Homebrew PCBs

Robert Hedan wrote:

> I LOVE THAT ONE!  It's now my new desktop so I can study it when I want.  :D
> 
> Note the centered screws on every axis, that's the best technique in my
> opinion.  Even if it is only a drilling station, that cuts down further on
> the play.  Those motors look powerful, that machine looks capable of CNC
> work.
> 


   It actually doesn't improve play as much as you might think off hand, there 
are some advantages but they're not that extreme.  My fav is really one high 
precision rail with both screw and load near it, and an anti-rotation arm or 
plate over to another rail that simply stops rotation and is very non-critical, 
it's play hardly affects the other side.  Most of the high powered engravers use 
this, with a plate across and just a plain ball bearing riding on a rail for the 
other side, all the precision is in one rail.


> For the clamps, I was planning on cutting scrap PCB into 2 L-shapes, glueing
> 2 identical pieces on top of those, but making the top layer protrude about
> 1/16" into the L opening.  That way the bottom layer is the exact thickness
> as a PCB and aligns it on the platform, and the top layer acts as a clamp.
> One set will be mounted permanently on the platform as the 'origin' corner,
> and the other set will be held down by a butterfly bolt (nut embedded within
> the platform surface).
> 
> That rubber hose coupling is hilarious. I wouldn't have thought of such a
> simple and effective design.
> 
> Robert
> :)
> 

   Well likely neither did we, it's been around a long time.  Actually Jameco or 
someone has some fairly good rubber type connectors.  Each end has a circle with 
two prongs sticking out, the rubber piece in the middle is cross shaped and fits 
between the prongs from both sides.  Simple and allows lots of play, yet is 
tight in the rotation direction.

http://www.jameco.com/webapp/wcs/stores/servlet/CategoryDisplay?storeId=10001&catalogId=10001&langId=-1&categoryId=754015

Under Robotics:mechanical:couplers if the link doesn't go through well.

   Wow their steel coupler is $4.49 that's nuts, mine were $1 retail I think. 
The spider couplers must be a nickel since they're selling them for $1-ish.

   See if I can look it up real quick..
There we go HH Smith.  http://www.abbatron.com/products/part/get/hdw_sha_shco
Shaft accessories shaft couplers..  Have to look around on the net a bit but I 
found them for not too much per bag of 25 even retail when I got mine..

Alan