L@@KING for gold-plated tellurium-copper banana plugs

[robrenz]

I would not trust a press fit with that thin of a wall in copper.

[quarks]

thanks robrenz,

when I stack 4mm banana plugs, it is the same wall thickness and I had the feeling it is stable enough, that is why I guessed it should work.
My other option with the 4mm thread idea, will than have the same problem and even envolves my imprecise handwork. So this should be even worse. 

What would you do to solve this?

[SeanB]

Get a rolled thread tap instead of a cutting thread tap and roll the threads into the material. You do not remove any material and the rolling work hardens the copper making it stiffer.

[quarks]

Hello SeanB,
 I have not thought of that, but it sounds like a very good idea and I even can disassemble it if neccessary. The only thing is I can not do it myself and have to find a shop who can/will do it for my few plugs.
Thanks
quarks

[robrenz]

Get a rolled thread tap instead of a cutting thread tap and roll the threads into the material. You do not remove any material and the rolling work hardens the copper making it stiffer.

Those parts would need to be supported in a collet while using a thread forming tap. The forces are high and would just expand the thin wall part if not supported.  I know you know this already but the work hardening does not make the part stiffer it just raises the yield point which makes it seem stiffer. The modulus if elasticity (real stiffness) is not significantly altered by heat treatments or work hardening.  The classic example of this is the question, which is stiffer a 66 RC high speed steel tool bit. or the same size piece in low carbon steel. Many machinists first answer is the tool bit and would prove it to you by putting both in a vise and trying to bend them with an adjustable wrench. The low carbon bends easily and the tool bit seemingly resists bending at all for the same pressure applied. In reality the deflection per unit load is basically identical on both (same modulus of elasticity) but the plastic yield point of the low carbon piece is much lower than the high speed tool bit and is reached very easily with the wrench. FWIW

[Galaxyrise]

I notice the IET SR1 series standard resistors have the jacks you're looking for.  I wonder if they could sell just the connectors? Or maybe hook you up with their suppliers.  If not, you could try to get lucky with some ebay units but it seems like most are missing the bottom posts.  I found http://myworld.ebay.com/bage9299/ selling a couple with the posts still; shame to tear them apart just for the banana parts!

[quarks]

@robrenz,
probably my english is not good enough, but does this mean a rolled thread is the wrong way to go?
Please let me know what you would try.

@Galaxyrise,
I have tested almost all products I could find so far. Actually I do even have the ESI bananas (see att. picture lower left).
As far as I can judge it, they are also Gold plated brass with Gold plated Beryllium Copper banana and therefore no improvement.

[robrenz]

@robrenz,
probably my english is not good enough, but does this mean a rolled thread is the wrong way to go?
Please let me know what you would try.

There is nothing wrong with the formed thread but it exerts very high forces on the material in the process of forming the threads.

I would machine a proper one piece unit from tellurium copper and just use deoxit to keep copper oxide from being an issue.