In article <
4325cd49.4a779270.42cf.33c9@...>,
Joe Xerox <
joe.xerox@...> wrote:
> Hi,
> I'm interested in this way of building enclosures. Can you post some
> pictures? An how do you bend the AL and make straight and nice looking
> corners?
I don't have a case I'm currently working on ATM, I can take pictures of.
I am very fortunate in that I have access to a metal cutting guillotine
(shear) and bender at work but with retirement looming I have to think of
alternatives. I have already aquired one of those benders that consists of
some pieces of angle iron and a lever, which you clamp in a vice. As far
as cutting goes it might have to be jigsaw or panel saw and a lot of
careful filling, though I'm starting to watch ebay to see if some sort of
guillotine comes up.
Smaller boxes, where the maximum bent length is less than 6" (the width of
my vice) I do bend up in my vice at home. Clamping it up carefully, I then
press against it with a length of 2x1 timber to form (or at least start)
the bend. Thin Al, such as you might use for a small box, bends quite
easily. If neccessary I use a hammer onto the 2x1 but never directly onto
the Al as it marks and bruises it
Ultimately the secret, even with the tools I can use ATM, comes down to
care, patience and practice - like most things.
One tip (and this is difficult to explain) is to make the sides which have
visible edges a little oversize so that when the box is finished you can
trim carefully with a file to get edges that are flush with the sides.
When bending metal you will never achieve a sharp corner, nor should you
try, you will always have a slight radius on the inside so where this fits
over the other piece of metal you will have to file a slight radius on the
corner to match.
When fixing the 1/4" square to the sheet I very carefully position it and
then clamp it. Only when I am satisfied it is in exactly the right
position do I drill straight through both pieces together with the tapping
drill, open up the hole through the sheet with the clearance drill and
then carry out the tapping operation. If using countersunk screws,
countersink the hole before tapping. The screws are then inserted before
releasing the clamp.
With the 1/4" square fixed to one piece, assemble with the other piece and
after careful alignment clamp, drill and tap as above.
Stuart