That was the clearest, most concise explanation of basic gear theory I have ever seen.

A book's worth of knowledge in thirteen minutes. Thank you.

Excellent! 25 years in a machine shop and I now know more about hobbling than ever.

Now I learned the basic of gear making, thanks for sharing this video…

Awesome video, everthing was very well explained. Now I need to watch the other video about the build of the gear hobbing attachment.

Thanks for going through the theory on gear design and gear standards, this is very helpful for understanding the engineering behind the standards.

You are a teacher more than a machinist ..thank you sir for sharing your knowledge.

Whelp... this is just the first of MANY times I'll be watching this.. So much valuable info here. Awesome work! Thank you!

Thanks for going through all the calculations, makes the process even more interesting when you can get a better grip on it!

Thank you and Greetings from Florida USA 🇺🇲😎

Probably the best video on hobbing I've seen. Thanks!

Goes to show how important mathematics truly is. Thanks for sharing such an awesome video!

Thanks Andy, Learning a ton

Wonderful explanation. Lots of time and energy went into this one!

You, sir are an excellent instructor. I was so focused during the math bit, I think I fainted for a second or two🤯🤣

Thanks, a lot of knowledge wrapped up in this video - very helpful!

Nicest explanation,thank you my teacher,....this trick is for my retire,if my wife will permits to take my my mill and lathe in garage

This was a great video! Prior to watching this and the two attachment videos I understood that hobbing existed but not what it entailed, and I've come away with a great appreciation for the mathematics, planning and applications of the process. I'm not a machinist, so it's always fascinating to learn about the techniques that are part of the manufacturing of precision components.

Very nicely done, Andy, very enjoyable-thank you very much ✅👍

fantastic video I been cutting gears 30+ years in work and I learnt something from it Thank you keep up the geat work

This is BEAUTIFUL! What a wealth of useful information without the nonsense. Thank you for this! Subscribed!

WHEN YOU KNOW YOU KNOW > You are an expert on this feild

Well done, Sir. Well done. A veritable masterclass.

I like your funny words magic man. But seriously, as a plumber who will never have to touch a lathe or mill to make a gear in my life this was cool

Brilliant work in After Effects; you've cleared up some long-standing uncertainty for me.

...................now this is the way to help ourselves in the '' real World'' my friend. Knowledge shared is a treasure we need to grow as a whole, Humanity must have people like you. [ good heart and mind ] ready to learn others what to do...many thanks for this little gem. Let it flow, so others can grow. Greetings from Holland.

Fantastic video and a great explanation of how to measure and figure out gear math!

Best video ever. I'm not kidding. Thank you for ALL the details!

Hello, Andy. I enjoy your relaxed and careful videos. Thanks for sharing! Stay Healthy!

man this video is an example of QUALITY content please keep making these Grüße aus dem Oberallgäu

My brain hurts lol no seriously you a genius love you videos , don’t think i will get to that level but it all helps me understand the process before i attempt my first gear thanks

Interesting and very well presented. You have and amazing amount of knowledge. Thank you

Absolutely superb presentation. Thank you :)

Thank you for an excellent explanation! Shows how useful math can be...

Great video, probably the best reference on the subject

You are actually good in metrology as well!

Great reference video we're saving for future use thank you.

Super interesting! Well done - excellent work

Geezus F*CK that was more than I anticipated. Well, it appears I'll be purchasing my own hobs because for my application, I certainly don't have the necessary tools nor the precision mathematical abilities to do so. WOW my friend, you have garnered my complete respect, and also, admiration in the time you spent in creating this video. I applaud you.

I think you don't take into an account something. I would prefer to be wrong here, but... Consider making a spur-gear having PA = 20°. That means that the toothed rack complementary to such gear would have trapezoidal profile of tooth with also 20° angle between trapezium s sides and axis of symmetry. If you going to cur the gear using the rack as a cutter, no problem: you have to move cutting rack towards the gear in direction parallel to gear axis. With the hob things change: to compensate for helical "nature" of gear hob, you make an adjustment of milling machine axis and you mention that at 11:30. Now projection of the cutting edge (of its contour) of the hob to imaginary vertical plane will differ from its real contour - it will be compressed in by vertical axis by the factor of cos(helix_angle). If the scaling transformation has different scaling factors on X/Y axes, that transformation does not preserve angles. Thus you'll get slightly decreased PA on your gear. You probably don't notice that the gears you make have decreased PA because with helix angles as low as 5° or 10° the cosine of helix angle is ~ 0.99619 or ~ 0.98481 respectively, which means one-axis scaling to a factor of 99.6%/98.4%. So depth of the groove you cut isn't affected, but the width of the groove is about 1% less than required. Also, if you making two gears that should couple to each other, they will mate perfectly even if it's PA angle is unintentionally decreased. However, you are getting non-standard and modified profile of your gear teeth, so it won't mate perfectly with the gear manufactured somewhere else. However, all this considerations become not actual if at the stage of thread cutting (07:17) you tilt you cutter by the angle matching the helix angle of you thread. Which isn't the case as far as I can see.

@AndysMachines

2 жыл бұрын

That's a very astute observation and clear description of this effect! Yes, you are correct, the tilt of the hob does affect the pressure angle of the gear it generates. This is known as 'cosine error', though in this case the effects are so small that I've never felt it necessary to correct for them as they will likely be swamped by other errors that are beyond the accuracy I can achieve. This hob was tilted to an angle of 4°, commercial hobs are generally larger diameter than my home-made ones and are tilted to less of an angle, around 1-2°. The cosine of 4 is 0.9976 giving a pitch error of 0.24%. At 1° the pitch error is only 0.015%. A tilt of 4° would change the pressure angle from 20° to 19.96°. I don't think I can grind the cutter used to cut the hob to within 0.04° even if I do it on the lathe and set the compound slide very carefully with a dial indicator. Also when I screw cut the hob I am not able to reproduce the module thread with an accuracy better than 0.2% on my lathe due to limitations of the leadscrew and change wheels. Also as you say, if I cut mating gears with the same hob then they can actually have quite large deviations from the pressure angle I was aiming for and they will still be perfectly matched to each other. However it is still useful to know about this effect and good that you pointed it out, as for example I can try and make the cosine error of the hob and the screwcutting pitch error cancel each other out rather than both adding up in the same direction.

WOW!!! New subscriber here. I understand almost none of what I just watched. But I really wish I did.

Excellent, highly informative video!

Very good explanation and demonstration.

What a great tutorial, I learnt a lot, thanks

Just watched the imperial version :) It makes me appreciate this video even more.

Very very informative video. Thanks for sharing

You are a friggin genius!!!

I think this was the best hobbing video I’ve seen. Nice work!

That's awesome! I have an old CNC lathe that the control didn't work and used LinuxCNC on it. It's really great at threading and can cut any thread, inch, metric or anything else. I'm thinking that it would be great for making hobs with the odd spacing on hobs for DP gears. I love it that one hob can replace a whole set of gear cutters. It would even be possible to put a hobbing attachment directly on the CNC lathe and synchronize with the spindle that is already encoded.

Man, that was GOOD!

Super professional video!! Thank you very much dear man. Waiting for your next video

Great video👌thank you for sharing

Great video, really interesting!

Excellent video !

very impressive but with all those calculations I can understand why some people prefer to save up and buy a commercially produced one.

@cooperised

2 жыл бұрын

Surely not! The maths takes a fraction of the time that the machining takes. Buying cutters is a good idea if you're "cash rich and time poor", but if you have the time to make them, don't let the maths put you off. :-)

@AndysMachines

2 жыл бұрын

Well said,@@cooperised The maths and theory behind it isn't actually that hard once you start looking into it, but I think a lot of people are put off by the very idea. It's also good to know this stuff if you never even make your own cutters as it's gives you a better understanding of how commercial ones work.

@death_parade

2 жыл бұрын

LOL. I am at the opposite spectrum. The math doesn't scare me but actually trying to machine it does.

Very interesting Thank you Impressive work 👍🎄

Thanks, After watching this video I've decided to purchase all gears instead ;-) Great info here.

Loved the video! Thanks

I think I sprained a frontal lobe.

@aunabreslingaming3279

3 ай бұрын

Yea

Excelente conteúdo! Muito agradecido por compartilhar. Inclusive a parte das fórmulas.

Great,amazing Video!

Thank you vey much excellent explanation!

Very detail, thx 4 sharing.

love this - thank u for sharing

Wow, Excellent. Thank you.

Thanks for sharing 👍

Stellar Work A Solid 10/10

You so amazing about your diy tools

This is a sound presentation. I have just learned the concepts of the module, addendum, dedendum, angle of pressure, the tip of width, and how to work them out.

ToT needs to try these

Vote up, nice video, thanks for sharing :)

Thank you for this video. I haven't been able to find anything on KZread. I'm needing to make a batch of 3 DP 67 tooth gears for my work. This helped me immensely.

@AndysMachines

2 жыл бұрын

Wow! Those are pretty big gears!

@elanjacobs1

2 жыл бұрын

If you need to make proper gears, buy a proper cutter. As impressive as this is, it's nowhere near good enough for a commercial product.

@AndysMachines

2 жыл бұрын

@@elanjacobs1 I'm not claiming my home-made hobs are as good as commercial cutters, and I'll always use a commercial one if I have the right size. But it is possible to make DIY cutters like this that produce results plenty good enough for most applications and at a fraction of the cost. I don't know what a 3DP gear hob would cost, but it's not going to be cheap!

@northernmetalworker

2 жыл бұрын

@@AndysMachines it's a small batch of maybe 5 or 6. I'm going to try and get a hold of some 6" diameter o1 tool steel for making the hob. Should work well enough if I take things slow.

Очень полезное видео.Всё показано детально и доходчиво.Большое спасибо.

Great video!!

Geee whiz what did I just look at. Got to love it because I think I just nailed the national standards test for the 2nd year mathematics of senior high school again, this time in one single 13,14 min sitting.

Great video

Nice and weary interesting video. Thank you

Very easy to understand gear calculation tutorial. Nice video👍

just amazing

Great job

Great vid. Thanks!

Brilliant!

Thanks for the investment and example

That is awesome!

Amazing!

Gear profile good explain ⚙️⚙️⚙️

👌outstanding 👌

Very good 👍

Well, know I know what those module and dp charts are for on the lathes. Neat.

Спасибо Вам, буржуи! Теперь будем делать червячные фрезы по науке!

You got the controller box or you made it, if so, you could make a video explaining how it works. Thank you very much and greetings.

Perfect ...👍

Good Job :)

Thank you !!! 👍👍

sos muy b pero muy bueno en lo que haces saludos desde argentina

Thank you very much

Awesome.

Thanks for video learning

This is deep

You just *won* a subscriber 😂