Best way to build rollcages?

For an RX7 I'm building, I want to scratch build a cage for it. I've never had much luck building cages before, I think because I use the wrong materia. Any one got any tips on building cages?

I just thought this up now, but you'll probably have to experiment with it. You know how the parts have the plastic tubing around them? and you have to cut them away with a razor? well you could use the leftover tubes and use a light flame to soften up the plastic so you caould bend it. Again, i just thought this up now, so test it before you go putting anything on the car and lighting it on fire!

It would be better to use styrene rod instead of tube as the latter will lose its shape when bending.

Originally posted by RyanGiorgio
I just thought this up now, but you'll probably have to experiment with it. You know how the parts have the plastic tubing around them? and you have to cut them away with a razor? well you could use the leftover tubes and use a light flame to soften up the plastic so you caould bend it. Again, i just thought this up now, so test it before you go putting anything on the car and lighting it on fire!

I'm pretty sure he's talking about the "trees" this method works, that's how I got the roll-cage for my Supra, AE86, Mustang. For my civic, I used metal rods, I didn't really like the rods, I tried super glue to contact them, but it never did stick!

What size styreen rod? I was looking at some today and couldn't decide.:confused:

3/32" (2.4mm) diameter works best, I just used this size to build a rol cage for my Renault Megane kit.
I took a piece of roll cage from one of my Tamiya WRC kits to the hobby store and actually compared it to what they had there, this was the absolute nearest to the right size.
Building a roll cage this way takes a lot of time and patience though, make sure you measure plenty and test fit everything before you glue everything in its final place. Remember you're making it to mount on the chassis section but fit inside the body(at least I did) so you have to test it.
Good Luck

Ray

To give an idea of what can be done:
http://files.automotiveforums.com/uploads/949045cage1.JPG
http://files.automotiveforums.com/uploads/610183cage3.JPG

Thanks alot man!:D

You can go to a hardware store and get some metal rods, Don't lnow how much it's cost but it's easy to make them, BUT DON"T USE THE "TREES" ,they're WAY too thinck for a roll cage so they're not real enough, use the recomended styrene stuff, and look at roll cages in race cars before you build one! I saw a guy just build a cage without looking at referance pics and it did'nt even look like a real cage ***caugh- kicker-caugh***

Thanks for the tips. I have plenty of plastic rod from other scratch building projects, I just wasn't sure it would bend OK... I'll give it a shot and show you guys what I come up with!

http://www.mas-parts.com/uploads/mas-models/37-pro_street/37ford.1.jpg
http://www.mas-parts.com/uploads/mas-models/37-pro_street/37ford.2.jpg
http://www.mas-parts.com/uploads/mas-models/37-pro_street/37ford.3.jpg
I built the rollcage and chassis for my '37 Ford ProStreet out of Plastruct tubing and rod. I used three different diameters to approximate the various sizes used in 1:1 cage construction. Plastruct's .080 dia. tubing replicates the 1 3/4 inch diameter that most cages are built from very closely.
Any decent hobbyshop should have a display rack with all of the sizes in stock.

Lotus_man,
I put wire inside the styrene tube before I bend it, then leave the wire inside, it helps it bend nicely and keep the bend(and stops any kinks forming).
I actually found the average paper-clip is the right diameter, and can be bent eaily enough, just bend it straight as you can first.:)

Ray

Originally posted by lotus_man
For an RX7 I'm building, I want to scratch build a cage for it. I've never had much luck building cages before, I think because I use the wrong materia. Any one got any tips on building cages?

I used 2.5mm brass rod for an RX-7 FC race car
once. Brass is easier to bend than polystyrene or
ABS rod, but soldering the welds requires a lot
of planning and patience.

The real car had 43 meters of tubing in the cage
(full cage interconnecting the shock towers front
and rear) and I managed to get over 1.5 meters of
rod in the model cage.

'have fun,
-- Eric.

Brass rods work very well. You can bend them easily and it'll hold shape and dimensions. To join these you'll need to use silver solder and a soldering iron. I think this has worked the best. If you're really good with soldering, you'll have minimal amount of sanding due to the flow characteristics of heated metal. It should blend real nicely to form the joints.

-Walter