Thinking about Buying a Bridgeport Mill

[CJ5Dave]

I saw a reference somewhere that if the accessories (power feed, coolant pump) are 3 phase that you need a separate phase converter for each. Not understanding why.

 

[Provincial]

Very few power feeds are three phase, and almost all are120V single phase. A three phase coolant pump can be replaced by a 120V unit, but can be run on a "static phase converter" probably cheaper than any other option.

 

[CJ5Dave]

But why can’t they all be run off one converter? I have a rotary converter.

 

[Danzo187]

But why can’t they all be run off one converter? I have a rotary converter.

same here, everything in my shop is run on a Phase-A-Matic RPC.
I know very little about electrical stuff, but I'm pretty sure my 110V, and 220v 3 PH come out of the same fused breaker box, I told my electrician what I needed,
and walla! next day it was done.

 

[PNW_Guy]

But why can’t they all be run off one converter? I have a rotary converter.

You can run multiple motors on a RPC, assuming it has enough horsepower.
It gets tricky if you have multiple motors and a VFD. It can be done, but all the motors need to run at the same speed, and at the same time.

A buddy of mine bought a mill with a 3 phase spindle as well as an 2 axis, integrated 3 phase power feed. He used a VFD for each motor.

 

[CJ5Dave]

I got the mill home. Motor runs smooth, table tight, gearbox powerfeed missing the gears, lever and limit arm. I think the powerfeed motor may be shot since they robbed out the gearbox (and busted the switch). . The coolant pump switch has a single phase wire going into it, and out of that box the wiring for the 3 phase powerfeed. Not sure what is going on there. The manual lever for the quill is very tight, and the quill powerfeed worked, then didn't. There is a brass block with a detent. I finally got it into the slot, now it won't come out. Tha table powerfeed had a roll pin right under the end of the table - maybe there is a stub shaft for the gearbox i can take off and replace. I would rather add an aftermarket powerfeed but if it is an one piece shaft the shaft will be too long anf need a new screw.

 

[OTmachine]

“but if it is an one piece shaft the shaft will be too long anf need a new screw.”
You could easily make an extended end plate to accommodate a longer lead screw to use one of the cheaper, ($115 - $350), aftermarket drives.

 

[CJ5Dave]

Might use a tube spacer, but the shaft extension is about 9 inches. The serail shows it made in 1966.




m

 

[Danzo187]

or take leadscrew out cut off and turn, thread to factory specs or whatever you need for a new power feed.

 

[OTmachine]

Align kit