Topic: Bass key bell crank problem on pokerwork (Read 2448 times)

Tone Dumb Greg · « **on:** September 17, 2017, 05:12:45 PM »

The Em bass key on my pokerwork failed to come out again few weeks ago. I assumed it was a broken spring and ordered a replacement. Came next day from Charlie. I went to fit it just now and discovered it wasn't the spring that was the problem, but the hinge pin in the bell crank linkage. Can anyone tell me the pukka way to replace the pin (the original has vanished off the face of the earth)? I have frigged it for now, but I would like something that would give me a longer standing repair than the bit of wire I've used.

Steve_freereeder · « **Reply #1 on:** September 17, 2017, 08:59:49 PM »

Use a steel veneer/laminate pin (a bit like a thin panel pin) obtainable from good DIY stores. Put the pin through the hinge holes in the levers and cut off about half its length with pliers or end-cutters. Then, with the pin head against the lever, bend the other end with pliers through about 90° to stop it slipping out.

Link to Amazon here.

Tone Dumb Greg · « **Reply #2 on:** September 17, 2017, 09:10:44 PM »

Thanks Steve.

playandteach · « **Reply #3 on:** September 17, 2017, 10:13:24 PM »

I found it easier to cut the pin before putting it through the holes. Doesn't really matter if you cut one or two too long or short first, they're plentiful enough. I also found it useful to have 2 pairs of jewellers pliers to make sure you don't twist the mechanism when you are bending the pins.

Tone Dumb Greg · « **Reply #4 on:** September 17, 2017, 10:39:44 PM »

Quote from: playandteach on September 17, 2017, 10:13:24 PM

I found it easier to cut the pin before putting it through the holes. Doesn't really matter if you cut one or two too long or short first, they're plentiful enough. I also found it useful to have 2 pairs of jewellers pliers to make sure you don't twist the mechanism when you are bending the pins.

Thanks that was going to be my next question: How do you bend the nail without damaging the rod.

Rob2Hook · « **Reply #5 on:** September 18, 2017, 07:52:39 PM »

I was advised that model railway track pins are just the right size - and they are.

Rob.

Theo · « **Reply #6 on:** September 18, 2017, 08:01:18 PM »

If you bend the nail slightly before inserting it, then after cutting to length squeeze end to end with a pair of pliers and the pin will continue to bend. Keep squeezing till it's sufficiently bent.

Lester · « **Reply #7 on:** September 18, 2017, 08:57:10 PM »

Quote from: Rob2Hook on September 18, 2017, 07:52:39 PM

I was advised that model railway track pins are just the right size - and they are.

Rob.

The ones I was able to source were just too big

malcolmbebb · « **Reply #8 on:** September 18, 2017, 10:08:55 PM »

Hornby R207 are 10mm long. Obtainable on Ebay and other good model railway stockists.

Tone Dumb Greg · « **Reply #9 on:** September 18, 2017, 11:23:25 PM »

Now I've got a dilemma. The pin I've put in, as a temporary measure, is 1.25mm. It goes. Not actually an interference fit, but without much clearance. Shall I get veneer pins, nominal size 1mm, or track pins possibly a closer fit? They're all so cheap it almost confuses the issue.

rees · « **Reply #10 on:** September 18, 2017, 11:35:03 PM »

The less "play" the better - clackety, clack ..............

Tone Dumb Greg · « **Reply #11 on:** September 19, 2017, 12:29:15 AM »

Quote from: Rees on September 18, 2017, 11:35:03 PM

The less "play" the better - clackety, clack ..............

Tell me about it. While I'm messing aroung with it, any suggestions for reducing that clackety, clack are welcome.

Lester · « **Reply #12 on:** September 19, 2017, 07:26:07 AM »

In my experience the major source of clack is from sideways movement of the buttons in the holes in the casework. This can be rectified by bushing the holes. The second main source is the pallets hitting the fondo and can be reduced by fitting better (thicker/softer) pallet facing material.

Theo · « **Reply #13 on:** September 19, 2017, 08:25:49 AM »

If the pin joint moves freely you don't need a thinner nail.

Tone Dumb Greg · « **Reply #14 on:** September 19, 2017, 09:20:54 AM »

Quote from: Lester on September 19, 2017, 07:26:07 AM

In my experience the major source of clack is from sideways movement of the buttons in the holes in the casework. This can be rectified by bushing the holes. The second main source is the pallets hitting the fondo and can be reduced by fitting better (thicker/softer) pallet facing material.

I think the first is my main issue, here. Are suitable bushing kits sold for this purpose, Lester? Or should I be asking Charlie this?

Lester · « **Reply #15 on:** September 19, 2017, 09:28:06 AM »

You need a farmer of some sort, I got mine from Maplins but they don't stock them any more. You also need proper bushing felt, I got mine from the concertina spares website, if link to it but I'm on my phone.

Theo · « **Reply #16 on:** September 19, 2017, 09:54:31 AM »

Lester meant to say "you need a reamer" to enlarge the holes. I use a 13/32" taper pin reamer from tracytools.com. You can get cheap reamers from many tool shops but they have too much taper for my liking. They are really designed for enlarging holes in sheet metal. With patience you can also enlarge the hole with a round file, but it is a very slow job.

http://www.tracytools.com/taper-pin-reamer-imperial?product_id=1451

playandteach · « **Reply #17 on:** September 19, 2017, 11:22:29 AM »

Don't do what I did and use a drill. The raised inner row plinth shattered and I had to rebuild it.
EDIT just to make this clear. Don't use a drill. - I realised the original wording is ambiguous.

Lester · « **Reply #18 on:** September 19, 2017, 12:08:33 PM »

First thing I do is to remove said plinth and glue it back in place before the reaming

Theo · « **Reply #19 on:** September 19, 2017, 02:20:44 PM »

But you still wouldn't use a drill would you Lester?

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Author Topic: Bass key bell crank problem on pokerwork (Read 2448 times)