Steel Tubing Question

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Hellfrog
Posts: 3
Joined: May 30, 2006, 8:47 pm

Steel Tubing Question

Post by Hellfrog »

I know "the book", as well as every other build I have seen has used 16 gauge steel. But... I have come across more than enough 1/8" thick tubing for FREE. Does anyone have any idea what kind of weight that would add? Other than saving a hundred plus bucks and adding weight, are there any positives or negatives I need to consider when thinking of using this thicker steel?
Thanks!!
chetcpo
Posts: 7043
Joined: August 15, 2005, 10:13 pm
Building: positive attitude
Location: Charleston, WV

Post by chetcpo »

Well on the upside it gives you some extra incentive to use that high powered V8 engine you've dreamed about. As far as how much weight it would add I'm guessing it would just about double your chassis weight. If the steel tubing is in good shape maybe you could work out an exchange deal with a local steel distributor. If he traded you even he would be coming out ahead and you would have something you could better use.
zetec7

Post by zetec7 »

:!: Yeah, that would about double the weight of your frame. Consider that the frame is about 20% of the weight of the whole car...doubling that is a LOT. The 16 ga. is preferable...
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mr.peabody.d
Locostering Information Liaison
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Joined: August 17, 2005, 1:30 am
Location: So CALIFORNIA

Post by mr.peabody.d »

Depending on how LOCOST you wanna go....

True to your name... fire yourself and Jump at the chance....but compensate with a robust engine to balance it out.

OR pay $120-$150 dollars for the 16 gauge steel......like I said it depends on how low cost you are.

*one more suggestion it to take the metal and pratice welding, build a frame, if cost is really and issue use it....but your weilding slills advance...if you decidel to switch your can make furiture or a welding rack or a automatic beer dispensor....


The point is it is FREE
I'll keep an eye out for you!

To err is human...
I am more human than most.
locostv8

Post by locostv8 »

Where do you live and do they have more. I wouldn't mind doing the bottom rails with 1/8th.
Hellfrog
Posts: 3
Joined: May 30, 2006, 8:47 pm

Post by Hellfrog »

Thanks for the input all. Does anyone have any idea what the actual weight difference would be. Ballaprk estimates work :wink:
The free steel would be nice as I have decided to spend some extra bucks on engine management for the 13B but 16 gauge steel wont break the bank or anything
chetcpo
Posts: 7043
Joined: August 15, 2005, 10:13 pm
Building: positive attitude
Location: Charleston, WV

Post by chetcpo »

Check this weight calculator out:

http://www.processassociates.com/proces ... beprop.htm

The following are for round steel tubing so the weights will be different than for square tube, but they do provide an apples to apples comparison.

1/8 inch thickness equals .125 in decimal. The closest pipe guage I could find to that in decimal was 11ga which is .120 so I used that in the calculator. It comes out at 1.1278lbs/ft.

The book suggests 16ga which is .065 thick and comes in at .649 lbs/ft.

Multiply these numbers by 110 to get a chassis worth of tubing and you get:

1/8 tubing chassis: 124.058lbs
16ga chassis:71.39lbs



So it will be nearly twice as heavy.
DanT
Posts: 9
Joined: May 31, 2006, 12:55 pm
Building: SR20DET Locost
Location: Clarence Creek, Ontario

steel tubing question

Post by DanT »

Hi Hellfrog,

A quick check at my metal suppliers websites (most tubing & steel suppliers have tables showing sizes & weights for their products) shows

3/4" sq .065 = .606 lb/ft
.120 = 1.03 lb/ft

1" sq .065 = .83 lb/ft
.120 = 1.436 lb/ft

Basically about 70% increase in weight.

Hope this helps

Dan
Navan, ON
DavidFE

Post by DavidFE »

Hellfrog,

I think if the tubing is clean inside, it is a good deal. Is it clean? Or rusty?

I also liked the suggestion of the lower rails being the thicker stuff. Great suggestion. I would also consider increasing the tube thickness where ever the suspension pieces are attached to the chassis.

Even the % increase in weight, it is not really much extra weight.
locostv8

Post by locostv8 »

I am using a 351/392 V* so I need a bit more chassis stiffness. I am also considering turning the tub section into somewhat a full cage with upright at front & rear of tub possibly upper rail in the tub area being 1/8. While this will add weight it will be low and centered so should be handling neutral.
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mr.peabody.d
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Post by mr.peabody.d »

I really like that the idea locostv8 With your application the bottom rail, suspension points, and the cockpit area would be a minimum.

I really like the idea of a strenghten cockpit area maybe incorperating the windscreen into the design and angling it back a little more. (The challenge would be to build strong crash/roll over protection while still being able to get in and out and preserving the open air qualities)
I'll keep an eye out for you!

To err is human...
I am more human than most.
locostv8

Post by locostv8 »

ImageImage
How bout this except narrowing it a bit so it could be incorporated into the chassis and bringing the top inner and outer bars in so they meet the X bar. Either welding in a flange around the front hoop or using Dunebuggy rail job windshield rubber to mount the windshield to the front hoop.
Hellfrog
Posts: 3
Joined: May 30, 2006, 8:47 pm

Post by Hellfrog »

I have decided to use the thicker (and heavier) stuff for the lower frame and use the 16 gauge for the remainder. Then trade off the remaining 1/8 steel for parts :-)
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