Splicing square tubing for frame for ease of construction?

[yuta]

Due to my personal situation, I'm entertaining the idea of building the frame in sections (maybe have someone build it for me) and then weld them together later.

Looks like it will involves splicing the square tubings. I may put a inner tube or outter tube to connect them.

My question is, is this a sound practice?

I can definately make the joint strong, by adding reinforcement inner or outter tubes. But the joint will be stronger (or I should say stiffer) than rest of the tube. Will this be any problems from structural point of view?

[davew]

You see splice joints in almost all production frames. But instead, of a 3rd inner part for alignment, one channel is neck down slightly to slide into the mating rail. This assures correct alignment and a quick and easy assembly. As long as you have good welds, very thing should be OK.

[Lonnie-S]

Splicing of RHS (Rectangular Hollow Section) is done all the time with hot rod chassis. Off road vehicles seem to favor joints joined by plates where chassis demands are very high. You might want to see if there is something from that world you can adapt.

Cheers,

[BostonWill]

If you use an inner square tube connecting the joints, suggest you drill holes in the outer tube (two per splice) staggered. After you join the tubes, rosette weld the outer tube to the inner splice tube at the predrilled holes. Then weld the seam joint.

[horchoha]

Like Thom said, bang on advice

[rx7locost]

Consider that the square tubing usually used in Locost construction has a seam that creates a buildup inside the tube. This prevents inserting a 7/8 tube splice (if available) from being inserted in a 1" 16ga tube without removing that buildup. Alternatively, grinding a small groove in the splice to make space for that seam buildup. It may seem like a quick solution. The devil is in the details. Tolerances of the inner tube splice may also prevent easily inserting that splice.

It might make sense to build the sections so that they connect in anormal joint location. This would likely require temporary bracing during building the sections. The bracing would then be removed when welding the sections together.

The Jag XKE bolts the front frame assembly to a monocoque body. It holds the entire front of the car including the engine and front suspension body parts etc. You might want to check out their assembly methods to see if it can be incorporated?

[tibimakai]

I'm worried about final alignment.