Greetings all;

I am now calibrated well enough that I can actually run wood carving 
code! And it looks like I could crank up the feed rate a bit, but the 
finish obtained will determine that.

The comment someone made about that BOB being slow, depends on the 
polarity of the pulses.  Using a common +5 for the opto source, and 
treating the BOB as an open collector, I am using 5i25 step and space 
timings of 2 u-secs.  The ugly slow can be seen on my Hitachi, but the 
motors run fine at 45 ipm, which is 35 faster that the little mill can 
run.

Now, if I had those slot opto's & switches, I could begin to bring the 
spindle under LCNC control too.

3 things of note, z would not go up to the end of the scale on the  post, 
but I did some disassembly, and the limit is the nut bracket, either 
one, OEM or the ball screw version, hitting the top of the slot in the 
post.  The other is that while those screws are supposedly 16x5's, my 
scales do not agree with a 1" range dial indicator. By 1 to 3%.  And I 
have taken considerable care to make sure the indicator was aligned with 
the axis I was checking.  Its not skipped steps as I stretched the 5i25 
timeing way out, and the error remains the same but somewhat different 
per screw.

There is a digital DRO on the quill, but I haven't thought to check it 
against the dial indicator.

What has been others experience in this calibration aspect?  Can I 
believe the dial indicator.  Being gear driven, over long ranges, since 
a full inch is 10 turns around the dial, my spidey sense says it could 
have a cyclic error, but from needle 0 to needle 0, it should be dead on 
with the real world.  Right?

3rd, is the very heavy preload on the spindle bearings as this one was 
shipped. Obviously heavy drag when the backgear was in neutral.

So I took it apart, loosened the tension nut about 5 degrees, padded the 
top of the shaft with a 1/2" thick block of alu and gave it a decent 
whack to drive the shaft back thru the upper bearing to gain some 
clearance.  Then drove the nut back to within a degree of its original 
position, at which point I was no longer able to feel any play, and the 
drag was just starting to increase.  Reassembled the whole thing.

Before I did that, 30 mins at 2300 revs was warming the spindle up, 
measured on the lower face of the quill, from 74F in the room to 121F, 
47F rise.  Now, an hour gets it to 86F, a 12F rise and much more 
tolerable & lots less spindle growth due to heat.

Anyway, progress, its alive!

I did have to reboot to regain the motor control once, this thing needs 
more memory, 384 megs just doesn't do it.  But my son will be here on 
the 7th, with another machine with more cpu and memory iron in it, which 
should help.  No chance in hell of finding another 256 meg pc-133 stick 
in these here parts.  That would give it 512megs.

I also think that will help the mouse.  As it sits, if the mouse gets 
blanked while geany or whatever is running, then when I go back to the 
LCNC screen, the pointer is gone, and it often takes half a minute or 
more of driving it around before the pointer becomes visible again.  
Thats a major PIMA to me.  And in the xfce prefs, no sign of any mouse 
blanker controls.  I wonder, could that be disabled in 
the /etc/X11/xorg.conf somehow?

Not exactly ready for prime time, but it is the middle of the 
afternoon. :)

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>

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