Technical 28-29 A Frame Gussets or ?

Currently welding in box plates on my 29 RPU frame. Wondering if gussets at the crossmembers are ok or should there be something more substantial?

 

need a lot more info on what you are building

 

29 RPU with 8BA motor, T5 trans and 1940 Banjo rear.

 

Here's a couple pics. In these pics it's just tacked together.

 

From what I can see your frame looks like it's boxed very well. HRP

 

Already way more than it needs.

 

I personally would add some legs to the center crossmember to make it a K or better yet an X.

 

I would add fish plates to the rear step. JMHO...

 

I'm not saying anything until you change your avatar to something more appropriate to this place!.

 

………says the man with a pineapple ? ………

besides, who doesn’t luv a Datsun with a bug catcher poking through the bonnet……..

 

What exactly do you see gussets etc. doing? What forces are they intended to resist? Have you been able to quantify these forces?

Good to see the triangulated 4-link. Have you plotted the instant centre in side elevation? I can't really tell from the pics but it might end up a tad low when there is more weight on the chassis. That would give the opposite of the hook characteristics you want. Depending on what you actually find you might want to raise the front ends of the lower bars a bit. If that is necessary to get your instant centre right, it would also raise your rear roll centre a bit, which suits your lightish rear spring — you might even be able to lose a leaf — and that in turn means that you get good damping out of soft dampers without overburdening those longish single-shear cantilever shock mountings. You're not done but it looks like you've got the makings of a positive spiral there.

When an axle is positively located like that you want the spring shackles closer to vertical than the commonly recommended 45°. Otherwise you'll have several different roll centres fighting each other.

 

It's a traditional pre 1965 plant.

 

Thanks for the tips. The instant center is a little far out. At this point it would be easy to raise the front of the lower bars. The rear spring is still questionable until I get all the weight on it. I did setup the mounts for coil overs i I don't like the leaf.

 

I would add some 2”x2” “K” legs to the trans crossmember, to keep the frame from racking.