Morning all

I'm actually going to have a couple of days to myself over the holiday period and want to get a job done but only have enough alumnium for 1 attempt.

This has always baffled me so need advice from the LCB. If bending 1.2mm aluminium sheet should I put the bend line level with the top of the vice or slightly higher/lower? What i want is the centre of the bending curve to run along the marked line but it ways seems to end up too big or small.

so any idiot guide tips to getting more accurate bends would be appreciated. I normall put the metal between two ali angle strips in a workmate if that's any help.

Cheers for all the assistance given this year and previous and hope you all have a very Merry Christmas & a happy 2012

In theory (and in thin material), always mark the bend line on the side that will become the inside of the bend, and bend with that line on the edge of the bending tool, if a sharp bend. If the bend has a generous radius the mark will have to be in the centre of the radius.

In practice, and with no experience, some experimentaion may be need to get a good result, if the sizes have to be exact.

Do you not have a say 50 mm wide strip off cut to make just a representation of the finished panels? Experiment on this before making the full width panels.

Cheers

Fred W B

On thicker stuff, you would normally deduct the thickness of the sheet for each bend and bend on the line. but with 1.2 sheet its hardly going to matter that much.

If your really keen and fancy a drive to Leeds you can use my guillotine and box/pan folder.

ATB
Al.



Originally posted by jabbahutt
Morning all

I'm actually going to have a couple of days to myself over the holiday period and want to get a job done but only have enough alumnium for 1 attempt.

This has always baffled me so need advice from the LCB. If bending 1.2mm aluminium sheet should I put the bend line level with the top of the vice or slightly higher/lower? What i want is the centre of the bending curve to run along the marked line but it ways seems to end up too big or small.

so any idiot guide tips to getting more accurate bends would be appreciated. I normall put the metal between two ali angle strips in a workmate if that's any help.

Cheers for all the assistance given this year and previous and hope you all have a very Merry Christmas & a happy 2012

Thanks for the help Fred. Just goes to prove that when you don't know what you're doing even the obvious is a relevation. I now know where I was going wrong in that a lot of the times I was marking the outside and bending away from myself where as you say I should of marked the inside and bent towards.

That gives me much more confidence that I'll get it right this time.

Thanks again and Merry Christmas

thanks for the very kind offer Wadders but it's onlt 4 bends so I'll try the workmate method first

I trust you are putting a radius on the bend and not just bending over the vise jaws?

no real radius just trying to accurately put bends in sheet but for some reason the bend line seems to end up not on the bend but instead at beginning/end so out by a couple of mm

Good Morning, just to add to what Fred has said,

Mark the bend line with a pencil. Don't scribe because that can cause the aluminium to crack. Clamp the aluminium down on a flat surface using a length of wood close to the bend line. The aluminium is actually sandwiched between the flat surface (table, Workmate or whatever). By clamping it in this way you will get a sharp bend on the line with a nice tight radius.

With the aluminium firmly clamped you can now either bend it by hand or tap it using a block of wood and a hammer a bit at a time.

I hope the attached picture shows what I'm trying to say.


Description

I clamp sheet aluminium between a pair of lengths of angle irons - they're something like 50mm x 3mm a metre long, makes the longer folds much easier.

quote:

---

Originally posted by BobM
I clamp sheet aluminium between a pair of lengths of angle irons - they're something like 50mm x 3mm a metre long, makes the longer folds much easier.

---

Have a look here, some useful stuff on here.

http://www.custompartnet.com/calculator/sheet-metal

Have fun

Thanks for all the assistance. Lady luck didn't smile on me over the holiday as your 2 year old was well under the weather so needed looking after. Still now I'm armed with a lot more knowledge to have a go early in the New year.

Many thanks for all your help.

2cv is the expert on this, but I am not too great at this either, and I've done a fair bit of it, including the length of my bonnet. A bending brake can be made or had pretty cheaply, and does a very very good job. The other way is possible, but you need to be extremely careful that things don't move in your clamps, which they somehow want to do continuously.

If you are putting one bend in a sheet, then you do have the option of putting the bend in first and then cutting the sheet.

Or cut the sheet over size, bend, and then trim to exact size. Then if the bend is out by 1-2mm then you can easily correct it.