What's new
What's new

VMC 800 Spindle Bearing Replacement

amh82

Plastic
Joined
Sep 2, 2020
Has anyone on this board attempted DIY spindle repair?

I have removed a spindle from a VMC 800 due to noise, and it is pretty rough when turned by hand.

I have been trying to get prices for bearings, but most suppliers are telling me that they recommend the spindle be sent to a specialist for refurb.

Has anyone sucessfully repaired one of these spindles and had good life following repair?
 
Sorry, the machine is a Bridgeport VMC 800 22, Model Year 2001. The spindle is marked W871, not sure how to ID other than that. It is just referred to as machine spindle in the parts diagrams.
 
It's probably similar to this: ▷ Used Bridgeport Vmc 800 for sale - Machineseeker

Does the machine have TSC, or anything else that's coupled to the spindle? Is there rigid tapping, so an encoder? Shot pin for orientation?

It's likely you "can" do the work yourself, if you're careful, good at note and picture taking, don't get frustrated and whip out the blue-tipped wrench, and can set up a "clean area" for removal of the bearings and reassembly. But can you afford the downtime, and do you have another machine (even manual) to make fixture or bearing pulling parts if you need them?

Search Youtube for CNC spindle repair videos to get a sense of what you're facing, and decide whether you can do a proper job.
 
Hi Milland, thanks for your reply.

The machine has an encoder coupled to the spindle, but no more than that from what I can see.

We have access to manual machines, other CNC's, arbour press - the usual workshop equipment, but I do not have a bearing heater at the moment.

I am awaiting estimates for rebuilds so I have nothing to lose at the moment, I have some experience of spindle bearings replacements, but where I used to work most of the spindles were high frequency and would be sent away to a specialist, and if they were done in house we had a well equipped workshop.

Sadly, I now have a less equipped workshop and no mechanical guys to help me!!

Will give it a go at least, nothing to lose just yet!
 
Let us know how the process goes...

Looks like I will have to send it away. Once you have the upper bearing cap off there is what is described in the drawing as a lockring.

The drawing doesn't show a thread on the shaft or the lockring itself, but does show a groove on the inside of the lockring. The lockring has a blind hole one side, presumably for a hook pin spanner and a small tapped through hole opposite. I tried to spin it off, but it's not moving.

With no sign of a thread on the drawing, and just a plain shaft when you look through the tapped hole in the lockring, I suspect this is a hydraulic lock nut and I don't have anything to remove it with other than trying to press it out - but I'd rather not risk causing damage.

Off to a pro it will go!
 








 
Back
Top