Grizzly G4003G - Installed rubber motor mounts, fixed motor alignment, pulley, wiring issue

[jarhead]

TX cowdoc, how did it turn out for you?

I am fighting a similar issue and am going to follow the advice posted here.
I have a G750G grizzly gunsmith lathe i bought used.

Thanks, Joe

 

[mksj]

This is a long known issue that is typically associated with the pulsations from single phase motors. It is usually seen with the smaller lathes that have the motors hanging off the back of the lathe. Different remedies to the situation, usually starting with some form of motor isolation with rubber mounts, and to some degree maybe trying different belts/tensions. Otherwise going to a 3 phase motors is the usual remedy. You might give some specifics as to what your seeing, the usual issue is repeat surface patterns seen in turning regardless of the material or if you are using HSS or inserts as seen below in both aluminum and steel.

 

[jarhead]

Actually i was moving the change gears to do some 18 TPI threads and went down a rabbit hole. I was hearing what sounded like bearing noise and the only way to tell was to remove the motor so i could listen to the bearings. It took and hour and a half to remove the motor due to poor design. I even had to get my wife to come out at 6:00 PM last night to help remove a bolt i couldn't get to with my Herman Munster hands.

So i came here to the search and found several threads like you mentioned. I thought i may as well isolate the motor while i am at it. Three phase isnt in the budget this time around.

I also have the motor pulley hanging out to the end of the shaft, etc.

Thanks, Joe

 

[TX COWDOC]

Lathe is running very well after working through a couple of issues.

One- the compound was not sitting flush on the cross-slide. This was discovered when Bamban / Nez Rongero came down from Austin to help me trouble shoot. We polished the irregularity and the facets in my threads went away.

Two - vibration in the machine. I installed the Baldor motor on rubber mounts, and used linked belts as suggested here. I used 2 belts and placed in opposite orientation. These steps really seemed to eliminate the harmonic vibration. See picture.

The end result is the lathe is doing exactly what it should.

Here is a chamber on a recent 6.5 PRC and the resulting group at 100 yards with Hornady 143ELDX.

My rifles are shooting very well. I am pleased as are my customers.

This forum is great!