What's new
What's new

Motor and VFD options for 2J Bridgport clone. Direct drive?

bugman53

Aluminum
Joined
Oct 7, 2007
Location
Greensboro NC
Good afternoon, A good friend of mine gave me a Enco milling machine Bridgeport clone. I striped it down and restored her. It has hard chrome ways with NO visible wear at all. Only .004-.006 backlash on the x and y axis. Absolutely great shape. The only issue with her is the motor shaft is broken. So it needs a motor. My buddy that gave it to me is a machinist and he made an adapter to fit a standard 184TC? face mount motor.

Option a

Source an original Motor and use the variable speed on the head.

Option B

Source a 184Tc Motor and install it with the adapter and extend the shaft to modify it to work with the Variable speed pulley

Option c (what i am leaning toward).

Install a 3-5HP 3 phase motor, Remove all the variable speed drive parts and install a fixed pulley ratio and control the speed with the VFD. Probably using j6 microgroove belts and pulleys.

Has anyone done the above?
 
Well, I'm no expert, but it appears nobody is responding. I find the mechanical variable speed nice to have, but it is not essential with the VFD. When using tiny mills, like 1/8" to 1/4", the middle mechanical speed range is on the slow side. If you single speed the pulley arrangement to the high side for small mills, then the VFD will only have trouble running at slow speeds and high chip loading. The VFD will trip a fault if the load is too high at slow speeds. So that is why I like my variable mechanical speed changer...for working on the slow and fast spindle speeds.

That said...I find the BP temperature limited rather than horsepower limited. Unless you find a way to run flood coolant, your part and tool temperature will be your limiting factor for heavy cutting. So it could work out finding an upper middle pulley arrangement and relying on the VFD.
 
I think i have decided to go with a 5HP 184TC 1725 RPM motor and VFD with a J6 belt setup.

still deciding on a pulley ratio. If it is "geared" For 1000 rpms at 60HZ, That should give 1.25 HP at 250RPM (30RPMS Back gear, 2.5HP at 500/60RPMS That should be plenty of low end power and a top speed in the 2200 RPM range.

or i could gear it faster Thoughts?
 








 
Back
Top