The JD squared machine will bend 1/2" to 2", pipe, tube or square section, with the correct die. Its the wall thinkness that will determine how successful the bend will be. I have bent 1.5mm with perfect results in this machine.
You could try filling your tube with dry sand if it is creasing.
The other thing to watch out for is that tube and pipe are different. If you have a pipe bender it is unlikely to be much good on engineering tube as the dies will not support the tube properly due to the different methods of sizing employed. Benders that push the tube through rollers are primarly intended for soft, thick walled material like steel pipes.
Have a look at this article on mandrel bending, its old but applies today still.
http://www.green-trust.org/junkyardprojects/FreeHomeWorkshopPlans/TubeBender-GSBates.pdf
Also
http://www.thefabricator.com/TubePipeFabrication/TubePipeFabrication_Article.cfm?ID=964
You could try filling your tube with dry sand if it is creasing.
The other thing to watch out for is that tube and pipe are different. If you have a pipe bender it is unlikely to be much good on engineering tube as the dies will not support the tube properly due to the different methods of sizing employed. Benders that push the tube through rollers are primarly intended for soft, thick walled material like steel pipes.
Have a look at this article on mandrel bending, its old but applies today still.
http://www.green-trust.org/junkyardprojects/FreeHomeWorkshopPlans/TubeBender-GSBates.pdf
Also
http://www.thefabricator.com/TubePipeFabrication/TubePipeFabrication_Article.cfm?ID=964