TheSamba.com :: View topic - Recommended gauge/thickness for frame and roll cage

Wed Sep 02, 2015 10:25 am

I am new to the fabrication side of things. I'm going to attempt making my own frame, floors and roll cage. I know I'm going to use 2x2 square tubing for the frame. I'm looking for advice on:
2x2 square tube thickness
Floor sheet metal thickness
What should I use as cross supports
What size tube and thickness for rollcage?

Wed Sep 02, 2015 11:49 am

Intended use of buggy?

bnc

Wed Sep 02, 2015 3:43 pm

Mostly street and a little off road. Nothing extreme, kids are the main reason for the cage

Wed Sep 02, 2015 6:56 pm

Most sanctioning bodies for racing events call for 1 5/8 inch tube with .120 wall....

I when build mine I went with 1 1/2 inch .120 wall DOM for cages on both my buggies as like most, the street buggy will not see extreme action and race buggy was build for mainly autocross action which in someways is not extreme either....

I think for frame depending on design 1-1/2 X 1-1/2 inch by .120 wall tubing may be big/large enough if you use good engineering design (trussed) ... Round tube wound be better but square tube can work... Another thing is with big tubing its tends to make projects grow in areas that do not need the extra size.....

take a look at these frames to see what you can do, or maybe just buy one already done...

http://www.manxchassis.com/

Dale

Wed Sep 02, 2015 8:15 pm

I use 0.120 wall boxed, rectangular and round tubing for the cage, bumpers and the chassis where applicable. 2 X 2 boxed, 2 X 3 rectangular, 1 Inch round DOM and 1 5/8 round DOM. Some 1 X 2 rectangular depending on the need.

For floors, I use 14 gauge and no under supports. The 14 gauge used with a boxed outer rail does not flex once complete. I do use 1/4 inch X 2 inch wide strap under the floor exactly where the seat bolts come through to ensure a solid mount. I attach the seat belts to original VW mounts on the side of the tunnel and to welded tabs on the roll cage/roll bar.

Wed Sep 02, 2015 9:29 pm

I used 1x3 .120 wall tube for my chassis. For the cage I used 1 1/2 .095 which was legal for auto-x at the time. IT will be more than heavy enough for a street car

Here's my build if you want some chassis ideas
http://www.dunebuggyarchives.com/forum/topic_show.pl?tid=1801

brad

Fri Sep 04, 2015 9:54 am

Cage plans, if this helps... http://vdubn.com/dunebuggys/Manx/rollcage/rollcageindex.htm

bnc

Tue Sep 08, 2015 5:16 pm

.120 x1.5 dom tubing. 1x3 rec tubing for lift kit, stock floor pan.
1.5 tubing has lots of accessory options.

first attempt, the upper bars were straight. changed them to have a helmet bump.

Wed Sep 09, 2015 6:35 am

How tall is your rear hoop? (from the floor boards). I am trying to decide to replace or add to my current rear hoop.

Thanks, Jeff

Wed Sep 09, 2015 5:12 pm

48 1/2" from top of hoop to lowest part of belly pan. And I have stock floor pans. The cage is custom bent to this buggy, and the seat rails wear cut 2 1/2"lower to place the seat bottom even with the top of the 3" lift kit.
My first buggy build and cage design.

Wed Sep 09, 2015 5:57 pm

I make the second hoop 44 inches from the body flange surface. This is measuring on the angle of the hoop, not straight up.

Wed Sep 09, 2015 7:15 pm

My cage is 1.5" .120 wall round tube. Chassis is 1.5x2.5 rectangle tube with pretty heavy wall, cant remember but its close to 3/16 or thicker.
Seats are bolted to 1" square tube.

If your sand only I dont see and issue with 1.5" .095 wall, ive seen alot of buggys roll pretty bad on sand and they survive excellent as long as there isnt rust in a tube or some huge heavy engine. Ive even seen a fugitive big boy 2+2 Tbone a buggy and both came out with no chassis failures. I think its false security on pavement in general, but of course 90% of buggys are running a show bar only.
I tried to build mine where it could take a good bit of side impact in a collision with bigger cars. The light weight is a big bennifit of a buggy they will tend to slide when hit.

Sat Sep 26, 2015 7:02 pm

Thanks for the help. Was able to start this weekend. A bit of a pain. The body has a gap I'll have to figure out. figuring it out as I go. This is kind of a practice build. I have another that I will spend more time on. But I can definitely tell how I'd do things a bit different. I'm not a fabricator at all but it's coming together and im enjoying it so far.