For the technically minded

[gingea1pom]

Evening all,

I have had half a day in the garage today and am slightly confused!

Hare goes stick with me and have your book to hand.

I have constructed the RS1, 2, 3 frame which is 430mm long along the RS1,2 length as per the book, as I understand it this is then placed centrally on BR12, 3mm from the front edge to allow CP1 and 2 to sit flush with the front of BR12, all with me so far.

My concern is in Fig 4.15 page 43 it shows the back end of the RS3 to be 406.9mm from the back of BR12. However if you work out 430mm (the length of RS1, 2) + 3mm (the thickness of CP1) – 25mm (the width of BR12) = 408mm. I have laid it all on the bench and I get 408mm.

So my question is really. Is the 406.9mm dimension the important bit, i.e. when I build it all make sure the back end of RS3 is 406.9mm from the back of BR12 or am I getting to picky I mean it is only 1.1mm!!

I will let you digest that over night as I am tacking it together tomorrow.

Cheers Ginge

[HandyAndy]

i think i see where you are trying to get clear in your mind, this may not be the absolute correct answer but here is how i tackled the process of fitting the parts you mention,......

the main point being CP1 & CP2, i,ll explain..... by positioning these parts into place & fully welding them onto BR12 & SB3 they ideally need to be totally flush at the front edge at the lean angle of the seat back , so even tho CP1 & CP2 are 3mm thickness don,t forget the actual lean angle, so yes 1.1mm is not going to create a major structural problem, i,m sure others have thought the same but if 1mm difference in the length of the chassis is the only concern then i for one would be happy to accept it.

my only suggestion is to trial fit the parts using clamps/magnets to check the whole area is "square", thats more important due to the geometry of the rear suspension.

hope that makes sense & maybe helps.

cheers
andy

[squbti]

I was not at all worried with 1 or 2mm longer or shorter on the chassis(do not need that kind of stress) but tried to make sure everything was square like Andy said because where it realy counts is the geometry of the suspension.
cheers
Samy

[gingea1pom]

Cheers Andy and Samy,

I thought/hoped that would be the answer as the maths doesn’t help. I am going to get it square and ensure RS3 is 406.9!mm from BR12.

I really need some chassis plates to go any further, time to assess the budget!

Cheers Ginge