DIY linear tonearm

[2A3SET]

Good to see lenco and TA here, this is my third lenco and linear tonearm.
Thinking about the LC mkiii now hopefully to beat the rs-lab.

[Mike56]

Originally Posted by 2A3SET

Good to see lenco and TA here, this is my third lenco and linear tonearm.
Thinking about the LC mkiii now hopefully to beat the rs-lab.

Great to see you on the thread and to see what you are doing.
We look forward to seeing more as you move on.
I would reach out to Carlo and see what feedback he gives you as well.
He has done so much work and development he has surely forgotten more than i know and can guide you if you tell him what youre aiming for.
My experience is short and limited but theres great feedback to be had and it gives you the opportunity to check things through carefully rather than rely on intuition or just one experience.

I am just starting on the Lenco and will try to do that like the arm, work rather than cost!

[Mike56]

Originally Posted by jw67

This is an excellent article which might help in choosing materials if you haven’t seen it already.
https://qualia.webs.com/plinthbuilding.htm

Interesting article and many thanks Jonathon for those various thoughts. i am going to read quite a lot before i start this one!

Originally Posted by jw67

My mindset was if you could build a very good deck for almost no money, is it possible to build a massively high performing deck with a relatively modest outlay in comparison with spending £10,000 upwards.

A very similar thought process to mine, but i am much more stingy than you!
Of course that doesnt mean it can be done, but i will have a go.
I hope to test out the theory/guesswork on here so look forward to your feedback!

Originally Posted by jw67

It’s all a journey and fun discovering. If you haven’t discovered it yet lenco heaven is a great resource, there is also a fb group which is extremely good.
Jonathan

I agree with that, great fun, even making mistakes as often as i do!
Mike

[jw67]

Originally Posted by 2A3SET

Good to see lenco and TA here, this is my third lenco and linear tonearm.
Thinking about the LC mkiii now hopefully to beat the rs-lab.

Looks great. Is that a Diy ptp type thing or a real one? Have you split the plinth? I’ve always been intrigued by that rs arm and never heard one. How does it sound in comparison with the linear one? Last question. What bearings do you use?

[2A3SET]

Originally Posted by jw67

Looks great. Is that a Diy ptp type thing or a real one? Have you split the plinth? I’ve always been intrigued by that rs arm and never heard one. How does it sound in comparison with the linear one? Last question. What bearings do you use?

That's a diy ptp on 4mm alu plate.
The motor is serviced, and on a separate island cut out from the main plinth.
RS-A1 is more organic and fluent even though can hardly get balanced.
I am using the SPH long bearing.

[jw67]

Thanks. If I were to build another one I’d do a Diy ptp as well.

Interesting re the arm. They are quite a rare thing.

Bw

[warrjon]

@jw67,

Bearings are a good point. My first LTA used 623's and found the arm miss tracked with the Stanton 881s, I made a lets call it a tyre from 316 stainless to increase the OD of the wheel to 19mm even though it added mass it stopped the miss tracking once I got the wiring sorted.

The larger the diameter of the wheel the lower the starting torque required to get the carriage moving.

Magnet wire works well I buy mine from RS Components as it not much more expensive than eBay.

I also like the way your LTA is mounted both sides which add stability. I measured the Pyrex rods and found them to vary in thickness and they were not concentric.

You can buy HSS or linear rails in 6mm these are far better than the glass and for the price IMO better than carbide. The carbide rods I bought were expensive and not straight.

[jw67]

Very interesting about the bearings. I think earlier in the thread niffy had mentioned inside 3mm outside 10mm and a width of 4mm. I am going to order some of those but I was worried about the width with the 2 6mm rods. A company sent me some 5mm width ones by mistake and they had nowhere near enough the right vertical movement, maybe 4mm is ok.

I spoke to a company that produced quartz glass rods yesterday . The MD asked me to call him as he was interested in the project and talked me through the different types of glass...none are round and all have a deviation(maybe not synthetic quartz but prohibitively expensive) The only way to get it completely straight is to grind it but then you have to flame glaze it to get it smooth and then you’re back to not straight. He picked me out 4 rods with a 0.2mm deviation and sent them free. I’ll see how they go but they feel a lot better than the current rods.

I haven’t come across hss linear rails, I’ll definitely look into that thanks. I had thought of carbide but your experience rules that one out.

The magnet wire came today, it is thin. They apparently sell it to audio companies to make transformers, chokes, speakers etc. 99.99 we shall see. It looks like the right thickness though and it sounds like the quality is ok. What a cheap way to get Tonearm wire..bargain.

[warrjon]

Linear rail - I bough these to try them, they have not arrived yet but they do spec for straightness.

Dia 4mm-22mm Cylinder Rail Linear Shaft Smooth Rod Optical Axis Various Lengths | eBay

6mm rail with 4mm wide bearings are correct according to Niffy's research. This is what I used for my first rail. Current rail uses pin bearings 4mm carbide rods and 2mm wheels.

[Mike56]

Originally Posted by jw67

The magnet wire came today, it is thin. They apparently sell it to audio companies to make transformers, chokes, speakers etc. 99.99 we shall see. It looks like the right thickness though and it sounds like the quality is ok. What a cheap way to get Tonearm wire..bargain.

Did you find niffy's "instructions" ok?
I solder it around 400c to make sur that the enamel burns off at the joint, i soldered up one set at 370 and got no connection, very disappointing .............