Re: ATM Plaster tool and grinding machine

[Bruce Swayze <swayze@europa.com>]

At 11:56 AM 7/18/97 -0300, you wrote:
>   I just received a 12" plain blank from NewportGlass (TPX1200) and I'm
>planning to make a pregenerated approximate curve dental plaster tool with
>tiles for it. (I'll stamp the curve from another mirror I have) 
>   Do someone can tell me how to adapt the back of the plaster tool to a
>grinding machine driving pin ? 
>   Will the plaster break, considering that the force from the machine is
>concentrated in a single point at the tool back? Do I have to place a
>plywood at back of tool to spread the tension ? Do plaster "glues" to wood?
>   I'm assuming I have to work TOT and the tool will swing a lot around the
>pin, right ?

For our machine, we don't use a pin directly on the tool.  We make a "cross"
out of two perpendicular bars that have 4 cleats on the ends that hang down
over the mirror or the blank.  The pin is in the middle of this device, and
the cleats are what push the tool (or mirror) around.  Much easier to show
than to describe, but I think you can get the idea.  A further elaboration
was to make this out of slotted steel bars, so the positions of the cleats
are adjustable for different size mirrors by loosening a locking nut and
bolt and sliding the cleats out or in.  

I hope this makes sense, and I hope it helps you.  Works for us!

Bruce Swayze
swayze@europa.com
http://www.europa.com/~swayze    Swayze Optical home page
http://www.europa.com/~swayze/spider.html  Homemade spider page