Tonearm woes

[Fran]

A few aul pics to keep yis going....


It all has to come off the table again to do the fixes....



Fran

[barry robin]

seriously purdy!!! hard to admit, but there's that WAF part of me that says who the f**k cares if'n it works-it looks great and accessorises nicely with my audio furniture...

i bet Sues likes it though.

-b

[bod]

Hi Fran. Glad the protractor helped. `Tis a great job on the arm. Lookin`sweet!

[Fran]

Barry: ah, it might look OK, but very frustrating when you want to actually listen to somethign and it doesn't work!!

BOD: I went and bought one after using yours. Well worth it, but you do have ot get over the sticker shock! Its a different version to yours too.

So, its hard to believe this, right. But the resonances created by the needle on the test track are being excited by the set up so that the top plate - yes, that 6mm thick alu top plate - is vibrating. Put your finger on it and its vibrating. Hard to believe that the tiny cantilever is doing that!!

Its not motor etc etc coming up through the arm, its the actual stylus.

I think thats amazing!

Frustrating too! But it shows how careful you need to be in designing something like this. I know Frank Schroeder obviously has a background in engineering or something, but without his help, I would be completely stuck and may well give up on it.

Fran

[Fran]

I did a few experiments with this last night - and while the faults have improved, its still not right. In short I think I have 2 main problems. It seems the magnets are on the small side, and then the alignment of the magnets in my implementation is not accurate enough. Actually theres a third one too -the counterweight is hung to low, but thats an easy fix.

So what I'm thinking is that I might order different magnets from ebay, and then make a new armwand for it. More work I know, but might as well at this stage!


Fran

[barry robin]

[quote="Fran"]It seems the magnets are on the small side, and...not accurate enough. the counterweight is hung to low.
... and then make a new armwand for it. /quote]


Ay Ay Ay!!! sorry about that. i'll keep my fingers crossed for you.

-b

[cybot]

It seems the magnets are on the small side, and...not accurate enough. the counterweight is hung to low.
... and then make a new armwand for it. /quote]


Ay Ay Ay!!! sorry about that. i'll keep my fingers crossed for you.

-b

We all will :-)

[Fran]

I bought some new magnets last night - these ones are a bit bigger and a bit stronger. I also did a lot of reading around and have a few more refinements to implement.

So its back to the machining again once this stuff comes in!

Fran

[bod]

Legend! Can you build me a Kuzma Airline while you`re at it :-)

[Fran]

Give me the nu-aire bearing (~600€) and I'll have a good stab at it!! I did build an air bearing linear tracker - and have it in daily use. To be honest its my reference and would be hard to beat.

In fact I had this conversation with jkeny last week. It was along the lines of "why are you bothering with the pivot arm - the linear is so good"... and so on. And it is pretty good. It took a bit of tricking about to get the air supply right, but I'm happy with that now.

There is certainly a cleanliness and purity to the sound with a linear tracker. If this schroeder can compete near it, I will be happy indeed.

Fran