Tonearm counterweight

[Hoodoo]

I have made counterweights for several of my machines to reduce the wear of the thorn and fibre needles I use. Here are a couple of them.
The Columbia BI:
I just created a forked end on a steel rod and attached it to the tonearm with a cable guide/stay from an old bicycle and used a bit of inner tube to keep the guide from marring the tonearm.
Stock, the weight at the needle tip was quite high, 170 grams, perhaps. I forget exactly. Now I usually set the weight around 60 to 80 grams.
I have read that too little is not good, but so far it has been working well.
The whole setup can be removed and the machine returned to stock form in less than half a minute.
If only I could do something about the less than ideal tracking!
The front-mount Frankenphone:
The traveling arm is completely scratch-built, so no original parts were altered in this project. It uses a spring rather than a weight to do it’s task.
I made a mount/pivot wide enough to accommodate a spring taken from a wood clamp and added an adjuster on the top which, when screwed in/downward reduces the weight of the needle on the record.
I also added a tiny thrust bearing where the travelling arm fits into its mount, to make it pivot nice and smoothly.
N.B. ! When setting the preload, the surface of the scale must be at the same height as the record surface for the scale reading to accurately show the weight at the needle tip.
The tracking of this machine is not too bad actually, because of the longish (14 inch) pivot to needle tip distance.
If I were to do another of this type I would make one or two small changes, but this works well.

[epigramophone]

A few manufacturers fitted counterweights as original equipment. The one on my Micro-Perophone Chromogram (the best cabinet gramophone most people have never heard of) is a simple and effective design.