Group Project: Dividing Head - The Build

[Shotgun]

Here is what I was thinking for the new end cap to mate with a 15° taper on the trunion.

I cut six slits. I like what you did, though. Should be relatively easy to cut either way with a slitting saw.

 

[rwm]

That could work, I would prefer that it be kept as large as possible. Just machine as little as possible for it to clean up or even leave stock surface, but it will not be pretty.

At 3.125 that only leaves .063 of bearing surface and some of that will be lost in deburring the hole, and the trunion would need an undercut at the shoulder to maximize bearing surface.

I agree with all those thoughts. What if we just machine the trunnion stock down to 3.20? Keep the deburr and undercut to a minimum. How will this fit in the existing plans?

 

[rwm]

Hey I had some time today. I'm not sure who was gonna do these items but I felt I could tackle them since I had some material:









I found out my lathe cuts a slight taper but all are within spec!

 

[rwm]

Jeff-After assembling this I have a question on function. It look from the drawings that the only thing keeping the 9/16 worm shaft from migrating towards the driven gear is the spring on the other end? Is this correct? I guess if the spring is stiff enough it would do the job. Should we consider adding something else in there? Jamb nut maybe? Maybe unnecessary.
I am also considering taking a little off the nose (small end) of the gear shift and putting in a bronze bushing where is meets the flange. Just a detail to keep the operation smooth. In fact the entire shaft could be brass? Hmmm.

 

[Shotgun]

You did all that in a day!!??
Wow!

 

[rwm]

No sorry. I made the shaft and the 1" worm to fit (pic 1)I have several gear shifts I made previously and 8 or 9 of the clamps, ball handles and shafts. I wanted to see how the whole thing fit together. I am very please and motivated by this!

 

[Flyinfool]

Yes it is just the spring holding it.
At the design compression the spring should have 18 lbs of pressure.
I had thought of adding a snap ring or something similar, But it is way to hard to hold a close tolerance on snap rings.

 

[rwm]

Jeff- That makes sense. I'm sure the spring will be fine with that much force. That also helps the backlash problem. You have done an outstanding job on this design. As a back up plan, I suppose one could cut a C clip groove at a distance and then carefully machine a spacer to get the clearance just right. I doubt that will be necessary.

It seems like we have lost a lot of people along the way. Currently it looks like, Myself, Jeff, Shotgun, Ericmannie, are actively following? Erichkeene and Lanagos are intermittent? I know life gets in the way but this project started back in 2021! I would like to finish something workable by years end. Can everybody following this thread chime is and give us some idea if they want to continue? I am certainly not trying to push anyone out if they are interested, there are plenty of parts to be made! Maybe we have some new followers that want to jump in? Thoughts?

 

[Shotgun]

I have several parts complete. Five of the bases are done. The spindle clamps, and the trunnion clamps just need the outside edge finished. I could get that all done in a weekend, if it weren't so hot, and I'd stop chasing side projects.
Remaking the auxiliary base is going to take a little longer, but in just a few more days I should be able to CNC them.

 

[rwm]

I forgot you were setting up CNC! Yeah that will help! I think if we have enough people to get the major parts accomplished there's a lot of small parts that we could each make ourselves. I may be able to make the driven gears but I need to wait and see how my hobbing with a tap idea works out. I think that it will. I'm a little worried about the amount of hogging out involved with the trunnion, especially trying to do multiple of those. I can probably get one done for myself if I had to do that.