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Box or round tube?
Strontium Dog - 6/3/10 at 12:42 PM

Hi, I am building some Chassis's from the Tiger Avon book and I am altering them to take an ally body similar to the "Book" Locost.

My question is, do I have to use the round tube at the sides of the cockpit or can I use box? The erw box for the rest of the chassis is 16 gauge and the tube is spec'd at 12 gauge. I would like to use some 12 gauge box instead, can anyone see any problems with this?

Cheers, Si.

Avoneer - 6/3/10 at 12:46 PM

I'd use 16 gauge box - it's quite a critical bar.

Pat...

Strontium Dog - 6/3/10 at 12:59 PM

quote:
Originally posted by Avoneer
I'd use 16 gauge box - it's quite a critical bar.

Pat...


I thought I'd use 12 gauge as the round tube is spec'd as that and I did not want to use anything lighter/weaker as it might effect rigidity and side impact protection.

It is more for the ease of fitting an ally tub than any other reason, and that my local steel stockist has trouble sourcing the 12 gauge round tube for some reason! The sides of the cockpit do seem a bit of a weak point in the chassis design considering how strong the rest of the build seems to be!

blakep82 - 6/3/10 at 03:37 PM

i think the reason for using thinner round tube is that the shape of the tube is a less flexible than square (ie the flat sides that make it up)

kinda like how you can bend a piece of card, but roll it into a tube and its less bendy. kinda, but not exactly.

i'd stick with 16 gauge for square tubes though

hicost blade - 6/3/10 at 05:10 PM

Isnt 12 gauge thicker than 16?!?

hicost blade - 6/3/10 at 05:13 PM

12 gauge = +/- 2mm

16 gauge = +/- 1.3mm

Avoneer - 6/3/10 at 07:08 PM

Yeah sorry - thicker tube rather than thinner.

Pat...

t.j. - 7/3/10 at 07:16 AM

I'm building everything from box 2.0 mm

The only round tubes are the "doorstep" and the wishbones (3.0mm)

I wouldn't use less than 1.5 mm.
I't not because of the tubes but cause our welding skills and some tubes will surely get higher tensioned then others....

Ps. watch out, there are a lot off errors in the book! If you have the possiblity first draw it.

[Edited on 7/3/10 by t.j.]

Strontium Dog - 7/3/10 at 12:17 PM

quote:
Originally posted by t.j.


Ps. watch out, there are a lot off errors in the book! If you have the possiblity first draw it.

[Edited on 7/3/10 by t.j.]


Your not wrong there! Lol!

I drew it out on my layout table and have still had to make adjustments as it all goes together. Building four of these at the moment but I think I'll work on my own design if/when we build some more!

I have been wondering if the mistakes are put in on purpose so Mr. DIY will go to them when it all goes TU to buy their chassis. I had already decided against using the Tiger body as I hear lots of negative things about them. The general design of the chassis looks quite good and seems very strong which we need as the cars will get some stick on the pot holed Dartmoor/West country roads they will primarily be used on!

I do plan on some mods to steering rack mounting and a few additional braces to beef it up a bit more and increase structural rigidity! Any ideas towards this would be of interest too.

t.j. - 8/3/10 at 11:47 AM



I modified it also at bit

So:
- raised the hight of the chassis to 360mm
- upperrail is flat, instead of decreasing towards rear
- made some camber in it. cause the lack of in the drawings.
- upper rear wishbone mountings to the lower due the positive camber change in the orginal design.
- longer wheelbase
- engine more to the rear (wider tunnel gearbox mt75)
- wider chassis (for me! at the seats

You can look in my blog, at U2U me by Q!

Grtz Theo