Probing conductive stock on nomad 3

Hey folks, I’ll try to be concise here. I’d like to probe conductive stock on the nomad 3. This is a bit of an issue as the stock needs to be isolated from the bed.

I am thinking I can isolate my vice with a layer of delrin and connect my probe to the vice. Then my entire vice and the conductive stock it holds becomes a probe…neat.
BUT I would still have electrical contact via the bolts going into the threaded bed of the nomad, not neat.

So I need a way to secure the vise to the bed in a non-conductive way. I don’t know much about the strength of different fasteners but maybe using PEEK bolts to fasten the vice would be sufficient?

Is it silly to think a plastic bolt is up to the task? Are there better ways to do this that I’ve just not considered?

Let me know what you think :slightly_smiling_face:

(Edit: Oh and I’ll be using gSender to take advantage of the probing possibilities this would open up.)

What kind of probe are you using?

I probe conductive stock on my Pro which should be similar. I have SMW fixture plates and the whole bed is now grounded including any vices I’m using and the material. I connect (via a magnet) the signal pin of the probe header to the spindle (Carbide router) and now the signal is pulled to ground whenever the bit in the collect touches the stock (or the bed for probing z height).

Does that not work for some reason on the Nomad?

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I don’t have a nomad either, but if the spindle and the bed are grounded, that won’t work.

The carbide router on the pro is not grounded. Is your spindle? Is the nomad’s? That would certainly make it harder…

I’d bet that the spindle is grounded.
I think this is why the newest BitZero is insulated.

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I believe Neil hit the nail on the head. The bed and spindle share a common ground.
(Probably… I’m a touch out of my depth at the moment. Been awhile since doing any kind of electronics work :upside_down_face: )

Neil, I played with your gSender macros for the bitsetter in preparation for writing my own probing macros! Thanks for those.
I also forgot to change the probe location and sent the bed careening into its limits :man_facepalming:
Other than that, they worked a treat!

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Peek bolts are hard to get, doubly so if you want a glass fiber reinforced variant.

I’ll go with regular unfilled peek for now and see how it goes. I’m worried any glass fill would be terrible for all of the aluminum mating surfaces.

I’ll report back when i get them in on Wednesday. McMaster Carr at 1am…what could go wrong.

I thought it was insulated so that you could probe conductive stock?

If you have a multi-meter, you can test this either by measuring the resistance (Ohms) or most multimeters have a continuity testing mode (if you touch the probes together it beeps). Just touch an endmill in the spindle with one probe and the bed with the other and see if it’s very low resistance (Ohms) or beeps (continuity mode). If so they are connected and if not then it sounds to me that you likely don’t need to try to isolate the vice.

Can confirm, there is continuity between the spindle and the bed. (And nearly everything else on the machine for that matter)

So it looks like I did not waste $25 on peek bolts after all. That’s a small win.

I wouldn’t trust plastic bolts to secure the vice, even on the small machine like nomad.

What I did to isolate my new fixture plate from the machine’s frame was add a sheet of HDPE in between.
You can easily bore m5 or m6 blind holes in the plastic and mount new aluminum fixture plate to it. In over 4 years haven’t had any problems with this setup.

If I’m not mistaken Bantamtools machines use pcb board to isolate their fixture plates from the machine.

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This is the kind of solution i was hoping to find.
One of the “Well that’s obvious, why didn’t i think of that!?” kind of deals.

I’ll likely end up going with a sheet of delrin. Given the size of the nomad bed it’s not terribly expensive.

Thanks again for the solution! (Though I’ve still got to at least try the peek bolts since i bought them anyway :wink:)

Unrelatedly… Is there a way to mark this as “Solved”? Maybe I’m just bad at Discourse but i can’t see any checkboxes :upside_down_face:

Yup…

You can mark a specific reply as a solution, so others will find the actual solution right away. If it’s not there, try the three little dots.

Nope, nothing. I wonder if it solutions are not enabled on the uncategorized topic :thinking:

Or maybe it’s just a quirk of mobile.

Here’s some proof that I’m not crazy:

@WillAdams you’ve been around the forum since the dawn of time, do you have any insight for me?

Ok, confirmed that the solution checkbox is not available on this post. It is available on a previous how-to post i created. Guessing it is just a topic/category thing.

Apologies for taking my own post so far off topic. (Though I think being able to mark uncategorized posts as solved is probably valuable if anyone with that power is reading :slight_smile:)

Wow, that came out stupid. I shouldn’t post things in the morning before my brain is actually working… FWIW, I was thinking because the bitzero has the signal line on the actual bitzero and not the spindle then they need to isolate it and I never really quite understood why they went with that arrangement.

Although, now that I know that the Nomad spindle is already grounded I understand why they would choose to do that instead of the (obvious to me on my pro) run the signal line to the spindle. By running the ground to the spindle it makes them all the same.

Edited to add: man, my early post sure did sound stupid! Doh.

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The PEEK m6 bolts came in and I’ve got to say, they’re ridiculous.
For what I do on the Nomad these are more than adequate, that said I’ll still go the route of full isolation. I do not want to risk chips building up and bridging my circuit during a cut, thereby ruining any in process probing I might have worked out.

Super neat that PEEK is so light and yet so strong. I’ll surely be keeping it in mind for future projects.

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