Well, I finished the dual spindle mount today.

I got it rough fitted right now. Still need to level the top and bottom
pieces, but the levelers for raising and lowering the spindles independently
work fine. I decided to add levelers to both handles so I could raise one
and lower the other for single cutting or level them both for dual cutting.
Nothing fancy. Just a 1/4 20 stainless bolt threaded on up the shoulder and
my original single clamps drilled and threaded to sit between the dual clamp
mount.

I had to pull the main spindle motor, and for the first time ever my stepper
motor was able to raise and lower the Z-Axis from stop to stop without
binding. I don't mean just short of the stop, but right up to it. I knew
that 12 pound (I put it on the scale) motor had to be a load for that little
280oz stepper motor. I imagine the twisting force had to be a lot more than
that since its center of gravity was several inches out in front of the
Z-Axis ways.

After I realized how much better the Z-Axis moved I decided to tighten it up
some and adjust the gibbs. It took a little while, but I got it dialed in
with zero noticeable slop, and it still ran stop to stop without binding.
Previously I always used the z-axis below 4 inches, kept it loose, and kept
it tuned at 10 IPM. By doing that I was able to do a lot of work without
too much trouble.

After doing all of that I got into my software motor tuning and set the Z
axis for 30 inches per minute for fast travels. Same speed as I have the X
& Y set for. Again, stop to stop repeatedly with no binding or even
sounding like it was working hard. I wrote a short piece of code to run it
too just short of its limits back and forth and ZIP.

If these flex handles work out and I can get a pair of those that will use
collets upto .250 I may NEVER put that spindle motor back on. I may even
remove the spindle itself and make a different set of dual spindle mounting
brackets that come right off the carriage instead of being mounted to the
spindle t-slots.

Oh, yeah. I go that new tool glow... only better.

"Bob La Londe" wrote in message
...
Well, I finished the dual spindle mount today.

I got it rough fitted right now. Still need to level the top and bottom
pieces, but the levelers for raising and lowering the spindles
independently work fine. I decided to add levelers to both handles so I
could raise one and lower the other for single cutting or level them both
for dual cutting. Nothing fancy. Just a 1/4 20 stainless bolt threaded on
up the shoulder and my original single clamps drilled and threaded to sit
between the dual clamp mount.

I had to pull the main spindle motor, and for the first time ever my
stepper motor was able to raise and lower the Z-Axis from stop to stop
without binding. I don't mean just short of the stop, but right up to it.
I knew that 12 pound (I put it on the scale) motor had to be a load for
that little 280oz stepper motor. I imagine the twisting force had to be a
lot more than that since its center of gravity was several inches out in
front of the Z-Axis ways.

After I realized how much better the Z-Axis moved I decided to tighten it
up some and adjust the gibbs. It took a little while, but I got it dialed
in with zero noticeable slop, and it still ran stop to stop without
binding. Previously I always used the z-axis below 4 inches, kept it
loose, and kept it tuned at 10 IPM. By doing that I was able to do a lot
of work without too much trouble.

After doing all of that I got into my software motor tuning and set the Z
axis for 30 inches per minute for fast travels. Same speed as I have the
X & Y set for. Again, stop to stop repeatedly with no binding or even
sounding like it was working hard. I wrote a short piece of code to run
it too just short of its limits back and forth and ZIP.

If these flex handles work out and I can get a pair of those that will use
collets upto .250 I may NEVER put that spindle motor back on. I may even
remove the spindle itself and make a different set of dual spindle
mounting brackets that come right off the carriage instead of being
mounted to the spindle t-slots.

Oh, yeah. I go that new tool glow... only better.


My thought was if I tightened it up just right it would be almost self
squaring and self leveling. I was wrong. In five inches of travel it was
off by 0.006" I made two very light taps with a brass mallet and tightened
the mounting screws up the rest of the way. Its level from left to right
relative to the spindle within about .002 and because I was lazy and didn't
surface the brackets before cutting them out that's as close as I am going
to get. They have that much irregularity in the surface. I haven't checked
it front to back. In order to change that I would have to use shims anyway.

Now its busy cutting its own very first work piece. A clamp down .005 wide
spacer and square to go between work pieces when I am cutting two at a time.

Cutting out the dual spindle mounting clamps.
http://a.imageshack.us/img291/8059/dscf1712b.jpg

All mounted up and using the old single clamps as part of my leveling tool.
Doesn't look as neat as cutting out matching ones, but I already had them.
http://a.imageshack.us/img291/8059/dscf1712b.jpg

30 inches per minute on all axis, and ramping in at 15 IPM to .006 with a
33% step over.
http://www.youtube.com/watch?v=RfcaT1AB2gM

Its amazing how much difference an extra 5000 RPM makes.