Extending Volume Control Shaft?

[pmc]

I'm ready to externally mount my volume control, but ran into a problem. I want to put the volume knob on the speaker-panel overhang so it's easy to get to and inconspicuous.

My speakers are from a gutted PC system and the volume and on/off switches are mounted directly to a baby circuit-board that once fit into the left speaker housing. I extended all the wiring so that the circuit-board and controls can go anywhere. The speakers are mounted in the usual spot below the marquee and over the screen. The sub is in the base of the cab next to the PC.

So I was going to drill a hole in the speaker panel and vertically mount the circuit board on the rear side next to the speakers. The volume control shaft would would stick through the hole and the knob would be fitted on the outside.

Turns out that panel is 3/4" thick and the shaft for the volume control is only 1/4" long. Unfortunately I've permanently mounted the speaker panel and no longer have router access to the rear side so I cannot recess the circuit board.

Is there an easy way to extend the shaft? It's one of those "D" shaped 1/4" shafts that accepts any knob. I can't think of an simple but crafty way to extend the knob but there must be a way. I've already rooted through Rat Shack looking for alternatives but came up empty handed short of replacing the whole control. Ideas?

[BobA]

You can get shaft extensions for metal shafts that use screws to tighten on the shaft.  Probably cost more then your speakers and available only at specialty electronics supplies.

You might consider epoxying a shaft extension made of dowling to the pot.   If you butt the dowling to the plastic shaft and use epoxy and a bit of plastic wrapped around the shafts if should be strong enough.  The dowling can be filed into the D shape required for your knob.

BobA

[grafixmonkey]

If I hear you right, your shaft is only 1/4" long, and you want it to be longer?

I think there are new pills for that.  



(I also recommend hollow metal dowels...   I've had success getting those things to do pretty much anything I want in the past.)

[hulkster]

im having the same problem....do you by chance have Bostom speakers?  my are, i got them for 50 bucks about 3 years ago at best buy...they were for my dorm at the time.  anyway, i took apart my speakers and am going to mount them but the little volume control thing (on its only little circuit board) is going to be the problem.  where to mount it?  now if i understand what you guys are saying about the hollow rods...hmmm...can you possibly show a picture of what these look like?  

and as a side note....can you hear the sound well enough through the speaker holes under the marquee?  i have an old cab, and it has routered grill marks underneath the marquee where speakers go...im just wondering if i stick two speakers up there...will it sound loud enough?

[GamingGreg]

You might also consider replacing the pot entirely with one with a long shaft.  (The replacement pot would need to have the same resistance).  See here for an example.

[hulkster]

is there no way i can just put like..the shaft in that picture, on the end of my current volume nob.  so that wouldnt require any wiring, it would just be kinda suctioned to the volume nob.  would that work?  or would something like that work?  if so, what part would i need?

[Todd H]

I like how Kevin Steele mounted the volume control for his Creative 2.1 speakers on the side of his control panel  Here's the picture...

http://www.retroblast.com/photos/volume.jpg

(note: I tried attaching it but it wouldn't work for some bizarre reason)

[hulkster]

well thats a good idea but i dont think my volume control will reach that far.  so thats why i want to get an attachment or something to lengthen the volume control knob.

[hulkster]

nobody knows?

[bdsjake]

see my cab in project announcements, 3rd pic.  I used a dowel rod about 4", exact diameter that would fit in side snugly in the volume knob that just pulled off.  Then I drill a small hole in other end that slips over the shaft the volume knob sat on.  So far haven't even had to glue it but probably will eventually.

[BobA]

That is the metal shaft and extension that I refered to in my original post.   Usually found at electronic supply houses or a mechanical parts place.   It is made for a metal shaft and probably would not hold very well on a plastic shaft.  That is why I suggested epoxy.

Oscar may be the one to ask as he makes the great spinners and probably knows the source of all the metal bits and pieces.

BobA

[hulkster]

ive heard this epoxy stuff several times...what is it?

[BobA]

It is a 2 part glue that usually comes in small tubes and has to be mixed together before it will start to harden.  Fast acting epoxy will harden in about 5 min while regular epoxy may take an hour or 2.  Available at any hardware store.

BobA

[hulkster]

so are you saying that i should get one of these metal rods from radio shack, and then get some epoxy, or super glue or something, and glue it to the volume knob?

[pmc]

so are you saying that i should get one of these metal rods from radio shack, and then get some epoxy, or super glue or something, and glue it to the volume knob?

I think he's saying that we should get a hollow metal dowel that fits over the volume shaft. My pot has  metal shaft so I think epoxy isn't neccesary (I can crimp to get it tight).

I'd consider replacing the pot (ala Oscar (http://www.oscarcontrols.com/volume/index.shtml)), but prefer not to have to solder. I'll look for a 1/4" hollow rod. Rat Shack? Really? I've never seen anything like that there.

[Lilwolf]

HEHEHE... nobody has any imagination....

I got mine working GREAT....

With a straw!

I got a good heavy straw of my kids... cut it down to the right size..  put it over the old pot... and put some tape over the end to keep the knob on...

Worked GREAT!  Cost about 2c

[hulkster]

well i want it to look halfway decent    i could just cut a big hole in the side of my cabinet and do that!  but thats retarded, so i need to find a better way.

[grafixmonkey]

it's so simple!  Go to a hardware store like Ace Hardware or something, and look for metal dowels.  There are various lengths, solid and hollow, and various inner hole sizes.  Bring your speakers along and find an inner hole radius that's decently close to your speaker.  Use a dremel to cut the hollow dowel short.  Get a solid dowel that fits inside the hollow one, and cut that too so it puts your knob where you want it.  

Use either long-set epoxy or solder to fasten the hollow dowel on your knob's old shaft.  (long set epoxy, because you want to make sure the dowel is on an axis with the knob shaft.  Solder you can re-adjust anytime, but you'll need a mini-torch to solder it on - solder gun won't do it.)

Use a dremel to cut a notch in the end of the solid dowel, so it fits into your knob.   Done!  your speaker knob is now any distance from the speaker you want it to be.


Or you can hack one of those devices that has a pair of speaker-volume buttons on it.  That'd allow you to  raise, lower, and mute the volume with pushbuttons.

[pmc]

it's so simple!  Go to a hardware store like Ace Hardware or something, and look for metal dowels.  There are various lengths, solid and hollow, and various inner hole sizes.  Bring your speakers along and find an inner hole radius that's decently close to your speaker.  Use a dremel to cut the hollow dowel short.  Get a solid dowel that fits inside the hollow one, and cut that too so it puts your knob where you want it.  

Use either long-set epoxy or solder to fasten the hollow dowel on your knob's old shaft.  (long set epoxy, because you want to make sure the dowel is on an axis with the knob shaft.  Solder you can re-adjust anytime, but you'll need a mini-torch to solder it on - solder gun won't do it.)

Use a dremel to cut a notch in the end of the solid dowel, so it fits into your knob.   Done!  your speaker knob is now any distance from the speaker you want it to be.

This is perfect. I'll get the parts tonight and try it. But that "drinking straw" technique sure is tempting to try too! Low tech but sounds very effective.

FYI, I did find an electronics supply house somewhere on the net that sells shaft couplers. It's basically an inch-long double female 1/4" ID tube with tiny set-screws to clamp either end to the original shaft and extension shaft respectively. Not too expensive, but you'd have to have it shipped too. I don't recall the URL.

I'm going to try the double dowels tonight...

Glad to hear I'm not alone in this. I thought for sure this would be a non-issue. Actually, it would be if I had remembered to route a recess before gluing up the speaker panel. If things go ugly for me, I'll cut the damn panel out and do it the way I originally planned!

[Thenasty]

this is what I found.. Not mine..
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=3229998525

[pmc]

...look for metal dowels.  There are various lengths, solid and hollow, and various inner hole sizes.  Bring your speakers along and find an inner hole radius that's decently close to your speaker.  Use a dremel to cut the hollow dowel short.  Get a solid dowel that fits inside the hollow one, and cut that too so it puts your knob where you want it.  

Use either long-set epoxy or solder to fasten the hollow dowel on your knob's old shaft.  (long set epoxy, because you want to make sure the dowel is on an axis with the knob shaft.  Solder you can re-adjust anytime, but you'll need a mini-torch to solder it on - solder gun won't do it.)

Use a dremel to cut a notch in the end of the solid dowel, so it fits into your knob.   Done!  your speaker knob is now any distance from the speaker you want it to be.

Aborted attempt tonight. I have a 1/4" aluminum tube that fits perfectly over the volume shaft. I shimmed it with a sliver of aluminum and crimped it all onto the shaft. Held well. But the other end caused me some trouble as the tube was too big. I only have a 25W soldering iron and no epoxy. So I tried crimping and squashing and what-not. Suceeded in wrecking the other end in the process...

So I'm going to try a 1/4" tube on the circuit board side and then epoxy that to a smaller tube that'll fit my shiny new knurled chrome knob (sounds like porno  ).

Unless a 25W soldering iron will do the job to solder all joints. Doable?

In the end, I now wish I had just removed the old control and soldered a longer shafted control into place (they had 'em Rat Shack for next to nothing). But I didn't want to risk damaging the circuit board. But I sure beat it up working on it tonight. I'll be lucky if it still works at all.

It'll look great in the end... but I wasted one night mucking with it... so far anyway...

[OSCAR]

It sounds like I'm probably too late to help, but for future reference it might have been easier to just use a set screw shaft coupling than to mess around with hollow tubes & epoxy.  Good hardware stores, farm equipment & machinery places (Tractor Supply & County Post around me), and other places like these will carry them.  You should be able to find them for about $5 for ones sized for 1/4" shafts.  To install, you would fix one end to the volume shaft with the set screw, then cut a 1/4" aluminum or steel round stock to the length you need for the other side.  Because it uses dual set screws, each side is fixed independently from each other, making it more forgiving if the two shafts aren't identical in diameter.

[grafixmonkey]

hey, cool, I didn't know they had those.  

Any glue that bonds metal should have worked for the shafts...   you don't have any super glue or anything?

[pmc]

It sounds like I'm probably too late to help, but for future reference it might have been easier to just use a set screw shaft coupling than to mess around with hollow tubes & epoxy.  Good hardware stores, farm equipment & machinery places (Tractor Supply & County Post around me), and other places like these will carry them.  You should be able to find them for about $5 for ones sized for 1/4" shafts.

I found those things on the Internet in the beginning but didn't want to wait (or pay for) shipping. I haven't seen them in any of the hardware / electronic stores (which I frequent almost daily due to this cabinet build). Rat Shack didn't even know what I was talking about. Then again, they never do.

I bought some epoxy and will try that 1st since I have everything I need. I'd have completed this by now, but I've been playing Rise of Nations all hours...  

Thanks for the response.