So as previously stated I bought three Legacy PowerMasters from Charlie, and the old bugaboo about connections being loose was back to haunt me; especially when using 14ga solid copper wire.
Ah, but at work, I have found out about something called a Belleville washer, a conical shaped washer that is normally used as a spring, but also makes a decent lock washer, and doesn't gouch up the surfaces as much.
I measure around 0.160 on the OD of the threads, and go to the McMaster-Carr website and found some 4mm Belleville aka spring washer aka conical spring washers, and probably some other names too. Hmm, the 4mm washers come in two outer diameters; if I went to the larger OD, I could use it with a wing nut. I then assume the threads are 8-32 and buy a box of 25 8-32 stainless steel wing nuts. After the shipment arrives, I try one on the Command Base. Hmm, something not right. Take a 8-32 tap and run it thru the wing nut. Try again after clearing the threads, still won't thread on. I also turned the nut on the CB, oops, better get a wrench and hold that nut. None of the SAE mini wrenches fit well, but one of the metric ones fits like a glove. Hmm. 0.160 * 25.4 = 4.064. Or, 4mm / 25.4 = 0.157. Uh oh, these could be metric.
Anybody know?
I suppose I could get a metric thread gauge. I really should have a metric version of the SAE tap and die set that includes a thread gauge too I suppose.