I need a knurled nut !

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Knurly

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Aug 5, 2013
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Hi
I'm trying to find a little assistance with a simple metalworking problem . I have an old and rare Sony microphone which has been abused during it's lifetime and now requires some very simple parts to get it back to health .

Specifically I need a small hollow circular 'nut' that serves as a strain relief for a cable that passes through it . It's difficult to find an engineeing firm interested in such a small job . I was wondering whether anyone here would like to offer assistance or might know where I could find some . I'm happy to offer remuneration .

Many thanks , Knurly .

Knurled Nut 1a.jpg
 
It doesn't look like an overly difficult piece to make, if you've got the right tools that is. Maybe you should include your location as there are members on here from all over the world.
 
Cogsy --is right looks like a ten minutes job
and anyone with a knurl can do this.. I think
 
Thanks Cogsy & CanadianHP . I'm in London . There's a little bit more to it , but the knurled nut is the crucial piece . It screws into a thin walled , possibly spun , metal housing . The thread has , over time , gouged the 'meat' from the hole it used to mount in and is now too loose to fit properly . I'd imagine the easiest solution is to simply increase the OD of the threaded portion .

The mic is a 1950's Sony C37A , a venerable and expensive piece of gear . Plenty of it's internal metalwork could stand replacement , but the 'nut' is the fundamental problem . I can post other photos for those who are interested .

Thanks again , Knurly .
 
Luc
Here's a few more . It's obvious that the mic internals have been desecrated over the years . Apart from the knurled nut and the horrible mess made of the mounting hole , there is an internal bracket (obscured by gaffer tape) that is fundamentally the wrong shape .

The cable clamp needs to allow the cable to exit at an angle , rather than at 90deg to the rest of the the frame . This is the flaw that causes many of the problems with maintaining these mics . Note that the heads of the cable clamp screws have been totally stripped , so it's may be easy to release but it'll be impossible to tighten .

I'll measure up some dims .

Thanks , Knurly .

Mic Complete 1a.jpg


Mic Internals 1a.jpg


Mic Body 1a.jpg
 
That's a ten minute job but as long as you don't enter your location in your profile, nobody will make the nut for a crate of beer...
 
Dimensions : The 'nut' is 14.25mm in diameter , 10.9mm in diam on the threaded portion , which has 2mm of thread , and 8.45mm 'thick' .

Knurly
 
That's a ten minute job but as long as you don't enter your location in your profile, nobody will make the nut for a crate of beer...

Thanks , Till . A very sensible nudge . Is there a bureau in Hamburg that can dispense crates of beer ? It'd be so useful to be able to arrange such a thing with a Paypal payment .

I often work with a guy , Hansi , who also from Hamburg . Maybe I can get him to drop by ? The only caveat is that it may arrive as half a crate of beer , Hansi's quite a thirsty chap .

Knurly .
 
Dimensions : The 'nut' is 14.25mm in diameter , 10.9mm in diam on the threaded portion , which has 2mm of thread , and 8.45mm 'thick' .

Knurly

the 8.45 thick does that include the thread of 2mm

the rest of the stuff can easily be fix with a small build up of silver solder
or even Devcon liquid metal

it's to bad your not close to mt place that's the kind of work I like doing
 
Luc
The 8.45mm includes the 2mm of thread . In the past someone had tried to build up the hole using solder , but used normal tin/lead solder . Doh !

Yes indeed , I'd quite like to be much closer to Ottawa ! That's the problem with this little job , it's proving very difficult to find a local 'light engineer' and I know that at some point anyone taking on the task would like to actually see and handle the various bits .

By the way , I like your photos in that thread about your new engine . Knurly .
 
If you can get it to Letchworth (daytime) or Hemel Hempstead (evening) I could have a look at it for you.
Message me for more information.
 
Hmmm. Why don't you silver solder it!
Its quite easy.
Or maybe bronze.
I'll look tomorrow, I may have a nut for you or two.
Don't hold your breadth though, i've had a clean out.
Shadow.
 
Two crucial points

Must the nut be threade last after the can is all closed or can be preassembbled with a tin nut inside?

The knurling is not a standard diamond pattern or little piramids, rather is the conjugate made up od piramidal indentations. If exact restoration is desired that can be a problem.
 
I don't see it any different then the one we use.
It looks like a regular knurl that was machine down after to remove
the spike
 
Last edited:
The wheels I bought from LMS don't make the line between the diamonds, at least on the knurls I've made. Maybe I'm not doing it right. Here's my latest effort: http://s571.photobucket.com/user/chucketn/media/Drawbar Wrench_Hammer/handle2_zps22186cab.jpg.html

Chuck

Edit: Maybe it's an optical illusion, but it looks like a positive ridge between the diamonds, mine makes a groove.

Chuck, you didn't go deep enough you would have the same pattern
then only machine it on the lathe to remove the excess of spike
you also need a constant flow of air and taping fluid when doing this
do you have the clamping style knurler??
 
Yes, Luc, I have a clamp type knurler that I built as well as single and double wheel bump types. I prefer the clamp type on my 7x14 lathe.
Can't remember now, but think I only bought medium wheels from LMS for the one I made.

Chuck
 

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