Aluminium temper tubing

[dnej]

G'day,
Want to build a targa, using 32mm aluminium tube, 3mm wall thickness.
The 6060 T81 temper seems to be the way to go, but difficult to find in Brisbane.
Can get the 1.6mm wall.

The T5 temper is readily available, and is apparently the next best thing.

Has any one any experience in this kind of structure, that can give an opinion of the T5 temper.Doesnt look to have the structural strength to me.
Dont want to go to SS.
David

[lethal098]

David,

i went down the same line when looking to my targa and launcher, in the end the ally just didnt stack up against the stainless, Resale and overall structural stability convinced me to go stainless. Might cost a little more but will be stronger and be better resale down the track.

cheers Lee

[dnej]

Thanks Lee, but it would really look out of place on my boat. I know what you are saying is correct, but that T81, has good structural strength, and is light weight. Just got to find it somewhere. no problem in NSW.

Regards David

PS got any pictures you can post.

[tropicrows]

David,

Capral aluminium are about the only placed left on QLD since they have bought out the opposition. I had the same problem getting hold of some heavy plate for work, and in the end had to purchase it from NSW and get it shipped up.

[dnej]

http://www.georgewhite.com.au/products/images/gw_logo.jpg Product listing for: Aluminium Tube - Round (Drawn)
Product Type: Aluminium Tube - Round (Drawn)
Alloy 6060 T81
Additional Info: Not all sizes are exstock
Sort Options: Sort By Outer Diameter (http://www.georgewhite.com.au/products/product_listing.asp?categorycode=AT-R&sortby=1) | Sort By Wall (http://www.georgewhite.com.au/products/product_listing.asp?categorycode=AT-R&sortby=2) | Sort By Std/Length (http://www.georgewhite.com.au/products/product_listing.asp?categorycode=AT-R&sortby=3)

Outer DiameterWallStd/Length

10.000 mm1.000 mm6.000 m
10.000 mm1.200 mm4.000 m
12.700 mm1.420 mm5.500 m
15.880 mm1.420 mm5.500 m
19.050 mm1.420 mm5.500 m
22.220 mm1.420 mm5.500 m
25.000 mm1.600 mm6.000 m
25.000 mm3.000 mm6.000 m
25.400 mm1.420 mm5.500 m
28.600 mm1.420 mm6.000 m
32.000 mm1.600 mm6.000 m
32.000 mm3.000 mm6.000 m
40.000 mm1.600 mm6.000 m
40.000 mm3.000 mm6.000 m
50.000 mm1.600 mm6.000 m
50.000 mm


The Drawn tube size in red, T81 is what I am chasing. Its used on bullbars.Capral have it ex Sydney, in the 1.6mm. Not sure if that wall thickness would suffice.

Just have to keep trying, and perhaps get it shipped up, from south.
David

[tunaticer]

Try Alrich Aluminium, Crockford Street Northgate.

[Cheech]

I don't know what the T81 means, but I happened to be looking for the same thing last week. ie 25 and 32mm 3mm wall tubing. There is a supplier in Brendale/Strathpine that has both sizes in stock. I am not home now, but can check actual address tomorrow. It is on Kremzow Rd. The 25mm was about $38.00 for 6m length, and the 32mm was about 45 by memory.

I needed it for strengthening my alloy rocket launcher, but am also looking at making a new canopy, and like the idea of the 3mm to make it more solid.

edit: I just google mapped it and then street view. It is Allmetal Service Centre at 38 Kremzow rd.

[dnej]

Alloy/Temper Commodity Applications


1200-0 Drawn tube Tight bends. Refrigeration appliances, very low
properties. Consistent bends.

1200-H12 Drawn tube Medium bends. Refrigeration appliances.

6060-T591 Extruded, rod, bar, tube
and some shapes
Tight bends. Consistent bending. Low properties.
Windows and difficult shapes.

6060-T595 Extruded, rod, bar, tube
and some shapes
Medium bends. Caravan windows and trim.

6060-T81 Drawn tube General purpose, high strength, large radii
necessary. Bull bars.

6060-T891 Drawn tube Good properties when flattening may be required.
Truck mirrors.

6106-T4 Extruded, rod, bar, tube
and some shapes
Tight bends. Consistent bending. Low properties.
Windows and difficult shapes

There are lots more, but these may help with your decision making
David

[Stuart]

Alsun ont he Sunshine Coast have it mate. I still think it will crack around the welds.

Stu

[dnej]

Stu, thanks for the info. Welds should be ok, as the mounting will be on the side of the cabin,and be bolted on, in a vertical position. I know what you are talking about though. It is a problem.
David

[dnej]

My thanks to everyone.
Just wanted to thank everyone who posted, and send PM, and email, to me on this subject.
While the 6060 T81 was indeed the correct way to go for strength, some organisations had the dyes to draw the tube, but unless you wanted a tonne of the stuff, no one had it available .
As I said , the T81 is used in Bull bar manufacture, but mainly in 75 mm. Shame because it has good bending,welding ,and above all strength.

Found some in Brisbane in 1.6mm wall, and in Sydney.
So had to go with th T5, and will need to gusset it up a bit.
Any way again my thanks, and a special thanks to Tim, and Steve, for the advice on bending, using a tube bender, hydraulic type.

Regards David

[Owen]

David,
Do yourself a favour and go study a couple of older tubular motorcycle chassis.
It will show you the correct way to gusset tubing.
i.e. Never put a gusset on the "inside" of the joint. You will create a guaranteed stress facture point.
The gusset must be placed on the point of least movement under load and there should be no weld across the "inside" to restrict flexing.

I worked in ally for many years and personally on a targa I'd use stainless.
You are going to have to put a lot of thought into how and where it moves under load and in heavy seas.
Of course if you are plating it up then there will be no issues.

[dnej]

Owen, sorry i missed your post untill now. Thanks for the information.
I will be plating up the frame, to about half way up, around 900mm, on both sides, port and starboard.
The top crowned horizontal also will be partially plated.
I am plating in between the legs, in the middle, (or around about) of the tube.
The gusset on the corners will be as per your good diagram, with accompaning diagonal tube, bent to a curve, so as to avoid the sharp edge, of the gusset.

How does that all sound to you.
David

[dnej]

http://www.homebuiltairplanes.com/forums/attachments/design-structures-cutting-edge-technology/2435d1225761358-thoughts-aluminium-tube-construction-dsc03449.jpg (http://www.homebuiltairplanes.com/forums/attachments/design-structures-cutting-edge-technology/2435d1225761358-thoughts-aluminium-tube-construction-dsc03449.jpg)

Plenty of gussets on this one Owen, as per your diagram.
David

[dnej]

Just wanted to bump this up for Owen.
David

[Owen]

Sounds like you've got it well sussed Dave
Didn't mean to make it sound otherwise.
Just seen so many jobs crack up for the sake of properly placed gusseting.

[dnej]

Owen, it was only because of your post, that I decided to place the gusset that way.
I would have done it incorrectly, if you had not posted.
Is the plating OK, welded on between the tubing legs . Iwould prefer to do it that way, purely for looks.
Is any thing affected by doing it that way.
Regards David

[Owen]

David,
In general terms it is better to put the gusset on the outside of the pipes, but it depends on how much movement there is likely to be.
If it's made in such a way as there is not much unsupported pipe, then the image I have marked as bad word most likely be fine if you find it more aesthetically pleasing, but having the gussets out flush with the outside cuts the risk of cracking.
See attahed image.

[dnej]

Owen, I am going to do approximately this , so far as plating is concerned.
David

[dnej]

PS can you use a hydraulic pipe bender in a horizontal position, instead of vertical.
David

[Owen]

David,
That design should be fine.
Yes you can use the bender in a horizontal position.
I'm guessing it's a plumbers type unit with cast centre die and two rollers?
If so you'll probably get poor results on alumiium. It will flatten badly as the dies are a poor fit.
You're better off paying to get it bent with a mandrel bender, though there are some pump style units with machined steel dies that work OK.

[dnej]

Owen, yep, cast type shoes.
However I was lucky enough to have Steve, from Ausfish contact me, as he uses the same type of unit.
He has an interesting method of drawing the tube around the shoe, by not starting in the middle of the bend.

He works from the end of the bend, working with 12 strokes of the ram, then working in 20mm increments, to the other end of the bend.
He gets a great result.

Professional benders are asking 16 dollars a bend, and I have 12 to do, and 6 crowns.
So work that out.
If I have any hassles, I will have to bend a former out of ply, similar to the one in the pic, I will post later.
Regards David