DIY API 1604 inspired mixer (16x8x2)

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Small update--  After mixed results using a brake for backplane brackets, going to instead try the brazing route.  Picts to follow after stuff arrives and I've got acquainted with the process.

loRY4dS.jpg


Some bent fine, some didn't. Didn't feel like doing cutting and measuring each piece only to gamble on the bend not turning into this:
dAMQ4ms.jpg


Edit: In retrospect, preheating the bend would have probably produced the results wanted, but the next method will hopefully look better and make for stronger brackets.
 
boji said:
, going to instead try the brazing route.  Picts to follow after stuff arrives and I've got acquainted with the process.


I’m interested to see that.
 
Ok...first try was...bad. Learned proper aluminum temp is sneaky tricky!  The way to determine proper temp is as follows: Absent direct torch heat, If dragging the rod across the metal seam to be brazed makes the rod melt, you've got the aluminum at the right temp.

Alloy rods melt at 700°F.  Aluminum melts at roughly 1200°F.  Aluminum oxide melts at much higher temp (3,762°F!)  so with thicker gauges, you can have a piece hold its shape in spongy fashion, but inside, beneath the oxide, it's liquifying!

8QTqbyN.jpg


After few failures, poor application on test pieces, first success pic below, prior to cleanup.

3EFWXgn.jpg


Ok after cleanup, this looks decent... not bad for a 'dry' application.  All about creating a 'V' divot in the joint, making sure seam is oxide free and acetone cleaned before laying-in filler:
nT2gOT7.jpg


Finished test pair.  They'd  work fine going in the console, but they are kinda ugly, and I'd prefer to wait for attempts with flux. 
YvZmBVm.jpg


I'm guessing flux will make joints look nicer with less post cleanup, and wick better for more strength.
KdVBRLj.jpg


 
What are you using to heat the metal??
Standard propane torch.  MAP-Pro gas produces a hotter flame,  but 4x the price per bottle.
Tis6J5S.jpg


Ceramic tiles reduce heat absorption into the vice somewhat.
QVQAV2N.jpg


So, flux does help a little if dropped into seam at the right point and temperature. But it also comes with its own set of problems, as it can pull bead out and create a thin braze. It can also be overused and create a hard shell which requires chisling, sanding and use of a grinder to produce a clean finish.

When it's all dialed in, you get a fairly solder-like finish:
M1yKiOa.jpg


Taking it to the next level Boji
Thanks squeaky, trying my best to not cut corners, inside and out.
 
Thanks for sharing all this!
You're quite welcome, least I can do.

So...feels like cheating to powdercoat over uglier brazes, but will add a sense of consistency...should anyone EVER decide to peer into 500 slot bay to look at support metalwork.  ::) ::)

EtLQmtU.jpg

sGOfSNL.jpg

MYuzT7K.jpg

 
Finished looks good.

My brother is a welder and talks about how a 100 amp welder is needed for aluminum because of its dissipative quality’s .  It takes an amazing amount of heat wherever the weld is. 
 
It takes an amazing amount of heat

Aint kidding.  Also  turns out the flux localizes the heat fast, so if temps are not just right, the flux pits the aluminum while I'm trying to add filler rod.  Real pain/art to it.
 
boji said:
Aint kidding.  Also  turns out the flux localizes the heat fast, so if temps are not just right, the flux pits the aluminum while I'm trying to add filler rod.  Real pain/art to it.

Aluminium is possibly the worst material to braze or weld. I take my hat off to you. Have you thought about using brass?

Cheers

Ian
 
I remember from school that spot welding is the most effective method for aluminium.. I heard there are plier-sized spot welding devices too, ours was like 1,5m tall that stood on the floor and you'd operate the electrodes with a pedal.

In your case it isn't much of a help though unless you know someone who has spot welding equipment, and as those corner-looking profile bits are sort of tricky.

I think you'd need to fold the corner, weld it, sand&grind the edges flush and coat it with some compound I guess, although I recall people making square boxes from aluminium by spot welding.

Anyway, nice looking build!
 
Scott keep looking you might find this console out there at some point  ;D

Thanks faze, but not really. Appreciate the love tho!  Keeps me going.
Slot backplanes work.
kNWJ3Sd.jpg


Locking it down:
7aUkCSP.jpg


500 backplanes mounted!  (happy to be done with this, alignments were not so fun.)
07tOCwE.jpg


Moving over to patch panel section for a bit, have to add some brackets for aux, cut some plate for monitor controller, etc.
lmlB74F.jpg


 
alignments were not so fun

Do you put a couple of 550 modules into backplane pcb’s and then seat into face plate rails and then screw in brackets to side panels?  Short of CNC it’s difficult to get it seated for faceplate to extrusion and seat edge connect to backplane .

I’m thinking about how you bolt switches and pots to a face plate and then solder to pcbs for alignment rather than solder first.  This also works good for stompbox pots and switches located to a drilled box.
 
Back
Top