Home depot galvanized steel pipe price?

[Alex Knappenberger]

Hey, I was in the homedepot a couple weeks ago, and I saw some of this galvanized steel pipe (1 inch round, 2ft long) with threads on the ends, and now I think that would be perfect to build a little 8ft crane out of or something, but I didn't look at any prices, and they don't have it listed on their website. So I was wondering if anyone knows what that stuff goes for before I make the trip all the way out to home depot, I don't see it being that expensive?

Or does anyone know of any other good INEXPENSIVE material to make a little 8ft or so crane out of...that can break down into 2-3ft peices?


Thanks


(opps, I could always call them tomorrow, I suppose. :D)

[Mike Rehmus]

Not a good building block for a boom. Too heavy, not very stiff and too weak.

An 8 foot boom is not a trivial construct. If you don't mind bulky, think about something on the order of 3" ABS (in black, please) as the main boom spar. Maybe 4" but I think that will really have a wind problem. 8 foot is probably too long without thinking through the statics and dynamics of the boom.

Do a search on the subject, there are free plans out there for booms.

Don't hang a large camera on it, BTW.

Truth is, they take a long time to build one properly. One that isn't built correctly and isn't stable is a real pain.

[Jeff Donald]

Very risky using the wrong material. I once saw a crane collapse during a rehearsal. No one was hurt, although a $50,000 Beta SP camera bit the dust. If it had happened a few hours later I'm sure people would have been killed.

[Alex Knappenberger]

Thanks guys, but it's just for my (non heavy) little consumer camera, probably weighing in under 3LBS, with the big battery on it. You don't think that galvanized steel pipe would do the job? When I say 8ft, i'm really talking 8ft total, so that the boom end will only be about 6.5ft.....


Hmmmm.

[Mike Rehmus]

No, I do not. Try it if you want but I think you are wasting your time for any serious work over any length of time. Think of the work you have to do to build any type of boom. Then ask yourself why you would use inferior materials instead of something that would perform better, be more convenient, and wouldn't look, as my grandchildren would say, "pretty doofus?"

It is not meant for that purpose and a lot of other products would do much better. Like the rigid conduit that is used for wiring.

[Brian Huey]

Check out the crane section of the homebuiltstabilizers.com forum
http://pub173.ezboard.com/fhomebuiltstabilizersfrm8

The have some good info there.

Cheers,
Huey

[Ken Tanaka]

Alex,
I'll join others in recommending that your consider this project carefully before spending time and money on it.

But when I was 15 I undertook many goofy projects of similar natures, so I can hardly criticize you if you move ahead with it.

Since you are in high school, this project represents a pretty good basic problem in physics and basic mechanics. For example, how fast would your 3lb camera be traveling when it disconnects from the boom and hits the ground from an elevation of, say, 7 ft? Or how much counter-force will be needed to provide balance to the boom with the camera mounted at its end if the boom is supported at 2 ft? 3 ft?

[Alex Knappenberger]

Jeez, alright, I get the point, heh. Thanks though guys.

Mike, someone else recommended "rigid conduit" also? What is it? Can you explain it a little more?

[Ken Tanaka]

"Rigid conduit" probably refers to electrical cable piping designed to provide a channel for electric cables within buildings. This would really not work at all, since it has a ribbed structure enabling it to be easily bent to fit through walls.

[Mike Rehmus]

Ken, rigid means just that. It is a welded sheetmetal tube and you need a special bender and some muscle to bend it. You are thinking of the flex stuff for taking wires to a piece of machinery that might vibrate a bit. You cannot put the flex stuff in walls.

Rigid tube comes in 1\2" to about 4" diameter and is quite inexpensive in the smaller sizes. I'd guess a 1" tube would do quite nicely.

Having said that, Alex. Understand that this is galvenized tubing that comes in 20 foot lengths. It can be welded as long as you don't breathe in the fumes from the hot zinc. Do that and you will get zinc poisoning which feels like you have the flue. Done that and been there.

But it is marvelously cheap steel tube for all of that. I'd make my boom pole of the 1 or 1.5" stuff and use wood for all the other parts. Wood is quite strong enough to use with a short boom. Clamp two pieces of 2 by 4 or 4 by 4 together, bore a hole for the tube right where the two pieces join and you have a clamp for the pipe. So you don't have to weld the pipe to put in pulleys and clamp it to your tripod or whatever you are going to use to hold the boom. You can even make a special tripod out of wood and this tubing.

The proper name for the tubing is PMT. I don't know what the initials stand for.

I've built shelving, specialized racks and a lot of stuff with this tubing. But I have learned to weld it with a good breeze between me and the welding smoke.

You could do the same thing with aluminum tubing from your local hardware store. It would just be more expensive if lighter.

[Ken Tanaka]

Mike,
I'm sure I was thinking of the steel conduit required by the Chicago Electrical Code, rather than the solid electrical piping. Mea culpa. Here in Chicago all concealed electrical wiring must pass through this semi-flexible conduit, or rigid electrical piping, in walls and ceilings. The joke is that it turns electricians into plumbers.

[Alex Knappenberger]

Thanks guys, i'll check that out.

The thing is, if this 8ft light stand will hold my camera at the end horizontally without even bowing, I don't see how that galvanized steel pipe wouldn't be strong enough.

[Bryan Beasleigh]

It's Electrical Metalic Tubing or EMT also known as thinwall. And yes it takes a fairly large bending tool and a fair bit of horsepower to put a kink in it.

While flexible conduit is necessary some of the time it's considered amatuerish in most applications. It's sure easy to run though.

[Dylan Couper]

Alex, while you are at Home Depot next, check out the painter's poles. They are cheap, and collapsable. The lightweight aluminum ones should be strong enough to hold your 3lb camera.

[Alex Knappenberger]

Cool, thanks guys, I'll be making a trip out to the home depot soon. My camera isn't even 3lbs, I have a 2.5LB weight here, and it's lighter then that for sure, even with the big battery on it, so I say its about 2LBs with the big battery. :D