Seeking 3/8-32 control front panel threaded spacer

GrampaDave

Active Member
I am repairing an SX-1010 that is missing the volume control. Correct part is ACV-134 which is scarce. An ACV-139 (from SX-636 etc) mounts, wires up, and works fine, but it lacks the threaded spacer used to secure the front panel. The spacer has female threads at the back end, and male threads at the front end. The female end, which looks like a thick hex nut on the outside, secures the pot to the chassis, and the male end pokes out through the front panel. When you put a standard 3/8-32 volume control nut on it, that secures the front panel.

Do you have one of these spacers, or a damaged and otherwise worthless control that has one?

Where else could I look for one, and what should I call it?

Thanks,
Dave
 
Found

Yesterday's Audio lists this part on their website, but they're out of stock. They call it "Attachment Nut For All Pioneer Receivers".

Therefore, I'm still looking.



If you can't find an ACV-134, then an ACV-139 plus one of these spacers will work great.

CAUTION: The tap wire color scheme is different. ACV-134 is green, and white with green stripe. ACV-139 is yellow, and green. When connecting ACV-139 to the circuit board pigtails, connect yellow to green, and green to white/green.
 
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Answering my own thread again. We may be able to use Keystone Electronics part number 1464, "Volume Control Extender", in stock at Mouser for about $2 each. A similar part - Abbatron/HH Smith/GH P/N 2351 "Bushing Extender" - is for sale at eBay. The hex portion is 5/8" long so it has to be sawed down to the proper length. I'll try one and see if the result has enough thread left inside.
 
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Kudos to eBay seller "sirnite1", the man who sold me the ACV-139. When I asked if he had an extra spacer, he mailed me one gratis, even though ACV-139 does not come with one.
 
Not confirmed. I mentioned it to him this morning, ten minutes later he said it was in the mail. I'll probably get it next week.

Likewise the Keystone - they put a sample of #1464 in the mail. When it arrives I will determine whether it can be modified. The question is whether the inside thread is tapped deep enough not to bottom out.
 
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Received the spacer from Sirnite1. Grinding is required, but

IT WORKS!

Final thickness is 0.205" from chassis to front panel. Chase the thread after grinding.
I don't know what this spacer came from, and probably can't find out.

Pictures 1 and 2 are the Pioneer spacer before grinding, and with the washer still in place. (Way too thick.)

Keystone #1464 DOES NOT WORK. The female threads were tapped with a taper or plug tap instead of a bottoming tap, and they run out before the nut is all the way on. I have asked Abbatron for a sample, then maybe I will get a 3/8-32 bottoming tap.

Pictures 3 and 4 are the Keystone after sawing.
 

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I received the sample from Abbatron. Unlike the Keystone part, this one is bottom-tapped. It might work. I returned the SX-1010 back to its owner, so I don't have a front panel to test it on. Do you?
 
Up to my eyebrows in other stuff, haven't had the opportunity to do ANY electronic work since Sept 3... No less dig out a unit, and remove the front panel.

No end in sight... sigh...
 
I hope things calm down for you.

The offer holds for anybody who's reading. If you have an SX-1010 with the front panel off, I'll saw down the Abbatron part and send it to you for testing. We want to know if you can screw it all the way on before it bottoms out.
 
Shipped; watch for it in a few days. I sawed, ground, and filed it down to 0.205", the height of the original Pioneer part. Don't use the washer.
 
GD,
Rec'd the part, the inner threads are not deep enough. On the Pioneer part there are 4 rows of threads before it hits the bottom/inner shoulder. The part did not bottom out. Photos of the Pioneer part adjacent to the modded Abbatron part will be posted shortly.
Sorry it didn't fit.
 
Photos of the part. I took them with my phone so they are not the highest quality.
 

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Thanks for testing it.

I will try one more thing. I have another sample. Using a Dremel cutoff wheel, I will cut away about 0.050" of hex where it transitions to external thread. This will allow us to keep more internal thread when I saw off the back end. If this works, then the Abbatron part is a viable, if inconvenient, substitute. If not, we can only use salvage.
 
GEDC0584.JPG GEDC0585.JPG GEDC0586.JPG

THIS MIGHT WORK.

Ingredients:

Abbatron 2351 Bushing Extender
Dremel tool with cutoff wheel
Hacksaw
Vise
File

Using the cutoff wheel, I sculpted 0.075" of material off the hexagonal shank just aft of the male threads. (If you had a lathe with good chuck centering, you could do it that way too.) I sawed off 0.075" of male thread, which happens to be two turns plus slop. The shank was originally 0.625"; now it is 0.550". The male threaded section protrudes 0.250" from the shank as before. The rearmost portion is unthreaded but that's okay, the front panel goes there. Then I sawed off 0.340" from the rear of the shank and filed it smooth taking a final 0.005". This gives 0.205" of shank, 0.250" male end, and four turns of female thread.

I'll ship it today.

Shaded areas in the sketch represent material removed.

GEDC0587.JPG
 
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Rec'd the second modded Abbatron today. Took my OEM bushing off of the 1010, left the washer on and installed the part. It works and when the faceplate is installed it fits perfect. The modded part even holds the faceplate in the correct position from the chassis. Looks like there is a sub for the OEM. I will post photos of the part on the shaft and when the faceplate is attached.
 
Great news, thanks for testing it.

I'm surprised that you got the right spacing with the washer in place; I intended the spacer to work without the washer. Oh well, I suppose I was a bit off. It just shows how important testing is.

This is not a difficult mod to comprehend, and if you can't get the real thing, this will work.
 
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