Bridgeport Power Feed intermnittent / identification

[portlandiron]

Howdy everyone,

I picked up this mill from an old shop that was closing down and it's had its issues. I'm no machinist, just getting my feet wet, but I'd like to get the cross/power feed working right.

When I turn the pot up, it doesn't want to move until around 3/4 IPM, sometimes it will stall and when i crank it to 20 IPM, it will move at around 1 or 2 IPM.

I inspected the brushes, checked for shorts from the windings to case, did a couple checks on the switches awhile back that I can't recall the results of - I considered changing out the Pot, but i'm not 100% certain if that will help. Not to mention i don't know what power feed I actually have and 2 hours of digging through images hasn't proven worth while.

Can someone please help guide me in what to do next/identify this controller? I've worked on bikes, cars, helicopters and manufacturing equipment, but those all had a manual. I can't seem to find one of these either.

The model is a 128141.
It has a Boehm 4640 cross feed motor.

Thank you!
- portlandiron

 

[Brandenberger]

Manual has detail on both 6f and 8f feed units:

https://www.hardinge.com/wp-content/uploads/KneeMill-Parts-Older.pdf

 

[thinktank]

Howdy everyone,

I picked up this mill from an old shop that was closing down and it's had its issues. I'm no machinist, just getting my feet wet, but I'd like to get the cross/power feed working right.

When I turn the pot up, it doesn't want to move until around 3/4 IPM, sometimes it will stall and when i crank it to 20 IPM, it will move at around 1 or 2 IPM.

I inspected the brushes, checked for shorts from the windings to case, did a couple checks on the switches awhile back that I can't recall the results of - I considered changing out the Pot, but i'm not 100% certain if that will help. Not to mention i don't know what power feed I actually have and 2 hours of digging through images hasn't proven worth while.

Can someone please help guide me in what to do next/identify this controller? I've worked on bikes, cars, helicopters and manufacturing equipment, but those all had a manual. I can't seem to find one of these either. View attachment 341095

The model is a 128141.
It has a Boehm 4640 cross feed motor.

Thank you!
- portlandiron

Hi for this problem you have to replace the potentiometer, 5 K ohm. you can get it from Cal-Metrics inc.