Cutting a circle in to a tube.

[Lee_D]

Whats the best way to cut a tube such that it mates neatly against another tube ready to be welded up into a T shape for example.

I'm toying with fabricating a wheel carrier as I have all the kit.... just not all the knowledge.. last time I fabbed something in tube it was lots of time spent with the grinder. Not well versed (yet) with tube fabrications. :?

Lee

[Stormin]

You've just about said it. :D  Depending in the size of tube, it's gas axe, grinder and/or file.

[LOFTY]

A quick on site method we use is,
from centreline of tube, cut back towards length at about 30 degrees, both sides of centreline,
this will leave  the end pointed, which fits over your your other tube, making a tidy joint.
Or for £200,000 approx, Mazak machinery do a lovely CNC laser tube cutting machine called a Fabri-gear, makes joints in box, tube, rsj a piece of cake.
 

[Manicminer]

A quick method if you only want to weld a 'T' shape is to put the open end in a vice and squeeze it until it's nearly shut. This will give you a nice straight edge to weld.
If you want to make a join where fluid travels through then you have to cut it.

[Bush Tucker Man]

Are varieties of Hole-Saw available for steel, perhaps with an extended drill-bit for work at angles???

[Reaper]

Ok well the best way to do it is to use one of these http://www.rollcentre.co.uk/rollcentre/html/rollcage_additions.html
but at 150 quid it a lot of cash.
Most of the time I use an end mill in my lathe as it gives a great cut when building chopper frames but the next best thing is to use a a tube mitre programe which allows you to put in the diameter of each peice of tube, the wall thickness and the angle you can then print out a template that you cut out and wrap roung the tube, then you can mark out the cut line and use a grinder to shape it.
here is a link to a very simple Tubemiter programe http://www.ihpva.org/tools/tubemiter.exe
download the programe then open it click file then settings to enter the dimensions then file and print to print out your template.

hope this helps :D

[rollazuki]

search the net for WINMITRE
Its a downloadable bit of software that you set your tube diameters and angles into, and it prints out a life size mask for you to mark out your steel with.
Then just break out the grinder and cut up to the mask and itll butt together just right.

[Lee_D]

Cheers chaps. Just given a new lease of life to my not so very much used plasma cutter (why it never occured to me before I'll never know!) and spawned a whole range of project ideas  :(shades):

Lee

[Reaper]

Ah where would I be without my Plasma Cutter :D
A truly great bit of kit!