welding dissimilar metals

[Boomer-61]

I'm not sure where else to post this question so here goes. I am welding mild steel tubing to cast iron in the fabrication of trailing arms. What are the tricks to getting good solid welds? The reason I ask is that I had one tube tacked onto the cast iron bearing carrier when it fell off of the work table. When it hit the two pieces popped apart. That didn't surprise me, what did was what I saw. The pipe and weld pulled a chunk of metal out of the carrier. Is this prone to fail? Please advise.
Boomer

[bdkw1]

Grind the surface to be welded clean. Pre-heat the cast iron. Use a high nickle filler rod. Let cool slowly, cover with a fire blanket. Surface area is your friend........

[Boomer-61]

Will give it a try, thanks so much.
Boomer

[Dezzrats]

If you have a tig unit try this: Get some cast welding rod made for a stick welder and remove the coating, then use this rod as your filler and your tig. All the recommendations above will apply.

[bdkw1]

If your MIGing it, I have used regular stainless with before with good results.

[nutz4sand]

Might consider buying a replaceable bearing carrier (first pic) and make a arm similiar to this in the (2nd) pic but to fit it.

[Boomer-61]

I've got a MIG. Can I still use a filler and stay with the standard wire? Nutz, with my sad, sad budget I have to try and make what I got work. But,,, those trailing arm carriers of Yoshi's look very well thought out. I could do something like that. That looks like a very smart idea. I've only got one arm built and I think I can still make a system like that one work. If I can't, I'll have to give the welding methods a try.
Thanks all!
Boomer

[nutz4sand]

Yoshis stuff is nice and top end but if you just making a smaller mini rail with less power (and perhaps a one seater?) you might look at these for simplicity.

The green one is how this guy used to make them off the Desert Kart Panther plans. He had issues with them bending and tweaking.

The red one is the same panther type frame but he used rectangular tubing (3/4 x 1/12 .095 rec tube) and then welded round tube at the back for bearing carriers. You machine bigger? Use larger thicker tube.

He said they never had issues with the rectangular arms. Very simple to do considering. I thought I had more trailing arm pics on this computer. Lotsa good designs out there that are not too hard to do.

Even mimic-ing the red buggies rear arms you could take a tube and machine bearing carrier grooves in it for the axle carrier. OR you add a lil cost and weight but make a larger tube with a flat flange on the outside to hold the removeable bearing carrier like I pictured in my above post.

Just nicer if you DO loose a bearing you can usually bolt in a new carrier and be back riding. Course a person could simply make two arms per side an carry spares.

[Boomer-61]

I like the concept a lot. I like the idea of it being servicable and replaceable. If it goes bad, just unbolt it and bolt in a new carrier. Or If I scrape up the beans for new, lighter parts the same is true. I used round tube steel on the arms but for the carriers I bought some 4" square tube which I hope to attach without too many headaches this weekend. It's a low powered buggy. I got a fantastic deal on one of those kawasaki 27hp industrial motors, essentially free. It only needs a good exhaust system. It is a two seater so there is more weight than average but hopefully the trailing arms will be strong enough. I may need some help with shock variations in the futre, more on that later. Thanks for the pics. Love'm.
Boomer