OldSynths

Hello All

I need to get one of the MS-10 or MS-20 "large" knobs (small style will do
at a pinch), as used on the VCO waveform select or filter cut-off etc.

If I can't buy one I might have a go at trying to mould one. the outside
shouldn't be too difficult to get right but the inside "spine" hole might be
beyond my meagre skills.

Has anyone got one for sale please? If so, could they contact me off-list.

Thanks

RMC, England

Hi RMC,

I saw your post about the missing knob on your Korg. I wish I was
writing you with good news, like I have one for you, but alas, that
is not the case. Instead I am writing to commiserate with you, as I
have a pair of Yamaha DMP11 mixers, one of which is missing a slider
knob, a part which is not available from the Yamaha legacy hardware
support depot here in "the colonies". It occurred to me as well that
I might have to wind up molding my own, if one can't be found from
the Yamaha factory in Japan (still awaiting reply to that post.) If,
in fact, you do find yourself molding a knob, if you would be kind
enough to share your method and materials selection with me, I would
be happy to do the same. I have been considering creating the mold
from that rubber-like molding material (much like silicone sealant,
only a bit harder on the Rockwell C-scale of durometer), and have the
same issues as yourself... getting a mold of the outside is simple,
but the internals (being a slot surrounded by a pair of square
depressions rather than a circular opening) are a bit more
challenging. Do you have any further thoughts on the matter? If so, I
would enjoy hearing from you. Good luck with your search and/or other
solution. Thanks for your time.

<Marv>

--- In oldsynths@yahoogroups.com, "RMC" <rmc@r...> wrote:
> Hello All
>
> I need to get one of the MS-10 or MS-20 "large" knobs (small style
will do
> at a pinch), as used on the VCO waveform select or filter cut-off
etc.
>
> If I can't buy one I might have a go at trying to mould one. the
outside
> shouldn't be too difficult to get right but the inside "spine" hole
might be
> beyond my meagre skills.
>
> Has anyone got one for sale please? If so, could they contact me
off-list.
>
> Thanks
>
> RMC, England

Marv

You and I are in the same boat - we need something idiot-proof if we want to
mould our own.

I reckon the only way I can do the insides of my Korg knob is to use a
process similar to that used in car tyre "re-treads"; you take a part-worn
tyre and coat the outside in fresh rubber into which you cut the tracks.

My "plan" is to find a knob whose mating mechanism is suitably similar or
identical to the spline approach that my Kog uses. I'll take it to work and
get it turned down on a lathe if necessary. Then I will make a mould of my
existing knob, try to find a suitable plastic to cast a replica, and then
suspend my donor knob in the middle of the mould and cast it into the middle
of a new copy.

If you can find something that fits your DMP11, even if it is wrong, I think
a similar half-way house approach might work.

As far as moulding is concerned, there are "alginate" based (seaweed)
jellies that give very high resolution, and also the silicon-elastomer type
that you refer to. The tricky but for me will to find a thermosetting
plastic that is self coloured and looks just right. If I am going to make a
copy it *has* to be perfect. Otherwise I might as well just stick some
bakelite knob off a 1942 valve wireless on the front!

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

----- Original Message -----
From: "Marvin Kaye" <marv@...>
To: <oldsynths@yahoogroups.com>
Sent: Sunday, January 16, 2005 6:27 PM
Subject: [oldsynths] Re: WTB: replacement knob for Korg MS-10 or 20 etc.


>
>
> Hi RMC,
>
> I saw your post about the missing knob on your Korg. I wish I was
> writing you with good news, like I have one for you, but alas, that
> is not the case. Instead I am writing to commiserate with you, as I
> have a pair of Yamaha DMP11 mixers, one of which is missing a slider
> knob, a part which is not available from the Yamaha legacy hardware
> support depot here in "the colonies". It occurred to me as well that
> I might have to wind up molding my own, if one can't be found from
> the Yamaha factory in Japan (still awaiting reply to that post.) If,
> in fact, you do find yourself molding a knob, if you would be kind
> enough to share your method and materials selection with me, I would
> be happy to do the same. I have been considering creating the mold
> from that rubber-like molding material (much like silicone sealant,
> only a bit harder on the Rockwell C-scale of durometer), and have the
> same issues as yourself... getting a mold of the outside is simple,
> but the internals (being a slot surrounded by a pair of square
> depressions rather than a circular opening) are a bit more
> challenging. Do you have any further thoughts on the matter? If so, I
> would enjoy hearing from you. Good luck with your search and/or other
> solution. Thanks for your time.
>
> <Marv>
>
>
> --- In oldsynths@yahoogroups.com, "RMC" <rmc@r...> wrote:
>> Hello All
>>
>> I need to get one of the MS-10 or MS-20 "large" knobs (small style
> will do
>> at a pinch), as used on the VCO waveform select or filter cut-off
> etc.
>>
>> If I can't buy one I might have a go at trying to mould one. the
> outside
>> shouldn't be too difficult to get right but the inside "spine" hole
> might be
>> beyond my meagre skills.
>>
>> Has anyone got one for sale please? If so, could they contact me
> off-list.
>>
>> Thanks
>>
>> RMC, England
>
>
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>

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

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

Rory

Thanks for offering to help, but in the end I found someone at work who has
a hobby interest in making plastic items. He has made a handful of perfect
replicas for me, indistinguishable from the originals!

Cheers

Richard Craven
England

----- Original Message -----
From: "ascii_me" <rorymcd@...>
To: <oldsynths@yahoogroups.com>
Sent: Tuesday, June 21, 2005 3:30 PM
Subject: [oldsynths] Re: WTB: replacement knob for Korg MS-10 or 20 etc.


> 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
>
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
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