Re: [CAD_CAM_EDM_DRO] Making leadscrews more accurate

> I'm sure it would be possible to mount a full length cam alongside the

lead

> screws but it would have to be planned for in advance, since you'd also

have

> to provide some pretty good support for the cam as well.
>

I did finite element on mine and found that a 3/8" x 3" steel cam supported
every 3 feet was more than rigid enough.
A 3/16 bending of the cam is .001" linear travel. One visitor
to the shop commented that the cam could be a piece of
wood and he is probably right.

> It's my guess that this system would even work with acme screws as well as
> plain old threaded rod. Now THAT (th'd rod) would really bring the cost
> down!
>

Yes as long as there is no backlash. If the leadscrew has severe drunken
threads (pitch changes within one rotation)
one would have to trade off axial stiffness for anti- backlash
with spring loaded double nuts. As long as the anti-backlash
did not unload with cutting forces it would work with the crappiest of
screws- its true. Hmmm ground ballscrew
precision with hardware store threaded rod....

Leslie Watts
L M Watts Furniture
Tiger, Georgia USA
http://www.rabun.net/~leswatts/wattsfurniturewp.html

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