Fidelity Research FR-54 Tonearm. ANTI-SKATE???

To get you started, an AS device creates a class 3 lever. Where the tonearm is the lever, the pivot is the fulcrum, and the cantilever is the load.  See here: https://en.wikipedia.org/wiki/Lever
That's if the AS force is applied to the arm wand.  In some cases, the AS force is applied to the short arm that holds the counterweight, to the rear of the pivot, and the AS force pulls the short arm inward.  In that case, we have a Class 1 lever.

thanks.

Sometimes I'm glad I ain't too smart. I get the distance from pivot varies the force.

I had SME 3009: dangling weight on line, 'inside' toward lp. hung on various notches on rod behind the pivot, progressive distances behind the pivot increase the force gradually. 

I see arms with the rod on the outside, with the notched rod forward of the pivot. same thing reversed, got it.

Fidelity Research FR-54 has an outside weight, the difference is, there is only one location to suspend the line, on a wire outside the arm, and, the line connects to only one place, a bimp on the bottom of the arm, about 1/2" in front of the center of the pivot.

No way to lighten, only threads in the bottom of the dangling weight to add sub weights.

If it weighs 2.5g, and it is connected 1/2" forward of the pivot, what amount of outward force do you estimate is produces?

What makes most sense to me is that it was designed in the days of heavy tracking weights, 2.5g start, method to add more if needed.

Exactly. Make that lighter weight and see how it tracks the run out area between grooves. It should just barely drift towards the spindle. 

I’ve never seen an FR 54, so I have no comment on its particular AS mechanism. My only point was that because the anti-skate weight itself weighs 2.5 g is not sufficient data to conclude it is putting 2.5 g of anti-skate force on your tone arm.  The net anti skating force might will be less than 1.5 g which is your VTF right now.  I suggest you examine the tonearm more closely. Maybe there is a way of changing the angle of the string, which also would change the anti-skating force. Also I would check the manual that was once provided with the tonearm. If there indeed were various anti-skating weights for different VTFs (something I’ve never heard of), it should show up in the manual. If it does not show up, I think you are just missing something . I am actually surprised that by now some other owner of an FR 54 hasn’t chimed in to explain what’s going on. Perhaps you can find the manual on vinyl engine, if you don’t already have one.

I did some research for you.  The manual IS available on Vinyl Engine but only in Japanese.  However, there are several older threads on this tonearm that are also mostly to be found on VE.  The consensus seems to be that your impression is correct; AS is not adjustable.  On the other hand, several persons agreed that the single weight provided gives approximately correct AS for a VTF = 1.5g.  So, you should be fine.  In future, you might check VE for answers to questions like this one. I found no evidence that FR ever provided a set of weights to accommodate different VTF values.  Apparently, Mr Ikeda was not obsessed with AS.