.. is amazing!!!

[@jlinkels]

Excellent presentation with real-time video and tool sounds. Satisfying to see how you did the math carefully like this.

[@Hazmatguy117]

You worked really hard to edit all of this and it shows. This was really cool thanks.

[@BasementEngineer]

A very clever and ingenious method for an emergency repair gear. The machining operations are tedious to say the least. Instead of a slitting saw, a shop-made PARALLEL HOB reduces the number of machining operations to 1, 2, or 3, depending on the number of teeth required. This parallel hob is worthwhile if a number of gears are required with differing tooth counts, because a hob will cut all tooth counts of a given pitch and pressure angle. Best of all this type of hob is quite easy to make because the teeth are circumferential. Think of rack teeth wound around a cylinder. The only relief for the hob teeth is radial, which is easily milled. The 6 gears for Maudslay's reversing gear for the steam engine on my channel were made by this method using the hob described. It was still tedious work! Thanks, Andy, for your work in developing this methodology. w

[@AndysMachines]

Thanks! Yes, I've made 'hobs' like this before and they are very useful. They look like a stack of no.1 involute cutters and you use them the same way, indexing one tooth (or fraction of a tooth) at a time so no need for a proper hobbing setup.

[@rickwest9904]

absolute in love with this gear cutting series. THANKS MY BROTHER

[@piter_sk]

I appreciate you for sharing a spreadsheet for free... Guys like you are leading me and others in my age (young 19 years old CNC lathe machinist) to be creative, to think about another ways, to improvise... Thank you!

[@ajenjohnson7413]

I like this man's teaching method. Very professional and accurate. Sometimes I wish I had those machines (CNC) machines. Very accurate output. Great work🙄👍👏

[@ASoftaaja]

Excellent demonstration and technique. I have been thinking for months how I can cut large module gears without buying a massive milling machine and yet I didn't have a clue about this method! Thanks a lot for making this 👍

[@AndysMachines]

Glad it was helpful!

[@victoryfirst2878]

I used the same method of cutting gears twenty five years ago. An old timer machinist showed me this very method. Works well but not to fast to cut.

[@davidryle]

You are the only person I think could create a miter gear on a simple setup. Love your channel!

[@rogueart7706]

This is a great method for making your first gears. It will teach you everything that you need to know about gear cutting. I like to first drill a hole circle at the depth of cut. Then I can just use a grinder cutoff wheel to make the teeth because the depth of cut is already done. Great video thank you.

[@stxrynn]

As I understand it, shapers were used to cut teeth in the old days. Your method may be a bit "hammer and tongs" but it very accurately explains how this was actually developed. Thank you for putting in the hard work to make this easy for your watchers. Even with the extra effort, I think a BS 0 dividing head would be a better use of my meager funds than a devoted set of gear cutters. Especially as you mentioned I only will be cutting the odd gear, and the expense of a cutter set is prohibitive. VERY WELL DONE!!!

[@leec2106]

I knew it could be done, I just had no clue on how, not that I need it today, but I will soon! Thank you, Lee

[@JesseSchoch]

This looks familiar! For folks interested in this I wrote a bit of python that can drive a 4th axis and do this on a CNC machine. Andy also helped me understand how to calculate the flat size of the cutter. I have not yet incorporated it into my code but if there is interest I can do it. If you want to see how it works the vid is "How to machine gears without a gear cutter" on my channel.

[@AndysMachines]

I thought I saw somebody do something similar on a CNC machine, I was trying to remember where, it must've been you! CNC is the perfect way to do this as you can take multiple cuts and end up with a better profile with fewer facets.

[@kailibxanitoez3528]

You just got yourself a new subscriber friend

[@tonywilson4713]

@@AndysMachines Have you considered a mix of this and a purpose made d-bit? There's been a few people make and use purpose ground D-bits (click spring is one), but they have a lot of work to do if asked to remove ALL of the metal. I can see using this like a roughing cut (as in those first 2 cuts up to about 9:30) where you made a "cartoon gear" and then using a D-bit to finish it off. Even if you have proper gear cutters using this to rough cut would makes sense as it would reduce the work of those expensive cutters. You could get a lot more life (as in more gears) out of those cutters. it would even work for those hobs you make by reducing their work to just the gear profile. This is really clever.

[@JesseSchoch]

@@AndysMachines I think my last comment got deleted. For those following along I just pushed a new video and added a github repo with my updated code.

[@Tonicwine999]

ooh, that'd be interesting to see

[@benmiller5015]

It was at 5:56 that I decided if I ever need to make a gear I'll just go buy a cutter lol. You're a better n more patient man than me sir

[@lv_woodturner3899]

Thanks for the video and spreadsheat. Impressive. I had not appreciated a slitting saw could do this. I will keep this in mind for the future. Dave.

[@davidwillard7334]

When l was a Child , l always wondered How Meccano Gears are made ! Thanks for your telling us if you have Angke ans Bevel Gears to do , not to mention Helical ! Always good too !

[@mexican_machinaner7532]

probably one of the best videos I've watched on youtube. Idk if I'd ever have the patience to ever do this but the appreciation for this is real. hats off my G.

[@TorquinDSL]

Thanks for this video. The cutting, math, and excellent camera work/video editing are appreciated.

[@backwardsmachining7526]

With the price of gear cutters this is pretty cool. Ty for the video.

[@flyingscottsman2608]

Ive been looking for this video for year.s Have an upcoming project where I only need to make 6 gears but didnt want to buy a ton of equipment. will be referencing this in the future! Thank you

[@lucascsrs2581]

I have absolutely no idea about what's going on here, but I watched it anyway. Very entertaining and nicely edited.

[@FRANKSBESEK]

I just watched this, as I was extremely CURIOUS. You are an absolute GENIUS dear sir. Your kindness for sharing your knowledge is to be commended. Warms the heart. Have a GREAT day INDEED !!!!!!

[@jasongarland3165]

This one kinda made my head hurt. I can follow the math but it's not something I do frequently enough that I would've thought of it. Props to you for figuring it all out and explaining in such a way as the math-impaired like me can understand it

[@danielleblanc5923]

Absolutely invaluable video, packed with information !! What I find most interesting is how you "lego"yourself to a solution, combining tools in the fabrication process. Of course the described method is very time consuming but it can be performed with a lot less equipment. It might be the difference between being able to complete a project or not.

[@kailibxanitoez3528]

IF YOUR NOT A TEACHER YOU SHOULD BE! You are awesome.

[@davidapp3730]

Very clever way to make a gear. A friend would do a similar process to remove the bulk of the material using a horizontal mill. He would then grind up a single point tool to get the gear profile. On some gears he did one side of the tooth then the other side.

[@cgoodwin2875]

Great video, thanks for posting. I drill the roots first and then machine up to them. It gives a nice rounded base and saves a couple of steps.

[@AndysMachines]

Yes, I do this too sometimes, (you can see this at 1:23, the holes were drilled first)

[@simpleman283]

I was thinking the same thing. & I'm only a carpenter, that has watched a lot of videos on machining. While waiting on machines.

[@James-fs4rn]

👍 that's thinking outside of the box! Math is part of the territory always good to see it explained. If people don't like it, don't be a machinist. Thanks for sharing!

[@lordchickenhawk]

Love this idea. I've done similar things with a shell end mill cutter in a mill to approximate a complex curved surface... it never occurred to me that gear teeth could be cut like this with a slitting saw!

[@MrPeterPanos]

I have a new appreciation for how gears are made - thank you for an excellent video. Like the spreadsheet too!

[@devinclark8689]

Your production value is killer!

[@benzflynn]

Happened on this by accident when looking into hobbing v hubbing (diesinking). Looks like something the small shop machinist - even small manufacturer with in-house toolmaker - could benefit from. Precise and concise explanation, good graphics and sensible use of spreadsheet for calcs. Good show all round. _Chapeau_ 👒

[@ka9dgx]

Having worked in a gear cutting job shop, I was aware it could be done with a 4th axis and CNC, using much smaller steps, but I'm quite impressed how well the approximation is with so few cuts per tooth. I appreciate the rounding out of the root to get rid of stress concentration. In a pinch, your method would likely produce a gear good enough for light duty use. Thanks so much for sharing this.

[@jeremycable51]

Hey I appreciate it your way of putting forth information works very well for me

[@GarranGossage]

Beautiful job! I was skeptical before I watched it, and I was quickly impressed. Well done!

[@micmike]

Let me say that was a easy to understand topic for what was a complicated topic for me. Thanks very much. I really enjoyed your presentation and explanation.

[@jameshisself9324]

I love this, especially the math. I do wonder how many will see this as proof that buying proper gear cutters is cheaper in the sense that it would reduce the smoke coming out of their ears.

[@TheMilkiman]

you just killed me when you turned on the sharpie bit, bravo!

[@ChristophLehner]

Your really upped your production value. Chapeau! Fantastic Video

[@Sam-ch4jh]

Certainly I am not going to do this but was curious to watch how you did it The explanations were very clear

[@BrightBlueJim]

Thank you very much for the boring math. Not that I couldn't have worked it out, but it certainly was easier having it spelled out!

[@chrisfisichella6659]

You did an excellent job with this video and presented a very cool technique. Thank you very much!

[@dointh4198]

Impressive, great and funny presentation! But man, you must have adamant endurance to do it that way.

[@shedtime_au]

That was a lot more cuts than I initially expected, but it's nice to know it can be done with simple tools.

[@jasonbell5905]

This is called advanced tinkering . Great stuff !!

[@chrisgarside7974]

Valuable insight into gear tooth geometry and method of manufacture using a slitting saw - many thanks for sharing

[@craigtate5930]

Wow, great explanation..a few months back I did a couple videos making a gear using a slitting saw and a couple of angle cutters...just by eye with reasonable success

[@hermit3400]

Subscribed!, You sir are a genius! This is the most impressive thing I have seen for a long long time

[@AndysMachines]

Well, thank you for the compliment!

[@Locoman3801]

Thank you Andy for showing everyone how to cut gears as I've always wanted to know how it's done for many years & it looks like plenty of work to me so I think that I shall leave it up to the professionals & just buy what's available to me ; Great work!

[@MartsGarage]

I found this very interesting, and was impressed by the quality of the videography. Very well presented and easy to follow. All the best, Mart in Solihull.

[@euclidallglorytotheloglady5500]

As if it wasn't obvious before... You Sir, are a master with gear geometry! Brilliant work! Thank you!

[@rameshcnc9157]

The way in which demonstrated is nice. explaining with sketches is so good. really excellent ...

[@jimsvideos7201]

Thank you for the lesson and the film-making! This puts the few funny change gears I need within reach!

[@Chris-w5p8g]

Thanks!

[@AndysMachines]

Thank you very much for your support!

[@koutros100]

Well done on a great video Well presented and easy to follow and also a free gift. Thank you sir and God bless you.

[@DEtchells]

Wow, that’s beautiful! Thanks for sharing and explaining, not to mention the spreadsheet 👍

[@harkbelial]

Fascinating, I will never use this in my life because I'm not a machinist.

[@tomgunn8004]

This guy is some kind of wizard.

[@nonsquid]

My only regret is that I have only one thumb up to give to this video. Well done.

[@grappler185]

We're going to need guys like you after the apocalypse. : )

[@wantafastz28]

You have the similarity of, this old tony, by making things look way easier to do than they are. Thanks for the content.

[@simpleman283]

ToT is a show BoT.

[@4dirt2racer0]

such a good video man thanks so much for showin us this i cant wait to start messin around, i have so many things that need gears also thanks for the spreadsheet man that makes things a lil easier

[@billshiff2060]

This is the kind of innovative content I love. Thank you!

[@toasttoriginal]

Just discovered your channel. I am amazed by your skills and love your sense of humour :D. You gained new subscriber 😎👍.

[@KallePihlajasaari]

Great technique, lovely video work and explanations. My dad was a gear designer so the terminology is familiar but I can see many may not understand why teeth are even an involute shape. Most people do not even know what module means and why they are specified in two different ways. There are older ISO, AGMA, DIN and BS standards for calculating gear profiles, spacing, corrections and more. My dad used to routinely do these calculations for the gear boxes that were put into production at all the places he worked. Knowing about strength of materials and hardening was important for lifetime wear calculations and dimensioning the gear widths and selecting bearings. Not many in South Africa who were doing the calculations in-house, most relied on service from tool suppliers or parent companies abroad.

[@Gottenhimfella]

At the risk of stating something aleady known to most of those who would be interested in knowing it, one key advantage of involute flank profiles (other profiles are available and viable!) is that involute gears will run smoothly even when the centre distance is larger than nominal. This can be very handy when sychronising top and bottom pinch rollers (as in a machine for rollforming, say metal roof guttering). It is necessary to be able to adjust the centre distance to achieve the desired result, and to accomodate roll wear. If smoothness is not paramount, by resorting to comparatively large teeth, quite a range of meshing distance variation is possible, especially in relatively agricultural applications, as with old-fashioned "mangles" for wringing wet clothes.

[@fredfarnackle5455]

Excellent video, very well documented and explained, and the downloadable spreadsheet is a bonus. Thank you.

[@EPaulIII]

The title says "Cut Any Gear ..." so I was wondering if the technique was good for other types, like helical and perhaps bevel gears. Spiral bevel is probably a stretch too far. But, after watching for the second time I wonder if you could cut helical or bevel gears with adaptations of it. The bevel gear is particularly intriguing as it can be done on a shaper with a straight edged tool and some geometric gymnastics. Just wondering.

[@AndysMachines]

Yes, it would be possible to do helical and bevel gears, in fact any gear can be generated from a rack profile which is really just two straight cuts at an angle to each other. It would be much more complicated of course and I haven't tried it and probably won't, at least manually, it really needs to be done on a CNC machine to keep track of all the numbers. Spiral bevel gears I find it hard to get my head around and they are actually cut to a modified profile to make them easier to manufacture. Some types of straight bevels are also cut to a modified profile rather than the geometrically correct one where the teeth would get smaller and smaller and eventually disappear at the point of the cone.