[Coco] Little Johns 8 slot MPI

[Gene Heskett]

On Saturday 21 September 2013 12:01:09 Louis Ciotti did opine:

> How about all the files?   Would like to see them myself, both schematic
> and layout.
> 
I found part 2, at <http://www.coco3.com/community/2010/07/this-is-part-2-
of-3-of-an-8-slot-mpi-multi-pak-interface-design-for-my-friends-at-coco3-
com-andor-the-maltedmedia-list-members-from-your-friend-johngimechip-com/>

There is a link there to the part 1 files I already have, but it turns out 
part 2 has the whole mary ann in it.

But when loaded into eagle, I find the .brd is 6.05" wide front to back and 
I would need about 1.5" more Y axis travel than my mill has.  So, short of 
building a new machine, which I might not have time to finish, I can't make 
it. On ebay, the cheapest I can get a machine suitable for this accuracy 
OOTB because it has ball screws is $1050, FOB Hong Kong, the only one I 
could find with ball screws for drive.  Ouch...  I could do it, but I'd 
have to make lots of boards to pay for that.  Unforch, it comes /with/ the 
motors drivers, something I really don't need if I switch cabling, or I'd 
need to find another atom based computer kit & monitor, another $350 & who 
knows what customs would want coming in from Hong Kong.  Thats a long boat 
& truck ride to WV, USA.

The $650 model is big enough, but has 2 start trapezoidal screws, whatever 
that means, I think 2 threads per revolution of the screw. They might be 
accurate enough if the nuts were molded in place out of delrin, but they 
would also use 90% of the motors to turn them, where ball screws are very 
low friction.  The molded in place delrin nuts are, according to what I've 
read very long lasting, like ball nuts if kept clean.  The spindle motor 
has an ER11 collet and only spins 8 grand where the bigger one spins at 20 
grand max.  I can't justify it, but I'm still thinking. ;-)

> Sent from my iPhone
> 
> > On Sep 21, 2013, at 11:44 AM, Gene Heskett <gheskett at wdtv.com> wrote:
> > 
> > Does anyone have the 2 of 2 files for that?
> > 
> > I grabbed the 1 of 2, which contained the isolation buffers etc for
> > it, and have made the files that will carve it and drill it, but
> > somewhere I missed the 2nd half of the project, which connected to
> > the first half with a 40 pin ribbon cable jumper.
> > 
> > If anyone has that 2 of 2 download, plz PM it to me, as it looks like
> > I might be able to make it.
> > 
> > Cheers, Gene
> 
> --
> Coco mailing list
> Coco at maltedmedia.com
> http://five.pairlist.net/mailman/listinfo/coco


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

lp1 on fire
(One of the more obfuscated kernel messages)
A pen in the hand of this president is far more
dangerous than 200 million guns in the hands of
         law-abiding citizens.