Re: [CAD_CAM_EDM_DRO] re:Re: maxnc/sherline (Z axis mods)

ballendo@... wrote:

> Would you please post a spec. or part number for these "constant
> force" springs.

Can't give a blanket number, it varies with the spring rate.
Reid's number is 800-253-0421.

Ideally, you wrap the spring onto a drum that is slightly larger in dia.
This is more important if you are driving or holding tension on the
drum. For our needs, it's not critical, just keeps the spring from
moving around. Mine is wrapped around a chunk of teflon that rolls on a
1/4 SS pin. Free end is secured by a #10 screw through a hole near the
end.
I'd recommend picking a spring that is 2-3 pounds lighter than the load
you want to assist. This will help make sure that in the event of any
backlash in the Z axis, the slide will follow the screw down and not
hang there from stiction as would happen if it were perfectly balanced.
Think I used a 7lb spring, with an estimated 9-10 lbs of
slide/spindle/motor to assist.

Jon