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Thread: Tripod for lifting BP
11-24-2005, 11:32 AM #1
I was just wondering if anyone else has made a tripod for lifting their BP sized mill on and off the back of a trailer before, for those of us who are forklift-challenged.
I'm thinking of something similar to this picture at one of our esteemed member's website (sauer38h).
I can't quite make out in the photo how he has gone about attaching the pipes and the hoist.
My biggest curiosity is a good method of tying all 3 pipes together, while still having room to connect a come-a-long (hoist). If it were just tying all 3 pipes together, I could see a large bolt going through each pipe. Do you just install a hoisting ring in one of the pipes as an attachment point for the come-a-long?
Or perhaps using a bunch of pipe fittings -- two angles attaching to a Tee (tee being used for the 3rd leg). I would be a little more concerned about this setup as much less of the load would seemingly get transmitted into the pipe legs.
11-24-2005, 11:53 AM #2
Not to say anything about a fellow board member, but a tripod is not the way to go. I made a rolling gantry crane that works so slick and you can move things from side to side and roll the whole thing to another spot. With a tripod you have to drive out from under it and the legs have to be so wide at the base to get a truck or trailer under it. You can go to Wallace cranes and take a look and get some ideas on what to build. If anybody is interested I can get a picture here to show you what I mean.
11-24-2005, 11:54 AM #3
I would weld the legs together. Just weld it so it's easy to get to the welds with an angle grinder if you plan on taking it apart some time.
11-24-2005, 12:12 PM #4
I would not use ordinary hardware store pipe fittings because they are likely to be cast iron.
It might work to make a plate with sockets welded to the bottom to accept the legs at the right angle and a lifting ring in the center to put the load equal on all legs. Also I would keep in mind that any threaded sections would be much weaker.
11-24-2005, 12:12 PM #5
I agree the tripod is not at all ideal due to the limitations you described (I recall an older thread where this particular member was flamed pretty bad for his moving adventures, of which this tripod was the least of his concerns). The one thing it really has going for it, in my mind, is that it is quite portable (assuming you DON'T weld the legs together ) That's why I'm trying to see if it is a feasible option for lifting a BP sized mill (~2200 lbs.)
A rolling gantry crane WOULD be much nicer. My concern with that is getting the i-beam into position, if you have to transport it to another location and set up. I'll look into it.
11-24-2005, 12:43 PM #6
I built a little 36"x36"x76" gantry for work that were going to use to lift out aluminum gates that seperate different parts of our settling basin. I used 2x2x3/16 tube to make it out of, which was really way overkill but now Im glad I used that size. I have used it more to position our 13x40 lathe for leveling than I ever will to lift out those gates. Best tool Ive ever built.
11-24-2005, 02:27 PM #7
Tripods are handy as the nearest 5" tree trunks that would make good poles. Chain saw trunks to make three 14 footers. Tie them together with about 6 turns of 3/4 rope and run the ends in under the turns like a whipping. Then you splay the legs the turns tighten up like crazy. Run a closed loop pendant over one leg and stuff it down the center.
I prefer a lifting horse assembled with bolts. A 10 ft 4 x 8 (prime material), four 12 ft 4 x 4's, and a couple of 2 x 4's for sway bracing is all it needs for material. Bird-mouth the 4 x 4 ends to provide good support for the 4 x 8; you don't want it hanging on the bolts.
Once it's built, two guys can assemble it on the ground in 20 minutes and walk it up. If you splay the legs a little you can back a pik-up or a flat bed under it easy. Use a piece or 4" channel about 2 ft long over the top to protect the wood from chafing the chain bail.
11-24-2005, 02:44 PM #8
For all that effort I'd rent a forklift. Its about $200 a day and much better and easier than doing all the work to make a lifting device. Plus from what I have seen, $200 is a lot cheaper than an Emergency Room Bill, or a broken machine.
Thats just my opinion though, after moving them a thousand different ways!
11-24-2005, 02:58 PM #9
Count yer blessings;
All them "late war of rebellion" chaps in the Artillery had to use portable tri-pods (gin poles) exclusively to handle their cannon off and onto the carriages. They are even speced out in the 1862 Ordnance manual.
11-24-2005, 05:49 PM #10
Here is one way to make the gantry so that it disassembles.
Another trick is to unbolt & remove the casters when you are going on the road...it makes setting it up 100% easier. Do the positioning with the trailer.
11-24-2005, 06:00 PM #11
How much do you reckon that lifting horse could lift?
11-24-2005, 06:52 PM #12
I like that gantry of yours (from the corner shot at least).
What sort of weight will lift? Got any dimensions to hand?
11-24-2005, 10:08 PM #13
11-24-2005, 10:45 PM #14
Charles, here is some info and more pics. Ask away if you don't find the right stuff below. It is conservatively rated at 4000#, really the casters are the weak link at 1600# each. Lifting out the Monarch EE (3450#) was no big thing.
You can kind of see in this very last picture that the hoist would be able to traverse much farther in the garage if the dang door opener was higher...possible project for later although I'm working on repairing a forklift.
11-24-2005, 11:25 PM #15
As always, I like your work. I may have to build one similar. After that, I'll have a similar phase converter AND a similar gantry crane. Nice work.
11-25-2005, 12:18 PM #16
Thanks for the nice compliment. Just be careful because a good hoisting system and nearby Uhaul yard expand the possibilities sooo much farther than ever before
11-25-2005, 01:11 PM #17
Cliff. The 4 x 8 timber beam of the lifting horse is adequate for 2500 lb working load if of Doug fir or SYP provided the channel I mentioned is used, the timber is sound, and no greater span (spprox 9 ft) is attempted. But no more than that. Longer spans, different species, soundness of timber will reduce the safe load capacity.
When in doubt, hoist the load just clear of the ground and let it sit for a few minutes. If the wood structure yields in that time it's not safe for that particular load.
11-25-2005, 04:04 PM #18
Here is a tripod for setting up cannon on Sullivans Island, near Charlston S.C.
11-25-2005, 09:57 PM #19
A gantry crane is really handy. Mine is used frequently to load the welding platform (engine-drive, tanks, cables) onto the truck.
The primary limiting factor on a gantry crane is the I-beam section and span. Other variables include the rating of the chain hoist & the casters.
These sites have lots of information on sizing & capacity. Mine is 60" wide, 100" tall, with a 9' span inside the posts. My hoist is rated for 2200#, but the platform weighs under 1500#. It takes very little space in the garage & allows one person to easily load & unload.
This site also has tripods.
11-26-2005, 11:34 AM #20
Well, you've all convinced me. I'm gonna build a gantry instead of a tripod. It'll take a bit longer and cost a little extra, but I should get a lot more mileage out of it. Here's something I drew up that isn't fully (or properly) dimensioned.
My goal is to have it fit under the low garage door (80"), but be adjustable up high enough to lift a BP ~1.5-2 ft off the ground. That's biting off quite a bit I think. I'm planning to use Matt's basic design, but whereas he used 4" x .25 square tubing for the vertical supports, I'm thinking of using 4" x .1875 square, with 3.5" x 0.25" square sliding inside of it. Ideally, I would use 4" x 0.25" square, but I don't have a mill (yet) to shave off a little bit on the 3.5" square for clearance.
Based on wall thickness, that leaves a clearance of 1/16" all around, but IIRC, there is often metal flashing on the inside of square tubing, so a tighter fit may not be feasible anyway.
I'm open to suggestions for alternate ways to achieve this adjustable-uprights goal.
Anyone know off-hand what the approximate deck height of Uhaul's double axle utility trailer is (Matt perhaps ??)