Bridgeport Circuit Questions

[Clive FosterParticipant @clivefoster55965]

Norm

I think it just stalls if against a really firm stop. Mine has enough oomph to overcome the X axis lock. So far I've not been careless enough to run it into a really solid stop. I tend to use the stops on the rod connected to the forward-neutral-reverse selector lever as a safety net.

When investigating fitting a stand alone VFD pretty sure I decided that taking the power feed through the old spindle motor contractor would be a minimum modifications method of keeping the standard emergency stop set-up and electrical interlocking. Keeping the standard box and switches on the knee too. Probably with a new overload unit. Never got as far as properly looking into the wiring needed to retain interlocking of spindle, pump and feed system but don't recall thinking it unduly difficult. If you drop the interlock wiring is trivial.

I still have the nice Siemens VFD I found for the Bridgeport tucked away at the back of a shelf.

Clive.

[Roger HeadParticipant @rogerhead16992]

Norm, your choice, obviously, but I would second Clive's words about keeping the wiring changes to a minimum. I have a circa 1986 BP with the 154-D control box, and it was a doddle to install the Genesis 2HP VFD down at bottom-rear inside the box. IIRC the wiring changes were trivial (I've probably got my notes somewhere), and I just mounted a small box underneath the DRO display with a pot and a fwd/rev toggle switch. All the main controls (emergency, x-feed, pump, etc) remain unaltered. The main BP motor switch remains permanently in the normal position, and I just flip the toggle switch on my speed-control box whenever I engage the low gear.

Roger

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