Questions on Tonearm Geometry

[mrvic2]

Thank you to everybody for all of your help.

[jamiegramo]

My pleasure Inigo, thank you. I think it is often quite hard to find previous articles and discussion on important topics in the forum so repetition can be useful.

Yes thank you for posting! Or reposting. The previous articles have lost your useful attachments. I remember I used them to help make my Exhibition soundbox tracking adapter.

[Curt A]

Ideas if leveling doesn't work:

When the reproducer is swung to the center, the needle should touch the center of the spindle. If not, rotate the reproducer slightly until it does. There are only a few adjustments that can be made to center the tone arm and reproducer. Other than rotating the reproducer, the length of the needle can be adjusted by moving it in or out of the needle chuck before tightening it.

You said the tonearm swings to the side while playing - if it does that with the needle touching the record, you may be trying to play a vertical cut or hill and dale record, which won't play correctly with a steel needle and will cause the tonearm to slide sideways.

It's hard to diagnose problems without seeing them in person.

As far as your key goes, you are looking for a "barrel" key which has a hole drilled in the center of the shaft. It will probably be short like a trunk key.

[mrvic2]

Ideas if leveling doesn't work:

When the reproducer is swung to the center, the needle should touch the center of the spindle. If not, rotate the reproducer slightly until it does.

This is how far I have to adjust the reproducer to make it hit the spindle. I doubt this is how it's designed to play, since the needle is vertical

20250316_181507.jpg

And about the comment of vertical records, i did not mean that it swings when playing, when I said the back of a Victrola record, i meant just a blank record, since they typically have a blank back side, that's an error on my part. I only play lateral records on this machine.

[mrvic2]

Forgive me, the image did not load.

[Curt A]

What brand is your portable? It may have the wrong reproducer on it - it appears too large.

[Curt A]

The correct angle for your needle when playing should be approx. 60-70 degrees off vertical...
It would be better to angle it slightly than to leave it vertical where it digs in.

Screenshot 2025-03-16 at 7.04.50 PM.png (82.91 KiB) Viewed 1149 times

[Orchorsol]

Today I stumbled across photos of the original Wilson Protractor I used to own. Alas, to my eternal regret I sold it before I became involved in EMGs, Experts and thorn and fibre needles, at which point I had no idea of its significance. Has anyone seen another?

A printable document from which one can be made appears earlier in this thread. Perhaps I should update the document to include these images.

[mrvic2]

Today I stumbled across photos of the original Wilson Protractor I used to own. Alas, to my eternal regret I sold it before I became involved in EMGs, Experts and thorn and fibre needles, at which point I had no idea of its significance. Has anyone seen another?

A printable document from which one can be made appears earlier in this thread. Perhaps I should update the document to include these images.

Thank you again for your help. Sadly, my printer is currently non functional, so i will have to wait on printing it.