Re-attaching needle bar to diaphragm HMV 5A

[Inigo]

Nice!

[mrrgstuff]

A bit late to the party here, however thought that anybody trying to do this in the future might be interested in this video where I reattach the needle bar on a 5B

https://youtu.be/H9BgfxvyaPw

Thanks

[Phono48]

For future reference, those chromium screw in each end of the stylus bar swivel are cosmetic only, and serve no practical purpose. They are actually screwed into the little brass cylinder which came out attached to the chromium screws in the video. Once the chromium screws have been unscrewed from the end of the cylinder, you can see that the cylinder itself has a screwdriver slot in the end. It's by turning that, whilst holding the nut steady, that the side-play of the stylus bar is adjusted correctly.

Barry

[mrrgstuff]

Thanks. Yes, I completely failed to understand how the adjustment was made on this . Glad it can be adjusted though as it will make things easier next time I do one!

[Inigo]

Don't fully agree, sorry guys. The inner brass cylinder and nut at each side set the adjustment, but these outer screws aren't cosmetic only ;in fact they fix the adjustment of the cylinder and nut. If you don't set properly the outer screws, the cylinders and nuts will move with each vibration of the needlebar, and the adjustment will be lost in a few playings. You need to set firmly these outer screws to complete the adjustment.

[leels1]

Think Inigo is right. Those chrome screws are what locks it all into place.

The things the nut attach to are only slid in and held by the nut the chrome screw helps to stop the nut working free.

[Phono48]

Think Inigo is right. Those chrome screws are what locks it all into place.

The things the nut attach to are only slid in and held by the nut the chrome screw helps to stop the nut working free.

I am obviously mistaken in my assumption that the chrome screws are "cosmetic only". I assumed that because I have a 5B that is missing the chrome screws and has been working well for years!

Barry

[Inigo]

Can be, with time the brass cylinders and nuts tend to get stuck in the soundbox body housings, so it's not rare that they are stable missing the outer screws. But continued playing might get them loose again with the vibration. I would advise to check if the adjustment is good (no rattle, needlebar moving freely, and having just a small end play between the two pivot points) with the highest care, not to provoke them loosening by the manipulation. If everything is fine, drop some white pva glue (Elmer's glue) on each end, where the outer screws should go, to help them maintaining their current position. Pva glue is simple, and can be removed with a toothpick if later this is required.
itoh, I always find tricky to adjust these end pivots, because once you've adjusted them, the insertion and screwing in of the outer screws tends to rotate the inner cylinders, the nuts, etc and makes a mess. It's the same with the no4 soundbox. I always fix one of the sides firmly with the outer screw, then work on the other pivot only. It is a bit tricky to get it firmly adjusted with that tiny end play..

[leels1]

Think Inigo is right. Those chrome screws are what locks it all into place.

The things the nut attach to are only slid in and held by the nut the chrome screw helps to stop the nut working free.

I am obviously mistaken in my assumption that the chrome screws are "cosmetic only". I assumed that because I have a 5B that is missing the chrome screws and has been working well for years!

Barry

I recently messed with a broken 5a that had the lugs the pivots fit into.

I had to solder some new brass ones on and all I’ve done is place the pivots in and it’s holding ok just by friction. The fact it sounds terrible is another story. I think the whole front is warped.

[Inigo]

That warping is what causes the lugs to break, because the needlebar pivots force the lugs if they are misaligned due to warping... I also had to repair one in my old golden 5a, which was warped too. But careful sanding, filing here and there, cutting and resoldering with epoxy, did the trick. Now it works wonderfully!