Variable Speed Control Not Working - Wiring Diagrams Attached

[jmccracken]

Hello all,

I am having trouble with my variable speed control on my Bridgeport Series I Interact w/ Heidenhain 151B that, I'm convinced, is control and/or wiring related. To help the discussion, I'm attaching two (2) wiring diagrams that came with my machine:

* 215-120 D - Series II Interact 2 Wiring Diagram
* 879-121 E - Series I Interact Wiring Diagram

Both of these documents came with my machine ... for the variable spindle speed control, see the upper right portion of either drawing (wiring numbers are the same on both documents).

OK ... bottom line, I'm not getting 24VDC on wire 61 ... which actuates the two (2) solenoid valves via the spring-loaded selector switch. I do have 24VDC power on wire 63 powering the spindle brake - the brake (switch, solenoid valve, cylinder, and brake itself) functions perfectly.

Note that I have thoroughly trouble-shot all the wiring that is on-board the milling machine but outside of the control enclosure ... everything is well labeled, clean, and has good continuity. The solenoid valves themselves behave properly when I apply 24VDC directly the positive side of the coil - thus they are functional, as are the 0VDC leads coming from the solenoid valves. Lastly, the air motor and the variable speed function properly.

Again, wire 61 needs to have 24VDC power ... why doesn't it? I think its some sort of interlock either in the control cabinet or via the Heidenhain 151B controller. On the wiring diagram I note that wire 61 gets 24VDC power through the contactors "3MF" or "4MR" ... terminations 53 & 54 ... inside the cabinet.

What is "3MF" and "4MR"? How do I enable 24VDC to wire 63?

Many thanks!

[jmccracken]

The attachments didn't appear to upload ... here they are (I hope) ...

[Al_The_Man]

Wire 61 is energised through 3MF or 4MR which is when spindle is either fwd or rev.
If spindle runs an no 24vdc then trouble shoot backwards with a VM.
Al.

[gus]

So what happens when you turn the UP/DOWN knob and push it in with the spindle running? No clicks etc?

The 151 does not control the spindle

[machintek]

The spindle has to be turning for the spindle speed to change.

George

[jmccracken]

Thanks all for the input. I found that, after opening the cabinet, a plastic piece had broken off of the low voltage auxilliary contactor afixed to the reverse contactor - thus, when the spindle egaged via the actuation of this contactor, the auxillliary contacts did not engage ... no 24VDC to the speed control. These are Yaskawa contactors by-the-way. Anyway, I fixed it in a jack-leg fashion by drilling and tapping an M3 BHCS onto the plastic plunger. Works good ... need to order replacement auxilliary contactor for eventual tapped hole failure.

Again ... many thanks!