I decided to make an attachment that could fit the Sherline 3/8" endmill holder. I first turned a piece of aluminum. Here you can see the slot being milled for a 1/4" lathe bit.
After the slot was done, I took it off the chuck and mounted it in the vise. I drilled for 2 3mm set screws to hold the lather bit. Coming along.
Completed Attachment
Here is the completed gear cutting attachment. Came out great! The 60 degree lathe bit is held in strong with the setscrews and if all went well, should be right in the middle.
Here is my setup for cutting the tiny gear. I have turned the head of the mill 90 degrees and am using my rotary table. Again, the attachment mounts on the Sherline 3/8" endmill holder.
Gear Blank
Here is the blank for the gear. 11.10mm in diameter with a 1mm depth for the gears. Again, I am using an endmill as a boring tool and it works great!
First Cuts! The attachment runs very true and I am very happy with it. There are 20 teeth so the rotary table is turned each 18 degrees (3.6 turns)
The gear is done! WOW, it looks really cool! The fly cutter made easy work of the aluminum. For my next gear I won't cut the teeth as deep.
I wanted to check the mesh and to my surprise is seems dead one! What a great fit. This is going much better then I thought it would.
My First Gear!
Here is the completed gear after the rear was turned and cut. I decided to put a setscrew in and the whole thing weights 0.7 grams. Not bad.
It's on and it works! The shaft of the carbon tube is not perfectly true so the gear wobbles just a bit. That is the next thing in line to modify :) Hope to try it soon!
(Hint: I think its the last one :)
My first gear stripped in a "mild" crash but I have to admit I set the mesh on the loose side due to it wobbling. I cut another gear (25 min on this one) and it wobbled! What's up with this? I found having one setscrew pushed the gear on the carbon shaft. Cure, 2 opposing setscrews or glue the gear first and then push it opposite of the set screw as you gently tighten it down. Below you can see how the teeth of the 2nd gear were pushed to one side. Plastic stronger then aluminum? Or is it simply that Cutting Gears Is MUCH More Complicated than this... 6-7-04
Old gear on left, new gear on right
