Newbie- Square tube verses round?

[David Lucas]

Hi, 1st timer but have square eyes from reading everything here, WOW. Can anyone enlighten me on why square tubing mounted on its 90 degree edge can not serve as a ridged x axis or y instead of round or angle rails? Any help would be great, thanking you, David.

[sonicwonder2000]

Square tubing can be used, depending upon your tolerance requirements. Because of the way square tubing is manufactured, internal stresses in the tubing cause the faces to deform from perfect flat surfaces. The thinner-walled the tubing, the more deformation is usually present. For this reason, most people don't use square tubing for linear rails.

Because of the radial symmetry of pipe and tubing, these stresses tend to equalize themselves and yeild more regular geometries.

[David Lucas]

Thanks a lot for the reply.

[dertsap]

http://www.cnczone.com/forums/showth...t=23120&page=8
I used square tubing and angle iron and I wouldn't trade it for anything short of true linear rails
my son an i are currently building a table for him and we are once again using square tubing and v-bearings
as far as accuracy goes ive cut aluminum within a couple of thou and have played around cutting steel with good success with the high rpm spindle (router)

YouTube - cutting steel

YouTube - cutting steel

[tobyaxis]

Nice Trochoidal Tool Path Curt. It reminds me of this Thread.

http://www.cnczone.com/forums/showthread.php?t=73902

[dertsap]

Originally Posted by tobyaxis Nice Trochoidal Tool Path Curt. It reminds me of this Thread. http://www.cnczone.com/forums/showthread.php?t=73902

too much air cutting for my liking , I dont particularly like that type of path in the real world but it works on the toys . i did it to prove two things , it doesn't take a whole lot of torque while using that type of path and the most important reason is that a guy can cut steel on a diy router something that everyone tends to rule out when someone mentions the desire to cut wood , ally and steel , its only a matter of having the right tooling and the right state of mind

[Jason Marsha]

Some possibilities. In both cases the setup is adjustable so they will be no play between bearing and hollow section.

In the last two pics the the hollow section to be used is 120mm(~5 inches) X 80mm (~3 inches) and is made from 6mm (~1/4 inch) material so its very heavy and very strong.

Jason

[dertsap]

that boxed in design is pretty good , I have a welded cage that i did in the same sort of bearing configuration that ran across a chunk of aluminum channel , it now sits on a shelf waiting to be used , now that i think about it i do believe it will fit well on my sons build , thanks

[Jason Marsha]

Forgot this pic

[Jason Marsha]

No prob dertsap.

I was drawn to the boxed in design because of its ease adjustment. It may be tight at first but running the bearings manually across the hollow section seats them on the running surface.

Jason

[dertsap]

Jason great setup

[FandZ]

I'm useing square too. I think it's the easiest to work with. Plus everything squares up nicely. I plan on useing 3x3x1/4 aluminum squares on my next build.

Jason, you have a build thread anywhere?

YouTube - cnctestrun

YouTube - cnctestrun