Surface grinder with ??s

chris609

chris609

Gold Member
Joined
Oct 6, 2003
Messages
274
Hi all, Got this old sanford off ebay 2 months back. She was extreamly filthy and in desprate need of new paint. Here she is so far I cleaned every nut, bolt, gear and painted her. Also had to clean out all the oil channels and replace some oil cups. I am debating the idea of 2x72 belt conversion. Maybe swap the the three phase motor out. I know the motor is balanced but for the conversion would it matter? Knifemakers dont need flatness out to several decimal places right?:) Maybe some of you who have done the conversion and or swaped in new motors can lend me some advise. Thanks

View attachment 164458

View attachment 164459

View attachment 164460
 
Sorry I can't help you on the conversion, but I have the same sanford, where did you get the oil cups? I had to make a copper elbow for one of the cups on the worktable. and the second one is held in by no friction at all.
 
chris609 said:
Maybe swap the the three phase motor out. I know the motor is balanced but for the conversion would it matter? Knifemakers dont need flatness out to several decimal places right?:)
Click to expand...

-It's not just the flatness, but also the finish.

What you tend to wind up with, with an unbalanced wheel or motor, is a "striped" surface finish that looks wavy- the variation in the actual surface height is nearly immeasurable, but the tiny variations in wheel speed change the surface finish to produce an "optical illusion" of waviness.

And it's not just balance- single phase motors have a 60Hz "hum", as the rotor speeds up and slows down, minutely, sixty times a second. In a 3-phase, the three sine waves help cancel each other out to produce a smoother, more consistent speed.

You'll already be fighting grooves caused by the belt seam, I wouldn't recommend taking on more issues if you don't absolutely need to. VFD's are cheap. :D

Doc.
 
Thanks doc you know your stuff:) I was thinking of getting a phase converter in case I pic up a bridgeport some day. Alot of makers do the 2x72 thing with there SG's. Maybe I will work with the stone wheels for a while.
 
You must log in or register to reply here.
Back
Top