U1/2 book error?

[Eternal]

Hay all i got a 10mm error here :D Right its in the height of U1 and U2. The distance between the top of br1 and tr1 is 305mm. But if you work out the height of U1 using the measurements in the back of the book it comes out at 315. With a hypotenuse of 345mm and an angle of 24' gives a height of 315.

Anyone else found this?

[Eternal]

Can anyone confirm the correct size for this part so i can continue tomorrow? :D Good night all

[HandyAndy]

I haven,t got the book at home with me,
but do you mean U1 & U2 ? If you do mean U3 , i,ll check my book in the morning :o :D

What is more critical is the distance between U1 & U2 where they sit on top of BR7, Tho are you altering those dimensions for your engine choice?

sorry can,t be more help till the morning :rolleyes: :o

cheers
andy

[Eternal]

here is a pic from gingea1pom's build showing what i mean.
http://img27.imageshack.us/img27/1296/chassisuprights.jpg
My book shows a 24 degree cut and a side lenth of 345mm this gives a hight of 315mm and wont fit in the 305mm gap. I have a revised book that has all the ammendments in so maby this is a new mistake?

[HandyAndy]

As I haven,t got the book with me,

The distance between U1 & U2 on the top face of BR7 if i remember correctly is 261mm ( i think thats correct, but check against the book diagram please),

Its a long time ago that I built my own chassis but don,t recall any problems fitting U1 & U2 , & yes my chassis is 305mm in overall height too...

I was never the best at maths :o so you now have me wishing I had my book with me :p

cheers
andy

[Eternal]

yeah 261 is right for the distance between the two uprights got that bit marked out ok. Its just when i got around to putting them in they were 10mm too high lol. I will do a scan of my book tomorrow morning just to show im not mad or anything

[Eternal]

http://img807.imageshack.us/img807/8379/u1and2bookerror.jpg
This book is the 2008 reprint. ISBN 9781844253913

[alga]

I think you forgot to substract sin(24°) * 25 from the length to get to the oblique end. When you do, the discrepancy is just 0.88 mm:

>>> (345 - (sin(24./180*pi) * 25)) * cos(24./180*pi)
305.88387256822983

[Eternal]

damn thats total length lol urrgh

Thanks for pointing that out lol :rolleyes:

problem solved lol and thanks.

[HandyAndy]

I,ve just arrived at where I,m building my car,...

I,ve just measured my own chassis as best as I could ( difficult to get the steel ruler into position as there is so much other stuff in the engine bay)

The length of U2 from the point of where it sits on top of BR7 closest to the center line of BR7 to where U2 meets the outer edge of TR2 is 320mm,

Tho like I say, its not easy to get the steel ruler in there ,

does this help at all?


oops, too slow.....nice one Alga , glad it came good in the end



cheers
andy

[Eternal]

nice thanks guys. So handy having people who are doing the same thing. My only worry is where u1 and u2 join at the top. As my engine bay is stretched so tr1 and tr2 are at a different angle. oh well will soon find out lol tell you what can someone measure the distance between u1 and u2 at the top?

[HandyAndy]

can someone measure the distance between u1 and u2 at the top?

do you want the inner engine bay measurement or the outer measurement between TR1 & TR2?

i,ll pop into the garage now and get both measurements for you.

cheers
andy

[HandyAndy]

the measurement between TR1 & TR2 at the center line of where U1 & U2 meet the top rails on the inner face of the top rails is 640mm....
just add 50mm for the outer measurement .

hope this helps.

cheers
andy

[Eternal]

http://img24.imageshack.us/img24/1862/u1u2top.jpg
basicaly the length of the green line measured from the inside of u1 and u2. Sorry about this but its kinda important i get this right for the wishbones lol

[HandyAndy]

see my post above this picture ;) :D

its no problem, ask for any help , thats what this forum is all about :cool:

cheers
andy

[Eternal]

Nice. thanks a load got the bits cut right now with the right distance between them. Only buggerance is the fact that they dont sit inside the chassis lol. Damn extended chassis! was really hoping i would get away with not messing with the suspension uprights. Any ideas?

http://img696.imageshack.us/img696/2517/img02081.jpg

[HandyAndy]

its difficult to comment as you are altering the dimensions but how about "fettling" U1 & U2 to make them fit correctly on the underside of TR1 & TR2,
then
make your suspension bracket jig as per the instruction in the book, place it into position on the chassis & you,ll then see how much "gap" is created by you altering the dimensions of the chassis, then maybe welding an additional section of box tube to the outer faces of U1 & U2 so that the suspension bracket jig meets the required positioning......just an idea :)

cheers
andy

[TQ_uk]

Not that I've started building yet, but also considering extending wheelbase so am following your build closely!

Can't you 'just' cut the uprights U1/U2 to fit, then modify the wishbone bracket postion(s) to match original spec/jig.

If you've extended the engine bay, and used standard front frame then won't the width between the side rails (TR1/2) be WIDER than book, thus U1/2 sitting inside the top rails (rather than outside as per your last pic?)

Also what affect do you imagine an increased wheelbase will have on steering geometry (ackerman etc) or will it be minimal & enough to ignore?


EDIT: Doh! Just beaten to it by Andy

[Eternal]

http://img205.imageshack.us/img205/2906/changes.jpg
green is original area.

Its hard to explane... yes you could change just the firewall forward but then the Top rail tr1/tr2 would not match the same angle as BR3 and BR4 so what i did was bring out br3/4 to the same angle that tr1 would be. this gave me a little bit more space in BR10. best way i can explane the way it sticks out is by getting

this kinda shows you why its out more. :D red shows original, blue shows my one green shows the length of U1/2 and why its sticking out.
http://img823.imageshack.us/img823/194/urlength.jpg

It now sticks out 7mm lol, ok i have a idea i can do a front frame type thing and take a wedge out sould not be too hard to work out :D

[Eternal]

and as if my magic problem solved! wooo.
http://img808.imageshack.us/img808/1927/img02091.jpg

Thanks for the help lads

[HandyAndy]

what a neat solution to the problem :cool:

but may I ask..........as its not easy to see from the angle of the photo, will the suspension bracket on U2 now be in the correct place when you use the standard suspension bracket jig? if so..........well done on solving the problem:cool:

cheers
andy

[Eternal]

yeah the bend in the u1/2 are both above the bend in the front frame. The brackets mount just below the front frame bend. :D

[HandyAndy]

yeah the bend in the u1/2 are both above the bend in the front frame. The brackets mount just below the front frame bend.

Nice one :cool:

You,ll soon have it on wheels now :eek: :D

looking forward to seeing pics as you complete the chassis:)

cheers
andy

[Eternal]

I hope to get it off the bench soon as i need the space to finish my cnc machine stand lol. Just got to work out when i can start fully welding stuff now. Im guessing i should fully weld after i have installed SB2 as i cant do the IRS box unless i move the chassis to make more space.