Long shaft pot

[62vauxhall]

I've been mulling over ideas for a replacement potentiometer to replace one where the shaft came out. I took the old one apart and thought I fixed it but no. Did generate a nice bright white light on the inside and some smoke though.

What I need is: single gang, linear, 20K ohms with a long shaft.

I do have one but i has a short shaft and in order to adapt it, I'd have to make a butt joint with a cut to fit piece of the old shaft onto the end of the new pot's shaft.

What do you guy's think my chances are that this will work?

The one I'm needing to replace is the one in the foreground (duh) that's missing it's shaft.

 

[VSAT88]

I've been mulling over ideas for a replacement potentiometer to replace one where the shaft came out. I took the old one apart and thought I fixed it but no. Did generate a nice bright white light on the inside and some smoke though.

What I need is: single gang, linear, 20K ohms with a long shaft.

I do have one but i has a short shaft and in order to adapt it, I'd have to make a butt joint with a cut to fit piece of the old shaft onto the end of the new pot's shaft.

What do you guy's think my chances are that this will work?

The one I'm needing to replace is the one in the foreground (duh) that's missing it's shaft.

View attachment 30998 View attachment 30999

What does it fit. I have a lot of spares around here, used ones. I need a place to start. I have also heard of folks using epoxy to make shaft extensions. I think they used a straw and cut a grove in the shaft to pour it down in.

 

[Bradrock]

For what it's worth: My big gun safe has had the shaft of the combination lock dial JB butt welded together for over ten years now. The push pull headlight switch on our 89 Ford van also JB welded on since we bought the van new. ( It's an extension for my Quadraplegic wife )

 

[Netfly]

On the short shaft pot, maybe you can use a tube it will fit in tightly to make a sleeve you can drill through to pin or epoxy to an extension shaft.

 

[WOPL Sniffer]

I second the sleeve and JB Weld (they have a new flavor out, vanilla).....

Huh?

 

[WOPL Sniffer]

I've been mulling over ideas for a replacement potentiometer to replace one where the shaft came out. I took the old one apart and thought I fixed it but no. Did generate a nice bright white light on the inside and some smoke though.

What I need is: single gang, linear, 20K ohms with a long shaft.

I do have one but i has a short shaft and in order to adapt it, I'd have to make a butt joint with a cut to fit piece of the old shaft onto the end of the new pot's shaft.

What do you guy's think my chances are that this will work?

The one I'm needing to replace is the one in the foreground (duh) that's missing it's shaft.

View attachment 30998 View attachment 30999

Maybe
https://www.ebay.com/itm/NOS-Vintag...d=152810957153&_trksid=p2385738.c100677.m4598

 

[62vauxhall]

I was trying to find out if JB Weld would work in a situation like this. I'm going to assume the shaft of the old pot is aluminum as it is not attracted to a magnet. I spent an hour or so last night Google searching bonding aluminum to aluminum and JB Weld was recommended by some and pronounced a failure by others. But I got nothing to lose so will give it a go.

I never thought of a straw, I was thinking more like nylon tubing or shrink tube.

What the pot is from is one of the DBX 3BX's I bought last week. It's the 3BX DS's transition control.

I'm guessing but I think someone before me tried prying the knob off (a couple of pots were a bit wobbly and needed tightening) but did not realize they were held on with a set screw. The result was pulling the shaft right out of the pot. I did not notice this until after I got the units home.

Thanks for the e-bay link but that particular pot has the wrong lugs plus it's a dual shaft/dual gang.

I have been browsing through e-bay but can only spend so much time doing it. Anyone know of sites other than Mouser/Digikey/Newark?

 

[VSAT88]

https://www.ebay.com/itm/NOS-unused...ar-4mm-silver-long-shaft-pot-DP-/321219322129 Would this one work if you did not have to finance it ? Jesus ! 38.00 !!!

These guys have a 25 K ohm with financing avalable as well. Not sure if you could get by with a 25 K though. https://www.electronicplus.com/content/ProductPage.asp?pagenum=7&lname=&maincat=RE&subcat=RPO

I am gonna go to the boneyard as soon as I can and poke around.

 

[62vauxhall]

https://www.ebay.com/itm/NOS-unused...ar-4mm-silver-long-shaft-pot-DP-/321219322129 Would this one work if you did not have to finance it ? Jesus ! 38.00 !!!

These guys have a 25 K ohm with financing avalable as well. Not sure if you could get by with a 25 K though. https://www.electronicplus.com/content/ProductPage.asp?pagenum=7&lname=&maincat=RE&subcat=RPO

I am gonna go to the boneyard as soon as I can and poke around.

Yah, that's crazy expensive and made more so by the US/CA currency difference.

I actually did see that pot. The reply I got back from Harman/DBX suggested Studio Electronics as a possible source. The pot I have with the short shaft cost $2.50.

It would not work anyway. It has a 4mm diameter shaft and I need 6mm.

I appreciate you taking the time to check out your stash.

 

[62vauxhall]

Emission accomplished

Just put that DBX 3BX SD back together, ran it for a while and it works like a hot damn.

Thanks for the JB Weld endorsements.

I got some yesterday (13 friggin' dollars and I hope it doesn't dry up before I need it again) and joined the old shaft to the new pot last night using a piece of clear nylon tubing for alignment. Cut off the tubing after 18 hours and it worked beautifully - straight as an arrow. Hacksawed off a bit off the old shaft's end for proper length, dremel ground off the excess epoxy, just a film really - that tubing was perfect fit. Soldered it in, knobs on, buttoned up and Bob's your uncle.



The examples by Bradrock convinced me to try this, especially the one about the pull on/push off headlight switch. I was concerned about the join as it's such a small surface area (I/4" diameter) so it seemed pretty similar. And a DBX rotary control will sure not have to endure the stress that headlight switch does.

 

[grapplesaw]

Just put that DBX 3BX SD back together, ran it for a while and it works like a hot damn.

Thanks for the JB Weld endorsements.

I got some yesterday (13 friggin' dollars and I hope it doesn't dry up before I need it again) and joined the old shaft to the new pot last night using a piece of clear nylon tubing for alignment. Cut off the tubing after 18 hours and it worked beautifully - straight as an arrow. Hacksawed off a bit off the old shaft's end for proper length, dremel ground off the excess epoxy, just a film really - that tubing was perfect fit. Soldered it in, knobs on, buttoned up and Bob's your uncle.

View attachment 31036

The examples by Bradrock convinced me to try this, especially the one about the pull on/push off headlight switch. I was concerned about the join as it's such a small surface area (I/4" diameter) so it seemed pretty similar. And a DBX rotary control will sure not have to endure the stress that headlight switch does.

Great job Gary
your unused JB Weld should last many years.

 

[VSAT88]

Jiminny Cricket it worked ! I never had time to look thru all the boneyard so I am really glad it worked so well but 13.00 for JB weld ???

 

[grapplesaw]

Jiminny Cricket it worked ! I never had time to look thru all the boneyard so I am really glad it worked so well but 13.00 for JB weld ???

Canadian dollars I suspect. Right Gary?

 

[62vauxhall]

Canadian dollars I suspect. Right Gary?

Yup, CAD - at Lordco.

It was $11 at Canadian Tire (checked their website) but since I was passing a Lordco on my way to a job, ducked in and got it.