Re: [CAD_CAM_EDM_DRO] Knee or Quill Drive?

Bridgett (Bridgeport series II) is driven on the knee with a 4:1 ratio and I
am reliable at 36 ipm with out using the air assist. She uses a ballscrew on
the knee and that likely makes a big difference. From the manuals I have
read on servicing the knee the table weight that is being lifted is in the
1100 - 1500 lbs range. Accuracy is better than .001". So, I know that a
properly designed knee drive can work very very well. Yes when you power off
the servo amp the knee does drop.

If you want to get this setup to work I would increase the reduction ratio
and put in a good ballscrew. After getting use to the large and accurate Z
travel I have with a driven knee I would not want to be forced to switch the
5" or so of a driven quill.

Tim
[Denver, CO]

----- Original Message -----
>
> Use a 4/1 ratio on the knee. That is what I have on my Knee mill and it
> raises the knee with the 105 lb mill vice with impunity and with good
> speed.