Free 3d software for designing a tubing/exhaust system?

[Teeps]

Well I need to send a blue-print off (with units of measurement)
to show a mandrel bender the sections of tube I need bent to demintion with acurate dimensions and curves.

The only way to really show him how this tubing has to be shaped, is with a 3d drawing.

This is kind of a one time thing, I'm looking for something tailored for this, but also free or cheap.

I tried the RHINO demo, and I can't figure out how to make a tube with the demo version, I'm not going to buy it if I can't make a simple object with the demo.

I've designed an EGR block off plate using the software at emachineshop.com just to try it, and it was fairly easy to use.

Just curious if you guys have had any luck with a particular software package and tubing.

Thanks,

Don

[satansfriend]

try the free 30 day trial version of autodesk inventor 9.

[dragracer1199]

if you're fabricating an exhaust system, why not just buy mandrel bends that are already bent in the form of "J" bends and "U" bends and cut/weld them where needed? I did this as my first welding project and it turned out great.you can buy the bends from summit racing, jegs high performance and others.

[Teeps]

Yes I'm doing that for 90% of the system.

However the 4" stainless tubing is hugely expensive, and to buy enough U-bends for a particular section (requiring several 90 degree bends, on semi-tight radius) it will actually be alot more expensive to buy the U-bends, then to have this particular section just mandrel bent to fit to the next straight weld joint.

Also In my experience, the less welds the better in an exhaust system in MI, I'm already going to have a huge amount of weld joints in the system with all the angles and U bends I'll be cutting to joint.

I also want to try out blue-printing, and try out this guys service.

In the future I could offer complete exhaust setups for cars, if I'm able to blue print a whole system.

I hopefully already have a CD coming in the mail, however If I understand correctly the demo version of that software does not give you measurements on the print

[afortier]

This may sound like the best way to approach your project, however you would be far better off building a prototype in mild steel and bringing it to the mandrel bending company then to do prints.