DIY Schroeder Tonearm?

Thanks Ron,

I like the sound a lot. This arm has a sure v15 type III. I like the sound of the Lenco with this arm and cartdridge better than my other clone in the SLQ2 with Dl103. The Dl103 is not modded though. Still sounds very good. I think the Lenco idler TT may have something to do with it. I am planning to mount the DL103 on the Lenco TT to see if there are differences.

Alfredo
 
I'm past the planning and drafting finally. ..............seems like 2 years now. Finally have some Brass and Aluminum shaving on my garage floor. I'll post some pics this weekend. Without a lathe it is difficult at best. I'll make 3 parts, throw 2 away. Takes much longer with only a drill press and belt sander............😱 Never give up! Never surrender!

Ron
 
Trzalica,
interesting name.....
But back to business so to speak, I'm sure that thread will be more than adequate for our purposes. The main thing is non-stretch and flexible. Both of those criteria are met with Kevlar. Plenty there to perfect your knot tying skills too! 😉
Let us know if we can help with anything else.
Show us some pictures of your progress too, we like pictures...

You may want to rethink the strength of your magnets thou. Maybe a little weak. I don't know for sure but most of us are using stronger / bigger ones. Mr Schroeder has suggested this too. It's all in this long thread. Long reading but well worth the effort of understanding.

Ron
 
In a different light / state of mind I have re-read the topic of pole pieces and now understand why they are important. Cool stuff here. I may have to pry out my lower magnet and rework the holder with some Iron in the base.

Anyone try with and with out the added pole pieces?
Any noticeable difference?

Opinions on using only one pole piece? Which one?
Conjecture welcome.

Ron
 
As promised, 'cause we all like pictures. Here's some of my modest attempt at this wonderful design by Mr. Schroeder.

Does anybody else's workbench end up looking like this when they are working on a project.....? Be honest now.
It does get cleaned up from time to time. 😉

Ron
 

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Headshell question

Mr. Davidson,
What is the width of the tonearm head which allows the cartridge carrier to swivel to an appropriate angle? ie 22*
I'm unsure just how wide to make it so I can reach my desired 22* offset. My cartridge bolts are the standard 1/2" apart.
Thanks,
Ron
 

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Mr. Davidson,
What is the width of the tonearm head which allows the cartridge carrier to swivel to an appropriate angle? ie 22*
I'm unsure just how wide to make it so I can reach my desired 22* offset. My cartridge bolts are the standard 1/2" apart.
Thanks,
Ron

Hi Renron,

From the photograph, it seems that you are using 2mm Hex Socket Head Cap Screws. Assuming a maximum head diameter of .1567", The width of your head shell should be a maximum of .3069". Depending upon the actual diameter of the heads of the screws in your possession, and the minus tolerance of your head shell, you could put shims between the screw heads and the head shell while tightening the central screw. The shims could be made from ordinary writing paper which is .004" thick.

Sincerely,

Ralf
 
Ralf,
Hey, that's my Dad's name!
The photo was of Mr. Davidson's tonearm, I'm still building mine....🙂

Thanks for your answer, but I'm not sure I asked the question correctly. The cartridge MUST be twisted 22* for MY tonearm design to function properly. I was inquiring what the width of the tonearm stub (center screw) is, because I need to have some space to twist the cartridge. Not so easy to describe. I may just file it down 'til it fits my needs.


Ron

damn, I darn near hogged this entire page! Oink!
 
Hello Renron,

Renron;2537870]Ralf,
Hey, that's my Dad's name!

With an "F" ?

Thanks for your answer, but I'm not sure I asked the question correctly.

I think you asked the question quite correctly.

I was inquiring what the width of the tonearm stub (center screw) is.

I would call that part the "head shell"

I am attaching two drawings to show what I am talking about.

As I understand your question, you want to rotate the cartridge mounting platform until the heads of the two cartridge mounting screws touch the Head shell and thus achieve a 22 degree offset at that location of the cartridge mounting platform.

My drawings show a head shell width of .3026" when the diameters of the screw heads are .1610". If the screw heads have a different diameter, then the width of the head shell would change. Knowing the diameters of the heads of the particular screws you are going to use, you can use trigonometry to figure out the width of the head shell. The center to center distance between the cartridge mounting screws remains constant at .500".

I cheated, I used my CAD program.

Sincerely,

Ralf
 

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Ralf,
With an "F"? Sadly, No.

I was wrong...........;( , after looking at the Tonearm Alignment Calculator again I see that using the Baerwald alignment I get a lower distortion with an offset angle of 23..016 (almost a whole number), which could be set pretty closely with an angle finder I have.

You are correct with your measurements, Mr. Mitutoyo says that the heads of my screws are .1610 in. diameter (standard size?) and the cartridge spacing is .500 in. .
Because I lack the proper (advanced engineering) tools, (save for Mr. Mitutoyo) I am forced into "making" things work with a file and sandpaper, which leaves much to be desired. I will make the "headshell" just under .300 in. which will give me a little fudge room if I need it. Shouldn't, but it can't hurt to have a little extra space. 23* is my desired offset angle for the 239mm effective length of my tonearm.

Thank you very much for those fantastic drawings. Just beautiful. Which CAD program is that? Just curious, I wouldn't know how to use it, but it sure looks awesome.

Thank you,
Ron