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Exhibition repair???

Posted: Sat Jan 12, 2019 6:05 pm
by Markola
So, I’ve gained possession of an otherwise functional (and decent-sounding) round-hole Exhibition reproducer, except the hole for the thumbscrew is stripped and oblong to the point where it doesn’t work reliably.

The needle hole is also out-of-round, but still works (assuming you could get the thumbscrew tight). And the thumbscrew itself is also a little worn but likewise works fine otherwise.

So, what I want to do is repair the thumbscrew hole situation and leave the rest alone, if possible.

What are my options? These are my thoughts…

(1) I’m thinking maybe I could fill the thumbscrew hole with solder, then drill and tap for the correct thumbscrew thread (placing something in the needle hole first, to avoid filling that with solder too).

[If so, what are the correct drill & tap sizes?]

(2) Or… just drill and tap the existing hole for the next larger size, assuming larger thumbscrews are available?

[Again, what would be the next larger drill & tap sizes for which a thumbscrew exists, and who might have that thumbscrew?]

(3) Or... something else I haven’t thought of but which is commonly done and works fine???

(4) Or maybe someone commonly does these repairs and I should just send it to him?

Thanks in advance for any help you can provide!
Mark

Re: Exhibition repair???

Posted: Sat Jan 12, 2019 6:13 pm
by JerryVan
Wow, where to begin. First, that's not the original thumbscrew. It looks bigger than the original and it's brass, where the original is steel. Solder will never be strong enough to make usable threads. It will strip out again the first time you use it. It needs to have an insert threaded and soldered in place to completely plug the wallowed out hole. Then, the insert needs to be drilled and tapped for the correct thumbscrew, (which I think is a 1-56, but not sure about that). Honestly, if it were mine, I'd remove the needle chuck from the plate and make a whole new one, then solder it on the plate.

Re: Exhibition repair???

Posted: Sat Jan 12, 2019 6:37 pm
by OrthoFan
You might also want to check with some of the supply companies, such as -- http://www.victroladoctor.com/reproduce ... und-boxes/ -- to see if they have a correct replacement (round hole) needle-bar assembly.

OrthoFan

Re: Exhibition repair???

Posted: Sat Jan 12, 2019 9:30 pm
by phonogfp
OrthoFan wrote:You might also want to check with some of the supply companies, such as -- http://www.victroladoctor.com/reproduce ... und-boxes/ -- to see if they have a correct replacement (round hole) needle-bar assembly.

OrthoFan
Bear in mind that George Vollema is closed until April.

George P.

Re: Exhibition repair???

Posted: Sun Jan 13, 2019 7:04 am
by Curt A
Just wait until you find the correct needle bar and screw to replace it... since both holes are screwed up.

Re: Exhibition repair???

Posted: Sun Jan 13, 2019 9:28 am
by zenith82
If it were some rare, unobtanium reproducer, I'd say try your best to save it. Basically JerryVan's comments are spot on. It would have to have a plug pressed in, the hole re-drilled and re-tapped. Even then, it still might not sound right.

Honestly, I'd swap it out for a different reproducer and keep that one for parts. Exhibition and No. 2 reproducers are both common, easily obtainable, and not hard to find.

Re: Exhibition repair???

Posted: Sun Jan 13, 2019 10:06 am
by alang
OrthoFan wrote:You might also want to check with some of the supply companies, such as -- http://www.victroladoctor.com/reproduce ... und-boxes/ -- to see if they have a correct replacement (round hole) needle-bar assembly.

OrthoFan
Unfortunately nobody makes replicas of the round hole Exhibition needle bar - at least to my knowledge. I did ask Ron Sitko and others. If someone has the skills and equipment it should not be too hard to replicate that block where that holds the needle, but there are other differences. The small nuts that hold the springs are knurled and I believe the thread might be different as well. You could ask one of the suppliers if they would repair it, but it might be cheaper to just wait for a working one to show up.

Andreas

Re: Exhibition repair???

Posted: Sun Jan 13, 2019 10:19 am
by soundgen
Just cut and shunt ! Remove the bottom of the needle bar , remove the bottom of another needle bar doesn't even have to be Victor but a derelict soundbox and solder it in place , 10 minute job ?

Re: Exhibition repair???

Posted: Sun Jan 13, 2019 10:49 pm
by Markola
Lots of good ideas here - I think between them I can see a few different potential solutions. Thanks much to everyone who responded! :)

Re: Exhibition repair???

Posted: Tue Jan 15, 2019 8:58 am
by MicaMonster
I would drill it and fill with brass rod, soldered in place...then re-drill needle hole, and then re-drill thumbscrew hole and tap it to 1-56 thread