After acquiring my Atlas 7B shaper, I had intended to disassemble, clean and rennovate it before starting to use it.
However, in preparing to work on another project, I found that I needed to use it right away. I discovered that I was missing a 20
tooth change gear with internal splines for my lathe (Colchester Mk1, 13x24) that was necessary in order to cut some metric threads.
The only source for the gear that I could locate wanted over $200 for it. I figured that if I could find a suitable gear,
I could cut the internal splines with my shaper.
I found a 20 tooth, 16DP gear made by Boston Gear that had an I.D. slightly smaller than I needed and it cost only $15.
Before I could cut the splines, however, I needed to do some preparatory work on the shaper. Firstly, I needed to figure out
a way to mount my Ellis dividing head on the shaper's table. Since the dividing head is rather large for the shaper, I ended up
making a table extension to hold the dividing head. A little cutting, drilling and welding resulted in a setup that I thought would
do the job.
Secondly, I needed to make a toolholder for the shaper and an extension for it
suitable for doing internal cutting. The toolholder and the extension are based on the drawings by Art Volz posted in the Files
section of the Yahoo group "Metal_Shapers" (use this link to visit).
More detailed information on the toolholder may be found here.
Thirdly, I needed to grind a cutting bit to match the profile of the splines. Although this may not be the best way to proceed,
I figured that it would be easiest to cut the width of the spline at once using a very light downfeed.
Lastly, I needed to make a holder so the gear could be mounted on the dividing head. This was
accomplished by boring a recess in a piece of 3/4 x 2" scrap stock into which the gear could be pressed. The boring operation was done
on the lathe since I didn't have a mill at the time. The finished holder can be seen here.