Roll cage Help Needed

[Hiroboy]

OK, I need a bit of help here, I'm trying to scratch bulid a roll cage. and I'm having trouble with the joints breaking when I work on it.
I have been using plastic tube or solid platic bar, but the connections are not strong enough even with superglue.

I have been trying to build with in the body to ensure the fit.

This is a 1:24 Rollcage therefore maybe too small to use brass and solder ?
I will post a diagram of what I want it to look like in the end it give an idea of the required section.

Thanks in advance for any tips

[proosen]

Couldn't you just reinforce the joints with a little metal pin, from a needle perhaps? Drill a hole and glue the pin in with CA, should do the trick I think.

Niclas

[aN4rK1]

i usually use the tree rods that are loeft over from old kits or the current kit. I find if you bend slowly it usually does the trick. Not as for joint. I use super glue just to get the part to stick, then i use tamiya basic putty, small amount to fill in the cracks/gaps. I find that this usually works.

[blubaja]

How about plastic welding glue? Tenax-7R

[mike@af]

Hey Steve, hopefully I can teach the master some new tricks. I've come across this problem with my scratch built hot rod. I use Testors Liquid Cement. CA is simply attaching the pieces together, where as liquid cement bonds the plastic.

Notch you joints using a round file, check the fit against the tube, and use a good amount of liquid cement on the tube edge to get it nice and soft. The plastic will then be melted together forming a strong joint. Now the problem may be with wall thickness of the tube. Take your normal roll cage tube, and find another tube that fits inside of it snuggly. Use the liquid cement and bond them together. Let them dry for a couple hours and you will have a thicker gluing area (thicker wall).

Then you may want to reinforce is some more with some CA around the joint then sprinkle baby powder or baking soda on it. Then sand.

This isnt guarenteed to last forever and be amazingly strong, but it works better than just CA.

The other alternative is brass and solder. This is really strong, and works well. Dont worry about it being to small for 1/24. If you use the correct tube, and good bender to keep the wall from collapsing it works. I've soldered rollcages for 1/43 without to many problems. It helps to pre bend all the pieces then mock them up in a clay base so you can solder them together.

[willimo]

For work like this I would do pretty much as Mike said but with one main difference - instead of using plastic tube, I would use plastic rod. I would have two diameters of rod, one that you use for the roll cage, and one much smaller one (.5-1mm) for "pins" like the metal ones suggested above. At joints, I would drill out a small hole in the end of the rod where it will butt up against the side of another, and put the smaller rod inside, cementing it with plastic cement. Then, drill a hole to accept the "pin" into the part that you are butting this up into, and cement it in. I use "pins" as long as I can get away with, 3-4mm each way if it's possible. This will end up working a lot like the positive locating pins that they engineer into kits, and the cement joint, inside and out, will be much stronger than just pressing two parts together, cementing, and hoping for the best. Bonus: it helps align the parts and prevents wandering parts with slow drying cement.

[proosen]

Hi again!

Just to show you how strong the bond gets from a similar product as Tenax. That is a full milk box, approximatly 1 kg on top of my scratch built tube frame.
It flexed a bit but as you can see it holds the weight just fine.
It's made of 1.5 mm rods and no fancy stuff just took care doing the joints as good as I could.
The frame was supposed to sit under a 1949 Ford but I blew the body on it so it has been sitting around for 6 or 7 years now.

Niclas

Edit: no pins what so ever!

[gionc]

I use plastic tube with inner brass "pins" but i prefere 2 part glue insthead CA or liquid cement: 2 part have more viscosity than others so its really easy take the component in shape. after gluing (5 mins. 2 part glue) I use to reinforce connections every with 2PG with a metal-sold effect.

[flyonthewall]

Originally Posted by willimo

For work like this I would do pretty much as Mike said but with one main difference - instead of using plastic tube, I would use plastic rod. I would have two diameters of rod, one that you use for the roll cage, and one much smaller one (.5-1mm) for "pins" like the metal ones suggested above. At joints, I would drill out a small hole in the end of the rod where it will butt up against the side of another, and put the smaller rod inside, cementing it with plastic cement. Then, drill a hole to accept the "pin" into the part that you are butting this up into, and cement it in. I use "pins" as long as I can get away with, 3-4mm each way if it's possible. This will end up working a lot like the positive locating pins that they engineer into kits, and the cement joint, inside and out, will be much stronger than just pressing two parts together, cementing, and hoping for the best. Bonus: it helps align the parts and prevents wandering parts with slow drying cement.

I do the same.

[exhaust smoke]

Hi steve,

I recommend using Plasticweld. Much better stonger than cyanoacrylate and liquid cement, but just as quick as cyano in setting time.

Also, as suggested previously, metal pins to reinforce the joints will be a safe bet.

Good luck!

[white97ex]

I would use brass rod. I typically use 1/16th for my cages. it looks pretty scale. I wouldn't mess with tubing.......when its all soldered together, you can't tell the difference any way

[Hiroboy]

Thanks guys the metal pins seem to be working a treat

[Hiroboy]

Thanks guys, this was the finished item before painting, I ended up making it from Aluminium Tubing and using pins to strengthen the joints.
So AF helped out again

[mike@af]

Did you smooth out the joints with putty?

[white97ex]

looks good