SB2 > D8 fitting problem

[will_08]

Hey guys,

ive been pondering this in my head for ages now and it doesnt make sense to me. at the minute ive attached both SB1 to the base tube BR12. I then tacked D7 and D8 (ive linished the tubes as in the book)

But where D7 is correct ie it finishes 491 from the base line, and ive went on a trial fitted D5, 9 and tr3 which all fit. D8 will not sit right, ive marked 491.5 from the base line and lined the end of D8 with that when i try and butt it up to SB2 its well out.

Thinking the SB1's werent leaning right but from measuring SB2 to Br12 both corners are 151 as per the book.

Other checks ive done U4 and U5 are the same distance from base line. and my diagonals are the same

any advice appreciated Will

[ozzy1]

have you linished enough off to allow D8 to push up against the SB1/SB2 ?
How far out is "well out" ?
If all measures ok and you are happy the angles etc are ok then you can fill the gap with weld and then blend it in with a grinder.;)

[will_08]

thanks for the reply, ive dressed D8 the same as D7, if i but D8 to SB2 it ends about 450mm from the base line intead of the 491 as in the book.

[ozzy1]

SB2 it ends about 450mm from the base line intead of the 491 as in the book.
Thats a big error.Are you sure the SB1 is at the correct angle?

[ozzy1]

If D8 is the correct length tack it at the 491 dimension and just push the SB1 up to meet it and tack it then check the measurements and angles in that position.

[will_08]

ive done that it makes the distance between SB2 and BR12 greater than the 151 check dimension. im so confused :confused:

Cheers Will

[ozzy1]

Is D8 the correct length of 809mm and the 40' and 50' angles correct?
And SB1 leaning back at 17' angle?

Just a thought you have got the D8 with the 50' angle at the bottom locating on D6 and the 40' angle meeting the SB1/2 ?

[will_08]

i know what you mean, the angles are the correct way round. if Sb 1 wasnt leaning right then i wouldnt get the correct gap between SB2 and Br12 which I do?

If i offer D8 up against D7 it would fit in there perfectly. not sure whats went wrong here! it will be something stupid no question!

Will

[K4KEV]

Hi Will.....I have just noticed that the 41mm that you are out by just happens to be the amount you would be out by if you got the front edge mixed up with the back edge of the bottom of d7/d8 ( where it meets br5)

[will_08]

thanks for the reply im not quite 41mm out if i but the 40 degree angle to where it should be on SB1 & 2, the bottom of D8 sits 450mm from the base line instead of the 451.5mm i should be, meaning D6 wont fit in?

the other side of the chassis is perfect though :confused:

Thanks again for all your help is much appreciated

[ozzy1]

Is the angle on the SB1 correct?It is possible that it is not leaning back the 17' over the full length of the SB1 and this would throw it out but not by 40mm+.
Are both SB1's in alignment and square?

[will_08]

I think the angle of SB1 is ok, because using the check dimensions on page 38, the rear face of SB2 is 151 behind the rear face BR12. if this angle wasnt right this measurement wouldnt be right? also im not 40mm out, D8 is landing 9 mm further along Br6 than what it should be if its butted to SB1/2.

[K4KEV]

thanks for the reply, ive dressed D8 the same as D7, if i but D8 to SB2 it ends about 450mm from the base line intead of the 491 as in the book.

this is where we are getting the 40+mm from :confused:

[will_08]

Sorry Kev, ive lost the plot, i mean it fits around 500mm from the baseline, something like 9mm longer.

Sorry again :o

[ozzy1]

Are BR5,BR12,BR6 square to each other?

[K4KEV]

Are BR5,BR12,BR6 square to each other?
think you might be right ozz.
that would explain a slight discrepancy like 9mm. If you cannot find out where it is Will, I would try and split the difference which would at least leave gaps that would be weldable, not ideal, but a compromise :(

[will_08]

Thanks again guys, ill have another good check round then go from there. i was thinking myself that the bottom rails might not be true.

Cheers Will

[will_08]

Further to this, ive assembled the rear suspension frame and the side that i had the problems with in this post. is about the same distance short from reaching the cross section. the other side is fine!

I dont have the book with me. to clarfy ive assembled the bottom section, put the uprights on, tacked it 3mm from the edge of BR12. when i put the top assebly on the uprights the left side meets, but the right side there is a gap.



am i right in thinking my base is well wonky?

Should i start again? :(

Will