Re: Head Relief

At 08:47 AM 12/20/02 -0000, Al wrote:

>Would be interested in hearing your comments, pro and con, based on
>your experience in actual use.

You pretty much nailed it, Al. The main benefit was relocating the spindle
motor behind the column, making the center of gravity of the whole head
assembly right at the ways. This *really* eased the Z movement by
eliminating the extra friction caused by the unbalanced head. The springs
are actually probably unnecessary. I have not tried running the mill
without them, but I might just. The main "con" is that I don't have ball
bearings in the idler pulley I added (just an Oilite,) and it is really
noisy. I add a drop of heavy oil every once in a while, but I really need
to make a new pulley with proper bearings. It is necessarily small
diameter, so its RPM is higher than either the motor or spindle.

I have not done a lot of countouring since I did the Moglice mod, but I
have not noticed any vertical stiction either before or after the Moglice.
For a dedicated CNC Sherline, I wouldn't hesitate to recommend the spindle
motor repositioning (keep in mind you can't rotate the head any more.) A
few new tapped holes in the head slide, a sheet metal bracket, a longer
belt and idler pulley and you have it.

Best regards,

Randy

Randy Gordon-Gilmore ,----.___________ ______________ _________________
ProtoTrains // = = === == || == == == = || == == == = == =|
Rio Vista, CA, USA /-O==O------------o==o------------o==o-----------o==o-'
zephyrus@... http://www.prototrains.com