clever scheme for electrical contact with needle?

[WayOutWest]

Is anybody aware of a particularly clever way to get a wire attached to the metal pickup needle without creating a hassle when changing needles or big bulky protrusions?

I need a grounding clip on the needle to prevent accumulated static electricity. Not for ESD, but to ensure that extremely tiny metal parts can be released from the needle (picking up is the easy part!).

Electrical access to the needle is also useful for various homing/probing tricks, although at the moment I don't need them. This is really popular among people who mill their own PCBs.

I've got all my upcam vision working without shades, so it'd be a shame to need them only in order to hide some big honking alligator clip. The plastic part of the needle and everything above it is far enough away to be significantly out-of-focus, which makes it easy to exclude in a robust way. Also I'm using MSER-based vision; one of its disadvantages is poor performance on blurry images, but in this case that disadvantage turns out to be an advantage -- it ends up culling anything that's out of focus.

[JuKu]

Thin springy steel wire bent so, that it leans against the needle?

[ameli]

Have you tried an anti-static spray on the parts that are non-conductive? This wouldn't help you with your future homing/probing tricks. But it might create enough of a dissipative layer between the conductive and non-conductive parts to prevent the static accumulation.

[WayOutWest]

Thin springy steel wire bent so, that it leans against the needle?

Ah, of course! So simple, and perfect.

Have you tried an anti-static spray on the parts that are non-conductive?

Hrm, I'd rather not mess around with any (more) chemicals... all this has to go through an oven and getting it to reflow correctly is already quite tricky (had to try a lot of fluxes to find the right one).

[mrandt]

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Have you tried an anti-static spray on the parts that are non-conductive?

Hrm, I'd rather not mess around with any (more) chemicals... all this has to go through an oven and getting it to reflow correctly is already quite tricky (had to try a lot of fluxes to find the right one).

Hey Adam,

why do you reflow solder the needle?

I think what ameli meant is to use a conductive "anti static" spray on the plastic holder (luer lock part) of the needle to give it a (slightly) conductive surface which might be enough to discharge the static electricity... Might work?

Regards
Malte