BOSS 6 Z Limit switch replacement

[Dennis Storzek]

Here's a simple replacement part question. Does anyone have a suggestion for a replacement for the Z limit switches, the ones on the quill drive behind the motor switch panel?

I'm running a BOSS 6 with a Centroid control conversion, and recently it as been faulting out during heavy cuts with a +Z Limit exceeded warning. Jumpering around the switch, which is normally closed, solves the problem, which must be contact bounce, or dirty or burned contacts. It doesn't look like these switches come apart for service.

The switch appears to be the functional equivalent of a standard short arm roller snap switch, but the ones on the machine seem to have an auxiliary spring and a keeper to prevent the roller from swinging out too far. All I am finding in the McMaster, Grainger, and MSC catalogs don't have the keeper. In addition, both Grainger and MSC only sell Omron brand, which in the past has proven to be light duty junk. McMaster's brand is, as always, not specified in the catalog.

Anyone have a suggestion, part number, source?

Dennis

[Dennis Storzek]

Looks like no one has had this problem, so no one has an answer at their finger tips.

I had some time to pull the switches out this afternoon, and they do have a part number on the back (hidden) side: MICRO BZ-RW922-A2. Honeywell shows it as a current part number, and Mouser lists them in their catalog, but no stock. In case anyone was wondering, they're $50 EACH.

So, I cleaned up what I had, and put an ohm meter on the one that was generating the fault. Looks fine, although the resistance goes up when I rapped it on the bench to simulate spindle vibration. Then again, the resistance of the one that wasn't generating the fault signal went up more….

So, I cleaned them up and put them back, swapping their locations. If the problem goes away, I'll pat myself on the back for solving it. If it moves with the switch, I'll order a replacement. If it persists but DOESN'T move with the switch, I'll have to look further for faults in the wiring back to the cabinet.

[HillBilly]

Ajax offers a optical replacement for that switch. It is at the bottom of this page.

http://ajaxcnc.com/cnc_components.htm

Darek

[Dennis Storzek]

Thanx. Wonder how well they work when the Bijur oil creeps over them? Worth a try if the mechanical switches continue to give problems.

Dennis