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Orthophonic needlebar - how does it come out?

Posted: Thu Nov 20, 2014 4:04 pm
by TonyJ
Took apart a junked orthophonic reproducer last night and curious on how the needlebar assembly is removed without destroying the front casting. Were the pivot pins pressed into the assembly while the rest of the needle bar in the front casting slot?

Re: Orthophonic needlebar - how does it come out?

Posted: Thu Nov 20, 2014 6:39 pm
by estott
TonyJ wrote:Took apart a junked orthophonic reproducer last night and curious on how the needlebar assembly is removed without destroying the front casting. Were the pivot pins pressed into the assembly while the rest of the needle bar in the front casting slot?
Correct- the pivot pin is magnetized (I believe) and then pressed in place before the bearings are inserted.

Re: Orthophonic needlebar - how does it come out?

Posted: Tue Nov 25, 2014 4:47 pm
by JerryVan
You remove the needle bar by first unsoldering the one end from the diaphragm spider. With the ball bearings removed, you slide a small metal tube over one end of the needle bar pivot pin. With the tube held firmly & vertically in a vise, you tap the other end of the pivot pin with a small hammer & pin punch until the pin is driven out. It's very tedious to do this while holding on to the rest of the reproducer, being careful not to exert any force on it, or on the bearing blocks. Reverse the procedure for re-assembly.

If it's a pot metal body, you'll almost always find that the hard metal sleeves that were once pressed into each bearing block, are now loose. When re-assembling, glue the sleeves back into the bearing blocks using Loc-Tite or epoxy. Otherwise, they will rattle around and cause a buzz when playing a record.

Re: Orthophonic needlebar - how does it come out?

Posted: Wed Nov 26, 2014 6:57 pm
by TonyJ
Thanks - sounds like quite the task. I've recently tried my hand at rebuilding a few No. 2 reproducers recently and they were pretty easy. The ortho is a different animal...I'll probably leave those to the pros!

Re: Orthophonic needlebar - how does it come out?

Posted: Sat Nov 29, 2014 9:32 pm
by Orthophonic
JerryVan wrote:You remove the needle bar by first unsoldering the one end from the diaphragm spider. With the ball bearings removed, you slide a small metal tube over one end of the needle bar pivot pin. With the tube held firmly & vertically in a vise, you tap the other end of the pivot pin with a small hammer & pin punch until the pin is driven out. It's very tedious to do this while holding on to the rest of the reproducer, being careful not to exert any force on it, or on the bearing blocks. Reverse the procedure for re-assembly.

If it's a pot metal body, you'll almost always find that the hard metal sleeves that were once pressed into each bearing block, are now loose. When re-assembling, glue the sleeves back into the bearing blocks using Loc-Tite or epoxy. Otherwise, they will rattle around and cause a buzz when playing a record.
Jerry, this is similar to how I do it except that I mounted the tube on a c-clamp that goes inside the bearing shell. The other end of the c-clamp has a "push pin" that is concave on its end to push against the needle bar pivot. Tighten the c-clamp and the pivot bar is pushed out with no damage to the sound box shell. To reinstall, simply reverse the c-clamp to push the bar back in. This way you can see just how far to push it when putting it back in. The pivot bars are serrated in the middle where they go through the needle bar. Hope this helps!

Re: Orthophonic needlebar - how does it come out?

Posted: Sun Nov 30, 2014 3:27 pm
by JerryVan
Orthophonic wrote:
JerryVan wrote:You remove the needle bar by first unsoldering the one end from the diaphragm spider. With the ball bearings removed, you slide a small metal tube over one end of the needle bar pivot pin. With the tube held firmly & vertically in a vise, you tap the other end of the pivot pin with a small hammer & pin punch until the pin is driven out. It's very tedious to do this while holding on to the rest of the reproducer, being careful not to exert any force on it, or on the bearing blocks. Reverse the procedure for re-assembly.

If it's a pot metal body, you'll almost always find that the hard metal sleeves that were once pressed into each bearing block, are now loose. When re-assembling, glue the sleeves back into the bearing blocks using Loc-Tite or epoxy. Otherwise, they will rattle around and cause a buzz when playing a record.
Jerry, this is similar to how I do it except that I mounted the tube on a c-clamp that goes inside the bearing shell. The other end of the c-clamp has a "push pin" that is concave on its end to push against the needle bar pivot. Tighten the c-clamp and the pivot bar is pushed out with no damage to the sound box shell. To reinstall, simply reverse the c-clamp to push the bar back in. This way you can see just how far to push it when putting it back in. The pivot bars are serrated in the middle where they go through the needle bar. Hope this helps!
Very interesting. Much more controlled than hammer, punch, etc. Good idea!