[phaedrus]

Has anyone found a good solution for tapping machine screw threads on the hammond cases?

I've now tried 6/32 and 8/32 screws with varying success. The case which is the owner of the 8/32's no longer has a removeable lid/bottom, but has already also stripped one of the thread sets out. I have considered filling the screw channels with something like JB Weld and then drilling and tapping for 6/32 screws. Is there a better solution?

I would like to have the flexibility to switch out opamps on my currently gestating PPA without feeling like I was playing russian roulette each time I re-installed the end panels.

 

[Voodoochile]

This won't be much help, but is just a thought I have been rolling over for a while, as a possible solution to the same problem.

I'd like to find some small diameter threaded rod stock, and acorn nuts... shoot the rod all the way through the case.

 

[Nisbeth]

Quote:

Originally posted by Voodoochile This won't be much help, but is just a thought I have been rolling over for a while, as a possible solution to the same problem. I'd like to find some small diameter threaded rod stock, and acorn nuts... shoot the rod all the way through the case.

Try serching stores that sell supplies to builders of model cars/ships/airplanes. I've seen threaded rods in brass or steel down to M2 and acorn nuts in brass or steel down to M2.5.

/U.

 

[tangent]

I use 8/32" screws and put them only on the front. I use the supplied screws on the back. The back panel is usually the one you want to remove anyway. I haven't stripped any of my 8/32" screws out yet, even on one amp which I had to take apart and put back together several times. You just have to be careful on the first few turns. At the first sign of cross-threading, back it out and try again.

Also, are you tapping the holes out with a proper tap set, or are you just drilling the hole out and letting the screw cut new holes? I've tried it both ways, and I think tapping it out gives a better set of threads. Forcing the screw in the first time gives a tighter fit, but at the same time you're more likely to cross-thread it because it's harder to tell the difference between the resistance of cross-threading and the natural resistance of the tight tolerances. If you tap it out, there's a tiny bit of play when you thread it in normally, which makes it obvious when it's cross-threading.

 

[Voodoochile]

Thanks Uffe... that source didn't occur to me. I just may have to test this out finally.

 

[Squalish]

Quote:

Originally posted by Voodoochile This won't be much help, but is just a thought I have been rolling over for a while, as a possible solution to the same problem. I'd like to find some small diameter threaded rod stock, and acorn nuts... shoot the rod all the way through the case.

This is how I'm doing a project right now, you can get whatever you need at Home Depot.

 

[Voodoochile]

Wow, even in tiny diameters like that? That makes this even more convenient.

 

[phaedrus]

Quote:

Originally posted by Voodoochile This won't be much help...

Actually, I think it may be a great solution.

Quote:

Originally posted by tangent ...are you tapping the holes out with a proper tap set... ...there's a tiny bit of play when you thread it in normally...

I'm tapping them. I'll run the tap through the one that feels like it has stripped again -- maybe I'll get lucky.

And, I'll pay better attention when starting them.

 

[was ist los?]

An M3.5 metric screw will work. Either sheet metal, or machine screw.

And the nonmetric: The 1455 uses a #6 Type B Flat head Phillips self tapping screw, with a #4
Head.
Length 0.300"

Mark Mercer
Hammond Mfg. Co., Inc.
E-mail: mmercer@hammfg.com

for 1455 cases. I asked before and this is the reply i got.