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Hints, Tips and Solutions (Do NOT post requests for help here) If you have any useful general hints and tips for vintage technology repair and restoration, please share them here. PLEASE DO NOT POST REQUESTS FOR HELP HERE! |
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20th May 2020, 1:09 pm | #1 |
Hexode
Join Date: Jan 2015
Location: Rustington, West Sussex, UK.
Posts: 382
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Knob puller
I have an old Bush AC41 that the knobs are refusing to come off. Inspired by a post here about a American knob puller for musical instruments I designed and built a small puller.
The outer tube is a offcut section of 63mm clear plastic pipe. The claws I designed around some M8 coach bolts, this meant that I could slide the jaws open to pass over the stuck knob, slide the jaws together and then hand tighten the retaining nut. The jaws would stay at 180° apart. I had the jaws punched and bent at my local sheet metal shop. They could not punch these until the following day so meanwhile I cut out a 68mm circle from a piece of 10mm thick poly prop sheet with a hole saw. This gave me a centre 6mm hole to place a bolt through so that I could hold it in the lathe chuck. I then machined the disk down to 65mm with a 2mm locating rebate that fitted snugly inside the clear tube. The next day the jaws arrived with me, the 8mm slide was a little tight so I opened this up with a file, now works well. The parts were assembled with a M10 nut as a spacer to allow for the end of the square on the coach bolt. On the puller outer end I fitted a m8 penny washer and a M8 wing-nut. Bob.
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Bob, BVWS member |
20th May 2020, 1:58 pm | #2 |
Guest
Posts: n/a
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Re: Knob puller
That's a proper job, you could rent it out!
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21st May 2020, 5:56 pm | #3 |
Heptode
Join Date: Nov 2009
Location: Scarborough, North Yorkshire, UK.
Posts: 510
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Re: Knob puller
Hello Bob, I like your idea and will make myself one. Thank you for posting the pictures and the description. Next I need to locate a piece of clear plastic. Ted
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21st May 2020, 7:00 pm | #4 |
Dekatron
Join Date: Sep 2011
Location: Rugeley, Staffordshire, UK.
Posts: 8,831
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Re: Knob puller
Yep, it was my original post back in 2015. Here's that post plus info re another home brewed one:
https://www.vintage-radio.net/forum/...d.php?t=116962 Excellent job Bob.
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A digital radio is the latest thing, but a vintage wireless is forever.. |
5th Jul 2020, 7:30 pm | #5 |
Dekatron
Join Date: Sep 2011
Location: Rugeley, Staffordshire, UK.
Posts: 8,831
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Re: Knob puller
Just bear in mind if you're making one of these that on the commercial one I bought the main tube's bottom edge is 'protected' with a rubber strip. If you don't fit some kind of softish protection like this then if the knob is stuck and a lot of pressure has to be applied, then the rim of the tube can dig into the finish of the radio/whatever.
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A digital radio is the latest thing, but a vintage wireless is forever.. |