Bending boxes

[Frank]

Nice, clean bends in 0.063 aluminum, homemade hardwood bender. Anything work better than 6061-T6?

 

[George Herold]

Nice, clean bends in 0.063 aluminum, homemade hardwood bender. Anything work better than 6061-T6?

I always got some corner cracking when I bent up 6061. I think the 'pure' 1100 works well... going to Mcmaster-Carr catalog they also list 5052 as excellent
and 3003,5005, 5086, 5205 as Good.

George H.

 

[Frank]

I always got some corner cracking when I bent up 6061.

Eased radius?

I think the 'pure' 1100 works well... going to Mcmaster-Carr
catalog they also list 5052 as excellent

and 3003,5005, 5086, 5205 as Good.

Thanks.

 

[Frank]

---

You should drill/punch a hole at the corner of the bend and let the

metal stretch instead of tear.

---






---

Pussy aluminum...

----



going to Mcmaster-Carr catalog they also list 5052 as excellent and

3003,5005, 5086, 5205 as Good.

Synthesizer modules. Just the long edges need to be bent,
no corners to drill.

 

[Carl Ijames]

The minimum bend radius of 6061-T6 is 3-4 times the material thickness. The
other readily available alloy that's much better for bending is 5052,
usually H32 or half hard. Minimum bend radius is just over the material
thickness, about 3/4 the strength of 6061T6, as weldable, and both take
anodizing well. Biggest difference is 6061 can be heat treated for more
strength (T0 is annealed, T6 is the common heat treated material) while 5052
is annealed with heat but can only be strengthened by work hardening. I buy
from McMaster Carr all the time at work for items they make sense for, but
if you need more than a few square feet you need to find a local metal
supplier since you can easily halve the McMC price and any good supplier
will shear a large 4x8 or 5x10' sheet into whatever pieces you need for very
little extra cost. (I say readily available because while McMC lists
several alloys in their catalog, if you go to a local metal supplier almost
anything but 6061 and 5052 in sheet is going to be a special order with a
big minimum so in practice you just ignore everything else .) Where are
you? If you are near Baltimore I can recommend some suppliers.

-----
Regards,
Carl Ijames
"Frank" wrote in message

Nice, clean bends in 0.063 aluminum, homemade hardwood bender. Anything
work better than 6061-T6?

 

[George Herold]

Eased radius?

No, just what ever metal break was in the machine shop.

George H.

 

[George Herold]

You'll get corner cracks if you use the common bending brake. The

inside of the bend radius gets compressed, but the outside is

stretched causing the cracking. Where you get into trouble is that

6061-T6 will crack unless the bend radius is fairly large. My

guess(tm) is about 2-3 times the sheet metal thickness. If you use an

industrial strength press, with a V-bender die set, you can get a much

sharper bend radius. The pressure between the punch and the die

compresses the bend area, making more of the bend in compression, and

less on the outside that gets stretched. The bend area does get

slightly thinner, but even with a smaller amount of stretch, it still

will crack slightly.

<http://www.custompartnet.com/wu/sheet-metal-forming>



I'm not so sure about using dead soft 1100 aluminum sheet. The stuff

is not very durable and is easily scratched, dinged or dented.

However, I haven't tried using it, so I'll remain neutral.

Grin, I'm not claiming it makes the best boxes, but it's easy to put a bendin it.
George H.

 

[George Herold]

---

You should drill/punch a hole at the corner of the bend and let the

metal stretch instead of tear.

---






---

Pussy aluminum...

----



going to Mcmaster-Carr catalog they also list 5052 as excellent and

3003,5005, 5086, 5205 as Good.

Bendability, ductility?? whatever they call it. Don't you have a McMaster catalog?

George H.

 

[Frank]

The minimum bend radius of 6061-T6 is 3-4 times the material thickness. The

other readily available alloy that's much better for bending is 5052,

usually H32 or half hard. Minimum bend radius is just over the material

thickness, about 3/4 the strength of 6061T6, as weldable, and both take

anodizing well. Biggest difference is 6061 can be heat treated for more

strength (T0 is annealed, T6 is the common heat treated material) while 5052

is annealed with heat but can only be strengthened by work hardening. I buy

from McMaster Carr all the time at work for items they make sense for, but

if you need more than a few square feet you need to find a local metal

supplier since you can easily halve the McMC price and any good supplier

will shear a large 4x8 or 5x10' sheet into whatever pieces you need for very

little extra cost. (I say readily available because while McMC lists

several alloys in their catalog, if you go to a local metal supplier almost

anything but 6061 and 5052 in sheet is going to be a special order with a

big minimum so in practice you just ignore everything else .) Where are

you? If you are near Baltimore I can recommend some suppliers.

Baltimore.

 

[Frank]

Well, there is one place where dead soft aluminum shines. VCO's that

have microphonic problems. I had to deal with a radio where the

designer (not me) threw in such a high divider ratio in the PLL phase

lock loops that it was almost impossible to remove the microphonics

from the system. My job was to fix the microphonics problem without

changing anything, spending any money, delaying deliveries, or

precipitating an FCC re-certification. Right, no problem...



I made some major improvements with Q dope, parts spacers, bees wax,

hot melt glue, and the blobs of silicon rubber goo, but it wasn't

enough. I coined and stiffened the tin covers on the VCO and glued

down any loose wires, but still not good enough. I then did some

vibration analysis (beat on the box with a small hammer and look at

what came out of the receiver on a scope) and found that the main

chassis was poorly stiffened and trying to "oil drum". The mechanical

resonance of the chassis was about the same as the microphonically

induced audio oscillations. Hmmm... I first tried to stiffen the

chassis with various brackets, but that only made it worse. What I

needed was a way to deaden the resonances. A sheet lead chassis would

probably have been best, but that was obviously unacceptable. So, I

convinced the fab shop to make a chassis out of 1xxx series 0.063 dead

soft aluminum. A hint is the "dead" in dead soft really means that

it's acoustically dead. Bingo. No more howling out of the speaker

and no more drum amplifier.



After they delivered a few such radios, I didn't hear any complaints

coming back so I assumed all was well. In reality, the design had

numerous other deficiencies that made a redesign necessary. However,

since I complained so much about the design and construction while I

was fixing the microphonics, the design job went to someone else. At

least I got paid.



So, if the synthesizer design has a microphonics problem, and the

usual fixes don't quite work, you can try dead soft aluminum for the

cans or that case.

Sounds useful for mounting piezo pickups.

 

[Carl Ijames]

[
"Frank" wrote in message

The minimum bend radius of 6061-T6 is 3-4 times the material thickness.
The

other readily available alloy that's much better for bending is 5052,

usually H32 or half hard. Minimum bend radius is just over the material

thickness, about 3/4 the strength of 6061T6, as weldable, and both take

anodizing well. Biggest difference is 6061 can be heat treated for more

strength (T0 is annealed, T6 is the common heat treated material) while
5052

is annealed with heat but can only be strengthened by work hardening. I
buy

from McMaster Carr all the time at work for items they make sense for, but

if you need more than a few square feet you need to find a local metal

supplier since you can easily halve the McMC price and any good supplier

will shear a large 4x8 or 5x10' sheet into whatever pieces you need for
very

little extra cost. (I say readily available because while McMC lists

several alloys in their catalog, if you go to a local metal supplier
almost

anything but 6061 and 5052 in sheet is going to be a special order with a

big minimum so in practice you just ignore everything else .) Where
are

you? If you are near Baltimore I can recommend some suppliers.

Baltimore.
]

Now that's funny . We mostly buy sheet aluminum (and steel) from High
Steel in Lancaster, PA, plus BMG south of Baltimore on Rt 1, and
Pennsylvania Steel in York, PA. Of course, we usually buy enough at a time
to get free delivery. You will have to call around and shop for price and
convenience. It all depends on how much you can buy at one shot.

 

[Frank]

On Tue, 02 Jul 2013 12:14:48 -0700 in sci.electronics.design, Jeff








Heat the bend line with a propane torch until it is no longer -T6

Or use 21 gauge instead of 16. Or design around the large radius
instead of driving yourself nuts trying to force it.

 

[John S]

Nice, clean bends in 0.063 aluminum, homemade hardwood bender. Anything work better than 6061-T6?

I'll bet Uri Geller could do it better. He should start a company doing
that.