I've got the 'tube mitre' program on one of my PCs, and it is really good for shaping one round tube to fit onto another. You tell it the size of one tube, together with its wall thickness, the diameter of the other tube and the angle that they will meet. Once that's entered you can print out the shape, wrap it round the tube and cut-and-file it to get a near-perfect fit.

What I'm looking for is a similar program or method for printing the shape of a 30-degree cut across a tube, so that I can mark it out for sawing. In effect it's the same sort of thing, but in this case the 'second tube' is a flat plane.

If I had an old-fashioned drawing board with all the accessories I could project the shape, ready for cutting out... but I haven't, so I can't!

Can anyone offer a solution?

Ta,
David

Seem to recall someone suggesting using a H U G E diameter for one of the tubes
as an approximation of a flat plate.
Don't recall if it worked

I tried that...It doesn't!

It just gives a stupid shape that goes off the edge of the window...

Use a protractor to start with but you can obviously only draw a wee line then use a bit of steel strapping or old tape measure to wrap around the tube along your scribed line....sounds nuts but it does work....honest.

Mark

If you have solidworks or any solid modeller that does sheet metal you could model it as a folded up box section, then make the angled cut and get the developed (flat) shape and print out 1:1 as your template.

You want to make a straight 30* cut in a tube to fasten to a flat surface? Mark 30* on a square section and clamp your round bar to it while you cut through them both. I just set the chop saw to 30* though, it's easier

[Edited on 22/10/07 by Peteff]

I've got a program that'll do a tube against a flat plate. The only problem is that it doesn't print the template, instead producing a DXF file that you can fiddle with in your favourite CAD package.


screenshot

Any chance of a copy of that? I can cope with DXF files - another bonus of Linux - free autocad-alike software!

NB: I do have access to a Win2K machine, if that's what the program needs!

If you get stuck I'll get my compass out and see what develops.

Sorry but I'm still in the 20th century.


Paul G

...I was going to make a rude and flippant comment then - but I still want you to weld up my manifold!

Think I'd better check to see if I still have lead in my pencil.



Paul G

I'd like a copy if possible too, please.

Chers

Chris

I'm lost - If the tube you are cutting already exists as a tube just cut it straight through on a flat plane?

Differnt story if you want to develop a flat pattern to cut a plate before you roll it up into a tube though

Cheers

Fred W B

quote:

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Originally posted by Fred W B
I'm lost - If the tube you are cutting already exists as a tube just cut it straight through on a flat plane?

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quote:

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Originally posted by chrisg
I'd like a copy if possible too, please.

Chers

Chris

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UPDATE:

I tried the program - it works! The output is a DXF file, and it's a bit small when printed - but that is most likely to be due to me using Linux, QCaD, and not knowing how to get the scaling right!

I shall persevere...

Can't help with a program David but have you thought about using a mitre saw with a metal cutting blade?

That's what I'm doing at the moment - got one of B&Q's finest yesterday!

I just used a combination set and put the tube in the vice, then eyed up my hacksaw against the combination set and vice jaw.
Cut it as near as I could and trimmed the end with a file to get final fit.
Paul.

hi
a good cheap bit of kit for that its called a line of chords
its a 2 ft folding steel rule
it has all angles on reverse side
all you need to go with it is a set of deviders
it has two centre pop marks on it
set the deviders to correct angle
fold the rule until line up with centre pops and the rule will give you correct angle
they cost about £12 from good tool shop
they work good enough to make staircases with in work
cheers
colin

I put a copy of the program up at http://www.talkingmonkey.co.uk/tubexp.exe, but it's just the executable. If you don't already have the VB common dialog routines on your machine, it won't run. I'll try to organise a properly installing version on the weekend.