Rear suspension frame

[TheArf]

I have been cutting the steel for this during the week ready for tacking together. Looking at the book it says to tack together RS1, RS2 and RS3 and similarly RS4,RS5, and RS6 and then to tack RS7,RS7a,RS8 and RS9 underneath. Now my question is should you fully weld the top face of say RS7& RS8 and the underside of RS4 & RS6 to achieve weld on all four sides of the joint, when placed one on top of the other. Dont know if I have explained myself properly

many thanks

[ozzy1]

Cant see a prob with that.Just tack in a brace to stop it bending in and then when fully welded to main chassis cut off the tacks for the brace.

[leroybrown911]

I am fully welding the 45 degree angles all the way around, then grinding flat to fit the uprights between the lower and upper frame, and between the two upper frames.

If this makes sense?!?!, basically no joints will be left without being fully welded.

[TheArf]

That was my concern too as I didn't like the idea of effectivly two welds only being welded fully on two sides.

[eSteve]

This is interesting and something I've had in mind for all the time I have been tacking together my chassis, as the meeting edges of tubes are covered by other tubes in the joint.


On several joints where multiple tubes meet, if one was to weld it up, with the chassis completely tacked up (i.e. all tubes in place), then as TheArf states, in some cases, some edges where tubes meet will not get welded.


My plan is to un-tack and remove the various tubes that cover the meeting edges of other tubes, weld the once covered part of the joint, grind back and then put back and weld in place the tube that was removed. As TheArf and leroybrown911 say, this will then ensure all meeting edges of the joint are fully welded.


Now we’ve been discussing the rear suspension area in this thread but what have members done with similar joints in other areas the chassis? Progressively welded/assembled the joint so all edges are welded or just welded the exposed meeting edges with all the joint’s tubes in place?

[monsterob]

I came to the conclusion that it would only cause a problem if you were using a slightly underpowered welder. With a powerfull welder there is probably enough penetration getting in there.

But theres no harm in going to that bit of extra trouble to over engineer something , and give you piece of mind.

Lol or have i under engineered my rear suspension area

[HandyAndy]

All good suggestions IMO,
Tho I would suggest that it is all welded together very carefully if fully welding all the RS parts together, what I mean is, be careful of heat distortion when fully welding, as the whole area is critical for the positioning of the rear wishbone brackets, so if that area has even a slight distortion it "could" affect the dimensions that would get "carried" along to the wishbones, & as most of us are using the standard layout on the wishbone adjustment ( lack of it unless using rose joints etc) might be difficult to adjust the distortion out.

Thats just my "two pennies worth"
On my own car, I have stitch welded along the lengths of the RS5 &7a, & RS4 & 7, on both sides, fully welded where all sides of RS8 & 9 meet RS6 & RS10, hope that makes sense

cheers
andy

[TheArf]

Thanks for all the comments they are much valued, I think I will tack weld all four sides and then run the tig along the two faces that come together making sure that the weld is not proud then I wont be putting in anymore heat with the angry grinder to get them flush and then tack them all together if that makes sense

[leroybrown911]

I have fully welded the frames RS1/2/3 and 4/5/6, I have minimzed distortion by tacking the frames to my bench when welding. The result is 2 flat C shaped frames ready to weld to frame and upright.

I have ground the welds flat so uprights sit flush on top of lower frame and, obviously, under upper frame. I was not happy to put the uprights in place without welding up the frames.

See my blog for picture, more coming soon.

I have not built the transmission tunnel yet but up to now I dont recall having this problem of 'hidden joints' anywhere else on the chassis. Everywhere else I have tacked only and will weld later.

Cheers
Leigh