[sdiy] Why I was asking about UNEF etc.

[Tim Parkhurst]

Since the pot's threads are plastic, I'd say they would be the first things
to strip. In this case, I'd say you're safe. AS LONG AS you don't strip the
threads in the panel when you're tapping it! Once you've got a good thread
in the panel, I think it will be okay. Still, you're only going to get 3 or
4 threads, and that would make me a little nervous. If you really want to go
this route, then be very careful when tapping the holes in the panel, and
apply a drop of Loctite to the threads once you have the pot in place. This
will help keep it from loosening. I think using the counter nut scheme would
just place more stress on the plastic threads. These are the weakest part of
this setup, so I'd probably avoid that.

I'd still see if you could fit a panel nut on there. Maybe you could drill
or mill out some additional room on the bottom face of the knob so that the
panel nut will fit up in there better? Just a thought.

BTW, I like those 3310 pots too. Nice and small, reasonably priced, decent
feel. I'm thinking of using those to retrofit all the sliders in my Odyssey
(FINALLY get rid of those impossible to find sliders). 

Tim Servo


*************************************
> -----Original Message-----
> From: jhaible at debitel.net [mailto:jhaible at debitel.net]
> Sent: Friday, May 16, 2003 9:29 AM
> To: Tim Parkhurst
> Cc: synth-diy at dropmix.xs4all.nl
> Subject: RE: [sdiy] Why I was asking about UNEF etc.
> 
> > Personally, I'd say you're asking for trouble by threading a pot
> directly
> > into an aluminum panel. In a relatively thin sheet of aluminum, you're
> not
> > going to get too many threads. For example, even if the panel were 1/4"
> > thick (about 6.3mm), you are only going to get 8 threads. If the panel
> is
> > 1/8", you're only getting 4 threads. You won't be able to get enough
> torque
> > on the pot to hold it in place reliably and this means that it is going
> to
> > be VERY easy for the threads to strip.
> 
> The panel is 3mm - this is thicker than the nut that comes with the
> pot, so I guess vertical forces cannot be a problem. The question
> is whether _rotational_ forces can do more harm in this case than
> with a nut. With a nut, the front panel is clamped between the
> pot's body on one side and the nut on the other side. If I apply
> rotational force on the body (via the shaft in end position),
> the nut can get loose, too. With a thread in the front panel,
> the front panel "is the nut". So there should be no difference:
> this the first resistance to overcome for turning anything loose
> would also be the clamping, or pressure - this time, between
> the panel and the pot's body. Is there a difference?
> 
> My gut feeling says there *must* be a difference, but
> I'm too blind to see it.
> 
> > Are you using panel nuts? They're special purpose nuts that
> > are very thin. Again, they'll only have 4 or 5 threads, but because
> they're
> > made of steel they are much stronger and will hold just fine.
> 
> Ahh, maybe this is the difference, steel vs. aluminium.
> But then again the thread on the pot is made of plastic anyway.
> So ist there a difference still ?
> 
> JH.
> 
> 
> -------------------------------------------------
> debitel.net Webmail



***************************************************************************
This message is confidential.  The information contained in
this e-mail message is intended only for confidential use of the
recipient(s) named above. If the reader of this message is not the intended
recipient or an agent responsible for delivering it to the intended
recipient, you are hereby notified that you have received this document in
error and that any review, dissemination, distribution, or copying of this
message is strictly prohibited.  If you have received this communication in
error, please notify us immediately by e-mail, and delete the original
message.
***************************************************************************