Re: [CAD_CAM_EDM_DRO] Re: Counterbalancing & Rong-Fu RF-45 Project

Ian Wright wrote:

> > Ian: A Bridgeport milling machine is not exactly a small machine.
> Just
> > the table is probably a couple hundred pound,s or more, with nothing
> on
> > it. The vise might be 50 pounds or more. That does not include the
> knee
> > itself. Or 3 stepper motors at 25 pounds each. A lot of weight to
> push
> > up. Gravity does a good job coming down.
> > I do a few Jaguar racing cylinder heads on this machine. They are 28
>
> > inches long and quite heavy. Add that to the mass and you can
> understand
> > why string and buckets won't get the job done.

I believe the 9 x 42" Bridgeport table weighs over 200 Lbs., the saddle
weighs
nearly 100 Lbs., and the knee must weigh several hundred lbs at least!
Lead screws, axis drive mounts, nuts, etc. all add to the above. (I'm
not sure how
an old round-ram Bridgeport like mine compares to that. The table is
shorter, and the knee is smaller, but it is still close to the above.)
So, the knee must have close to a half ton of weight pushing down
on the lifting screw.

Jon