UK Vintage Radio Repair and Restoration Discussion Forum

UK Vintage Radio Repair and Restoration Discussion Forum (https://www.vintage-radio.net/forum/index.php)
-   Cabinet and Chassis Restoration and Refinishing (https://www.vintage-radio.net/forum/forumdisplay.php?f=21)
-   -   Anyone ever made any of these? (https://www.vintage-radio.net/forum/showthread.php?t=191019)

stevehertz 9th May 2022 11:40 am

Anyone ever made any of these?
 
2 Attachment(s)
These tiny, brass, knurled, domed topped nuts are used to hold the dial scale in place on certain prewar Ekco sets. Such sets often come with at least one or more of these missing, and that's the situation with me presently. Given their size (8BA) I wouldn't say they're the easiest thing to make but saying that, far from impossible for someone with a nice model makers lathe and a deft touch. I feel sure I'm not the first person to be in need of some of these, so my question is, has anyone ever made any?

This may be considered more of a 'wanted' ad, so mods please place as you feel appropriate, thanks.

Station X 9th May 2022 11:52 am

Re: Anyone ever made any of these?
 
I haven't made any, but it wouldn't be difficult.

Chuck some brass bar and knurl it.

Drill and tap 8BA.

Part off to length.

Repeat for however many parts are needed.

Make a stub mandrel threaded 8BA male, screw the part onto it and turn the dome on the outer end.

stevehertz 9th May 2022 12:00 pm

Re: Anyone ever made any of these?
 
Indeed Graham. Any takers please?!

Techman 9th May 2022 3:24 pm

Re: Anyone ever made any of these?
 
2 Attachment(s)
They look a bit like bicycle valve caps.

I've just checked out mine and shown below is a new one I obtained a few years back from an ebay seller in Ireland when I needed a couple for one of my vintage bikes. Also shown are a couple of original old ones of slightly different styles. I've checked these against my 'BA' nut, bolt and washer kits and as can be seen they're 2 BA internal thread as apposed to 8 BA. I reckon they're about the same other than that the radio ones are a thicker wall with obviously a smaller internal thread - you could probably fill a bicycle valve cap with something like plastic metal and then drill and tap.

I've not checked availability of them now on such as ebay, but I've seen old original used ones for sale as well as modern replicas. The only grumble I had regarding the replica ones was that they didn't come with the small rubber internal sealing washer, which wouldn't matter for the intended use in this instance.

Nickthedentist 9th May 2022 3:31 pm

Re: Anyone ever made any of these?
 
Those would be for "Woods" valves, I think.

stevehertz 9th May 2022 4:40 pm

Re: Anyone ever made any of these?
 
Thanks for the input and suggestions guys but I'm looking for the actual thing either by them being faithfully made or if someone may have some spare from a scrap chassis. I already have some cute little brass 8BA domed nuts that are available on Ebay, but although they will do the job*, it's not the same as having the proper thing.

* In actual fact the depth of thread in them is less than the knurled ones and so they bottom out on the captive 8BA pins before tightening up onto the dial scale. Again, yes I could pad the gap out with washers, but it just moves even further away from being a pukka job.

The Philpott 9th May 2022 9:00 pm

Re: Anyone ever made any of these?
 
1 Attachment(s)
-Steve, i wonder if this was an off-the-shelf captive nut, that E K Cole repurposed as a retaining nut. Seen here on an avometer, albeit there's a chamfer leading into the thread.
Remains to be seen if a) same BA thread b) knurled finish c) domed end. This avo is heavily damaged so i can chop one of them out in the near future.

Dave

joebog1 9th May 2022 11:08 pm

Re: Anyone ever made any of these?
 
I think those are different Dave. I think yours are called "Dodge Inserts ". They will have a split cut into the blind end before being tapped so that when you screw the screw into it when fitting, the insert will expand and bind into the bakelite in the Avo case. They are also extensivly used in fibreglass work.

Joe

Silicon 10th May 2022 12:50 am

Re: Anyone ever made any of these?
 
If you look inside the brittle plastic back boxes used for power sockets and light switches you will see threaded brass inserts. Some are knurled on the outside.

When I replace broken back boxes I sometimes remove the brass inserts.
They normally fit 3.5mm screws. Vintage ones might be BA size.

These inserts might be useful for repairing the screw holes in bakelite radio cabinets that are used to retain the card backs.

Station X 10th May 2022 8:36 am

Re: Anyone ever made any of these?
 
Anyone making these is going to need a dimensioned drawing or at he very least a set of dimensions.

stevehertz 10th May 2022 10:38 am

Re: Anyone ever made any of these?
 
No problem with that. First we need to find someone with the capability and willingness to make some.

The Philpott 10th May 2022 11:18 am

Re: Anyone ever made any of these?
 
Thanks Joe. It was worth a go..

I believe the cycle ones Techman shows are usually nickel plated so it's a shame the thread depth and diam. is different. I almost certainly have one or two of them.

Dave

Radio Wrangler 10th May 2022 4:45 pm

Re: Anyone ever made any of these?
 
Quote:

Originally Posted by stevehertz (Post 1469484)
First we need to find someone with the capability and willingness to make some.

That's not how they work.

You send them a drawing THEN they can tell you whether they can make it. No drawing, and they can't be sure.

They also need the drawing to be able to quote on price.

David

The Philpott 10th May 2022 5:01 pm

Re: Anyone ever made any of these?
 
2 Attachment(s)
Well it's a fail with the Avo captive nuts:
They're 6BA, splined, open ended and this one's smeared with solder on one side as part of the fixation. (Probably wiped along cored solder, tapped in, then heated.)

I'll keep an eye open!

Dave

joebog1 10th May 2022 11:20 pm

Re: Anyone ever made any of these?
 
I found this example.

https://catalog.swaco.com/category/dodge-inserts

Maybe I am wrong.

Joe

Radio Wrangler 11th May 2022 1:54 am

Re: Anyone ever made any of these?
 
Even this lot only go down to 6BA in Acorn nuts

https://www.ba-bolts.co.uk/steelnut.html

David

stevehertz 11th May 2022 12:58 pm

Re: Anyone ever made any of these?
 
Quote:

Originally Posted by Radio Wrangler (Post 1469595)
Quote:

Originally Posted by stevehertz (Post 1469484)
First we need to find someone with the capability and willingness to make some.

That's not how they work.

You send them a drawing THEN they can tell you whether they can make it. No drawing, and they can't be sure.

They also need the drawing to be able to quote on price.

David

That doesn't work David, send a drawing to who? Until someone comes forwards there's no one to send drawings to. Anyone used to making small parts on a model making lathe will know from the photos I've provided whether or not they have capability to make an 8ba knurled nut. Then I'm more than happy to provide a detailed drawing to anyone who is interested in taking on the job, and obviously they'll need it. But until someone comes forward, I don't know who's out there.

The Philpott 11th May 2022 2:08 pm

Re: Anyone ever made any of these?
 
-You've had >600 views so that's a start..What is the thread depth required to avoid them bottoming out before they nip up? Were they plain originally or nickel plated?

The people that come to mind are miniature steam engine buffs (just don't call them model steam engines)

Joe, you're not necessarily wrong, the example i showed is from 1953 so AVO may have upgraded later on to something with more bite. Still 6BA though.

Dave

Station X 11th May 2022 2:14 pm

Re: Anyone ever made any of these?
 
I guess the next question is how many parts does the OP require and how much is he prepared to pay for them?

stevehertz 11th May 2022 2:35 pm

Re: Anyone ever made any of these?
 
I need a minimum of three. I'll pay what I think is a fair price to someone who is prepared to make them. Saying that, I'm not a cheapskate, I'm quite prepared to pay a good price. But there must be loads of these knurled nuts missing on sets, it might be worth having 'a number' of them made to the benefit of others.


All times are GMT +1. The time now is 10:55 am.

Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.