U47-style bodies - who can make one?

[CroatianSensation]

I will so buy 2 full body/psu kits when they are ready....man....I'm tellin' you.
I will.
Really.
(yup.)

 

[Skylar]

I'm ready for a mic body.

ME TOO!


Okay, here's the final hole config. for capsule mounts.
The two smaller holes are M2, 8mm apart (for Chinese mounts).
The larger center hole is M3 (for original-style mount).

This allows you to use either a chinese mount or a traditional U47-ish mount (like Thiersch's).


After some more thought, I think the capsule mount plate should definitely be acrylic.
The M7 mounts in the black market are ~43mm from bottom to capsule center, so you may have to shim up a bit (original spec is 45mm), and you won't want to use the acrylic spacer part in this case.
This kind of makes it necessary for the capsule mount disc to be acrylic.

If you want to use a mount more like the original:

then you'll want to use the acrylic spacer part.


The three outer holes on the capsule mounting plate are for running wires to the capsule.

 

[mad.ax]

Skylar,

I don't know if there are different type of acrylic, and which one did you planed to use...
If it is the same material that is used in the Flea bodies (and AFAIK in the original U47), then my experience is that this material is very weak, and "fragile"... You tighten a screw just a bit too much and it breaks!

So if the price difference is not too big I would consider using teflon. It's a pleasure to machine, almost unbreakable, and it have much better isolation properties than acrylic which would make it an improvment on the original design.

Axel

 

[craptical]

Beautiful work, Skylar! I´m in for two full kits! And I´m voting for the Neumann grey finnish (seen too many "sparkling" chinese mics...).


/Dave

 

[Emperor-TK]

I've used acrylic plates in mics exactly like Skylar drew.  I didn't have problems with cracking due to the thickness of the plate.  The thicker the acrylic, the less prone to cracking it is.  However, if the shim is a separate piece, that's a different story.

-Chris

 

[Skylar]

It seems that Teflon would be 5–10% more expensive than acrylic.

Polycarbonate (Lexan) is another option and would be 1–2% more than acrylic.

This seems pretty negligible to me.


So, we should probably shy away from the acrylic (even though that's what the original used).

Teflon is a translucent white.
PC is clear.

Any opinions?

 

[Jeremy.Starseed]

Considering where this piece will sit (inside the head of what will be my one of my most valued microphones) the idea of a fragile materials seems only matter of fact.

However, it seems the "Teufel"-on (devil in German), I believe a registered trademark of the remarkably un-cool brand DuPont...could actually be an improvement

As long as no slow-release chemical vapours are known to eminate from said material...

: joking...

 

[Martin B. Kantola]

Polyoxymethylene

 

[Jeremy.Starseed]

Teflon ® - Roy Plunkett By Mary Bellis

PTFE or polytetrafluoroethylene was discovered on April 6, 1938 by Dr. Roy Plunkett at the DuPont research laboratories.

Ok, no reason for alarm.

 

[FerrariT]

I do not think it matters.
lol whatever is easiest sourced I think should be the deciding factor.

Skylar are the places that are giving you qoutes, well have you given them the slightest idea of how many we are going to actually want?

 

[Skylar]

Skylar are the places that are giving you qoutes, well have you given them the slightest idea of how many we are going to actually want?

Yes, I've been having these quoted at 100 pieces.

 

[discobloud]

Amazing work.  I know they aren't ready, but I'm in for 2 body & psu kits when they are.

mark

 

[mad.ax]

Hello,
I have compiled some info from this website: www.boedeker.com
about the electrical properties of the possible materials:

PTFE Water Absorption, 24 hrs (%) < 0.01
(Teflon) Volume Resistivity (ohm-cm)at 50% RH > 10^18
Dielectric Strength (V/mil) short time, 1/8" thick 285

Polyethylene Water Absorption, 24 hrs (%) <0.01
Volume Resistivity (ohm-cm) at 50% RH 10^15
Dielectric Strength (V/mil) short time, 1/8" thick 460-700

Polycarbonate Water Absorption, 24 hrs (%) 0.12
(Lexan) Volume Resistivity (ohm-cm)at 50% RH 10^16
Dielectric Strength (V/mil) short time, 1/8" thick 390

Polyoxymethylene  Water Absorption, 24 hrs (%) 0.2
(Delrin) Volume Resistivity (ohm-cm) at 50% RH 10^15
Dielectric Strength (V/mil) short time, 1/8" thick 450

Acrylic Water Absorption, 24 hrs (%) 0.3
Volume Resistivity (ohm-cm) at 50% RH Missing
Dielectric Strength (V/mil) short time, 1/8" thick 400

edit: I found the volume resistivity for Acrylic: 10^14

While not an “electrical” parameter per se, the water absorption coef is utterly important in our application...

Axel

 

[synthi]

Looking at the tables I understand why teflon is used as a good insulator!

Synthi

 

[Skylar]

To me it seems that Polycarbonate is a good balance between Acrylic & Teflon.

 

[hitchcaster]

if theres a vote, id say go with teflon!

 

[Skylar]

Think I found a supplier for the body.

Still working with them on price, tooling expenses, shipping options, lead times, etc.
But we're getting closer.

I'm also getting quotes for the wire mesh and finishing.

I'll keep everyone updated as things progress.

 

[Jim50hertz]

Nice work once again Skylar

 

[Skylar]

Good news lads & lasses...

(any lasses here?)


Anyway, I'm ordering mic body prototypes this week.
In a couple of weeks, I'll have something to show!

 

[mitsos]

AWESOME!!