Problem- hurco sm1

[redford1955]

i have started to repair vari drive on my Hurco SM1 cnc mill. mill is very noisy at higher speeds and doesn't change much when spindle is disengaged with high low lever. the top of the mill comes apart fairly easily and i found that all bearings are a little rough but none are really bad. i am going to replace them all and am wondering if i should stop there, or replace the spindle bearings too. does anyone know the procedure to pull the spindle apart on one of these old hurco's?

thanks
keith

[bloke]

Chances are, the spindle bearings are fine. Do the head bearings and if the spindle needs doing, post back and I'll tell you how to go about it.

[redford1955]

i have everything cleaned up now and do not see how the noise came from anything in the upper head. i will check the bearings between the drive and the spindle, located below the driven pulley at the top of the spindle. i still think i should change the grease for the spindle bearings due to the age of the machine.

keith

[Rich Carlstedt]

"If" the SM 1 has the same vari-drive as the KM series, I would say the noise is from the vari-drive bushings.
they are made of UHMW and when loose on the spline, make huge noises as the sheeves vibrate.

[redford1955]

last night i tore the mill down all the way to the spindle bearings. i am glad that i did this because the grease on the spindle bearings had hardened and was not doing much for lubrication. also going to replace the ball bearing at the top of the spindle shaft because of excessive play even though it spins freely. the spindle bearings are Barden and appear in good shape after cleaning them up. i used a magnifying glass to check for pitting or skidding. going to pick up some high speed spindle grease today from local bearing distributor and reassemble mill this weekend

thanks
keith