Project "Groove Scribe"- A DYI stereo 45/45 head.

[EpicenterBryan]

Having checked the filler powder material spec it contains calcium oxide.

Interesting!
Calcium oxide and water is the heat source for those self heating cans. I'm not sure if you have seen them. I bought a few filled with coffee at WalMart several few years ago just for the novelty factor. I have also see soup in those cans. Very wasteful packaging in my opinion.

070319ag04.gif

[EpicenterBryan]

Prototype progress...
Here is a prototype spacer and V spring. Also how it will fit in the head. Notice a groove for the FB wires on each side. The bottom will have a plate and 2 screws to tension the piano wire. The spacer will be attached with screws from the back of the head.

IMG_4584.JPG

The torque tube right now is shown as a solid bar but will be hollowed out where possible when final dimensions are made and the angle is calculated.

IMG_4579.JPG

That's it for tonight.

Bryan

[sakuszi]

it will be okay

[Ciuens]

Bryan, in my tests with torque tube, I noticed that the tube width directly affects the amplitude of the high frequencies.
Using an aluminum tube with 4mm diameter = 14kHz max. Using a torque tube brass with 2mm diameter = 20 kHz easy.

Ciuens.

[Snug Music]

And here is a graphic from the B. B. Bauer patent that shows the stylus and head angle combination well:

head angle shim.jpg

hey my friend Bryan, is that correct? The stylus is located, according to B. Bauer in the 90 degree position and the cutting head is inclined 20 degrees to the rear? Did I understand correctly now? Ingenious idea with the slope in the Torque !!!

Best regards...

Scotty

[Snug Music]

Bryan, in my tests with torque tube, I noticed that the tube width directly affects the amplitude of the high frequencies.
Using an aluminum tube with 4mm diameter = 14kHz max. Using a torque tube brass with 2mm diameter = 20 kHz easy.

Ciuens.

hey cius,
how come? If the material is dependent? Had notice also with my cutter head ... (had previously used carbon!) ... now brass rods that the heights are better transmitted. So I've heard it right! hehee ..

best regards

Scotty

[EpicenterBryan]

Bryan, in my tests with torque tube, I noticed that the tube width directly affects the amplitude of the high frequencies.

Hey Ciuens, can you post a picture of what your most recent Torque tube looks like?

I can understand HF loss due to mass, so if the tube is solid then a bigger diameter would weigh more especially is solid. My plan is to only have the tube solid where the stylus goes, and a small segment at the end where the set screw needs threads. The rest of it will be drilled out and become hollow.

aluminum tube with 4mm diameter = 14kHz max.

When you say "tube", was it solid or hollow?

Bryan

[EpicenterBryan]

The stylus is located, according to B. Bauer in the 90 degree position and the cutting head is inclined 20 degrees to the rear?

The stylus is 90 degrees to the disc. The head is angled 15 degrees, and the stylus is angled in the tube by 15 degrees. Really, either the stylus is bent 15 degrees and the hole is straight or the stylus is straight, and the hole is angled. That's what I was planning so I could use a standard stylus.

Bryan

[Ciuens]

IMG_5332.JPG

[Ciuens]

When you say "tube", was it solid or hollow?

Solid

[EpicenterBryan]

Ciuens, I see...
So you went with the tapered stylus and eliminated a lot of mass at the same time.

It probably makes sense for me to go that way and figure out how to do the taper.
I bought some used styli on E-bay the other day so I could measure them and try it out.

How did you attach the V-spring?

Bryan

[EpicenterBryan]

Holy crap!

I bought a batch of used Neumann 320 styli on E-bay last week. The hope was that one would be usable, but I could use bad ones to measure and mess with. These are totally different from anything I know! I only have stuff that uses Presto shank style styli. These things are insanely small and have ZERO mass! Here is the short end...

IMG_4597[1].JPG

Now that I look at a photo of an SX like below and knowing the thick part of the tapered shank is around 1.4mm, I can see the SX torque tube is also WAY smaller than I thought!

NeumanSX68_06.jpg

So from this photo and using the wide end of the stylus hole as a reference, I'm thinking the SX torque tube is something around 3mm wide, and the termination links to the tube are something like 0.5mm!

People in the know may not want to share details. I get that. For the rest of us - what do you guys think? Using about 1.4mm external hole size for the stylus, what size do you think the Tube diameter and connecting rod diamerters are?

Bryan

[sakuszi]

hi, I think that is the same diameter as for me, that is 3.5mm, if it would be less in diameter, the side walls burst as a result of vibration and temperature knife 120 -150 C . A screw that secures the knife having a thread 1, 8 mm, lower diameter of the thread broke off
westrex pipe min 6mm brass and beautifully recorded

[sakuszi]

Vestax cutter head vrx2000 min pipe dia 8,5 mm 12,5 kHz

[Ciuens]

Hello Bryan,
the rod I I'm using is 2mm in diameter. Size 25mm.
The spring is also made of brass. I used tin solder, worked well.

Ciuens

[juba bc]

Bryan, here you should find hollow tubes of various measures

[EpicenterBryan]

Hey guys,

I want to thank everyone for their inputs. I've got an update for you...

A machinist is working on a torque tube for me to go into Groove Scribe. I think it will be done and in my hands in less than 2 weeks.

It's like a Neumann SX tube - not an exact duplicate - but very similar. It will have the driver / push rod connections in front of the stylus, and will have a 7 degree angle on the stylus hole and the hole will be tapered to be able to use standard 1:20 taper Neumann 320 styli.

This is a major departure from the whole concept of a DIY head. However, now I realize details like Vertical Modulation Angle (VMA) and spring back angle of the material being cut are important things to think about. Since I only want to build this version one last time, I want to make sure I cover the bases.

The Neumann like torque tube and V-spring will be adapted to this existing Groove Scribe housing. If it works out, a similar tube and spring may be available for purchase (not from me but from the guy who is making them) if enough people are interested. As I've mentioned before - I'm not interested in making money from this project, this belongs to all the lathe trolls - everyone who has graciously contributed their time and ideas to help make it work better. But I also know that this damn torque tube and stylus mount is the down fall of most of our DIY projects! If a generic version could be made available at a reasonable price, I think more DIY projects can succeeded and the art continues.

So, I'm asking if people think they might be interested in buying a torque tube and V spring (not from me - but from the machinist) if this works out well, and if he decides it is worth his time to make a batch for sale? Please let me know via PM.

Now let me go over a few things... While the machinist is making the tube for me, I really wanted to see if I could make something myself, with what I have or what I have recently purchased. Over the last week I have tried a few things that seam to work well and I want to share some photos. Again, this kind of goes beyond a DIY project mainly because of the whole angle issue. But I know some of you guys can adapt this! You can do it!

But first, even with the gizmos I have and the procedures there is a final hurdle if you want to deviate from the normal Presto style styli and want to use the 320 Neumann styli. It involves a special metric tapered reamer and it costs a pile of cash! The Neumann 320 styli has what is called a 1:20 taper to it, and it's metric. For those who don't know (like I didn't know) in metric, when they specify a 1:20 taper, it means that it has a 1 mm change in diameter per 20 mm of length. So if you had a 1mm 1:20 tapered reamer, you could drill a 1mm pilot hole, then ream it out until the top diameter of the hole is 1.4mm and the 320 stylus should in theory fit.

cosmO_O sent me a link to an European site that has such a beast, and I'll pass it along (I'm sure he is OK with that):
https://www.phantom.eu/en-us/phantom-hss-e-taper-pin-reamer-taper-1-20-1-mm-518200100
That's around $192 USD! Ouch. And, I was not able to calculate shipping cost to the USA so I'm sure it's WAY over $200.

d1 min. 1 mm
d1 max 2 mm
Flute length 20 mm
Spiral angle Spiral angle 0°

Image.jpg

The machinist who is making the torque tube for me has recently purchased one (but has not arrived yet). This brings up the next question. He thinks he can make these special tapered reamers at a lower cost if enough people are interested. So again, if you have interest in this special tapered reamer, send me a PM and I'll pass it on to the machinist.

Now for some photos of my recent attempts at making a torque tube with 7 degree stylus hole and front driver connections.

Here is a diamond cutoff disc been used along with a rotary table and tilt table to cut a flat area at 7 degrees... and then drill a 1.2mm hole.

IMG_4631.JPG

IMG_4632.JPG

And then, cut the driver link grooves at -45 degrees, and +45 degrees. This was the first test... How far should the stylus really be from the front drive connections and all that? Some times you have to do it a few times to nail down the the numbers. After this, the things were tightened up like the real deal...

IMG_4633.JPG

Out of photo space, but you get the idea.... It's possible, but barley possible for DIY. Using the Neumann 320 Styli has lots of advantages like availability and such, but for a DIY guy, I'm not sure how to make it fit without a $200 reamer.

Comments?

Bryan

[Sillitoe]

Nice one Bryan!
I'm using the amazing Myshank 320P diamonds.

I also saw the price of those reamers from phantom and decided to first try a 1.2mm drill bit to make the stylus mounting hole.
With very slow and precise movement of the workpiece I was able to bore a very nice tapered hole the torque tube.

The 320s fit perfectly with no movement at all.

Great for preliminary experiments but I purchased the reamer after I found my head design to be successful.

Cheers
James

[EpicenterBryan]

With very slow and precise movement of the workpiece I was able to bore a very nice tapered hole the torque tube.

Hi James,
I'll give that a try. I'm also going to see if I can sand down a 2mm drill to get the right taper. I'm not expecting to be able to use it as a drill, but if it even slightly works as a reamer, I'll post some pictures.

[flozki]

i am willing to sell a (limited quantity ) set of original neumann sx74/SC99 torque tube with v-spring to experimenters.
so all angles are ok and the stylus bore is right to specs. this is the real part used in any SX68,74, SC99 and the last series of CARUSO heads.
made in switzerland on state of the art watchmaking machinery with highest precision and to original specs.

for non commercial use only. if you want to sell your heads with that torque tube please contact me.
price will be organized in a "cuban way". the more you buy. the more expensive. so more people have a chance to grab one.
that means:
1 set=CHF 106.- includes priority shipping and tracking number.
2 sets's =CHF 250.- includes priority shipping and tracking number.
3 sets's =CHF 450.- includes priority shipping and tracking number

the SET includes torque tube,insert with 0.5mm hole already glued and V-spring with original treatment
and a nice FLoKaSon post card of legendary cutting equipment.

i just sell. no additional support at all.
please only buy if you know what you buy.and why.
if you dont know what the use of this is.please dont buy !!!!
and dont send emails or ask anything how to build your head.
i dont have the time to help and answer.
and there is tons of infos here on the forum.

f.