Linear Tracker ...I was wondering

The Trans-Fi also has a very short arm wand. I think that you are absolutely correct in your last sentence - that's exactly why I don't want one. Years ago I talked with the late Tom Fletcher of Nottingham Analogue fame, and he warned me against his linear tracker for exactly that reason, "It skips, so you clean the beam. It still skips and you clean it again. Sometimes twice is enough. Sometimes you can't see a thing and it still skips. Sometimes you clean 10 times. But when it doesn't skip, it's all worth it - to the right person."

Inclined plane. If the record groove is viewed as a curled inclined plane in which the stylus rides, then it is easy to calculate the forces acting on the stylus. An old mathematical trick: translate the problem you have into a problem you have already solved.

terry9"If the record groove is viewed as a curled inclined plane in which the stylus rides"

A plane is not curled by mathamatical definition it looks like you have founded a whole new branch of math, geometry and physics I am sure a Nobel prize is in store for you congratulations!!

@ terry9     perhaps coiled or spiral might have been a more accurate choice of words.

Terry9
It skips, so you clean the beam. It still skips and you clean it again. Sometimes twice is enough. Sometimes you can’t see a thing and it still skips. Sometimes you clean 10 times. But when it doesn’t skip, it’s all worth it - to the right person."

This is all part of a design and execution that separates the men from the boys. ....
I would not put up with that design.Like I said earlier in this thread all Linear trackers are very unique in the way they are designed and built.

Terry - very surprised you are saying negative things about another tonearm. Fremer reviewed one of the 360 degree air bearing designs, declared it better than his pivot - he could hear it- but said it wasn’t worth the extra effort. At some point we all gravitate towards convenience.

And you keep referring to the Transfi as an air bearing, but it is a multi point bearing which also includes mechanical bearing. Better to call it a hybrid.  

The most linear tonearm in both planes is a full 360 air bearing.

Sorry to disappoint you, CT. I was reporting a conversation with an expert who realized the limitations of his design, and warned me against it when I asked. A true gentleman, Tom Fletcher.

You are of course correct that the Trans-Fi is a hybrid linear tracker. But, I note that the two plane air bushing is usually compromised by a relatively stiff air hose to pressurize that bearing, so I can’t agree that it is the most linear. That hose generates large forces relative to other forces on the stylus.

Big problem, or so it seems to me, considering Hooke’s Law (as the air hose acts like a spring); displacement is linear in force, but restoring force is proportional to offset from the centre, so it changes as the air bushing traverses the beam. Assuming that the air hose is centred at 4 cm from the rim of the record, this causes the stylus to press into the left channel, decreasing to 0 force at centring, and increasingly press into the right channel.

Trans-Fi finesses this problem by pressurizing the beam on which the saddle rides, and taking care of vertical motion by very low friction pivots. The only external force on the saddle is the tonearm’s cable - still a spring, but a very, very tiny one! The pivots only need to handle a few grams each - I like copper for the Koetsu, nylon for the Miyajima. Agreed that air would be best here too, but it’s not obvious how to do it.

What do you think?

I have discussed the weaknesses of this design in other postings, but overall I like the compromises which this design represents. My main modification is another support at the end of the beam, which allows me to adjust horizontality to 1 minute of arc, and maintain that setting.