U47-style bodies - who can make one?

[bobine]

Great ideas for refining the fit.  I found similar issues.

The length of the side rails is critical. When I bent the tops of the rails to a proper 90 degrees, the overall length was a bit too short and the top plate was not contacting the flange in the head basket. I added thin washers between the rails and the top plate, which fixed that problem but left the bell end not fitting well. I may try grinding the tops of the rails flat. I also thought of making a gasket to seat the top plate into the head more securely.

I ground a slight radius onto the bottom rails so they contact the curved bottom bell better.

There actually does seem to be a sweet spot where the screw holes line up and the top and bottom parts fit well, but it takes some tweaking to get there.

 

[tommypiper]

Skylar, thanks for your transparency and helping us through.  I know you must be frustrated with some of these issues too.

To help us all out, here's a few questions.  Skylar if you could answer that would be great, thanks.

1 - What are the threads and sizing of the screws?  We may need to replace them, or rethread to the next size up in some cases, particularly the bottom screw.

2 - Are the replacement screws you sent stainless steel?  Do you have McMaster-Carr or other part numbers for the large and the small screws?

3 - What about the internal screws?  Do you have their sizing, just in case we need to replace them.  (I looked at your datasheet, none of this is in there.)

4 - Are you sure the plastic plate will work for the capsule mounts?  Are the little black pins meant to replace the screws?  A little more info would help... thanks.

5 - Another concern is the Binder connector.  Have you confirmed that the pins seat deeply into the female connector?

6 - The headbaskets don't mount very square and often have a tilt... any further suggestions? 

7 - As UBXF mentioned, the Binder threads seem a bit thin and.... fragile.  How strong is the end cap metal?  Any concern about this wearing?

Thanks.

Thanks to everyone for working on these issues.

 

[Skylar]

1) All screws and threads are metric.

The single, small bottom screw that holds the body tube in place is M2
The 3 headbasket screws are M3
[internal] The 4 bottom rail screws are M3
[internal] The 2 screws that fasten the rails and top circular plate together are M3
[internal] The 2 small, black set screws that hold the clear capsule plate in place are M2

The manual is a good reference for assembly instructions:
http://equinoxsystems.net/wp-content/uploads/manuals/EQMBU47/EQU47%20Manual%20Rev%20B.pdf

2) The 3 oval M3 screws packed in every order are stainless steel. The M2 set screws are black-oxide-coated alloy steel

If you wanted to replace every screw, here's a McMaster shopping list (quantities are per mic body):
3 x 90258A178
2 x 91390A002
2 x 91800A116
1 x 91430A052
4 x 91430A116

3) answered above

4) Yes, the clear plastic plate will work for either the typical Chinese capsule mount or the Thiersch capsule mount.
Yes, the black set screws are for securing the plastic plate in place if you're using a Thiersch mount. If using the Chinese mounts, you can use the black set screws, the screws that were pre-fastened to the EQU47 capsule plate, or the screws that came with your capsule mount. In either case, screw them in from the bottom. See the manual and the images below for more info.
   

5) Yes, the Binder connector works perfectly. Don't worry about it.

6) If your headbasket seems to have a tilt or doesn't seem secure, the internal rails probably need to be straightened. These rails have a big impact on how everything fits together ultimately. Read bobine's suggestions a couple posts back for some good tips here.

7) I have no concerns about the end cap thread wearing over time unless one is not careful and cross-threads it. I have been using the approved "golden" sample mic body since July 2010, and I have had no problems with the threading. It has held up quite well. I actually did quite a bit of endurance testing because I had a similar concern at first. I think that the threads look "thin" because some of them may have a bit of flash material on the edges. After repeated fastenings, this thin flash will wear off, and the thread will look much smoother.

 

[Skylar]

Oh, and I wanted to thank everyone for being so supportive and patient!

 

[tommypiper]

Thanks, Skylar. 

All questions answered nicely, appreciate it.

A follow up on my question about the headbasket being tilted -- what I mean was not the rails sides, but the middle screw being a bit too high or low.  I noticed that the basket is aligned on the rails axis with this middle screw, and it seems it's too high or too low, thus tilting the basket along the rails axis.  And the cylinder is not threaded for this middle screw, so the screw just sits there basically, not securely.  This middle screw's purpose is purely for alignment of the headbasket, it doesn't support weight or hold anything together.  We may need to raise or lower this middle screw position to properly align the headbasket. 

Any ideas?  (I think it was discussed on the previous page but I haven't quite understood...)  A couple of my ideas:

A threaded plate on the back of the cylinder which could be glued or soldered into place...?  Filling the hole and re-drilling it with a smaller diameter thread, then using a smaller diameter screw?  What materials would we use? 

Anyone else have this issue?

 

[bobine]

 
I noticed that the basket is aligned on the rails axis with this middle screw, and it seems it's too high or too low, thus tilting the basket along the rails axis. 

The important thing is to get the inner flange of the head basket to sit securely on the top plate. Then the basket won't tilt. The key to that is getting the right length to the side rails. Try adding thin washers between the top plate and the side rails.

The side screw helps stabilize the head basket but isn't really responsible for getting it to sit straight.

btw... I finished mine and just tried it out. First impression is it sounds very special. Very satisfying and a great relief!

(my only remaining issue is the BeezNeez shock mount doesn't hold the body quite tightly enough...it's slipping) 

 

[crackerzot]

Got a real noob question.  Forgive me.  This is my first mic build.  I just assembled my MK47 kit today, but cannot mount it yet because I need some angle stock in order to mount the PCB board to the EQ47 rails.  Where would I find this sort of material?  Thank you.

 

[barney]

I used alumimium sheet (approx 1-1.5mm) and made my own small L brackets.

 

[plumsolly]

Got a real noob question.  Forgive me.  This is my first mic build.  I just assembled my MK47 kit today, but cannot mount it yet because I need some angle stock in order to mount the PCB board to the EQ47 rails.  Where would I find this sort of material?  Thank you.

Mouser 534-621

Best, Ben

 

[Skylar]

Mouser 534-621

Best, Ben

Thanks, Ben. Those are what I use...along with some undercut 4-40 screws.

Check out this post:
http://www.groupdiy.com/index.php?topic=40191.msg497551#msg497551

 

[plumsolly]

Check out this post:
http://www.groupdiy.com/index.php?topic=40191.msg497551#msg497551

That's how I learned about them. It was easier to look on my mouser order than to search for that post.

So, is everyone just tapping the front hole in the headbasket for the next screw size up?

Best, Ben

 

[crackerzot]

Thanks Ben and Skylar.  Where do I find brass 4-40 undercut screws?  I can't seem to find them on the Mouser site.  Thanks!

 

[matta]

If you live in metric land like I do, just drill out the threads and use an M3 screw and nut, it's what I plan on doing.

Matt

Thanks Ben and Skylar.  Where do I find brass 4-40 undercut screws?  I can't seem to find them on the Mouser site.  Thanks!

 

[plumsolly]

So, is everyone just tapping the front hole in the headbasket for the next screw size up?

Best, Ben

 

[plumsolly]

OK - I went ahead and tapped the front hole for m4 threads. It worked fine. The only problem was the flange on the m4 screw was to big to fit in the counter-sink, so I used a button-head. It looks good but isn't quite as nice as would be if it was flush with the mic body. If I were to do it again, I would look for a screw size that was only slightly larger than m3 - might have to look at standard sizes (as opposed to metric). 

Best, Ben

 

[guavatone]

Maybe they sell slightly oversized M3's for stripped M3's.

 

[MagnetoSound]

An M3.5 would probably be perfect, then.

 

[mrcase]

Hi skylar!

got my body! all great - screws went out smoothly and the stripes on the body aren´t that bad. You have to look for them.
Thanks for making these!
one question though.
how high should the capsule be fitted?
I have a thiersch and a beezneez capsule. should I use either with the plastic plate or without?
if I use the plastic plate the membrane is partly behind the upper ring of the basket. (dunno how to explain that better...)
Is it supposed to be like that? does my question make any sense at all ;-)

cheers

 

[JW]

Can someone tell me how to disassemble the female binder connector? No idea.

 

[Sredna]

Inside there's a ring that you can unscrew with a coin or similar. Just watch for sharp edges!  8)