DIY Schroeder Tonearm???

[deadhead]

Did you profile the pair of magnets as per Herr Schroeders suggestions? I seem to recall that is done to counteract the problem you describe.

 

[Adelmo]

Has anyone experienced a decreasing tracking force from the outside of the record to the inside? Is it a natural phenomenon or more likely something in my build construction?

Hi,

How much is such difference?
In my clone of the TA, once set it properly with a really minimal gap between the upper and bottom mags I recall the tracking force was almost optimal, just a 0.0x Gr. in the entire LP using electronic scale for cart. ( not recall the exact figue ). The setting was for Denon DL 103 I.E. 2.6 Gr.
I used N42 mags, Diam 10mm and thickness 5mm.
The TA was a 12 Inch.

The clearance between the 2 mags I started was the thickness of a name card and from that I decreased as much as I could avoiding that the mags touch each other.

Rgds

Adelmo

 

[stoN_Cold]

Has anyone experienced a decreasing tracking force from the outside of the record to the inside? Is it a natural phenomenon or more likely something in my build construction?

AS force?

 

[stephan-schulz]

Did you profile the pair of magnets as per Herr Schroeders suggestions? I seem to recall that is done to counteract the problem you describe.

Deadhead, can you point direction on that?
My setup is quite good but may be there‘s some room for improvement.

All I can say is, make sure that the magnets are perfectly in line.

 

[deadhead]

You will find a lot of the technical information post by Herr Schroeder ( posts under username berlinta on here ) on page 8 of this thread. Over a couple of posts he gives a lot of helpful insights into his workings.

 

[Mark Tillotson]

Has anyone experienced a decreasing tracking force from the outside of the record to the inside? Is it a natural phenomenon or more likely something in my build construction?

Perhaps having the wires emerge away from the bearing axis is adding unexpected forces - normal arms have the wires acting as torsional springs co-axially with the arm bearing, which will only affect the anti-skating force, and with a small magnitude as only wire torque is involved. Might be worth doing some maths to figure this out.

 

[stoN_Cold]

All I can say is, make sure that the magnets are perfectly in line.

Magnets have nothing to do with AS force!

 

[Pogany]

Gundrill solution!

 

[Trzalica]

Mine is............... cartridge with aluminium screws- head shell plate ( Titanium ) - head shell plate screw ( Titanium ) Headshell ( aluminium ) Rosewood arm wand- aluminium bearing section- Brass counterweight isolated by silicone tube from the arm.
The tone arm wire runs inside a fine PTFE tube which in turn runs inside a fine brass tube inside the wand.

The wand was soaked in oils for quite a time to help towards deadening any resonance inherent in the wood.

The element at the top of the suspension thread that contains the adjustment grub screw is held in place by an O-ring with a strong interference fit in the hope that that too adds some damping to the arm.

View attachment 1330194

Really nice execution deadhead!

What is an Arm Lift that you have?

 

[deadhead]

It is a standard Rega arm lift body but the actual arm lift 'finger' I made myself. I have couple of them. The one that is fitted in that photo has the up rise at one end to stop the arm swinging too far out. It is simply constructed out of two different thickness's of brass rod.