Another Silly Crane

A bit of a dangerous wonky design. There is no compression member at the pivot end of the triangle, so any load on the extended arm pivots at the angle brace, putting a lifting moment at the pivot, which is only restrained by the shear strength of the cotter pin ( and the bending moment of the outer tube on the inner tube - which at the very least will cause a binding situation) By inverting the lower pivot and resting the arm on the lower bracket the arm is properly restrained in both directions, not depending on he cotter pin ( and jamming force of the outer tube on the inner tube as the arm pivots)

MIGHT not prove to be a failure point, but it for sure is NOT a sound mechanical design!!!!

With a hundred dollar budget you can build one with 3X the capacity ... and make a dent in the cost of the winch to power it too .

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I agree with the others. The 2000 Lb capacity boom on my shop crane is much more substantial. You are limited by the strength of the building structure. If you can determine or increase it then figuring the forces in a triangular brace and the reactions at its mounts is pretty simple, I learned it in high school AP Physics without calculus.

Size all parts for full load deflection plus a safety factor and make the joints flexible so they don't suffer unnecessary extra bending stress. The type of connection determines the "K" in compressive strength formulas, and a flexible pinned or ball joint is the simplest to consider. That's part of the objection to the Vevor's pivots. Their pintle and gudgeon style is appropriate for a rigid boat rudder but not even a garden gate that kids might swing on. Fork or clevis hinges that hold the hinge pin at both ends are much better, and in this case should allow for the beam to flex up (beam bows) or down (brace stretches) at the hinge.

I might support the horizontal beam with Grade 100 chain and add a rope and pulley to swivel it up out of the way. Then it could be low enough to attach a heavy hoist without climbing a ladder, and able to be repositioned higher if necessary. Both are very helpful features of my gantry.

The local logging equipment and chain dealer stocks Grade 100 instead of Grade 80 because he says the price difference is minimal. They are rated for overhead use because they are alloy steel that can deform to absorb overload shocks better than carbon steel lower grades, which may be more brittle. I've broken 3/8" logging chain. My 1300 Lb HF electric hoist deflects the gantry beam at startup with less than half load more than at full static load.

I bought a handful like these locally for less than $5 each.

This has been a useful find from Vevor:

A folding shop crane might do all you need if you make shorter folding legs that let it fit crosswise in front of your machines.

With an added winch or hoist they lift straight up, for the lathe chuck. You could make a secure clamp for the chuck from perforated steel strapping, a clamping and a lifting bolt.

I might support the horizontal beam with Grade 100 chain and add a rope and pulley to swivel it up out of the way.

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I've previously suggested a boat trailer winch for hoisting and forgot to mention that they spin dangerously when lowering vertical loads if the handle slips from your grip. With a rope you can at least use the tiedown cleat as a friction drag.

The Vestil lift I ordered for Segway had a cable winch with a built-in lowering brake which I haven't seen available separately.

I'm not at all a fan of boat winches for lifting. They do one thing, and they don't do that all that well. I know. There are a few of them on trailers out front, along side, and inside my shop right now clipped to boats.

I have gotten quite good at tying a bowline to affect a field repair of a broken strap, and I've gone for a swim to recover a boat a couple times. I'm very familiar with the boat winches.

The lighter cheaper boat winches have steel cables, but many of the middle weight have nylon straps that all break eventually about an or or so behind the stitching. I can't recall if they heavier ones on my dad's old sport fishers have nylon straps or steel cables, but I'll have to look at them eventually. They are among the things I need to sell sooner or later.

The handles tend to be relatively flimsy, easily bent, and connected with a slot onto an oval end shaft with a nut. Often that part comes apart as well. Some people cringe when I weld a handle back on, but the weld will outlast the rest of the winch.

No. Boat winches are only marginally not terrible at one thing.

I'm not at all a fan of boat winches for lifting. They do one thing, and they don't do that all that well. I know. There are a few of them on trailers out front, along side, and inside my shop right now clipped to boats.

I have gotten quite good at tying a bowline to affect a field repair of a broken strap, and I've gone for a swim to recover a boat a couple times. I'm very familiar with the boat winches.

The lighter cheaper boat winches have steel cables, but many of the middle weight have nylon straps that all break eventually about an or or so behind the stitching. I can't recall if they heavier ones on my dad's old sport fishers have nylon straps or steel cables, but I'll have to look at them eventually. They are among the things I need to sell sooner or later.

The handles tend to be relatively flimsy, easily bent, and connected with a slot onto an oval end shaft with a nut. Often that part comes apart as well. Some people cringe when I weld a handle back on, but the weld will outlast the rest of the winch.

No. Boat winches are only marginally not terrible at one thing.

Bob La Londe CNC Molds N Stuff

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I use them for lack of a better inexpensive alternative. Mine are acceptable after replacing the axles with Grade 8 bolts and better bushings and aligning the gears. Synthetic winch cable is safer to handle and doesn't spring loose on the reel. The upgrades are only on loan and can be passed on after one fails.

I might try the HF with its worm gear lubed with the dry moly grease I bought for the 6-jaw.

A come-a-long, while slower, is marginally safer when operated correctly and it is actually rated for lifting. Yes, they tend to be a little more expensive, but not prohibitively so. I have used a come-a-long for things like lifting a burnt-out compressor out the center of a condensing unit with a straight bar and a ladder. No fear of failure. I've got a couple of them for such tasks. I also have a couple chain falls.

Heat and UV eats up synthetic winch cable. All the cool kids in the off road community use the stuff, but all three of my electric loading/recovery winches have steel cable. I run steel on my electric recovery/loading winches because I tend to run solo so the only one who could stupidly stand right next to it is me, and I don't use them all that often so I would rather they didn't sun rot before the next time I need it.

Its a choice. Much greater longevity VS some protection against stupidity. If I did the weekend group trail rides I would switch to synthetic on my primary off road vehicle.

A come-a-long, while slower, is marginally safer when operated correctly and it is actually rated for lifting. Yes, they tend to be a little more expensive, but not prohibitively so. I have used a come-a-long for things like lifting a burnt-out compressor out the center of a condensing unit with a straight bar and a ladder. No fear of failure. I've got a couple of them for such tasks. I also have a couple chain falls.

Heat and UV eats up synthetic winch cable. All the cool kids in the off road community use the stuff, but all three of my electric loading/recovery winches have steel cable. I run steel on my electric recovery/loading winches because I tend to run solo so the only one who could stupidly stand right next to it is me, and I don't use them all that often so I would rather they didn't sun rot before the next time I need it.

Its a choice. Much greater longevity VS some protection against stupidity. If I did the weekend group trail rides I would switch to synthetic on my primary off road vehicle.

--------------------------------------- Thanks for the info. I bought the synthetic cable for an ATV winch but never installed it. The boat winch I put it on mostly stays in a shed, and last summer was under the rain shelter for the gantry and sawmill. It happened that the track hoisting (not supporting) winch on the sunny end tripod had steel cable and I did all the gantry track leveling with the shaded synthetic cable winch. There was a lot of readjustment because after sawing the lighter logs I upgraded the gantry hardware for two 4000+ lb logs. What I post about hoisting is from personal experience studying for, designing, building and using the equipment.

I began logging with generic lever cable pullers, to pull down trees lodged against others or guide ones likely to be. The cheap ones wore out very quickly and greasing them made little difference. Replacing the axles with harder steel bolts and shimming for better alignment partly helped, the ratchets were next to fail. When I figured out how to join fence posts into folding tripods to lift firewood logs off the rocky ground and spare my back from bending over with a heavy chainsaw they were useless because of their length, so I switched to shorter lever chain hoists. With one exception these were so much more satisfactory and durable that I parked all the come-alongs. The 1000 and 1500 Lb hoists get the most use. I need one at each end to center the wider logs on the sawmill track.

The lever chain hoists are about as good as come-alongs for horizontal pulls on dry ground, and better than chainfalls whose hand chain doesn't feed well horizontally. If I expected I might get stuck without a mounted winch I'd bring my 2000 Lb x 12' lever chain hoist from Northern Tool. It has pulled a trailer load up a hill too steep for my tractor. I've had four chain hoists in use at once lifting a shed on and off a construction trailer.

A 2" ratchet cargo strap can pull 1000 Lbs (measured) in short steps and may be useful for unintentional recovery and towing in addition to tie-down.

I'd like to have a jib crane just inside a 12'H x 10'W overhead door. Its a silly reason. It might be handy for a few things, but the main one is to reach out side and lift the 5th wheel companion (locks into my under bed goose neck hitch) out of the bed of the truck, swing it inside and set it on a relatively high shelf out of the way.

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Farming equipment "trunnion bearings" would make the rest of a pivoting jib crane simple to fabricate.

Oh, I am absolutely not buying the item linked in post one for the primary application. I recently ran across several pieces of H/I (wide flange) beams for free to me. Enough to build a gantry crane and a jib crane and have some left over. The title indicated I thought it was silly, and if I had any plan to use it I think I talked myself out of it.

For my primary jib crane application. I would ideally want about 9' to

I wouldn't say I have a plan, but I have ideas.

The jib crane Jason with Fireball tools installed in this shop was an inspiration for me. Its secured to the floor and "ceiling" with what seems like tapered roller bearings top and bottom.

I'd like to know what the rating is for their crane. I know... I know... its shop made so no rating. LOL. They show lifting half a sheet of 1/4 inch plate. Seems heavy, but a full sheet is less than 300 lbs. I know I have 9 of them stacked out back. The 10th one is the top on my welding table. (The price was right. If I'd had a heavy trailer at the time I would have bought more of them.) Oh, they say 500lbs at the end of the boom. Bracing could definitely increase that. Maybe removable bracing so it can have greater trolley travel OR greater lift capacity as needed.

Yeah, I'm dreaming. I barely have time to get customer jobs finished these days.

I grabbed a couple RAM 3500 front 4x4 wheel bearing/hub assemblies being tossed by a friend. Thought one would make a great base to mount to the floor for spinning something on top of it. They already have bolts or threaded holes on both sides and a bearing. They didn't run right on the road but for something like this you wouldn't notice.

A smaller version is this Impala front wheel hub/bearing assembly:

Oh, I am absolutely not buying the item linked in post one for the primary application. I recently ran across several pieces of H/I (wide flange) beams for free to me. Enough to build a gantry crane and a jib crane and have some left over. The title indicated I thought it was silly, and if I had any plan to use it I think I talked myself out of it.

For my primary jib crane application. I would ideally want about 9' to

I wouldn't say I have a plan, but I have ideas.

The jib crane Jason with Fireball tools installed in this shop was an inspiration for me. Its secured to the floor and "ceiling" with what seems like tapered roller bearings top and bottom.

I'd like to know what the rating is for their crane. I know... I know... its shop made so no rating. LOL. They show lifting half a sheet of 1/4 inch plate. Seems heavy, but a full sheet is less than 300 lbs. I know I have 9 of them stacked out back. The 10th one is the top on my welding table. (The price was right. If I'd had a heavy trailer at the time I would have bought more of them.) Oh, they say 500lbs at the end of the boom. Bracing could definitely increase that. Maybe removable bracing so it can have greater trolley travel OR greater lift capacity as needed.

Yeah, I'm dreaming. I barely have time to get customer jobs finished these days. Bob La Londe

----------------------------------- The Vevor beam pivot was simple to make, bad to copy. For occasional use you can get away with a steel on steel beam pivot bearing, perhaps with a replaceable sheetmetal wear surface. It will be harder to swing, more likely to stay where you leave it. That's all the 1000 Lb truck bed crane has, and steel on steel pivots are common in yard equipment. I fixed 20 years of wear on some with bronze bushings and new pins.

A step up that's easy to make is a needle bearing using welding rod or music wire for the needles. Races for a homebrew ball thrust bearing can be turned with the sharpened shank end of a carbide endmill.

I've examined a broken logging truck crane that failed from lift cylinder base pin hole to mounting bracket edge tearout before the bearings went. It was puzzling because normally the boom weight and load push the pin inward toward the column yet the metal tore outward. My guess is that the boom pivot was worn enough to transfer turning torque to the lift cylinder, and abrupt starts and stops from swinging horizontally twisted the lower pin sideways to create unanticipated outward force on one end.

In ship building 1" steel plate is taken as 40 Lbs per square foot for ease of weight estimation. Plate thickness is designated by weight PSF, such as

The removable bracing that's worked for me is shear legs joined at the bottom with chain and a lever hoist. The top joint is two triangles bolted to the pipe, a third bolt passes through the pin end of a large shackle with chain attached for coarse initial height adjustment. Pulling the feet together lifts the beam. Unlike a single post the legs won't tip sideways, and they can straddle the load. On mine the lower end is half balls turned from a dumbbell riding in pyramidal plywood cups on a baseplate like an Army mortar for outdoor swinging loads like stacking logs, for an indoor upright it could be a simpler single pivot, U bracketed to a steel plate.

The shear legs can be draped over the beam, chained to it loosely at the top, then snugged up from below, each a simple one-man operation. Mine is water pipe and difficult to set up because the CG is so high, 2" x 10' EMT like my taller tripods is easier. 2" EMT and chain link fence posts should telescope together for longer lengths, depending on tolerance. jsw

I grabbed a couple RAM 3500 front 4x4 wheel bearing/hub assemblies being tossed by a friend. Thought one would make a great base to mount to the floor for spinning something on top of it. They already have bolts or threaded holes on both sides and a bearing. They didn't run right on the road but for something like this you wouldn't notice.

A smaller version is this Impala front wheel hub/bearing assembly:

These wheel bearing/hubs are throw aways. There was no provision in them for repacking the bearing or replacing it. So if you checked around the repair shops you could probably get them for free. A lot of times they make noises while driving but would be suitable for what Bob wants to do. Mount one to the floor and another overhead to ceiling. Put flanges on a pipe, channel... that matches bolt pattern on the hub. Or find a tire rim that fits them if that would work better in some way.

A lot of my old sources for stuff have disappeared too. I think part of it is liability worries and businesses being regulated/taxed beyond reason nowadays🤷

These wheel bearing/hubs are throw aways. There was no provision in them for repacking the bearing or replacing it. So if you checked around the repair shops you could probably get them for free. A lot of times they make noises while driving but would be suitable for what Bob wants to do. Mount one to the floor and another overhead to ceiling. Put flanges on a pipe, channel... that matches bolt pattern on the hub. Or find a tire rim that fits them if that would work better in some way.

A lot of my old sources for stuff have disappeared too. I think part of it is liability worries and businesses being regulated/taxed beyond reason nowadays🤷 Leon Fisk

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Many possibilities. I've found that if I acquire materials for one design they may be useful for several others as well. Quick estimates when I stumble onto something interesting are usually good enough, as long as I know the requirements like the expected load.

Unfortunately the sawmill and gantry hoist were designed for logs up to 2' across at the base and 2000 Lbs. I didn't expect the bigger trees to ever come down... jsw

Oh, I am absolutely not buying the item linked in post one for the primary application. ... The title indicated I thought it was silly, and if I had any plan to use it I think I talked myself out of it.

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You wouldn't, someone less experienced might mistake your mention of it as a recommendation.

I was thinking wheel bearings might be a cheap option. I have actually replaced (and saved for a while) three spindle hub assemblies off the front of the Silverado 2500HD over the years I owned it. Like a lot of junk I thought I might use it someday, and then I threw it away. LOL. Pitched the last one after I sold the truck last year.

I still have the OEM wheels off that truck Chevy truck I mentioned. I used one for a concrete filled base for a grinder pedestal. The others I had planned for hose hangers. Dang it. I'm never going to be able to throw anything away ever again am I?