Now this is proper old-school engineering!
Making your own internal gear cutting attachment is the kind of project that separates machinists from ordinary mortals.
Beautiful work — the machine probably gained +20 years of life and +200% personality.

Idea - if you have trouble with fused belts breaking, make the cuts at an angle.  The surface area will be increased.

please youtube, suggest me more channels like this!

I approve of arc-second precision when making chamfers.

Every time I watch your videos, I wish YT would allow me to like it more than once.
Awesome project, glad I could contribute to it!
The indexer came out very neat!
I am waiting for the day you will get your well deserved place in the clickspring league! 😎

60 years ago, for Christmas, I asked for a Spirograph, you have made the same thing here. Thanks for bringing back a fond memory. Regards, Bernie W.

Necessity is the mother of invention.

Great idea for a new tool!  Thanks for sharing it with us.
You said something like, "I'm going to stop yapping now so you can enjoy the video."  
...I can only speak for myself, but please don't stop "yapping!"  The more verbal description you include, about what you're doing and why you're doing it the way you are, the better chance I'll have of understanding what's happening and why.  I'd much rather hear extra commentary that explains stuff I already understand, than to risk missing out on some subtle design feature that I didn't pick up on by just watching parts get made.
Thanks again for sharing.  +1 new Subscriber!

Back in 1998 had to make a device to cut 60 internal slots in a blind stainless hole. 45 mm bore x 75 deep. Put a slitting saw on a chain drive attachment I made for a Bridgeport style mill. Cuts were 6mm deep. Had to get hss cutters coated with Tin compound, used 800psi straight cutting oil. Took about 90 min per component. Made thousands over next few years.

Very nice, very impressive job.
Nice design and function.
Thanks for sharing the process.
And I did watch the whole video👍.
Have a great day.

Nobody has mentioned that the best part of this design is that for milling machine lacking workshops,  it would work on our pillar drills too.

Your mechanical engineering is amazing. I have nothing to do with lathe machines and machining parts on CNC or manual lathe machines but I like to watch when a crossive and rusty steel rod turns into a shining steel piece, cutting, making teeth, and other stuff is so fascinating. I liked your video. It is so beautiful and designed to achieve the job. Great! thanks for sharing.

Hi, that was a good idea.
I have made a slotting head for my vertical mill using part of a angle grinder.
It has a vertical stroke, so I use a rotary table to divide.

i was picturing a tool like this, and i'm glad someone else made it first to iron out the bugs! and internal ring gear seems like a uniquely annoying thing to cut, but an absolutely necessary part of a planetary gear box

Victor   extraordinar,perfect  ar putea invata si viitori ingineri TCM

way nice spiro-graph maker.  thanks

Outside the Box thinking, Shared.

Like the use of bearings for filing buttons 😀 tightening rod  thing might be a tommy bar? Nice job look forward to seeing what you do with it 😀

Sorry.  Your build is pretty ingenious though too.

Very well done, the part and the video equally.