F
Frank
Nice, clean bends in 0.063 aluminum, homemade hardwood bender. Anything work better than 6061-T6?
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.
---
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.
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.
Bendability, ductility?? whatever they call it. Don't you have a McMaster catalog?---
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.
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.
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.
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.
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
Nice, clean bends in 0.063 aluminum, homemade hardwood bender. Anything work better than 6061-T6?