In the past, hoping to get the boring mechanical bit over and done
with, I drilled my aluminium freehand, with the result that a lot
of filing then had to be done to align the screw holes of different bits.

But, now I have a drill press and an engineer's vice to hold everything
down, it's a different world!

The only skill that I have yet to master is that the bend in the aluminium
is where I marked it, and not a couple of mm distant!

On Wed, 15 Oct 2014, gareth wrote:

In the past, hoping to get the boring mechanical bit over and done
with, I drilled my aluminium freehand, with the result that a lot
of filing then had to be done to align the screw holes of different bits.

But, now I have a drill press and an engineer's vice to hold everything
down, it's a different world!

The only skill that I have yet to master is that the bend in the aluminium
is where I marked it, and not a couple of mm distant!

This is why things like bezels were invented.

Michael

On 15/10/2014 11:31, gareth wrote:
In the past, hoping to get the boring mechanical bit over and done
with, I drilled my aluminium freehand, with the result that a lot
of filing then had to be done to align the screw holes of different bits.

But, now I have a drill press and an engineer's vice to hold everything
down, it's a different world!

I found that the best way to align holes was to print out a full sized
drawing of the hole layouts, glue it on and then centre punch the holes.
As long as you have accurate reference points on all parts then the
holes line up.
I gave up drawing and marking the individual parts as being too
error-prone and labour intensive.

But drill presses are good kit.

Andy

AndyW wrote in
:

I found that the best way to align holes was to print out a full sized
drawing of the hole layouts, glue it on and then centre punch the holes.


Seconded, totally! Also, can't beat a good X/Y machine table on a drill
press. 1mm dril, 1mm increments, any shape you want. Join the dots... For
one-off projects the speed is good, the precision, amazing.

On 10/15/2014 6:31 AM, gareth wrote:
In the past, hoping to get the boring mechanical bit over and done
with, I drilled my aluminium freehand, with the result that a lot
of filing then had to be done to align the screw holes of different bits.

But, now I have a drill press and an engineer's vice to hold everything
down, it's a different world!

The only skill that I have yet to master is that the bend in the aluminium
is where I marked it, and not a couple of mm distant!

I was taught that a brake is used to bend sheet metal. It's not a power
tool so can be had fairly inexpensively. I found one at the top of a
google search with removable fingers for $300. The removable fingers
let you bend things like four sided boxes.

If you don't want to spring the cash for one, you can just use angle
iron and your vise. To do four sided boxes you need to cut the angle
iron to the right length for each bend.

--

Rick

rickman wrote in :

If you don't want to spring the cash for one, you can just use angle
iron and your vise. To do four sided boxes you need to cut the angle
iron to the right length for each bend.


Either that, or cut the metal after the bend, which introduces another
indispesible tool: a bandsaw. Given a drill press and a bandsaw, and an
accurate X/Y table for the drill, it can go a long way before any other tool
is needed, though a small Proxxon IBE drill with various widgets is also
vital, especially if you make PCB's and get a stand and X/Y table to go
with.. Carbide bits seem to last forever with those tools.

On Thu, 16 Oct 2014 04:28:00 -0500, Lostgallifreyan wrote:

rickman wrote in :

If you don't want to spring the cash for one, you can just use angle
iron and your vise. To do four sided boxes you need to cut the angle
iron to the right length for each bend.


Either that, or cut the metal after the bend, which introduces another
indispesible tool: a bandsaw. Given a drill press and a bandsaw, and an
accurate X/Y table for the drill, it can go a long way before any other
tool is needed, though a small Proxxon IBE drill with various widgets is
also vital, especially if you make PCB's and get a stand and X/Y table
to go with.. Carbide bits seem to last forever with those tools.

Don't forget to allow for the thickness of the material and it's minimum
bending radius. A few practice bends in scraps of the same material will
get that settled. You have to use the same material since different
alloys and different thicknesses behave differently. And, unless you
bought the metal from a metal dealer, you probably don't know the alloy.

Good luck,

--
Jim Mueller

To get my real email address, replace wrongname with dadoheadman.
Then replace nospam with fastmail. Lastly, replace com with us.

Jim Mueller wrote in
eb.com:

Don't forget to allow for the thickness of the material and it's minimum
bending radius. A few practice bends in scraps of the same material will
get that settled. You have to use the same material since different
alloys and different thicknesses behave differently. And, unless you
bought the metal from a metal dealer, you probably don't know the alloy.


I usually get round that lack of knowledge by using a good hard edge on the
inside of the bend and also one on the outside, then hammer gently on the
outer bar held right onto the bend to press it against the immer supporting
bar (or vice edge, whatever I can make fit). It's a bit tedious, but can
result in very nice clean and sharp angles at 90° regardless of metal used.
Penalty for error is usually no worse than a slight thinning at the crease.
I've considered trying to build a DIY tool based on a good quality hinge, but
never done it.

On 17/10/2014 01:32, Lostgallifreyan wrote:

I usually get round that lack of knowledge by using a good hard edge on the
inside of the bend and also one on the outside, then hammer gently on the
outer bar held right onto the bend to press it against the immer supporting
bar (or vice edge, whatever I can make fit). It's a bit tedious, but can
result in very nice clean and sharp angles at 90° regardless of metal used.
Penalty for error is usually no worse than a slight thinning at the crease.
I've considered trying to build a DIY tool based on a good quality hinge, but
never done it.

Some lightweight alloys I have used have cracked on a sharp edge. Often
I just use sheet steel a blowtorch, flux and braze it together. A LOT
easier than bending without the right kit.

Andy

AndyW wrote in
:

Some lightweight alloys I have used have cracked on a sharp edge.

Yep, I gate those. If that happens I either chuck it or use it where it
won't get bent. Most thin Al sheet is very ductile though, if anything, too
much so, hard to make clean edged holes in without good tools.