Chevalier 2040 CNC Bed Mill Restoration

[matthewsx]

Perfect as I was going to bake them in the oven and they only cost like $2.

And, you have a useful piece left over when you’re done. Always need one of those little
boxes for projects around the shop.

John

 

[mksj]

You might check this vendor for quality name brand bearings, they are located in the UK but have fast shipments. I recall someone else used them for their spindle bearings and was happy with them.

Quality Bearings Online - Deep Groove, Tapers, Precision

The best value Bearings and other engineering products Online. We can source any bearing and will not be beaten on price

www.qualitybearingsonline.com

 

[coolidge]

You might check this vendor for quality name brand bearings, they are located in the UK but have fast shipments. I recall someone else used them for their spindle bearings and was happy with them.

Quality Bearings Online - Deep Groove, Tapers, Precision

The best value Bearings and other engineering products Online. We can source any bearing and will not be beaten on price

www.qualitybearingsonline.com

Good to know. So far I was able to source them all in the US.

 

[coolidge]

I disassembled deeper into the head and stumbled into a known issue with these bridgeport type heads. For the high speed range there are two hubs that mesh together to turn the spindle.

These hubs have wedge shaped teeth that interlock. They wear over time, the fit becoming loose. There's an adjuster on the speed range shift lever for this. It basically raises the splined gear hub up farther into the pulley hub to take up the slop. Rinse and repeat.

Eventually they wear to the point of bottoming out in one another with no adjustment left. From there they get looser and sloppier and if you don't replace them they start taking out other parts of the head as they self destruct.

The good news, while I'm close to bottoming out and my hubs are close to end of life, they are still tight, just barely. I could maybe squeeze another .005 of adjustment. The bad news is while you can buy new hubs for Bridgeports and clones all over the internet, nobody makes the oversized hubs on this mill. I'm assuming larger due to the mills size and 5hp.

So when the day comes that these need to be replaced, I'll have to buy a whole new head. I'm considering doing that now. Buying a new bolt on head has a bunch of advantages.

First it's brand new, zero wear. They make direct drive VFD inverter versions of the heads. I could get parts for it unlike this 1996 head. New motor vs the 1996 motor. Maybe 1/3 of the cost of the new head I'd be paying for a VFD, motor and related bits that come with a new head. So something to consider.

For now I'm moving forward with the existing head.

 

[coolidge]

The 11 bearings for the head have arrived. I went NSK Japan for all, as were the original bearings. Not sure they all needed to be replaced but since I'll have the head completely disassembled for cleaning and inspection now is the time to refresh bearings.

 

[coolidge]

The tear down picks up speed...the 40 taper spindle/quill removed!!



The big azz Z thing chain rigged and ready for removal.

 

[coolidge]

Trivia - I'm now up to 462 photos taken of the machine as I have disassembled it. I should be able to get it back together properly. lol

 

[coolidge]

Spindle now removed from the massive quill. I drowned the quill in way oil then sealed it until it's time for reassembly.

 

[coolidge]

Well I found a broken off tap in one of the spindle tool dog holes. Which explains why that dog was laying loose in a toolbox. Two Dremel grinding stones and a diamond bit gave their lives in the removal.

I thought I'd chase the threads with a tap while I was at it, WRONG! The spindle is obviously hardened, too hard for a HSS tap. The factory didn't fully tap that hole (the other is) which is why someone was trying to run a tap up there.

So I could order a $129 carbide tap and go looking for trouble in the tap destroyer hole...or just use a shorter dog screw there's plenty of threads...yeah the latter.

 

[coolidge]

This morning I was contemplating how to clean the center of the 23 inch long spindle. It looked nasty up there. I stuffed a rubber stopper in the top and filled it with mineral spirits to soak overnight.

Then...lightbulb! Shotgun cleaner, BRLLIANT! She's gleaming clean now. Ahem, I may have purchased a dozen other size brass cleaners for cleaning bolt holes because, BRILLIANT!