Has anyone seen quick-connect M6 nuts, for use on PCBA ring crimps in test jigs

[Psi]

Just wondering if anyone has seen something that is basically an M6 nut but intended for rapid install/remove.
Something you don't need to screw-on. Maybe it's in 2 halves and you can simply clip it with internal down force spring.
It would be used to allow for rapid connect/disconnect of test jig cables (with ring crimps) onto a PCB mount press fit M6 terminal.
It could just be a nut, or a nut and wire terminal in one.

Currently i'm using a 3D printed spacer over a normal M6 nut so the number of turns required is small.
But I would like something quicker if possible.

(I looked into option of a pogo-pin array under the PCB up against the press fit connector pins/pcb copper. But that has its own problems due to currents involved and requiring so many pogo's in parallel that the press down force is huge (5 terminals * 16 per terminal = 80 * 2N = 16kg) )

[ajb]

How much current are you trying to get in and out of these things?  Which is the DUT, the wire harness or the PCB?  Guess it's the PCB if current is a concern, since you wouldn't need a ton of current for most harness testing purposes?

Conventional solution to pogo pin pressure is to use a mechanical clamp system, like a cam-like style of thing that has high mechanical advantage to make opening and closing easy.  Potentially many other solutions--maybe even just some big heavy alligator clips that can clip onto the terminal? 

[Psi]

How much current are you trying to get in and out of these things?  Which is the DUT, the wire harness or the PCB?  Guess it's the PCB if current is a concern, since you wouldn't need a ton of current for most harness testing purposes?

Conventional solution to pogo pin pressure is to use a mechanical clamp system, like a cam-like style of thing that has high mechanical advantage to make opening and closing easy.  Potentially many other solutions--maybe even just some big heavy alligator clips that can clip onto the terminal?

DUT is PCBA with the press fit terminals on it.   To test it I have to connect the motors to the PCB with thick ring terminal wires.
The power also comes in on other terminals as well. So 5 terminals total (motors have a common).

It peaks up to 180A when starting and when I test the motor overload trip, but usually during test it's around/under 40A.

I found some much cheaper INGUN (clone/copy) pogo's on aliexpress that i'm going to do some testing with, see how well it works.
If it seems to work ok or borderline with the clone pogos i'll order some genuine ones.
Just don't want to fork out $400 for 100 pogos and receptacles unless it's going to work.

Was thinking of using an array of 4x4 of these 16Amp ones per press-fit PCB terminal.
They would fit offset into the gaps between the 5x5 press fit PCB holes.
However the force required to get that many to their recommend working stroke scares me.
There is also the risk that the current will heat the springs up and they will lose their springiness.
But given that the 180A is only for a short time, might be able to get away with using less of them

16A pogo
https://ingun.com/en-GB/HSS-100-306-150-A-2000/HSS-100-0006?fbclid=IwAR38iOb58KjU8AwWl8MI8eeTEnOA2agJyUq0LKrHyRx1ZG6O90Q80uNYsfs

This is the kind of terminal
https://www.digikey.co.nz/en/products/detail/w%C3%BCrth-elektronik/7461098/2092196

[JURP]

Quick nuts are popularly used on CNC.
Look for example for:
1) TWINNUT 381772
2) Elesa+Ganter  GN 6303.1-M6
3) MORTON MACHINE WORKS  code 01376664
You just have to survive the price.

[Gribo]

If you must use pogo pins, Ingun also has 100A probes.
If you can use multiple probes QA tech has 24A partshttps://www.qatech.com/en/products/conventional-probes/187-25.html

[mikeselectricstuff]

Maybe add a spacer to the lugs on the test setup the nut only needs a couple of turns?
Also, using  threaded spacers, maybe 10mm long,  instead of nuts  makes them much easier to start and hand-tighten

[mikeselectricstuff]

I also wonder if you could make something like croc/alligator clips with a cylindrical profile inside the jaws. Maybe copper braid.
Or maybe  cut a brass M6 nut in half and solder the halves inside the jaws of croc-clips

[langwadt]

How much current are you trying to get in and out of these things?  Which is the DUT, the wire harness or the PCB?  Guess it's the PCB if current is a concern, since you wouldn't need a ton of current for most harness testing purposes?

Conventional solution to pogo pin pressure is to use a mechanical clamp system, like a cam-like style of thing that has high mechanical advantage to make opening and closing easy.  Potentially many other solutions--maybe even just some big heavy alligator clips that can clip onto the terminal?

DUT is PCBA with the press fit terminals on it.   To test it I have to connect the motors to the PCB with thick ring terminal wires.
The power also comes in on other terminals as well. So 5 terminals total (motors have a common).

if it is just for a test fixture can't you just make a "hat" that clamps on top pushing on top each of the ring terminals

[Psi]

How much current are you trying to get in and out of these things?  Which is the DUT, the wire harness or the PCB?  Guess it's the PCB if current is a concern, since you wouldn't need a ton of current for most harness testing purposes?

Conventional solution to pogo pin pressure is to use a mechanical clamp system, like a cam-like style of thing that has high mechanical advantage to make opening and closing easy.  Potentially many other solutions--maybe even just some big heavy alligator clips that can clip onto the terminal?

DUT is PCBA with the press fit terminals on it.   To test it I have to connect the motors to the PCB with thick ring terminal wires.
The power also comes in on other terminals as well. So 5 terminals total (motors have a common).

if it is just for a test fixture can't you just make a "hat" that clamps on top pushing on top each of the ring terminals

Yeah, that is the kind of thing i want.  Do you know if anyone makes something like that ready to go?

[Psi]

Maybe add a spacer to the lugs on the test setup the nut only needs a couple of turns?
Also, using  threaded spacers, maybe 10mm long,  instead of nuts  makes them much easier to start and hand-tighten

Yep, that is my current solution, 3D printed hex block with the nut recessed into it.
It's good, but still slowish because you have to do 5 of them

[langwadt]

How much current are you trying to get in and out of these things?  Which is the DUT, the wire harness or the PCB?  Guess it's the PCB if current is a concern, since you wouldn't need a ton of current for most harness testing purposes?

Conventional solution to pogo pin pressure is to use a mechanical clamp system, like a cam-like style of thing that has high mechanical advantage to make opening and closing easy.  Potentially many other solutions--maybe even just some big heavy alligator clips that can clip onto the terminal?

DUT is PCBA with the press fit terminals on it.   To test it I have to connect the motors to the PCB with thick ring terminal wires.
The power also comes in on other terminals as well. So 5 terminals total (motors have a common).

if it is just for a test fixture can't you just make a "hat" that clamps on top pushing on top each of the ring terminals

Yeah, that is the kind of thing i want.  Do you know if anyone makes something like that ready to go?

I was thinking something like this: https://www.robotdigg.com/product/1527/PCB-testing-jig-PCBA-test-fixture

but instead of pogo pins on the movable top plate, have tubes the size of an M6 nut pressing down on each of the ring terminals

so you put the ring terminals on and clamp them all with top plate in one go

[ajb]

I also wonder if you could make something like croc/alligator clips with a cylindrical profile inside the jaws. Maybe copper braid.
Or maybe  cut a brass M6 nut in half and solder the halves inside the jaws of croc-clips

I'd be concerned about the contact pressure not being high enough for 180A  with that method.  Without sharp points like pogo pins have to punch through oxides and crud on the surface or a lot more contact force having more contact area doesn't necessarily help.  Might be fine as long as everything stays clean.

I think the best solution would be a pretty conventional bed-of-nails setup, more or less along the lines of what langwadt linked.  Designing those sorts of things can be a bit tedious, though, so might not be worthwhile unless the quantities are relatively high.

There is also the risk that the current will heat the springs up and they will lose their springiness.
But given that the 180A is only for a short time, might be able to get away with using less of them

Might be worth including a couple of extra pogo pins for each terminal so you can monitor contact resistance.  Two additional pins that are isolated from the other pins but contact the same copper area would allow you to take a four-wire measurement of the total pin+contact resistance for your power handling pins.  The measurement pins don't even need to be the fancy high-current ones.  You could take measurements periodically to monitor if/how the contact resistance degrades over time, or make it part of every test cycle.  The latter would be a good way to verify that the board is properly loaded into the fixture before starting the test and trying to get 180A through only half of the pogo pins.   In a more pedestrian test fixture you might just use some detector pins set at a lower height than the rest of the test pins for that purpose.

[Psi]

There is also the risk that the current will heat the springs up and they will lose their springiness.
But given that the 180A is only for a short time, might be able to get away with using less of them

Might be worth including a couple of extra pogo pins for each terminal so you can monitor contact resistance.  Two additional pins that are isolated from the other pins but contact the same copper area would allow you to take a four-wire measurement of the total pin+contact resistance for your power handling pins.  The measurement pins don't even need to be the fancy high-current ones.  You could take measurements periodically to monitor if/how the contact resistance degrades over time, or make it part of every test cycle.  The latter would be a good way to verify that the board is properly loaded into the fixture before starting the test and trying to get 180A through only half of the pogo pins.   In a more pedestrian test fixture you might just use some detector pins set at a lower height than the rest of the test pins for that purpose.

good idea

[tszaboo]

Can't you test the PCB before the press fit terminals are installed? You have a nice number of through hole connections where those pogo pins would make ideal contact.

[Psi]

Can't you test the PCB before the press fit terminals are installed? You have a nice number of through hole connections where those pogo pins would make ideal contact.

I could do, it's an option.

[ajb]

Can't you test the PCB before the press fit terminals are installed? You have a nice number of through hole connections where those pogo pins would make ideal contact.

I could do, it's an option.

On the other hand, do it after and you can throw a couple pogo pins on the legs of the terminal for a 4-wire measurement to validate the press fit.

[tooki]

What about a female “banana” jack (I use the term loosely, because these jacks have the springy lantern inside the jack, intended for use with solid pins) like the ones from Stäubli? They come in numerous diameters, including 6mm, which you could push onto the M6 stud.

Look at Stäubli 01.0005:
https://de.rs-online.com/web/p/bananenstecker/4321698
Pages 12-13 of https://www.staubli.com/content/dam/spot/PL-Main-Uninsulated-11013980-en.pdf
Page 31 shows crimp adapters to turn those into wire-mounted sockets if need be.

The 6mm ones are rated for 100A, and up to 180A at higher temperatures, so surely perfectly adequate.

Also, there are similar 6mm sockets sold as medical grounding connectors, see pp.17-18:
https://www.staubli.com/content/dam/spot/MED-Main-11014109-en.pdf

[Psi]

What about a female “banana” jack (I use the term loosely, because these jacks have the springy lantern inside the jack, intended for use with solid pins) like the ones from Stäubli? They come in numerous diameters, including 6mm, which you could push onto the M6 stud.

That is interesting, might be worth buying one of those to check them out.

Thanks