I hear the conversions in the book are a bit ropey and it started on imperial measurements (in 1996 lol)
What did everyone use in their build, the imperial or metric dimensions?
did you build using inch tube or 25mm?
just use 25.4mm tube
. . . and use the McSorley plans:
http://mcsorley.net/locost/drawings/bookChassis.pdf
[Edited on 16/7/09 by ironside]
most square tube comes in metric sizes - e.g. 25mm
and most round tube comes in imperial sizes (converted to metric) e.g. 25.4mm
Or use, oh I don't know, maybe a newer book with all the dimensions in mm? 
I would have done, but I bought a book chassis, then bought a load of parts, then decided to build a fresh chassis and I dont really want to go back to the beginning and do a roadster. I have both books tho.
Gawd bless yer, Guvnor!
quote:
Originally posted by alistairolsen
I hear the conversions in the book are a bit ropey and it started on imperial measurements (in 1996 lol)
What did everyone use in their build, the imperial or metric dimensions?
did you build using inch tube or 25mm?
My tape has metric one side and imperial the other, toss a coin FFS
thats fine, I dont care which I use as a measurement system when theyre equivalent. Point is, with steel and plans that are badly sorted they arent and using a set of metric plans and inch tube when its actually 25 cos thats all you could get results in errors, hence my asking which people used in this application
I'd use mm, they're smaller than inches
quote:
Originally posted by alistairolsen
thats fine, I dont care which I use as a measurement system when theyre equivalent. Point is, with steel and plans that are badly sorted they arent and using a set of metric plans and inch tube when its actually 25 cos thats all you could get results in errors, hence my asking which people used in this application
quote:
http://mcsorley.net/locost/
Notes regarding Unit of Measure:
The CAD models were developed using standard measures based on 1" and 3/4" rectangular tubing. The drawings show secondary dimensions in metric and the build accuracy when using the metric measurements should not be an issue. Each measurement that depends on the tubing thickness may be off by at least .4mm (25mm vs. 25.4mm) and this small difference may be compounded during the assembly process. However, the overall effect of the discrepancy is probably negligible given the accuracy of most shop tools (or lack thereof).
Thats good to know. Yeah, Id read that note when I dwnloaded the plans, just wondered if anyone had made a conscious decision and run into any problems.
If you cut all your pieces of metal and weld them together and are less than 3mm out over the length of your chassis you are doing very well, don't sweat the little things or you will never get the job done.
quote:
Originally posted by Staple balls
I'd use mm, they're smaller than inches
Here's the site but it's in the forum links as well under the title top left of your browser.
gotto be the same whether its imerial or metric
me id go for metric purely for sourcing fixings
aitch
If you build in imperial it will shrink 3mm when you weld it.
If you build in metric it will only shrink an eighth.
Paul G
just divide or times by 25.4.....
then they are all the same.....
I don't use foriegn.
The discussion wasnt about imperial or metric as such, I know they are equivalent. The discussion stemmed from the reported inaccuracy in uncle rons conversion from one to the other, and the reputed fact that the plans were originally imperial
Hi
The Westfield chassis he copied was in imperial. He just didn't know how many MM's there where in an Inch.
Chers Matt
Some of his measurements work in imperial, others work in metric...
I found that making the pieces oversize and adjusting them to fit was the best policy. I didn't have the McSorley plans when I made my
chassis... 
I used the Mcsorely plans and cut oversize by hacksaw and filed back to ensure a close fit to reduce weld shrinkage.
The book might be metric but Ron original drawings were in imperial.
So it started out as imperial was converted to metric then a back to imperial conversion --- argh no wonder it had so many rounding errors.
quote:
Originally posted by James
To be fair to Chairman Ron, The Book was originally written in metric.
It was the people who added the imperial who cocked up the conversions.
I mentally used something of a mix in the end as a 40" width seemed far simpler than 1016mm!
Regardless of that, you're mad not to download the McSorley plans and use them!
Cheers,
James