For reference when referring to the rotor, that is the plastic carrier for the contact fingers, the PCB is the Stator and the knob would be the 'clicker plate' just like any rotary wafer switch assembly.
You are right. I used the words switch rotor when I meant knob. I have corrected it.
Okay when making it worse are you referring to the small sleeve or the PTFE under the circlip ?.
For the sleeve i disagree that any additional stress is being applied to the contacts or the PCB. The dimensions of it are carefully chosen by measurement to only
apply enough pressure to the plastic fingers of the rotor body to the PCB hole reducing only lateral free play ,(which in my opinion is excessive ), to a minimum without
adversely effecting the effort required to rotate. This mechanical change guarantees alignment of the switch contacts on the rotor with the PCB stator and how will this
introduce ant further stress on the contacts.
I believe that when you put the PTFE under the circlip, then the circlip does push downwards on the switch rotor slightly. Not much deflection, but I don't think anything you do on the knob should be pushing the rotor up and down.
The way I have fixed my meter, there is a clear gap between the circlip and the rotor.
As far as the sleeve goes, I do not think you need any reduction in play of the rotor since the hex shaft from the knob locates the position of the rotor. You should have a knob that is centred and doesn't wobble.
If you need the sleeve to help stop the knob from wobbling, then I think you are making the switch rotor do something it shouldn't be doing. Any rotating pressure on the knob is transferred directly to the rotor and the PCB. There is no need for this to be so.
Now for the PTFE under the circlip, has anyone measured the distance from the top of the rotor body to the underside of the circlip to determine how much distance
there actually is ?. I will admit it has crossed my mind and yet I did not actually do it myself , so as soon as I can I will take the meter apart again I will attempt to get some
measurement done there and post back, as well as try the knob without the PTFE spacers to see if only the sleeve cured my issue or it is indeed needed to apply light pressure to the rotor.
If even that is actually happening with the spacers installed.
I just observed some deflection, but I didn't measure the amount. I had already decided to go a different way. The best way to measure this deflection may be to measure the height of the rotor clip above the PCB on the component side.
What struck me is that when the front case was away from the switch, the knob was really loose - much worse then when attached to the switch.
The problem is threefold - the circlip allows a big vertical movement, the knob sides have too much clearance and the knob moulding taper is all wrong. The knob hole in the case gets wider at the top, and so the knob should also get wider and not narrower at the top. I wanted a knob that on its own wasn't wobbling and that didn't rely on the tightness of the circlip to stop the wobbling.
Now both our "fixes" are definitely not approved by Dave or the manufacturer, so they are both just our own opinion of a solution. Given that it seems that a new knob is coming, it is probably best to wait if you have no problem right now - just be careful with the knob.