Made a thing today... (Z axis probe)

I’ve been wanting to do this for some time now, and finally got around to it today. I’ve never been a fan of clipping an alligator clip on the tool when probing, just seemed like an unnecessary step for the sake of simply completing a circuit. So, I ended up with a low-profile probe that is self-contained with no alligator clip. Works exactly as I had hoped. Collateral damage was a Microsoft mouse & a 6" scale. It has a very nice tactile feedback at a consistent .242"

The CAD work…

Machined body with switch installed…

Fully assembled & compared to previous probe plate…

The collateral damage…


Hey Bill,

a microswitch? Don’t you fear that the tin-plated contact will affect repeatiblity over time?

Bill you need a spindle :slight_smile:

Poor mouse :scream_cat: :smile_cat:

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:joy: It’s ok, it outlived its useful life (except for the microswitch).

No, the plating is satin chrome over stainless steel, so not concerned in the least. It’s pretty durable.

I do need a spindle, but not the typical VFD spindle, I have no use for one of those. Need something that has good torque at lower RPM’s. I’m going to look into this one that utilizes standard ER-16 collets. Depends on how extensive the rework is to adapt the mount for it. I’m pretty much at a loss without a mill or access to a mill.

Hey Bill,

I meant the tin-plating of the contacts inside the microswitch! My mice accumulate in a heap because after a year the buttons always start to bounce and I never find time to solder microswitches with gold-plated contacts into them (or an ATtiny that takes away the bouncing)

I just meant that because a spindle is grounded, you don’t need an alligator clip or magnet anymore :slight_smile:

Then those motors may not be that satisfying. You would find a spindle nice which has 4 magnetic poles. Compared to the 24,000 RPM constant torque spindles with 2 magnetic poles (=1 pole pair) which have full torque at 6,000 RPM, those with 4 magnetic poles (=2 pole pairs) max out at 12,000 RPM and have full torque at 3,000 RPM or below. If you look at the Torque/RPM diagram at the bottom of this datasheet you will see those with 4 poles can have 2 Nm torque from 1,500 RPM on!

2 poles
4 poles


I think the microswitch I used (under the scroll wheel) is probably like new, I rarely ever use that button. I did not realize that about the spindles. I had read somewhere that the torque was very low at low RPM’s. This may have been someone’s assumption, it wasn’t hard data.

Interesting data you posted though, will be looking closer at that for sure. More good info as usual, @Aiph5u !

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