OldSynths

Can you send me a pic of the knob you are looking for?
I may have it.
Email to rorymcd@...
Thanks
Rory McDonald
OldSynths Moderator


--- In oldsynths@yahoogroups.com, "Marvin Kaye" <marv@l...> wrote:
> 
> HI again, Richard,
> 
> I've been kicking around the idea of molding up some other (non-
> musical) parts for awhile, and this little episode has finally pushed 
> me over the edge.  I went ahead and ordered some molding silicone, 
> release agent, and black urethane casting resin.  I imagine I'll have 
> all the "fixins" by next weekend.  Naturally I had to order enough to 
> make 200 slider knobs, but if I have good luck with my parts I'll be 
> glad to make you a copy of yours... although all that shipping back 
> and forth across the pond could make this a very long process.  I've 
> been working with composites for a number of years, although this 
> will be my first venture into do-it-yourself injection molding, so 
> I'm looking forward to the new challenge.  My slider knob has a 1mm 
> thick white (pointer) line that runs horizontally around its 
> circumference that adds a bit more challenge to the project... I'm 
> thinking I'll make an initial cast part into which I can mill the 1mm 
> slot around its middle (it's nice to have a machine shop at hand) and 
> use that to create a new exterior mold, then use an actual knob to 
> mold the rear, with the notch for the slider shaft.  One advantage to 
> this approach is that the parting line will be at the exact back of 
> the knob, so any flash will be removed invisibly.  Once the black 
> part is released from the mold I can apply some white casting resin 
> to the slot, sand away the excess and polish off the whole thing once 
> it's all cured up.  A ton of work to duplicate a 50 cent part, but at 
> least it will be right.  I just hope the casting resin's black 
> matches the black of the original knob.  We'll see.
> 
>  <marv>
> 
> 
> --- In oldsynths@yahoogroups.com, "RMC" <rmc@r...> wrote:
> 
> > if I do get anywhere with making a mould, I will let you know. 
> Thanks for 
> > getting in touch - at least we both know we aren't alone in our 
> feeble 
> > quest!
> > 
> > Cheers
> > 
> > Richard Craven
> > England