FF3 and suspension bracket

[voucht]

Hello,
I have a concern about the front frame, and I'm wondering if I'm completely wrong, or if there is something I missed ?
If the front and back face of FF2 and FF3 are respectively parallel to the front and back face of FF1 on their lower part, and if the top part of FF2 et FF3 are square on each face with FF4, then the outer and inner face (leaning part) of FF2 and FF3 can't be parallel to the outer and inner ends of FF1, as their base section, when cut and put flat on FF1 is a rhomb (see 2D sketch below). Stop me now if I'm wrong.
FF1-FF3Problem.jpg
But if I'm right, how the axis of the suspension brackets attached on FF2 and FF3 can be parallel to the central line of the chassis, as the back plate of these brackets should be welded on the outer side of FF2 et FF3 which is NOT parallel to the centreline of the chassis ?
On the 3D view, the axis and back plate of the bracket is parallel to the centreline, and the back face of this bracket cannot be plated to the outer face of FF2 or FF3. There is a gap, as the two faces are not parallel.
My guess is when you put the suspension brackets with the rigs, you cheat and fill the small gap with welding. Does not sounds very good to me, but I might be worrying for nothing.
GapOnBracketAndFF3.jpg
Could anybody who has already been to this point please explain what he did, and the magic trick ?
Thanks a lot.
Regards.

[michael92]

I belive this to be normal, when discussing this with handyandy he said most times people need to use packing plates

hope that clears a bit up


Michael

[ayjay]

That worried me too.I was convinced I'd got it all wrong --measured a million times, checked the jig etc --- then just welded in a little packer and put in a couple of support fillets where it overhangs the chassis tube

[voucht]

Hello,
Thank you so much for your answers, they confirm me the positions of my FF2-FF3 are right (whew !)
Sorry, I'm not English, and I have hard time to understand what you mean by "packing plate" or "then just welded in a little packer".
Thank you for your clarifications.
Bye.

[Talonmotorsport]

yes you are correct the design in the book is wrong as you have proven with autoCAD. DO NOT NOTCH AND BEND FF3! Make FF3 in two independant sections weld the short upper section to FF4 then add the lower section while in the jig,when you make your front frame jig add two 90' uprights either side of the lower section of FF3 and clamp these SQUARE TO THE BASE OF THE JIG.

[voodoo]

Originally Posted by Talonmotorsport

yes you are correct the design in the book is wrong as you have proven with autoCAD.

Careful mate - you'll get lynched!

[voucht]

Originally Posted by Talonmotorsport

yes you are correct the design in the book is wrong as you have proven with autoCAD. DO NOT NOTCH AND BEND FF3! Make FF3 in two independant sections weld the short upper section to FF4 then add the lower section while in the jig,when you make your front frame jig add two 90' uprights either side of the lower section of FF3 and clamp these SQUARE TO THE BASE OF THE JIG.

I've been trying to figure out how to do it (simulating on my 3D software), but each time you turn the tube, or/and change an angle, the complete geometry is modified, and then the suspensions brackets (I mean the axis) will lot have the correct position. Can't figure out how you did it. Do you have any drawing, 3D views, sketches, dimensions and angle cuts you can send me please ? Otherwise I will leave it like in the book, and pack the gap, as it looks like the majority of builder do.
Thanks.
S.