James
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 posted on 23/4/02 at 04:49 PM |
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Chassis rail 'C'
Please please please could someone confirm for me that 'C' as listed in the book is 10mm too short as has been suggested here.
Since reading that, I've cut a piece 10mm longer and have to say that it doesn't fit aswell as the shorter 'C' did. I'm quite tempted to stick to
the shorter one but I'm worried about the effect on the suspension brackets.
I really need to start welding tomorrow so would like to know one way or the other!
If no'ones got it worked out, could someone with a built chassis measure their's for me.
Thanks in advance,
James
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theconrodkid
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| posted on 23/4/02 at 06:23 PM |
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Yo James just looked at my colouring book ,the tubes taper there ,so if you cut to the long length on 1 side and the short length the other it should
fit hopefully? 
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JohnFol
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| posted on 24/4/02 at 07:50 AM |
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Yes, C is too short by about 10mm.
Also found that G1 G2 are too short if you do the 5" bit, and the 'L' Uprights by 5mm.
Also if you do the maths on the J's they are too long. . .
For a 2nd edition of the book to contain all these inaccuacies is not good. . .
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James
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| posted on 24/4/02 at 11:07 AM |
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Hi JohnFol,
How did you calculate 'C' as being too short.
Sorry to question you but I've now cut all the lengths for the bottom rails and having laid them out on the jig it all fits together pretty well with
'C' as per the book. I've cut an additional 'C' with 10mm extra and fitting this pushes all the rest of the joints out.
So, if the extra 10mm is needed then I've somehow cocked up a load of other rails and they'll all need adjusting/re-cutting. Which is probably why
you'll understand me double checking with you!
How did you conclude 'C' was wrong?
Thanks,
James
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JohnFol
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| posted on 24/4/02 at 01:08 PM |
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I'll dig out the book tonight as I don't have fgures to hand. . .
Anyone got a scan of the page?
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jbmcsorley
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| posted on 29/4/02 at 09:45 PM |
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A good way to confirm the length of C is to lay it all out and then measure the angle between D and B2. The angle should be exactly 80 degrees. At
least with angles we don't need to worry about inches vs. mm! ;-)
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JohnFol
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| posted on 30/4/02 at 07:14 AM |
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PS I did dig out the book and a quick look suggests C is listed correctly. What puzzles me is several other people have also said C is 10mm too short
.. . wierd!
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jbmcsorley
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| posted on 30/4/02 at 01:56 PM |
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Have you placed 'C' on the correct side of the line drawn on the layout board? If you place the front of C on the rear side of the line, it will
appear to be 10mm too short.
-Jim M.
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JohnFol
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| posted on 30/4/02 at 02:01 PM |
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I am sure I placed it on the correct side of the line. If it were on the rear I would have squared off ends.
(all from memory I'm afraid)
PS I thought I hit reply whilst in a different forum / . . .. .
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JohnFol
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| posted on 30/4/02 at 02:03 PM |
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Yep I'm right. I go to
http://www.locostbuilders.co.uk/xmb/viewthread.php?tid=437
read jbmcsorley's last comment and hit reply . I then get the screen I am typing into now, but the last comment is from James. . .
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jbmcsorley
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| posted on 30/4/02 at 05:54 PM |
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Did you draw the line on the correct side of the line?  I'm being silly... but my point is this; head out to the shop with a tape measure and
confirm that you have a 21.5" (546mm) spread between the closest sides of B2 and C.
Is it just that the book is wrong? I measure 'C' in the book design at 823mm on it's longest face and the cut angle should be exactly 10 degrees
(I know, cutting exact angles is nearly impossible... but a steel protractor is one of my favorite tools).
-Jim M.
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James
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| posted on 1/5/02 at 09:09 AM |
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quote:
(546mm) spread between the closest sides of B2 and C.
Is it just that the book is wrong? I measure 'C' in the book design at 823mm on it's longest face and the cut angle should be exactly 10 degrees
(I know, cutting exact angles is nearly impossible... but a steel protractor is one of my favorite tools).
-Jim M.
Using the book dimensions I've indeed got 546mm between B2 and C1.
As regards the angles- I got 10 degrees* (think it may have been 9.5degrees but over 25mm it doesn't matter much!).
And as regards cutting them- fortunately for me the circular 'cut-off' saw I'm using lets you set angles up to 45degrees... which is nice!
What I have noticed is that when TIG welding the acute angles (between B2&D1 and C&F1) it's really f'ing difficult not to melt through D1 and F1. So
beware anyone who's trying to do something similar with as little welding experience as I've got!
Happy cutting,
James
*What's a degree sign in ASCII?
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James
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| posted on 1/5/02 at 10:02 AM |
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quote:
Yep I'm right. I go to
http://www.locostbuilders.co.uk/xmb/viewthread.php?tid=437
read jbmcsorley's last comment and hit reply . I then get the screen I am typing into now, but the last comment is from James. . .
You know when you reply to a message, all the other previous messages get resorted so that the oldest (the first) is at the bottom of the page and the
newest (the one you're replying to) is at the top?
You probably did know that so sorry if I'm being condescending!
James
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Dunc
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| posted on 1/5/02 at 10:03 AM |
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ALT 248 °°°° Yep ALT 248
When I was working out the angles to cut I looked at the plan and calculated the angle from the dimensions. I worked out 9.5°, which I thought at the
time was a bit strange and wondered why he hadn't used 10° but that was before I understood the truth and became bitter and twisted.
PS so how did you get the 50° angle on K1? That was one I boobed the first time.
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James
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| posted on 1/5/02 at 10:06 AM |
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quote:
*What's a degree sign in ASCII?
Oh, what a geek you are James: it's Alt-248
See:
10°
James
Anyone'd think I'm bored at work or something...
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Dunc
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| posted on 1/5/02 at 10:18 AM |
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Me too. °
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James
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| posted on 1/5/02 at 10:28 AM |
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quote:
ALT 248 °°°° Yep ALT 248
When I was working out the angles to cut I looked at the plan and calculated the angle from the dimensions. I worked out 9.5°, which I thought at the
time was a bit strange and wondered why he hadn't used 10° but that was before I understood the truth and became bitter and twisted.
Have to admit I'm a bit annoyed that there's this many inaccuracies in a 2nd edition- I really don't think it it'd be that hard for Heynes
to make an amendment- even if it's only as much as a new cutting list on an extra sheet slipped inside the cover.
What I am quite pleased about is that I've been forced to re-learn a load of basic trigonometry that I'd forgotten since school. What I regret is
not getting round to working out how to use a CAD system and doing it properly- it'd probably have been quicker in the long run, particularly with
the amount of changes I've included to fit the IRS and back axle track change.
PS so how did you get the 50° angle on K1? That was one I boobed the first time.
Erm, haven't got that far yet with cutting- will need to work it out in the next week or so though.
I may be being a 'complete focking eejit' by saying this but can I not just set the saw to 40° and then turn the metal around and cut from 'the
other side' as it were?
James
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Dunc
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| posted on 1/5/02 at 11:14 AM |
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That's what I tried but I still ended up with 40° but upside down and not 50° as I had initially thought. Hmmmm. Really need to put it in at right
angles to the clamp to get 50 I think. Same goes for TR1-6 which have acute angles too.
Dunc.
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James
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| posted on 1/5/02 at 11:30 AM |
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Oh, ok, weird! Interesting problem- I'll think about it a bit because I'm sure it muct be possible!
To be honest though, with the time I've got available (only 6 hours per week) in the college workshop and my deadline of having the chassis done by
the end of term I think I'll just cut by hand and think about how to do it on the saw later!
James
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