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NC KS | I sam thinking about redoing the booms on my pickup sprayer due to welds upon welds. I noticed the Miller Nitro sprayers use a really simple to build boom of square tubing using the tubing on edge or diamond shaped. I was wondering if pipe would have the same strength as square tubing. I am thinking about 4" 1/4 wall square tubing or 3"-4" round oil field pipe. Which one would have more strength?
Also, is their an online sight giving the weight per foot of various steel products?
Thanks |
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Brazilton KS | Hot damn, that's gonna be one heavy sumbitch
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| http://www.jimssupply.com/square%20rec_tubing.htm well this is an obvious answer. Anyone knows that ROUND tubing or containers hold more volume. This is not my word, it is science. That is why drinking glasses are round. Pie is round. On of my favorite math jokes is : " PI are not square, PI are round!"
Go round. BTW, In my opnion, you are running a bit on the top heavy side. Hope you don't topple over. Think "weeble wobble" mentality.
Edited by jeepmonkey 3/21/2007 01:32
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NW Washington | Wow, 4x4 quarter wall weighs 12.2 pounds per foot. So your going to have one heavy boom. Hope your planning on a wheel boom.
BTW, square tubing is stronger in bending than round., but in this situation rectangular tubing that is higher than it is wide would be better since your main load is vertical in bending. The best way to engineer this project is to copy one that does the job. No need to re-invent the wheel. |
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NC KS | I was wanting to copy the Miller Nitro boom. They are much wider but it looks like they start out with 5x5 and by the time they get to the end they have stepped down to 3x3. What I like about it is the fact they don't have all the crazy bracing going on (harder for a farmer to do with limited tooling). They just run the tubing out with a single piece coming down from the lift cylinder. I do have a good supply of 3" oil field pipe on hand or maybe 2" would work.. |
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Sac & Story county IA | If you have a good suppy of pipe, maybe we could work a trade. Factory here that makes boat trailers that throws away lots of rectangular tube. Start building in the center with something like 5x3 11ga then get to 2x2 at the ends.
A rule that is easy figuring in your head - not real accurate but close. If a pound is an inch away from the support. it is a pound. If a pound is 10 inches out from the support, it is 10 pounds. If a pound is 100 inches out, it is equal to 100 pounds. You get the idea. So, that extra weight is critical --way out there. |
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Watford City, ND | If you're still thinking about that 3" pipe you got, (its possibly 2&7/8) I believe that stuff weighs 7lbs per foot. Also, if its anything like the pipe I've worked with, its polarized, so wire feed won't work. Has to be a 7014 or 7018 rod or something like that.
Good luck! |
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North Central Iowa | I think that you're looking at a lot of extra weight there for the little extra strength that you are getting for your application. I would think that a pickup sprayer would be an application where you would want to reduce that weight as much as possible. I know that I looked at sprayer booms at the last couple of farm shows that I have been to, and Bestway's boom appeared to be made out of 4x4 square tubing, and the end looked like it was 1/4" or so. Looking a little closer, the whole outer section of the boom was a carbon fiber material, instead of steel, which made it MUCH lighter. They had a piece of the carbon fiber stuff on the table with the same length of steel tubing, and I bet the carbon fiber weighed 1/3 or less of what the steel tubing weighed. Maybe the boom that you looked at was the same? Anyway, I could see 1/4" for the inner sections, but the weight of an outer section made from 1/4" wall would require some really heavy supports and cylinders. I think that you'd be better off to look at some of the truss designs and copy one of them. There are some pretty simple booms out there that would be lighter and still pretty easy to make with a chop saw and welder. As far as the round vs. square or rectangular, I think the major reason there aren't many round ones is the lack of flat surfaces. Everything you mount to a round tube as far as bracing and such needs to be coped, which is a pain in the rear, unless you have a tubing notcher (and I don't mean a fixture with a hole saw, if you're doing very many). Anyway, that's my two cents, which you didn't even pay for, so you got a deal. Good luck and let us know how it turns out, whichever route you go, Mike |
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Hagen Brothers farms,Goodrich ND | Square tubing has a lot more strength for a given size than round, square also has more weight. Draw a 4 inch square, than draw a 4 inch circle in the center of it, what does the square section tube have that the round tube does not ? Those four corners add a lot of strength to the tube. |
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NC KS | I haven't sit down and figured up the weight of my current boom but with all of the bracing going on, I bet I have the weight of the pipe in it or more. I have (1) 1.5x2.5 11 ga running length of boom. (2), 1.5x2 11 ga running nearly the length of the boom plus all of the bracing which some is 1xq 11 ga and some a little bigger.
Looks like I got some 3" oilfield pipe and some 2??" on hand. Old Virgil Simpson sold a ton of sprayers with a wheel or coulter on the end, supported by cables but the main frame was 2??" oilfield pipe. I would love to use square tubing but I have to buy it (being a tightwad).
What is the lightest square tubing that would go the distance without failures or considerably "x" bracing? Distance is roughly 25' on each side of pickup. |
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| If it was me, I'd probably go with a truss design because trusses are lighter and stronger. If tubing was the only way, then I'd look at something like 2x6 or 3x8 or something like that. Take a length of tubing and lift it by one end and look at the deflection in it. Now consider that most of the forces involved with a sprayer boom are vertical, not horizontal. DO you need that strength of square tubing for horizontal forces that don't exist? I also doubt that 4x4 or 5x5, unless it's a very heavy wall would be sufficient on any length of boom. It's going to have too much deflection. I guess you could beat deflection by using support cables, if you can swing them, and mount them high enough to help. However, to me, square tubing seems to have a lot of dead weight involved that's not helping you. With steel, dead weight seldom helps, and often hinders. The strength is in the depth of it's section.... so a rectangle is probably of more use to you here unless you want to go with a lightweight truss, and then mabey 1" sq tubing would do.... I'd want it as light as possible.... Good luck. BTW, pricing out 1/4" wall HSS will scare you. Bad.
Rod |
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Brazilton KS | I built a 42' boom some years ago from old Ditchwitch boring machine stem. It is 1" OD and about 1/4" thick, and is very high tensile stuff. I used one piece about 18' long, one piece about 8' long angled ahead with about 1' space between at the inside, where it hooked to the fold hinge. Then used a third piece about ten feet long which I heated and bent in the middle to make a trangular truss on top. The center of the truss was where I attaced the chains to the top support, which were spaced out fore and aft similar to a Blumhart boom, and attached to a linkage suspended by an air shock. It survived as long as I knew where the sprayer was, and I was covering quite a few acres with the rig at the time. Wish I had a picture of it, I considered it to be a very successful design.
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Eastern Iowa | If you were to pick up a 15 foot piece of 1/4" wall 4x4 you would realize it is way to heavy. I still think your idea can work, just start with the first 1/3 of the boom on each side made out of 1/8 inch 4x4 or 3x3 then the middle 1/3 use something lighter and on the outer 1/3 you can use something like 2 x 2 thin wall steel. You don't need alot of strength on the end. |
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Brazilton KS | Rod, I'm gonna have to disagree with your contention that the forces on a boom are vertical. Damage to the boom is almost sure to come from fore and aft load from bouncing off of terrain or obsticals.
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| I spose so.... although I try not to hit things. Don't the booms break away on most sprayers when they hit something anyway? I know mine do.
Rod |
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Pipe vs square tubing for strength?
