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DIY tonearm

Joe

Joe

pfm Member
I am gathering information with a view to making my own tonearm.

Does any one have any links to useful website with the maths and the science involved? ( particularly 12" arms )

I won't be building one out of a bamboo garden stake and old VCR parts so I don't need those links to things that homemade . ( I have seen most of them already )

But... I would like to attempt a really posh effort. So . Anyone got any helpful links you would share?

Many thanks in advance.
 
h.g. said:
A linear tracking or a more conventional effort?
Click to expand...

Simon ( SQ on here ) fancies a linear tracker , I can agree to the more perfect science of them but I just don't think that I want to live with the look of one. So I will watch Si build his.

So , for me , a conventional arm probably.

Links to the Naim Aro clone would be handy.
 
Enjoy the process of designing and building your arm, you may find it difficult to get the quality you are looking for.

My father tried to build a cassette recorder. He found that while he was a good model engineer his engineering was not fine enough to build something as good as a basic commercial deck.
 
There was someone used arrow shafts quite successfully to make a tonearm I think. Carbon wrapped aluminium tube was a pretty top spec but affordable option I believe.
 
From a precision POV a unipivot is the easiest to get right. Overhang, offset and PTS are easy to work out, just pick an effective length in mm and we can start. In fact just copy the geometry if my 12" Stabi.
 
Pete MB&D said:
I fancy making a Well tempered style arm.

Pete
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A fellow customer of my local hifi store lately told me the thread on his Well Tempered tore apart & his Lyra Atlas took a nose-dive..
I had never envisioned this or even thought of it..but since he told me I feel quite uncomfortable about the idea of
the value of an expensive MC hanging on just a thread.
 
I had the idea of trying an arm myself yesterday too, coincidently.
A different approach though...my idea was with a big emphasis on 'trying' w/o expecting I will really build a good arm.

The way I came to that was I was tempted to try an elderly quite good cart, but the arms in fashion now won't suit such carts too well from compliance, mostly.
Well not the arms I would like to try...and to buy a really expensive arm just to run a cart in it that doesn't run near optimum from compliance point of view means that part of the arm's cost is kind of wasted not suiting the cart really perfectly..so my guess.
The whole thing started off with resonance-testing records for carts, the idea of the elderly but obviously good MC I had in mind
and then try with quite a simple self made unipivot to get some arm together to match the compliance of that cart more or less spot on
via test-record and software.

No expecting to build a great arm in first instance..just to get one build that matches this cart perfectly from the compliance point of view.
Then check if the arm is any good at all, compare it putting the cart into a good arm that will suit it's compliance quite not so well.
Either my selfmade approach is a total looser then despite perfect compliance match, then I will stop at that point.
(not having invested much time into it really)
...or my arm is doing somewhat that far ok that it seems worth try refining it a bit or think further in that direction.

So, as a thought for a start, I would start with the choice of an MC system and try to make an arm that suits the compliance of that MC perfectly.
If your choice is a modern MC system, your proffessional present competition, also s/h will be rather tough, obviously..

The base-idea of my aproach is to have the arm-cart compliance spot-on on my side
and hope to compensate a certain part of my not-really-existant competence to build a good arm.
In other words I don't think I can match any professional arm-maker, but am curious about how far or close I will be able to place my throw..

In short: Fix your choice to a specific system and compliance and I'm sure you will have a bit of a head-start with your arm.
I do like the idea !
I'll do a 12"..if it sounds shit, at least it will look impressive.. :p
Uni..like Simon said, I can't imagine making a cardanic on my own in my more or less just-for-fun approach..
 
torstoi said:
A fellow customer of my local hifi store lately told me the thread on his Well Tempered tore apart & his Lyra Atlas took a nose-dive..
I had never envisioned this or even thought of it..but since he told me I feel quite uncomfortable about the idea of
the value of an expensive MC hanging on just a thread.
Click to expand...

I bet more have succumbed to the yellow duster!

Pete
 
..that's well true, as well as the statistical likeliness of such happening to two customers of a small hifi shop is near zero,
but...the thought..is the prob.
If I make a mistake, at least I know who's to blame.

The only cart I ever destroyed was the Shure in my dad's Braun Atelier at age of 5.
I was aiming at a 1 meter round straw-target from 4 meter distance with bow and arrow.
Due utterly clumsy mishandling the arrow flew off 90° to the right of me into my dad's deck.
And I hit the cart precisely from a 4,5 meter distance.

Despite my admirable precision I was never gratulated for that.. :)
 
Pete MB&D said:
I fancy making a Well tempered style arm.

Pete
Click to expand...
I am pretty sure that the two string dangled arm in bucket of oil was first proposed in a DIY article in HFNRR or maybe Wireless World many, many years ago. Long before the Well Tempered appeared. I was quite tempted at the time, but didn't have a suitable deck, so it could have been 1981/2 when I had my Rega 3.
 
torstoi said:
https://calvins-audio-page.jimdo.com/projects/vinyl/thekiller-12-tonearm/

This is a nice read I had yesterday..it's a cardanic though..and if I were to start with a cardanic, I would probably start with some existing design like him and keep the base and bearing assembly & add my own preferences of design around it.

Not sure that's what you wanna do, but it's an interesting read anyway.
Click to expand...

Thats a pretty good effort; though , for all the work put in I would maybe have chosen a better donor bearing ( unlessI have misunderstood the quality of it )

I have thought about just lengthening an Audiomods arm into a 12 incher. Simple enough to do and his latest ceramic bearings are very good.

You could either chop the arm off at the bearings ( almost ) and add your own arm wand or chop it off at the headshell end and add a few centimetres more aluminium tube to it. With careful machining you could do a seamless finish. High quality !2 inch arm for a couple of hundred pounds.
 
Here's the 12" Kuzma specs

Effective length: 304.8mm
Mounting distance: 291mm
Offset angle: 17.8 degrees
Effective mass; 13g
Pivot height: Platter level.
 
Joe said:
You could either chop the arm off at the bearings ( almost ) and add your own arm wand or chop it off at the headshell end and add a few centimetres more aluminium tube to it. With careful machining you could do a seamless finish. High quality !2 inch arm for a couple of hundred pounds.
Click to expand...

I'd make that decision rgrdg keeping or changing the wand dependend on your desired cartridge
bc I think the kind of tube gives you a lot of mass + energy-transfer +damping options,
I think if I started making one I wouldn't miss out using this opportunity.

In any case I'd make the tube from one piece w/o interruption within the tube itself,
from what I read the uninterupted energy transfer from the cart to the TA base is a significant factor for better arms.
You'll have a little compromise in the two points headshell-tube and tube-bearing assembly, but I wouldn't make it more than that voluntarily.
In the headshell there's the possibility of gluing and better energy transfer vs. movable with azimuth adjustment chance.
I think I'd try a mechanical fixture as good as any possible but take the chance on azimuth tuning here. (in a cardanic, in an uni I can do it tilting the entire arm by a few degree)
 
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