OK I have a chunk of 8mm aluminium and and I need to cut the sshape of a windscreen bracket out of this. What is the best / easiers way.

This bracket has nice flowing curves and is about 444mm x 130mm

Need to cut two out of a bit of Ally 520 x 139 x 8

Tools I have :

Plasma Cutter (My skill is not brilliant with this yet)
Jigsaw
Files
Grinder
DIE gringer
Bench Drill with Drill bits for HOLES
Some holesaws BI-METAL
Probably an old FREET saw somewhere
Mig Welder (STEEL)
Various other handtools you find in a garage.


Suggestions welcome

Should be a PIC of the design attached belowBut can;t figure out how to attache IMAGE

<- IMAGE IN ARCHIVE as WIndscreen Bracket



[Edited on 21/101/09 by mad4x4]

[Edited on 21/101/09 by mad4x4]

I'd go for the jig saw with a coarse blade & slow speed, 8mm seems a bit excessive tbh, I'd have used 5mm. If you dab on a bit of paraffin with an old paint brush the aluminium will cut very well and not clog the blade, this works extremely well when fettling too (little tip there). Obviously just don't get it in the saw or it might catch fire (another little tip there )

yikes this is it?

WindScreen Braket

very nice but maybe you'd have been best getting this laser out in 3mm stainless...? It's going to take a while to cut with a jigsaw Also how are you going to bend a bracket round the side of the cowl, 8mm aluminium is very tough to bend accurately.

James Aiken Sheet Metal Ltd
10, Wellington St, Aberdeen, Aberdeenshire AB11 5BT
Tel: 01224 572555

down at the harbour has a gas torch CNC Cutter and the sheet rollers to do the curves btw.


[Edited on 21/1/09 by Mr Whippy]

If you HAVE to do this yourself then I'm with Wippy and would use the jigsaw. It will cut it quite cleanly but its a slow process.

If it was me, I would contact one of the boys on here (forget his user name) who does water jet cutting and have them done that way!

I agree since it's such a visible bit, full of curves and already CAD'ed I'd get it done with waterjet or laser in something a little thinner.

In fact, since the setup costs are the highest bit, generally, I'd do a few more to sell on.

andyw7de is the waterjet man.

quote:

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Originally posted by carpmart
If it was me, I would contact one of the boys on here (forget his user name) who does water jet cutting and have them done that way!

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8mm is too thick surely?

whatever you do don't grind it! unless that is, you like exploding grinding discs. I,d agree with the others guys, jigsaw the shape out and then hand file any rough edges and sharp corners.

8mm does seem excessive though.

What , you have no Flowjet machine

hi there
be very carefull using 8mm, i made mine in the original lotus shape, out of 5mm material.
it proved very difficult to bend to suit the ally scutle sides. drill the holes after bending as they will pull eg distort.
regards graham

if you tell me what he need i may have a bit he can have for free i have loads of ally off cuts .3mm 4mm 5mm 6mmect.

Wow 8mm sure is thick!!
I'd also go for a jigsaw. You'd need a fine tooth metal cutting blade but they're easily available.
Make sure you clean up the swarf before doing any rust grinding or you'll have a nice little thermite reaction going on

quote:

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Originally posted by g.gilo
drill the holes after bending as they will pull eg distort.
regards graham

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Right then - Think I may have a go with the Jigsaw see how we get on.

Alt plan is see if andy can cut them....

Will post a follow up to this

depends how good your plasma cutter is (ally needs a lot of amps, you'll need around 50 amps cut current for 8mm ally)

if it has that power then I'd plasma it a mm or so oversize then file to size to be honest, or just get em lasered or water jetted out.

My local laser place would charge around £40

I cut my inlet manifold from 12mm ally plate using a woodworking coping saw and plenty of cutting fluid. Lot easier than you would think.

Where you have an inside radius drill a hole so that the edge of the hole is the finished surface.
It is then just a matter of joining up the holes with straight cuts with the jig saw.
It will save filing out the corners too.


(I agree with others; 8mm is ott. Bending to the scuttle shape will be well hard.)

HTH
Paul G

I've used 6mm extruded ali (which I think is over the top and 5mm would be ample) and this cut very easily with a jigsaw (coarse blade and plenty of lube).

I've used 907s trick of doing the curves with a hole saw and joining up with a jigsaw and it really does work.

John

From the Only GCE I left school with (Metalwork) I recall that Parafin is the correct cutting lubricant for Alluminium.

God... Where did that come from.... that was over 40 years ago! (being mentioned above must have jogged my memory!)

There is probably a modern cutting lubricant that is better than parafin. However, you wont be far wrong using parafin when cutting ally.

I agree 8mm is much too thick.

5mm max and water cut if you already have the CAD files.

Update,
OK so far have managed to get the outside porfiles cut with a jigsaw and some Burst oil as a LUB. Took a while but Bladed on Jigsaw is still good.

Wll now start on the inner cuts and see how I get on, As for Bending if worst comes to worst them BFH will bend it

It will Bend ----Somehow. Udates and Photos to follow