Alligator Clip

[Keith Larrett]

Searching the forums I have found numerous threads where people talk about attaching their z-zero alligator clip permanently to the machine somewhere. I have tried searching for a place to attach the clip on my machine. I've been holding the z-zero plate on the router bit and then touching the alligator clip to all different places on the machine and I can't close the circuit and get the input switch to come on.

I have an HSD spindle and did find some references to this not being possible with these spindles due to ceramic bearings. Is this correct or am I missing something here?

It would be great not to have to attach the alligator clip to router bit every time I zero the bit.

[Brady Watson]

No spindles sold by SB have ever had ceramic bearings. If you have a PRS, just clip it to the upper V-roller nut on the right side of the YZ car and leave it. If you have a desktop, clip it to the left front leveling foot stem.

If you are a lurker and have a router (not a spindle)...keep clipping it to the bit. Brushes wear & break continuity and Zzeroing fails.

-B

[Keith Larrett]

Thanks Brady. I have a PRSalpha with HSD Spindle. I will try your suggestion. Am I correct that if I hold the z-zero plate to the router bit and the alligator clip to the v-roller nut, then the input switch should light up?

[Brady Watson]

Yes, it should.

-B

[Burkhardt]

Maybe I am weird....
I have a fully functioning z-zero system on my machine (not a Shopbot but the methods are the same) and even used a fixed position tool length sensor for a while to simplify bit changes.
But for whatever reason I still prefer the manual zeroing with a thin (4/1000") strip of spring steel. I just move down the bit quickly with the pendant until close, go to slow jog, then step until I the strip gets stuck. Takes only a few seconds.
But maybe I am just old...

[Brady Watson]

Maybe I am weird....

[...]

But maybe I am just old...

Well...which is it? :cool:

-B

[tri4sale]

Well...which is it? :cool:

-B

Can't we be Old AND Weird?

[shilala]

The only reason that I never permanently installed my z-clip is that in my reading on the probe, it said if the clip is attached it'll wreck the probe.
Maybe that's not so anymore, dunno.
I don't have my probe anymore, so it wouldn't matter. I just hate to break habit at this point. My whole brain could come unwired. :D

[Burkhardt]

Well...which is it? :cool:

-B

Hm...or it might just be ingrained habits and laziness. I think I should give it another try and see if I can actually save some time doing automatic zeroing. Another thing I never used is the automatic edge, corner and center finding function. I probably should try that as well.

[Brady Watson]

I think old & weird is a pretty good demographic here...There's no getting around it! :p

As long as Zzeroing with the plate is reliable, it isn't a problem. Early on, the SB routines were a bit coarse and tended to be a bit rough on the bit when zeroing. Somewhere down the line there was a kinder, gentler machine tool hand & the routine got better. It used to be a no-no to use small bits (less than 1/8") with the plate because they'd sometimes shatter. I've used down to .015" dia with absolutely no problem, with excellent repeatability and accuracy. As long as you mic out the plate precisely, and tell SB3 it is that exact thickness, life is good. You would be *amazed* if you knew how many shops I've visited that never checked the thickness of their plate against the SB3 value for it...

Mechanical limit/prox switches are more accurate/repeatable than inductive ones...for obvious reasons.

-B

[Keith Larrett]

No spindles sold by SB have ever had ceramic bearings. If you have a PRS, just clip it to the upper V-roller nut on the right side of the YZ car and leave it.

-B

That didn't work. I'm starting to wonder if the reason it won't work is because of the draw bar in the ATC.

[Brady Watson]

This is kind of a hack...and it *may* make your machine more susceptible to static electricity, BUT I've done this to my own machine because Zzeroing wasn't reliable for me. I have no experienced any issues at all with it for the past 8 years.

In the control box, look for the ground bus bar. Take a 24" piece of electrical wire (16-18 ga is fine) and run it from the ground bus bar to any blue Gnd terminal on the control board.

Then test by touching the plate to the spindle (anywhere) and then try it at the end of the tool holder. You *should* be good.

Ground is ground the world around as they say...

-B