My Uni-Protractor arrived today....setup photos included

After many months of waiting and some shipping snafus, I finally recevied my Uni-Protractor today for cartridge setup today.

As this is a precision made product from Germany, the quality of the construction are excellent, with one caveat I will touch on later.

The materials are well-packed in plenty of foam with custom cutouts. Assembing the protractor fairly straightforward, with the instructions being reasonably good, but not superb. The vernier adjustment for each protractor template (e.g. each geometry or arm) is way cool, and allows very precise geometry adjustment per the needs of each protractor.

I ordered one SME V protractor, and a DIN and IEC protractor for both Baerwald and Stevenson, for a total of five protractors. The protractors are made of mirror backed acrylic, with laser etched alignment lines which are made with excellent precision with respect to the parallel and perpindicular lines. The acrylic arm that sets offset comes with a pointed tip pin, or a rounded tip pin with two reticles, one black and one white, to be used depending on the color of your arm.

Below are some pix of protractor and it's setup:
The protractor plate, arm template, and spindle plug. Each plug inserts into the arm template, but has slightly different spindle I.D. to ensure a snug fit with your spindle. This ensures precision geometry with respect to the positioning of the template.



The vernier adjuster that optimally positions the template for a specific arm or geometry.


The assembled protractor with the spindle to pivot arm and reticle.


Closeup of the reticle and arm:


As the SME has a peaked, triangular shaped bridge over the pivot point and makes it difficult to keep the adjustment arm perfectly centered over this pointed "roof", I removed it and decided to use the pointed alignment pin:


The screw here is directly over the pivot point of the arm.

Here is the pointed pivot pin being aligned with the pivot point; apologies for the motion blur, the shutter speed was low, but you get the idea. I had to spend a while ensuring the pointed tip was perfectly centered, which it is not in this pic:


And here is the final setup, which the arm/cart in position on the template, the magnifying glass in place to check the position of the stylus on the template:


The one caveat I have is the that templates are made from acrylic, and in the process of moving the stylus around on the template to get it to fit perfectly into the very small indentation that represents the perfect alignment and position of the stylus in the template, the diamond stylus scratches up the template a bit, which might make it hard to ensure that the desired stylus indentation stays perfectly intact, or that your stylus does not get caught in the template that might have a scracth on it.

I will post impressions as I get some listening in on it with this setup.

 

I like the protractor design but don't like the acrylic. (seems flimsy on the distance arm and as you say, scratches on the surface for zenith angle adjustment)... Too bad all parts weren't like dr feickert (anodized machine aluminum alloy).

 

What cart is that?

 

Koetsu Urushi Vermilion.

 

Nice

 

Actually, it's key that the template is mirrored....and that you can see the reflection of the etched lines in the mirror. This ensures you view the cantilever from perfectly straight on when checking that the cantilever is straight with respect to it's reference "north" line. If all parts were aluminum, you would not be able to view a reflection of the etched lines and minimize viewing the cantilever with virtually no parallax error. I believe the Wally tractor used a mirrored protractor for the same reason. The ideal material for the template would be etched and silvered glass, much like than on a hemacytometer.

Having worked with the protractor more today, I've figured out a way to get the stylus in the template stylus pit very quickly with only a bare minimum of movement; by using the loupe to move the stylus into the stylus pit. This should minimize the risk of scratches.

See my post below.

 

So, gang, I've been playing with the UNI protractor a bit more and have figured out how better to use it. The magnifying loupe and mirrored template work really well together.

Here is a pic showing the correct configuration of the loupe lens and view frame for my table:



One thing I figured out today is that it is best to set the focus of the loupe lens on the template etched lines without the arm over the template first. You do this by looking through the frame and tilting the loupe forward or back until the stylus pit and the etched lines snap into focus. Ideally, you will be able to have the stylus pit and the single line that is "north" (in front) of and in line with the stylus pit both in focus. Behind the stylus pit and to either side are another series of etched lines. One function of these is to ensure that you view the cantilever perfectly straight on (no parallax error). Because there is a mirrored reflection of these etched lines, you can ensure that there is no parallax error when viewing the cantilever from perfectly straight on from the front because if you view the canti/cartridge from any other position than perfectly in front, the reflected etched lines on the sides will have their mirror images shifted to one side or another. Very well thought out.

Shown here is a view of the loupe set up, but as the camera has trouble focusing it's lens through another lens some distance away, the cartidge appears out of focus. You can sort of make out the series of etched lines, though.



Once the cartridge is put into place on template and the stylus rests in the stylus pit, you can check very easily to see if the cantilever is pefectly in line with the "north" line. The etched lines to the sides ensure you're viewing the canti from dead straight on. If the north line is in alignment with the cantilever, you're good to go as your offset is perfect as is your horizontal alignment (HTA).

Here's a pic showing as best I can the cartridge in focus through the lens. This is not exactly what your eye sees, but it gives you an idea. What you see with your eye is much clearer and you can clearly see if the canti is in alignment with the north reference line.



Something that I learned from this with respect to SME arms is is that if you get the offset precisely dead-on using the Uni-protractor, the HTA (cantilever alignment) is also perfectly on.

This speaks volumes to the precision of SME arms.

 

Excellent post, Puma Cat.

This is basically the same approach I took with Fieckert protractor. The only thing I would add is make sure you have plenty of lighting around the table when aligning the stylus/cantilever. I ended up using an adjustable miner's light(like this one) to enhance my visual accuracy.

 

I forgot to mention that the Uni-Protractor kit comes with a portable, battery-powered little LED gooseneck desk lamp for providing plenty of light.

I find doing it in a brightly lit room during the daytime works very well, too. The mirrored surface of the template itself provides plenty of light. Much more than a metal template would, of course.

 

Nice protractor, what's the price on this?

 

It was on special at Audiogon when I bought it in March for $650; it is now $750. Somewhat expensive, but if you saw the level of custom and precision machining and manufacturing with respect to the kit components, it's not completely unreasonable. It's like a protractor SME would make if they made one. Nice thing is that you could use it with any TT as the mfr can make optimal, custom templates for your tonearm.

If you have a $4600 cart, it's worth it to do all you can to get it dialed in as best you can, and I can safely say my Urushi Vermilion has never sounded better.

 

Cool, thanks

 

Very cool Puma. Looks like a precision made tool.

 

What can I say? It's German. They just can't bring themselves not do things right...the vernier adjuster is like something off a Zeiss oil immersion phase contrast microscope.

 

Nice product.

Anybody have an idea of what they call that type of lupe / magnafier ?

 

I don't know what type of lupe it is, but the lens is excellent. I just used it as a magnifier lupe for checking the angle of the stylus in the groove, and it is really nice for that.

 

Thanks for all the details Puma Cat. I see what you mean about the need for the mirror on the alignment etchings.

 

Those are usually known as linen tester or linen magnifier. Originally for counting threads in cloth, but used for all sorts of flat things.

 

That is it, found it originally on vinyl asylum, could not remember tje name. I wanted one but forgot. They are avaiable all over on line.