How do I make my own gear hobs? (Gear cutting) 

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.

Thank you and Greetings from Florida USA 🇺🇲😎

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

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

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

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

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

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

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

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

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

Thanks Andy, Learning a ton

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

...................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.

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.

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

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

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

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

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

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.

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.

You are actually good in metrology as well!

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

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

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

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

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

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

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!

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.

Very good explanation and demonstration.

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

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

I think I sprained a frontal lobe.

Super interesting! Well done - excellent work

Absolutely superb presentation. Thank you :)

Great video, probably the best reference on the subject

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

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

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

Excellent, highly informative video!

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

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

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

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

Very very informative video. Thanks for sharing

Vote up, nice video, thanks for sharing :)

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.

What a great tutorial, I learnt a lot, thanks

Great,amazing Video!

Man, that was GOOD!

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

Great video, really interesting!

Great video👌thank you for sharing

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

Love it. Thank you so much for sharing this

Excellent video !

You are a friggin genius!!!

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

Very interesting Thank you Impressive work 👍🎄

Great video

Nice and weary interesting video. Thank you

Wow, Excellent. Thank you.

Very detail, thx 4 sharing.

You so amazing about your diy tools

Thank you vey much excellent explanation!

Great job

Loved the video! Thanks

ToT needs to try these

Great video!!

love this - thank u for sharing

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

Great vid. Thanks!

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.

Stellar Work A Solid 10/10

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

Thanks for sharing 👍

Gear profile good explain ⚙️⚙️⚙️

That is awesome!

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

Very easy to understand gear calculation tutorial. Nice video👍

just amazing

sweet, thanks for showing the cutter flat calculation!!! Not sure if you've checked out my video on cnc gear cutting without a gear cutter but I was hoping to find this calculation and now I can update my simulator!

Thanks for the investment and example

Very good 👍

Amazing!

Brilliant!

👌outstanding 👌

Good Job :)

After the delights of the imperial version I was hoping for the Harold Wilson ‘white heat of technology’ version with shots of Concorde & V bombers plus ‘Arold’ & his pipe & Mac!

You just *won* a subscriber 😂

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.

I don't know 'nothing' about the gears and I find this very interesting. But I wish you have included explanation of how do you synchronize the speeds(RPM) on both, attachment and the spindle.

Supreme Mathematics!

Brilliant, Andy! Are you using a "Pi cluster" (22T/14T, set lathe to 1.6mm) to get the right pitch? Some other way? Anyway, thanks for sharing.

Just amazing ! You really explained the whole thing better then a 1000 pages book ;) , Just curious where did you learn all o this ?