tjc
Expert
this for you guys who build your own chassis'
I only have a mig, would it be dumb to use a mig on 4130 tubing?
I see most people use 3/4" .065 wall.
What gauge aluminum is used to skin out the tube tunnel?
THanks, just brainstorming.
I only have a mig, would it be dumb to use a mig on 4130 tubing?
I see most people use 3/4" .065 wall.
What gauge aluminum is used to skin out the tube tunnel?
THanks, just brainstorming.
There is no doubt that mig does make 4130 more prone to stress cracking. But as with any structural products, you can over come flaws with over building stuff. My boards are all built with 3/4" .035" and way tough. Skinz aluminum is 1" .250" wall on the outer tube.
Sportsterdanne
TY 4 Stroke Guru
4130 is expensive as gold here in Sweden, what tube size is equal in strength with regular steel tubing ?
Nikolai
TY 4 Stroke God
Would it be significantly less to have it shipped to you? 3/4 .035 is around $6/ft and 5/8 .035 is $5/ft I think. I'm not sure what shipping would cost but I could send a bundle of 5' sticks to you.
If 4130 was not an option I'd build boards out of .25" wall aluminum tubing before I used mild steel. Aluminum will be way lighter and plenty strong.
If 4130 was not an option I'd build boards out of .25" wall aluminum tubing before I used mild steel. Aluminum will be way lighter and plenty strong.
Depends on the type of aluminum and how much it's being used as a structural member.
In quick figuring, some is from memory some is from quick research. But even 1020 steel is still 60 percent as strong as 4130. Steel as I remember is 3 times the weight of aluminum. So .065" mild should be as strong as 4130. 0.250" aluminum /3 to get a rough figure on weight is equivalent to .083".
I try to avoid using aluminum for anything structural that requires welding.
Feel free to pick the figures apart but I believe steel will come out on top of the weight battle.
I try to avoid using aluminum for anything structural that requires welding.
Feel free to pick the figures apart but I believe steel will come out on top of the weight battle.
Nikolai
TY 4 Stroke God
So I did some quick math and Rick is right, steel would be lighter and probably stronger as well. Onlinemetals.com is a good source for material weights for anyone who wants to get real picky.
6061 alu tube
3/4" .125 for the crossbars .288 lbs/ft. x 10 ft. = 2.88 lbs
1" .25 for the main tubes .692 lbs/ft. x 10 ft. = 6.92 lb
Total board weight 9.8 lbs
Steel weights are for DOM tube
5/8" .065 for the crossbars .35 lbs/ft. x 10 ft. = 3.5 lbs
3/4" .065 for the main bars .43 lbs/ft. x 10 ft. = 4.3 lbs
Total board weight 7.8 lbs
6061 alu tube
3/4" .125 for the crossbars .288 lbs/ft. x 10 ft. = 2.88 lbs
1" .25 for the main tubes .692 lbs/ft. x 10 ft. = 6.92 lb
Total board weight 9.8 lbs
Steel weights are for DOM tube
5/8" .065 for the crossbars .35 lbs/ft. x 10 ft. = 3.5 lbs
3/4" .065 for the main bars .43 lbs/ft. x 10 ft. = 4.3 lbs
Total board weight 7.8 lbs
Sportsterdanne
TY 4 Stroke Guru
Im thinking of a tubular tunnel, so i feel like alu is out of the question, for runningboards only i would consider it.
shipping of longer tubes would really suck, Alatalo did some research on long items like ski rails and its in the 500 to 1000 bucks range!!
if i decide to get 4130 i still have to ship it almost across whole Sweden. in a pricelist from 2010 i see the price of 3/4 .035 at approx 10$/ft + shipping.
shipping of longer tubes would really suck, Alatalo did some research on long items like ski rails and its in the 500 to 1000 bucks range!!
if i decide to get 4130 i still have to ship it almost across whole Sweden. in a pricelist from 2010 i see the price of 3/4 .035 at approx 10$/ft + shipping.
Sportsterdanne said:
I don't think you'll regret going mild with mig. Go like .065" outside tube and .049" for everything else but the bumper, make the rear a big triangle and run it! I really like the design we used on Drews tunnel, you could go lighter on the skin if you brought the tube forward, but thats a dang tough tunnel and performs great. I'm jealous
Sportsterdanne
TY 4 Stroke Guru
I feel like i hijacked TJC:s thread.
i only have a TIG
i only have a TIG
tjc
Expert
No problem haha this is helping me too.
kennyspec
Expert
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This thread is awesome.
kennyspec
Expert
- Joined
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Maybe I will see if I can list the tubing sizes based on weight/foot and by strength of alum and the chromo.
Nikolai
TY 4 Stroke God
The problem with aluminum is that once its welded you've annealed the tube. 6061 boards would need to be heat treated to get the strength back.
The outer tube on boards would be better off with 5052 than 6061 unless you heat treat it after welding. 6061 is very soft it its annealed state and the outer tube has enough welds that basically the whole tube is in the HAZ causing it to become weak and have to be overbuilt to overcome that.
To work with aluminum structurally you have a couple options
-Use billet
-Engineer the welds so the HAZ does not effect strength for example, triangles can still be fairly strong
-Over build it (how Skinz boards over come it)
-Heat treat the finished product
Or the method I normally use is chromoly that is very strong in its annealed state, a even better option is titanium. 60-70 percent the weight, welds good and about the same strength as 4130
To work with aluminum structurally you have a couple options
-Use billet
-Engineer the welds so the HAZ does not effect strength for example, triangles can still be fairly strong
-Over build it (how Skinz boards over come it)
-Heat treat the finished product
Or the method I normally use is chromoly that is very strong in its annealed state, a even better option is titanium. 60-70 percent the weight, welds good and about the same strength as 4130
