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Chassis rail 'C'
James - 23/4/02 at 04:49 PM

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

theconrodkid - 23/4/02 at 06:23 PM

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?

JohnFol - 24/4/02 at 07:50 AM

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. . .

James - 24/4/02 at 11:07 AM

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

JohnFol - 24/4/02 at 01:08 PM

I'll dig out the book tonight as I don't have fgures to hand. . .

Anyone got a scan of the page?

jbmcsorley - 29/4/02 at 09:45 PM

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! ;-)

JohnFol - 30/4/02 at 07:14 AM

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!

jbmcsorley - 30/4/02 at 01:56 PM

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.

JohnFol - 30/4/02 at 02:01 PM

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 / . . .. .

JohnFol - 30/4/02 at 02:03 PM

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. . .

jbmcsorley - 30/4/02 at 05:54 PM

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.

James - 1/5/02 at 09:09 AM

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?

James - 1/5/02 at 10:02 AM

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

Dunc - 1/5/02 at 10:03 AM

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.

James - 1/5/02 at 10:06 AM

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...

Dunc - 1/5/02 at 10:18 AM

Me too. °

James - 1/5/02 at 10:28 AM

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

Dunc - 1/5/02 at 11:14 AM

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.

James - 1/5/02 at 11:30 AM

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