Greetings all;

They arrived today, and the first thing of note is that the 1.5" diameter 
section with a tool holder groove in it, is a much shorter, no groove, 
cylinder thats about 2 thou bigger than the TTS holder.  There is no 
chamfer at the top of the 3/4 diameter section, so it would 
not "auto-center" as the spindle descends over it in an ATC situation.

Overall, its nominally 1/2" shorter.  As to that being a problem, I 
changed all 3 tools to the new holders but have not corrected the top of 
the board Z "seed" in my gcode yet.  They do look to be well built with 
a potential exception of the eccentricity of the extraction groove 
engagement, its obviously not as pronounced an offcenter compared to the 
real TTS holder.

More news later after I've had a chance to actually use them.

With the space considerations, it looks as if I'll need to rethink the 
tool changer into one with a transfer arm to move the tool to/from the 
spindle, probably with 2 sides, one to accept the tool being dropped, 
and one to grab a tool from the wheel and bring it to the spindle. 
Putting the removed tool back in the correct pocket doesn't look like an 
insurmountable problem, just one I'll likely pester someone about. ;-)
 
But I can see the need for an additional motor to rotate the transfer 
arm.

fleabay has some 99/1 geared nema 11 steppers, pretty small but they're 
about $40 a copy.  Can anyone comment on those?  Since there would not 
be more than one motor running at any one time in my vision of this, I 
am inclined to rig a rack of 4PST ice cubes, closing the relay to that 
motors coils with about 100 ms make delay before enabling the driver, 
and a similar stop steps, disable 100 ms later, then drop the relay so 
that I could drive all the motors from one driver.

Yeah, I know, a miss-cue in a contact will probably blow the driver, but 
ice-cubes seem pretty dependable. All this switching would of course 
take place with the drivers enable line off, so when it becomes enabled 
the relay has had time to close.  Conversely, at stop time, leave it 
enabled for long enough to bring the motor to a solid stop, then 
disable, and drop the relay 100 ms later.

Comments on this idea?

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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