[00:24:56] <skunkworks> http://www.electronicsam.com/images/KandT/conversion/curvictogether.jpg
heh, the scale on that is bigger than I expected...
so the sitting down on this locking ring is what actually positions it accurately?
I wonder if you want some lash in the gears on purpose for that to work well
skunkworks: what is *that*?
that is what indexes the B axis - 72 teeth 5 degree index
yes - that is what positions the axis accurately
cradek: good point. I suppose we could disable the servo amp/pid after it gets in position. didn't really think about that/.
what would you have to disable so that when it gets reactivated it doesn't try to jump.
unless we got the backlash perfectly inside its slack
gear train slack
maybe it isn't a problem. If we home to an index and figure out the offset so that it is right in the middle of the gear train slack.
skunkworks: That can be dad's next project, to design and build a gearbox suitable for continuous backlash-free rotation, and get rid of the curvic coupling. "Your mission, should you decide to accept it...", lol. No, maybe not, that is a pretty big platter you've got there, and you don't want to have to baby it while cutting. Tempting, but nevermind.
skunkworks: BTW, curvictogether.jpg is a nice pic, as it shows the necessary gaps on the tops and bottoms, it should only seat on the tapers, and it does.
KimK: that would be nice - but I don't know if that is needed. ;)
yes once you get it right, it should stay right - but seems finicky
cradek: should be an interesting experiment.
how do other locking rotorys get handled. I could see a wind-up issue
(if it is a little off)
I agree - I would not use I gain. not sure how servos on locking axes should work.
on my locking indexer it a quarter turn of the worm backlash, and the indexing lock is what did the final orientation. so it would be fine, even with rough homing.
I think yours would need slack to work right, too.
you could disable the amp when the table is down, but I agree you might get jumps when reenabling it.
I don't think it is a 1/4 turn - but there is some backlash in the gear train
I bet that's good
don't fix it this time :-)
that was never designed to be 0 backlash - no adjustments anywhere.
we could add backlash... it is going to be run with a chain :)
The only other thing I need to worry about is if there is an even number of rotations of the input shaft for one complete rotation of the table.
oh you mean integral number of rotations - for index
they had a resolver in the original gearbox - but that was driven by some extra gears. So I am not sure.
yeah, hope it is integral...
probably it is?
heh - no clue
looks like the resolver was geared 2:1
so that is promising