Vintage knob, I want to reduce the inner diameter......

[momo]

Any thoughts/tricks to permit me to use these knobs on regular pots?

[GREEN FUZ]

I would think something like this STUFF pushed into the cavity of the knob and then pressed onto the pot shaft might do the trick. That or something like Fimo, you know, that pliable plasticine type product that dries hard.

[John Lyons]

Get some 5 minute epoxy.
Get a scrap pot shaft, maybe a cut off one from a long shaft pot.
Figure out a way to center the shaft in the new knob. mark some guide lines...
Pour in the epoxy, spray the pot shaft with oil or wipe with wax so if won't stick to the epoxy.
Push the shaft into the wet epoxy and wait for it to set up hard enough to hold the shaft up by itself.
When the epoxy dries solid (wait overnight) then twist out the shaft with pliers.
Clean up any slop in the knob/hole and your ready to sport some cool old knobs!!

john

[frank_p]

Check if a mechanical nylon (or brass) bushing could fit in the gap.  McMaster Carr...  This should be std. diam. for turning shafts.

[Thomas3D]

hot glue gun from a crafts store.

[bumblebee]

Get some 5 minute epoxy.
Get a scrap pot shaft, maybe a cut off one from a long shaft pot.
Figure out a way to center the shaft in the new knob. mark some guide lines...
Pour in the epoxy, spray the pot shaft with oil or wipe with wax so if won't stick to the epoxy.
Push the shaft into the wet epoxy and wait for it to set up hard enough to hold the shaft up by itself.
When the epoxy dries solid (wait overnight) then twist out the shaft with pliers.
Clean up any slop in the knob/hole and your ready to sport some cool old knobs!!

john

+1

[theundeadelvis]

I'd pretty much do what John suggested except I'd just fill it up and then drill it out with a drill press after it dries. I often drill out knobs for pots with larger posts.

[John Lyons]

That's true, It would be simpler to just fill in the hole and drill it out once it's cured.
That way you would have better luck centering the hole. Good thinking!
It looks like there is a set screw, you want to make sure that the epoxy doesn't lock it up in it's threads.
I'd take out the screw and fill that hole with wax, then when the epoxy is cured you can remove the wax with a small screwdriver.

John

[drewl]

Use shrink tubing, you may have to take the knobs or pots off someday.

[davent]

Hello
I needed  to convert a 1/4" knob for use on 1/8" pot shaft. To do it, clamped a board to the drill press table chucked up a 1/4" drill bit and drilled a shallow hole (the same depth as the knob hole) into the board, . Took a piece of 1/4" brass rod the same length as the knob hole depth and stuck it into the hole just drilled in the board still clamped to the drill press table. Changed the drill bit for a 1/8" (pot shaft diameter) then drilled through the brass rod and had a perfectly centered hole. Took the rod out of the piece of wood, clamped it up in a vice and drilled a hole through the side to allow the knob set screw to pass through. Job done.

You may need to get a longer set screw to reach from the threaded section of your knob to the pot shaft or you could tap the side hole you drill through the insert  you make.

Have fun!
dave

[John Lyons]

How did you keep the 1/4" diameter brass rod from spinning in the 1/4" hole in the wood?

Didn't think of the set screw length...Hmmm....

[momo]

Hello
I needed  to convert a 1/4" knob for use on 1/8" pot shaft. To do it, clamped a board to the drill press table chucked up a 1/4" drill bit and drilled a shallow hole (the same depth as the knob hole) into the board, . Took a piece of 1/4" brass rod the same length as the knob hole depth and stuck it into the hole just drilled in the board still clamped to the drill press table. Changed the drill bit for a 1/8" (pot shaft diameter) then drilled through the brass rod and had a perfectly centered hole. Took the rod out of the piece of wood, clamped it up in a vice and drilled a hole through the side to allow the knob set screw to pass through. Job done.

You may need to get a longer set screw to reach from the threaded section of your knob to the pot shaft or you could tap the side hole you drill through the insert  you make.

Have fun!
dave

Whooaaa.....its too late, I have no idea what your talkin bout!! Im trying to visualize it and I don't get it
OK, to bed im going and Ill read this tomorrow......its been a long day.!!!!
thanks guys for all the tips

[theundeadelvis]

How did you keep the 1/4" diameter brass rod from spinning in the 1/4" hole in the wood?

Didn't think of the set screw length...Hmmm....

Maybe switch to a knurled split shaft pot and treat it as a press fit knob.

[RickL]

You might be able to make a bushing out of multiple pieces of nesting tubing (aluminum or brass). I've done it successfully to mount 1/4" knobs on 1/8" shafts. Check a hobby supply shop for the tubing.

[gutsofgold]

Not to steal the thread here but...

does anyone have any tips for REMOVING epoxy? I am thinking lacquer thinner and a heat gun. is it even possible? I need to get rid of some epoxy that is holding a large dial type knob onto a regular smooth shaft pot.

[Paul Perry (Frostwave)]

does anyone have any tips for REMOVING epoxy? I am thinking lacquer thinner and a heat gun. is it even possible? I need to get rid of some epoxy that is holding a large dial type knob onto a regular smooth shaft pot.

It is possible to soften epoxy with a blowtorch & pick away at it, but usually the epoxy is more resilient than whatever it is stuck to.
A lot of bad news, form industrial chemists: http://yarchive.net/chem/epoxy_solvent.html
I don't think there is anything that will attack epoxy, that won't attack YOU!

[petemoore]

  I've had some luck attacking unwanted epoxies with sheer mechanical force.
  No luck I've tried or heard of using chemicals to softer or remove it.
  IOW pretty much permanent unless you can wrestle it off without damaging what it clings to.
  Cutting through thick portions first may reduce the amount of mechanical force necessary to defeat the epoxy stick....such as drill or hacksaw most of the way through first, then pry/pull/peel etc.

[davent]

Hello
I needed  to convert a 1/4" knob for use on 1/8" pot shaft. To do it, clamped a board to the drill press table chucked up a 1/4" drill bit and drilled a shallow hole (the same depth as the knob hole) into the board, . Took a piece of 1/4" brass rod the same length as the knob hole depth and stuck it into the hole just drilled in the board still clamped to the drill press table. Changed the drill bit for a 1/8" (pot shaft diameter) then drilled through the brass rod and had a perfectly centered hole. Took the rod out of the piece of wood, clamped it up in a vice and drilled a hole through the side to allow the knob set screw to pass through. Job done.

You may need to get a longer set screw to reach from the threaded section of your knob to the pot shaft or you could tap the side hole you drill through the insert  you make.

Have fun!
dave

Whooaaa.....its too late, I have no idea what your talkin bout!! Im trying to visualize it and I don't get it
OK, to bed im going and Ill read this tomorrow......its been a long day.!!!!
thanks guys for all the tips

Confusing I know, I need visuals, words are rarely enough.  Hopefully a picture of the finished product will help clarify the process. 

How did you keep the 1/4" diameter brass rod from spinning in the 1/4" hole in the wood?

Didn't think of the set screw length...Hmmm....

I may have used a drop of glue in the hole but it was a number of years ago using my dad's drillpress and I can't remember if it was solely friction holding it in place or whether i did anything to prevent the brass from spinning. You wouldn't necessarily need to use brass but I had it on hand. You  need something the same diameter as the shaft opening in the knob of choice (and hard enough that you could tap a thread) then you can drill it out to match the shaft diameter of your pot.

The set screw was long enough to reach through the bushing and engage the pot shaft but momo's is going to be too short. You would need to glue the bushing into the knob if the set screw wasn't long enough to pass through both the knob and the new bushing.

dave

[frank_p]

Davent,
This is looking like a set screw fixed collar...

[joegagan]

the bushing idea sounds like less work than the epoxy option to me. IF you don't spend a lot of time making or finding a bushing.

both home depot and lowes have some pretty extensive bushing and misc hardware selections these days.

if you need a longer setscrew, buy a pan head stainless screw of proper thread at home depot,  cut to length then put a slot head in with your dremel saw perpendicular across the top