Hello from Darren

[jolly_roger187]

hi, i'm Darren J, 20, from nottingham and have never welded before! suppose this is a different way to start eh? well.....being an off-road bike rider that i am, i have recently been harbouring a fantacy of constructing some sort of off-road dune buggy or something, infact.......im off to buy myself a 'Sealey Mightmig 140 Amp Turbo Mig Welder' this week end, heard this is the right tool for the job.....that right? Also buying various other tools and equiptment such as a 12 ton hydraulic pipe bender for making the framework and roll-cage and so-on. just wondering if anyone here has done similar work before and could direct me with usefull info? cheers!

 

[malcolm]

Hi Darren, welcome to the forum.

That sounds like an excellent project, and the welder sounds fine for the job.

I bought a hydraulic pipe bender with the hope of bending an exhaust pipe. It really made a mess of 50mm diamerer tube with 1.5mm wall thickness - it just kinked the pipe. For that sort of thing you'd need a mandrel. It works fine on smaller diameter and thicker tubes, but it might be worth buying a small amount of tube to start with just to check the bender will work.

Are you designing the frame from scratch? One useful trick we did at college was to make models of structures out of straws (I think they were joined by pipe cleaners). That was excellent for finding potential stiffness problems and getting a nice triangulation for the structural members.

Malcolm

 

[jolly_roger187]

Thanks for your info malcolm.
yes, i intend to make my frame from scratch. i'm not going for the proffisional look though, everythings being constructed on my brothers drive-way! it will be good to see what can be achieved from being basic eh?
i am actually planning to use the chassis of a small car, and building the frame around it. is it a good idea to mount the engien in the rear? i will have a load more questions that i will ask in this forum, i'll need all the tips i can get, then i will post the finnished result.
malcome, your idea with the straws is inspiring and i will put it into practice, cheers again. All ideas are welcome thanx.

 

[malcolm]

It will certainly save a lot of time using the chassis and suspension from another car. I scratch built some suspension once - took me a year! For anything running on a loose surface (off road) you'll definately want rear wheel drive for power sliding. Putting the engine over the rear wheels improves traction, and putting it behind the rear wheels makes for a tail happy car. I think that's one of the main reasons why VW Beetles are a popular base for dune buggies.

For welding outside you might find fluxed wire is better as it doesn't take much breeze to blow away shielding gas. I was reliably informed the other day that the polarity of the gun needs to be negative for this (well worth a look at the manual).

One thing worth thinking about is attaching the roll cage mountings as close to the suspension mountings as possible. That's what the saloon car racers do and it really stiffens up the chassis.