U47-style bodies - who can make one?

[Skylar]

That's EXACTLY what I needed, Dave!

I thank you again!

 

[FerrariT]

From those pictures it looks to me as if the sidebar is soldered to the mesh first and then it is soldered to the lower ring.

just my .02

 

[craptical]

That occurred to me too.

EDIT: However the FLEA website shows rings and bars mounted, without the mesh...

 

[Skylar]

That makes three of us.

By the way, Dave, you take great photos!

 

[craptical]

Thank you, Sir!

 

[Skylar]

That FLEA picture has always puzzled me.

The top mesh in this picture are pre-mounted to the top rings.

Yet, we also see assemblies in the back without top mesh but WITH the top rings.

They obviously don't do double top rings, so what's going on?

????

Two different construction methods?

 

[Skylar]

Maybe they place the top mesh in the top rings to help form the mesh or to inspect the fit of each mesh piece.
Then they remove the mesh when they're ready to construct the main portion of the grille.
After all, you probably have to have the top mesh removed to get in there and solder.

Just a theory.

 

[seavote]

"you probably have to have the top mesh removed to get in there and solder."
how does this sound?  shape and fit top mesh and lower mesh (single circular piece)in the fully constructed(except for mesh) headbasket. remove top mesh and solder lower mesh against the side rails.
glue top mesh into the dado in the top rail with conductive paste?
if this is obvious  and/or  mentioned already  please ignore.
i liked the idea of the extra dado for the mesh in the bottom rail as is allows for a simple continuous circle shape for the bottom mesh. but the photos seem to show no such dado.

 

[mad.ax]

Thanks Dave for those pics and measurements.
This confirm that the upper ring  diameter is 1 millimeter smaller than the lower one.
On some of your pics, one can see some kind of recess machined on the lower ring, where the vertical rail is soldered.
I made one drawing (left) to illustrate the original mounting scheme as I understand it, and another one (right) to show what I propose. I hope it makes sense.

I didn't see any kind of rabbet on the Flea process pics, (which prove nothing), but there's definitely one on the U87 video...
About the Flea pic showing 9 head baskets and 18 upper rings, my guess is that there's only one upper ring. But for the picture, the grill dome just look prettier with a ring!

Obviously, Flea use steel meshes.... In the video, we can see that, at least for U87, Neumann use brass meshes. So the question is: steel or brass?
Can somebody perform a quick magnet test on an original U47 headbasket?

Axel

 

[Skylar]

Axel,

I think your proposal (right diagram) is the most elegant/foolproof solution.
The cost may be a little extra, but I think the ease of construction would make up for that.

I think brass mesh would be easier to deal with, though more expensive (same story as above).


Also, we might as well start getting opinions on whether we prefer the shiny nickel-plated headbasket or the matte headbasket.
So which is it?

I prefer shiny!

 

[craptical]

It´s actually hard to see in the pictures but the lower joint actually looks very much like the upper. I chose to show the (most) misaligned joints to make it more obvious that the side bar simply stands on the lower ring like this (sorry for sloppy edit.. ). (The side bars are also @ about ø61.5mm, .25mm diff to top ring, which is 1.25 mm thick, not illustrated in my edit!):

I didn´t see any signs of a rabbet while doing my take-a-part, just lots of solder:

 

[Skylar]

Oh, and before I can commit Axel's design, I am going to have to get mesh samples to determine the exact width of the 3 layers.

This means that we need to quickly decide what mesh material & what combination of mesh we're going to use.

For each of the three layers, we need to know:

1. wire diameter
2. width of openings (or mesh per inch)
3. % open space (not necessary but nice to have)

I know there are a lot of posts on this topic, so I'm going to look back at these and compile my findings.

 

[craptical]

Best pic I have, IIRC outer mesh wire is .6 mm:

 

[Igor]

Where is the ordering thread for these beauties??????

 

[Skylar]

Not quite there yet Igor, hang tight!

 

[klaus2you]

I'll be in for 1 when the order thread start!

 

[Skylar]

MESH

Here's what I've found based on ratio deduction from Dave's wire mesh photo & measurements:

outer mesh:
wire diameter = 0.023" (0.6mm)
mesh per inch = 9x9

middle mesh:
wire diameter = 0.005" (0.125mm)
mesh per inch = 42x42

inner mesh (this may be identical to outer mesh):
wire diameter = 0.020" (0.5mm) maybe 0.023" (0.6mm)
mesh per inch = 9x9 maybe 10x10


Closest McMaster-Carr equivalents:
outer = 85385T702
middle = 85385T92
inner = 85385T702 or 9238T524

All stainless steel

Do we know yet if the original grille mesh is brass or stainless or ?

 

[Skylar]

I'm guessing the original mesh is brass, due to the soldering.

We know the U87 mesh is brass.

 

[craptical]

IIRC I found the inner mesh to be .5mm. I´ll bring a magnet to the studio tomorrow! ;D

/Dave

 

[craptical]

The matte, however, is not!