U47-style bodies - who can make one?

[bradb]

Just so that no one starts lining up now, we'll make a NEW thread when it gets to that point.  Keep watching and hang tight.

DO NOT start lining up now!  we'll keep this thread for the technical discussions.

Thanks Skylar!

 

[Skylar]

Thanks Brad!

Yes, NO LINING UP at the moment!

 

[maxwall]

I 've been eye balling this thread from the beginning and I like the progress so far

keep up the good work !!!

 

[FerrariT]

Skylar how much more work are you going to do to the design before you start getting price qoutes?

 

[Skylar]

I'm already sending out for quotes.

Here's my most up-to-date design.
The headbasket on this one follows the original measurements, as discussed in this thread, to the letter.
It is two rings of lathed brass with vertical brass support rails.

The capsule-mounting disc is aluminum with several holes to accommodate varying configurations.

The body is aluminum tube.

Inner rails are steel.

The end-cap is lathed aluminum with a threaded post, which will mate with a sealcon connector.
A male 7-pin M23 sealcon insert will fit in the post. The full details of how the insert will secure into the
end-cap are TBD, though, as I wait for samples (CAD drawings on website are not accurate).
I also may go with a binder connector in a similar configuration if that will work better.

 

[FerrariT]

for lack of a better phrase, and pardon me to any one who might take offense but: THAT SHIT IS HOT!!! lol [beauty]

 

[Whoops]

Amazing Work,
I'm sure a lot of people will fight for this!!!!!!!!!!!!!11

 

[t-wurst]

Very nice!
Looks a bit like my prototype i did years ago. But till now i didnt find somebody who machine me the hole thing. Its made out of an old stand for Clothes  ;D
Go for it! 

 

[mad.ax]

Great job Skylar!
I'm affraid the headbasket design still needs some modification though...
The vertical brass support rails have a thickness, and in your design, they are mounted inside the ring.
So, if the internal ring diameter is, say 60mm., and the thickness of the vertical brass support rails is, say 1mm., that leaves us with a 58mm. useful diameter for the grill, and a 1mm. gap between said grill and ring...

I guess the original vertical brass support rails are thinner than 1mm, but still, they shouldn't cause a gap. Perhaps the solution is to provide some cutout in the ring in order to solder the vertical rails IN the thickness of the ring rather than inside them... I Know, that would mean some milling which cannot be done on the lathe...

Axel

 

[synthi]

Awesome!!!

Synthi

 

[Lee]

A thing of Beauty Skylar -  nicely done. This thing may actually become a reality. Thanks for all your efforts.....Lee.

 

[bradb]

Great job Skylar!
I'm affraid the headbasket design still needs some modification though...
The vertical brass support rails have a thickness, and in your design, they are mounted inside the ring.
So, if the internal ring diameter is, say 60mm., and the thickness of the vertical brass support rails is, say 1mm., that leaves us with a 58mm. useful diameter for the grill, and a 1mm. gap between said grill and ring...

I guess the original vertical brass support rails are thinner than 1mm, but still, they shouldn't cause a gap. Perhaps the solution is to provide some cutout in the ring in order to solder the vertical rails IN the thickness of the ring rather than inside them... I Know, that would mean some milling which cannot be done on the lathe...

Axel

Axel,

good observation.  There is going to have to be at least one seam in the vertical grill screen, so why not make the vertical screens in 2 pieces with vertical edges that have a little bend in them to mate with these vertical supports.  Basically the screen will mate with the vertical rails to create a relatively smooth looking screen-to-vertical support surface. 

its good to think ahead about these next steps..


awesome work skylar!

 

[0dbfs]

These appear to have slightly different headbaskets:

Some appear to have he vertical basket/grill support rails flush with the inside of the ring while others do not:

 

[mad.ax]

Bradb,

the screen is already made of 3 different thickness layers of meshes, which makes it difficult enough to manipulate. If you try to bend them before soldering, they will likely never match, and if you solder them before, the solder joint will make them impossible to bend, or it will break...

An added problem with your solution would be the thickness of the bend inside the headbasket, which may cause un-desirable reflections and change the sonic characteristics.

I think we'd better stay with a circular grill, which is easier to manufacture, and is likely to show the most accurate acoustical properties.

0dbfs,

I agree with you... I have looked closely at many headbasket pics, and there are a lot of difference. My guess is that it's due to the manual soldering...  Most seems to have the vertical rails on the same level than the upper ring, while it look to be inside the lower one... Maybe something like my upper drawing....
My bottom drawing is the solution I propose. It would add two milling operations on the lower ring.

I wonder if the upper and lower ring are the same diameter? Did somebody actually measured this?
Looks like the upper one is slightly smaller...

Axel

 

[craptical]

Judging from what can be seen in terms of flatness of mesh etc. on the inside, I´d go for the bottom drawing to be the real deal. If the upper drawing is correct, there has to be a corresponding cut-out in the outer mesh layer. My guess is also that the inner diameter of upper and lower ring is the same (the inside looks like a perfect cylinder to me), while the outer (obviously) is not.

Best,

/Dave

 

[Skylar]

Through the course of my research, I have acquired several hundred U47 pictures.

There are images that would indicate the vertical rails are tucked into the lower ring (the mesh actually looks somewhat bent around the rails).

There are images that would indicate the vertical rails are flush with the lower ring.


The thickness of these rails should be somewhere between 0.5mm and 1mm.
I've spec'd mine for either 0.75mm or 1/32"
Does anyone have a definite measurement for this thickness.

AND

Those of you lucky enough to have a U47 or access, can we get some high-res photos of these vertical rails and how they attach to the top and bottom rings of the headbasket?
Or can we at least get a professional opinion based on examination.


My research also shows that there is likely no recess cut into the lower ring to allow for flush mounting of the vertical rails, BUT this might be an option to explore, as it would definitely make the build more consistent/easier.


As the design is now, there may or may not be build problems...my plan was to get protos, see how it went, and adjust from there if needed.

I leaning towards revising the design further to include recesses (mad.ax style), and asking my suppliers to update their quotes.


SO, if we can get some good pictures or info on this issue, we'll be one step closer.
Thanks to EVERYONE for their help and support on this. I appreciate you all!

 

[craptical]

My above post is based upon examination, don´t know how professional though ;D

There are images that would indicate the vertical rails are tucked into the lower ring (the mesh actually looks somewhat bent around the rails).

There are images that would indicate the vertical rails are flush with the lower ring.

On the inside of the one I looked into, there are no signs of the mesh being bent. I´ll try and take some more pics if you like.

/Dave

 

[mad.ax]

I don't know if there was anything like this in the original design or not, but I think it might help to have some kind of rabbet machined in the rings to help keeping the mesh in place.
I guess some prototyping is needed here in order to determine the size of the rabbet, and how to assemble and solder the 3 layer mesh.
It may be better to solder the vertical rails to the grill to avoid possible vibrations.

Axel

 

[craptical]

Full album, hi-res:

http://twin-x.com/groupdiy/thumbnails.php?album=316

As far as I can see, there´s actually no overlap at all where the side bars meets the rings. I tried to take as revealing pics as possible, but it´s still harder to see in 2D than in real life. Details:

Some measurements:

Chrome top:

Side bar: 45x6.75x1mm
Top ring: ø61.75, width 4.5mm
Bottom ring: ø63, width 17mm
(Body length: 136 mm)

Matte:

Side bar: Same as above
Top ring: ø62, width 4.5mm
Bottom ring: ø63, width 18mm
(Body length: 135 mm)

Side bar looks to be 1 mm thick, and also has a slight radius.

I´m in for two, by the way ;D

/Dave

 

[Jeremy.Starseed]

I am definitely in for one, this is a serious effort.