Repairing Power Distribution Metric "Studs"

[de_]

I have tried to contact the manufacturer Diversified Systems twice with no reply.

Some students installed imperial nuts on the metric studs on our test power distribution board trashing the studs. Anyone know where to obtain replacement studs from ? Anyone know why they were metric ?

If the studs are not available, alternatives appear to solder a lug on to the stud or cut the thread section of the stud off and drill and tap the body of the stud.

[Mark McLeod]

The lugs are integral to the PD board and can't be directly replaced.

I'd think rethreading them to a smaller size would work to keep it operational for non-competition use.

[Joe Ross]

According to AndyMark this year's power distribution board is made by Total Electronics and not by Diversified Systems.

[MrForbes]

Originally Posted by de_

Anyone know why they were metric ?

They were designed this millennium?

I guess the FIRST spec didn't take into account that most of us robot folks are still using the traditional methods (inches)

[de_]

This was actually a past years one (hence test). It was made by DS. Didn't know about this years. Good to know.

The stud appears to be soldered into the PCB via a pad of contacts. I have desoldering equipment that should be able to get it off. But I am currently thinking of drilling a threaded hole (hard to avoid drilling through the PCB but that's probably okay) or soldering a lug on. Obviously it can't be used in the competition.

[Al Skierkiewicz]

Dave,
The studs used on the PD are first press fit (under great force) and then the board is wave soldered. The studs are not repairable, sorry. If you choose to modify the threads, the PD can no longer be used in competition. No modification of electrical components is allowed.

[IndySam]

Diversified Systems is no longer in business (at least in it's past form.) A great supporter of FIRST became a victim of the poor economy.

Like Al said those studs we pressed in on a large press and can't be replaced.

[de_]

Really sorry to hear about Diversified. Ouch.

Good to know about the press fit.

I'm currently liking silver soldering on copper lugs. Good enough for a test robot... But first we better finish this years robot

[EricVanWyk]

Originally Posted by de_

Anyone know why they were metric ?

They aren't available in english units.

Originally Posted by de_

If the studs are not available, alternatives appear to solder a lug on to the stud or cut the thread section of the stud off and drill and tap the body of the stud.

Bear in mind that these studs are carrying burst currents in the several hundred amp range. This is not the part of the robot you want to jury rig.

[de_]

I ended up cutting off the (brass) studs, filing for smooth electrical contact surface, drilling and tapping for 1/4 NC, and used a 1/2" bolt with washer. Lots of contact pressure, good enough for a test robot, not legal for competition.