# Wired up the VFD on my Bridgeport Mill



## Tmate (May 20, 2021)

I stripped off all the electrical apparatus from my Bridgeport J Head step pulley mill, and ran wiring directly from the VFD to the motor.  I took the works out of the factory reverse/drum switch and left the terminal blocks.  This reduced the motor connection to three leads and a ground.

The fifty year old (1969) 1 hp 3 phase motor works as smooth as silk with the new KBAC 27D VFD.  I used a 2 hp capacity VFD in case I ever want to switch to a more powerful motor.  Since the VFD provides an electronic reverse, the back gear can still operate in a forward direction.


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## hman (May 21, 2021)

Bein's how the VFD uses low voltage inputs to control direction, etc., you might be interested in a feature I added to a Bridgeport look-alike.  It's an industrial grade microswitch that detects the position of the back gear lever and "corrects" the forward/reverse function.









						Converting a knee mill to 3phase/VFD
					

I've recently bought a Precision Matthews PM-835S.  Advertised as a "small" knee mill, it's still amazingly massive - and TALL.  I've had to build a platform to stand on (re-using some of the the 2x4s and OSB the mill was crated with), just to be able to reach some of the controls and levers...




					www.hobby-machinist.com


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## Eddyde (May 21, 2021)

hman said:


> Bein's how the VFD uses low voltage inputs to control direction, etc., you might be interested in a feature I added to a Bridgeport look-alike.  It's an industrial grade microswitch that detects the position of the back gear lever and "corrects" the forward/reverse function.


I did the same to my mill, though I had to build a simple relay circuit to get it to interface with my VFD. I also added a instant reverse feature that is awesome for tapping.








						Wiring A Vfd To A Momentary Pushbutton Switch (update)
					

A while back I had a request for a design to use momentary switches on a VFD (TECO JNEV) that did not support 3 wire control. Attached is a schematic using momentary switches and latching relays that could be used on different machines that includes forward/reverse and stop. The left side of the...




					www.hobby-machinist.com


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