Bridgeport Manual to CNC conversion...

[komatias]

Dave,

out of interest: what paint did you use?

[Davek0974]

It's from a UK company called Craftmaster Paints, it's their "Engine Enamel" range in Bridgeport Grey.

Its the same company I used for painting the traction engines - the best paint I've ever used :) Not cheap it cost £30 for the 1ltr tin inc postage but well worth it.

[Davek0974]

Hi all, back again after the holiday :)


Wasted no time in getting out to the shop, started catching up on customer orders and did some work on the mill.


Seems I have ordered a screw set for the Z axis that is far too long - bum
Will eBay that one for a few quid - its a 20/05 zero backlash unit 360mm long if anyone wants it.


Then i discovered the motor bearings are half-shot , a bit of slack and grumble when spun. It will work ok but not sure having come this far if i should refit or replace with something else - options would be repair (expensive), fit a new vfd style motor with shaft extended (more expensive) or throw on a servo motor (a bit more expensive).

Having replaced nearly all the bearings it seems daft to refit the duff motor now - time to think here.

[Boyan Silyavski]

How much could be that motor bearings? it seems cheaper to replace them, right? Aren't they some standard size?

Having done all that work til now, the logic is not to leave anything unrepaired.

[Davek0974]

I have read some tales as its a US motor and a bit awkward to dismantle, to find bearings size i would have to strip down which risks disturbing old and fragile varnished wiring etc. Not a big issue but could end up in a trashed motor.

The extended/custom shaft makes replacements a total bugger - practically impossible to fit a new motor and re-use the Reeves vari-speed drive system as new motor shafts are far too short.

This was the reason Bridgeport motors are stupid expensive.

So, options - strip and attempt repair.

Fit a servo and dump the Reeves drive but retain back-gear ?

The budget for this job went silly a long time ago - i was not intending on replacing all the ball bearings etc and some of them are £££ so it seems now that an extra £300 or so on a 3kw servo/drive is pretty irrelevant overall.

The servo would likely be the easiest option - just a new mount plate and two pulleys, the repair on the bearings could be the cheapest option but would still leave an inferior, power-sucking drive system on what is now a damn expensive machine.

I'll work some prices out.

[Boyan Silyavski]

What about repairing it on place with graphite or bronze filled epoxy ,Moglice and others? Why dont you check if that's a possibility. It would be dirt cheap

[Davek0974]

These would be ball bearing races so not repairable in that way.