With some plate of wood, an digital gradenboog (sorry don't know the english word of it, it is the yellow thing), an cupper hamer, water-level and an pipebender I'm starting to make my own rollcage.
P.s. I use 1 1/4 tube.. That is 42,4mm with an thickness of 3,25 mm
p.s.2 This is only 1 tube of my rollcage (from B-pilar to B-pilar)... the other will be bend in about several weeks (I'm verry shirt with time the coming weeks.. it's a pitty )
Not sure how it compares to European materials but in North America, tubing is different from pipe. Pipe is not used for roll bars. I am not sure of the reasons but there are numerous warnings about how it is not suitable (or safe). A pipe bender makes a total mess out of tubing. A tubing bender bends the tube around the die where a pipe bender pushes the die into the pipe bending the pipe around it. If you use a pipe bender on tubing, the tube kinks very badly. Assuming the above warning is not applicable, nice looking work!
Brian Murray wrote:that looks more or less like a tube bender.
Ummmm, it does? Looks like a pipe bender to me. Notice the die is mounted to the ram, which pushes the die INTO the pipe-- its a pipe bender. Bhowden is correct-- a pipe bender creases the hell outta tubing if you crank on it, or will oval the tubing if you only bend it alittle.
Proper tools, proper materials, proper job. Im not proper, so Im exempt from this rule.
Yep it is a pipe-bender.. If I understand it right what you guys say above.
But a tube-bender I couldn't find it any where in the Netherlands, Belgium, Germany or England.. where I could buy them. I've only seen them on american sites.
And the knicks or oval bending is nearly impossible to only feel or see it!!!
SO I think there is no problem with the safety or so for the rollcage.
Greetings Wiebrand...
p.s. yeah yeah with alot of beer i can only bend straight hahahaha
Ow yeah almost forgotten. I use tube that they call in Holland gastube!! It is proven on pressure and it is heated up after the rolling-mill (hope this is the good word for it) so that the inner forces (be with you ) from the rollingproces are relaised.
I am not sure why so perhaps get the final answer from somebody that knows what they are talking about. The HP books book on building off road VW's lists mild steel 1.5 or 1.75 inch outside dia .095 wall or higher DOM (Drawn over Mandrel) as the best. ERW (Electric resistance welded?) is acceptable, 4130 chrome moly best for experts and not home builders. "Totally unacceptable under any circumstances is pipe as used for gas or water". Again, not sure why. I have heard it refered to as black iron pipe so maybe it is an alloy that is good for resisting corosion but not good for strength? In North america, tubing is sold by OD and pipe by ID but that could well just be convention. Pipe is typically joined by threading with a standard pipe thread (tapered) and fittings. All the dies I have seen are sized for pipe sizes. I have never seen threaded tubing. I have a pipe bender which looks similar to what is in your pictures. I lined the dies with pipe split down the sides (eg 1.5" pipe die with 1.5" pipe liner split down the side of the die.) I pack the tubing with sand and it bends acceptably but it is not as nice as bends I have had done with a tubing bender. Somewhere in the future is a blind chicken racing style bender. I hope to salvage the ram from the pipe bender and am toying with trying to cast the dies from pistonium.
When I made the roll bar for my Ghia, I first tried to bend the tubing with a hydraulic pipe bender I borrowed from my bro-in-law. I wasted several feet of pipe and verbalized over 100 cuss words in the process because EVERYTIME I tried to bend the tubing it would crease or at least oval the tube. Frustration prevailed, so I headed over to see my buddy at the local muffler shop who bent the tubing DEAD ON BALLS with a Mandrel. I took him the "pattern" I made using copper water tubing (the stuff you usually see behind a fridge for an ice maker) and bent it to the fit I needed inside the car. One case of Coors Light later, everything was bent perfectly.
I admire how much dedication you have for your car... you're doing EVERYTHING yourself, that's cool. I do everything myself too, but that's the reason why my car was off the road for 3 years... You seem to have a knack for getting a LOT done in a short amount of time!
When you're done with the cage, and before you weld it in, can you weigh the pieces? I'm curious how much weight a cage like you're building adds to a car.
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! keep us posted, i cant wait to see that sucker in your car!
hahahaha
I do everything myself too, but that's the reason why my car was off the road for 3 years... You seem to have a knack for getting a LOT done in a short amount of time! 
