they were a little touchy to get good quadrature waveforms
I've thought about using some kind of magnetic sensors to detect the teeth on the spindle gear (inside the headstock)
I havent had the headstock apart... what is in there? mine rattles a lot
a gear on the spindle
an idler shaft with two gears
and the shaft that comes out in the "belt box" to drive the threading/power feed geartrain
ok for the power feeds (not used on cnc)
that gear would be a nice place
I have no idea how many teeth it has
other than "not all that many"
it would be a fairly coarse encoder
add a piece of ketstock for an index pulse
I hadn't even thought about the index
thats easier to get.... maybe something on the drive pulleu
my encoder is 360 counts/rev.... and rpm pyvcp meter shows +-rpms
I was fighting with a hal config for the lathe.... it seems to want x,y,z config settings.... and I just redirected the x,z pulses to the right parallel port pins
emc doesn't deal gracefully with non-sequential axes
but at least everything is working in the right direction (jogs, moves etc)... now to figure out threading
I have no idea how to setup to cut an M10 thread for a drawbar
just need to figure out what the key diameters are
get out the thread wires ;-)
next project is some 10-24 thumb screws for my pcb hold-downs
(on the thumbscrews)
* skunkworks yells vacumm table!
yup..... chance to try knurling, threadcutting and cutoof tool
lets see at $70/hr... I figure they should be worth a fortune
I cheat for things like that
drill, tap (female thread), then screw in and locktite a socket set screw
gives me a grade 8 or so quality steel thread
my tabletop is 3/16 lexan... I dont thing grade 8 is necessary, but it may be faster to knurl some stock and cut off some knowbs and do what you suggested
whew... my fingers must be broken today
hmmm. given that brass knurled thumbscrews, 10-24 (1/3-1") are betwen $0.50 and $0.72, I'm not positive about the economics of making them yourself :)
err - 3/8 to 1", that is
I definately wont have a market selling them to china!
or to McMaster ;)
now how many do I have to make to justify having this shoptask?
43557, at least
LawrenceG: can you use link-belts?
on your shoptask-lathe
yes.. that would be an idea.... I can move the belts fine, its just when I have to replace it, I will have to move the encoder pickups
they are supposed to be better anyway, and only cost about 3x as much
I am still using the orignal belts from 1995, but they are cheap crap
I would like to find a 1.5hp 3phase 220 motor.... I have a VFD that mould make a nice spindle driver
some of the servo motors are approaching that size
I think "tool setter" is not pending - it works fine
mach, turbocnc, deskcnc can probably do thread milling (helixes). I doubt any of them can do rigid tapping.
I was wondering why mach couldn't rigid tapping as it does lathe threading.. THen I remembered you have to reverse the spindle..
and follow back out
yeah, 1ppr only works if you assume the spindle never changes speed
reversing ... is a speed change
I hear with a 3ph motor you can just smack it from fwd to reverse - I'm scared to try it on my mill though
(in theory I could rigid tap that way)
I think you get very big screams from the supply wires if you try to "thwack" a 3-phase motor into reverse
yeah I was concerned about nuking my phase converter
you might end up reversing your phase converter ;)
startup sounds a bit hard on it already