Shop Crane Revisited

Hmmmm.... I wonder if I 'll get lucky and stumble across a big piece of thick wall steel tube I can use to make a jib crane over by the mills and lathe in the back of the shop.

Depending on the load capacity needed ... I built 2 swiveling jib cranes with a portable base* for handling firewood . My first out of 2x2 thin wall square tube and I've handled up to about 400 lbs with it using a hand crank . Then I got some thick wall and built another with a 2500 Lb electric winch mounted on it . *I also built a pivot mount in the front corner of my 5z8 utility trailer . The light unit with the hand crank stays on the portable base , been useful for tasks like hanging a truck door out of my way while I replace hinge pins . The other stays on the trailer for handling firewood rounds and dragging logs out of a tangle .

... Anyway, out by the back fence I found several fairly large I-beams setting up off the ground on wood beams. I think I just found my gantry crane. Now if only I can stumble across some big steel casters out there somewhere I'll be set. Maybe they are under the old gas pumps over by the south fence. ;^) Bob La Londe

------------------------------------------ If you don't need to roll a loaded gantry you can use trailer tongue jacks for retractable casters. Position them so you can crank both at one end up and down simultaneously. You can still travel with a load above their rating in steps, moving the load and gantry alternately.

Adding outrigger wheels to the casters lets them roll better on dirt but then they don't swivel well. They can be linked and controlled with steering knuckles made from strap steel, drilled to go on the axle, with a pull handle.

Custom axles are a use for a lathe.

I've seen boat trailer winches on commercial gantries to raise and lower the unloaded beam. I use them on my tripod supports, attached to a leg with muffler clamps. I would want a lowest beam height that allows hooking on the chainfall without a ladder, they are heavy and awkward. I modified my trolleys with connecting rod sleeves that the chainfall hook fits over (endwise), increasing the working height and allowing the nuts to be tightened without restricting the hook. I put the chainfall on a table and lower the beam to match so I have both hands free to assemble the trolley to them.

Unbreakable rubber farm buckets are good for storing and carrying a chainfall, and in use they can keep the hand chain out of the dirt/mud.

The sleeves were a lathe job, water pipe bored to fit over the trolley rod. Much of what I make could be done on a small inexpensive hobby lathe, the shafts and bushings, but not the gears and pulleys. My small lathe turns much faster than my larger one, which is handy to drill deep grease holes in axles. I use the little one for grinding, sanding and polishing to keep grit off the ways of the good one.

The tripods stand upright without the beam, which makes one-man assembly easy. Published specs suggest that some sizes of water pipe, EMT and chain link fence post may telescope together, I haven't tried with the 2" sizes appropriate for a tripod gantry support. You can check their column strengths with on-line calculators, I know what loading my rigging gear has proof tested to but can't guarantee it for someone else's likely different construction. Single post uprights with free rolling bases would need to be much stronger. The conventional rolling design makes sense on level pavement, mine is for uneven ground outdoors and disassembles for storage.

I didn't specifically include loading the truck in my gantry design because the towable shop crane that moves in all directions is more convenient for slung loads, the platform lift for others. Plus I can mount the bed crane to lift on or off anywhere.

For the heaviest log loads (>3000#) I moved and secured the trolley with two blocks-and-tackle, operated from outside the danger area. They gave fine control to center a maximum sized log within 1/2" on the sawmill and should help to position a heavy lathe chuck or workpiece.

jsw

Depending on the load capacity needed ... I built 2 swiveling jib cranes with a portable base* for handling firewood . My first out of 2x2 thin wall square tube and I've handled up to about 400 lbs with it using a hand crank . Then I got some thick wall and built another with a 2500 Lb electric winch mounted on it . *I also built a pivot mount in the front corner of my 5z8 utility trailer . The light unit with the hand crank stays on the portable base , been useful for tasks like hanging a truck door out of my way while I replace hinge pins . The other stays on the trailer for handling firewood rounds and dragging logs out of a tangle .

For a jib crane I am thinking something a little more substantial. although bolting part of an engine hoist or truck bed crane on to the roof of my office did occur to me. I'd like something for triple duty. I don;t often swing heavy parts onto the lathe or mill in the back, but I do from time to time. Heavier than the hundred pound vise I take off and put on the mill table. I'd like to have a jig with a trolley so I can set things on the mill table, into the chuck jaws, and lift things up to the roof of my office. Standard height 8' ceiling office inside a metal building with a 16' eve height. Roof of office was built with

I'm thinking if I could find a twenty foot piece of 6inch well casing or similar I could build both ends onto roller bearings and easily swing

A jib crane is really secondary. Primary is a gantry crane to meet most of my needs without buying a forklift. Yes I have bucket forks, but they will only lift about 1500 (and it complains about it) pounds, the tractor doesn't have room in the shop, and it doesn't reach high enough.

Actually their individual load times four. Just like any other caster. Trailer jacks is not a bad idea, and I have seen this sort of thing done on other equipment. They are also available (at a substantial cost) at much higher ratings. Having seen a few failures generally the limitation of most lighter ones is the plastic wheel. I've seen them break.

Actually their individual load times four. Just like any other caster. Trailer jacks is not a bad idea, and I have seen this sort of thing done on other equipment. They are also available (at a substantial cost) at much higher ratings. Having seen a few failures generally the limitation of most lighter ones is the plastic wheel. I've seen them break.

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I found tongue jack replacement wheels in a discount store to add on with a longer axle.

Steel wheels aren't that hard to make. I welded crossed plates for spokes into a slice of 6" stainless pipe, bored the center a snug fit for pipe and welded it, then bored the pipe to accept needle bearings cut from stainless welding rod. These are the oversized all-terrain replacement wheels for my platform lift which is stored on sometimes wet ground.

The HF 1300 Lb electric winch starts with a considerable jolt and is meant to mount on horizontal pipe with the included straps. The cable would bunch up at an end instead of winding evenly if the winch was somehow hooked to a trolley hoist and could tilt.

I scratch-built a trolley with a flat bottom the winch bolts to. That was the project behind my posting of a few years ago about boring a recess to press in a bearing. Mostly I use this trolley with a chain or lever hoist hung from a central eye bolt because the electric winch is too hard to control precisely. When positioning a log or partly cut cant on the sawmill I lift it only enough that it can be slid into position and will stay there.

The electric winch was good for stacking logs because I could stand clear in case the pile shifted. Stacking cut timbers with it was a nuisance because it wouldn't partially support them while I aligned the stack.

For a jib crane I am thinking something a little more substantial. although bolting part of an engine hoist or truck bed crane on to the roof of my office did occur to me. I'd like something for triple duty. I don;t often swing heavy parts onto the lathe or mill in the back, but I do from time to time. Heavier than the hundred pound vise I take off and put on the mill table. I'd like to have a jig with a trolley so I can set things on the mill table, into the chuck jaws, and lift things up to the roof of my office. ...

I'm thinking if I could find a twenty foot piece of 6inch well casing or similar I could build both ends onto roller bearings and easily swing

A jib crane is really secondary. Primary is a gantry crane to meet most of my needs without buying a forklift. Yes I have bucket forks, but they will only lift about 1500 (and it complains about it) pounds, the tractor doesn't have room in the shop, and it doesn't reach high enough.

-- Bob La Londe

-------------------------- This past summer I had to move a 20' log that was hanging from the gantry sideways to swing the ends past its supports. I set up two tripods with lever hoists in more or less a triangle with the gantry hoist and was able to move the log in any direction after a 3-D learning curve. Three 1-ton chainfalls hung from your roof (if strong enough or braced) could let you position a load anywhere within their triangle.

Actually their individual load times four. Just like any other caster. Trailer jacks is not a bad idea, and I have seen this sort of thing done on other equipment. They are also available (at a substantial cost) at much higher ratings. Having seen a few failures generally the limitation of most lighter ones is the plastic wheel. I've seen them break.

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I've seen advice to select casters rated for 1/3 of the load instead of 1/4, floors aren't always flat and level. 1/4 should apply to a gantry that isn't torsionally rigid as long as the load is secured in the center, 1/2 if it can roll to an end while moving. Unlike square tubing, H, I and C section beams are made from the least metal that will be strong in one direction. They are relatively easy to bend sideways or twist, as I found from straightening salvaged ones.

My source of strong steel wheels and casters is second-hand, obviously removed from machinery from the tread nicks and grit on them. Thus I can't give a reference to buy them. I've picked them over and already bought most of the good ones. I'll know the capacity if I break one.

When I had a new section of driveway paved I asked them to level it as best they could, as the old section has a considerable slope and I jack up and work under vehicles on it. The new part looks level but when I set up and leveled the sawmill track on it I found a drop of 9" in 16'.

A vehicle on downhill end ramps on the sloped section will be nearly level. I push the ramps against the low end tires and chocks against the upper end ones, measure from the center of the ramp top depression to the wheel center, and advance the chocks that far to stop the vehicle when in place on the ramps.

I looked into the size and weight of a one piece end supported gantry track for my sawmill but I couldn't lift or store it. The compromise is a track in shorter manageable sections supported at the splice for heavier loads. This is a rough guide to the size of a one piece beam for load weights and span lengths.

That could be an issue...

and is

I am sure the winch could be hooked to a trolley even if mounts had to be fabricated. As to the cable, I've seen it done with a series of mini rolling hangers. It would/could bunch up, but it would roll out and roll back just fine. Te real expense if it were used often would be replacing the cords with high flex cord.

Use a DC winch with a speed control or "soft start" or get all fancy schmantzy with a hydraulic winch - - - - -

I am sure the winch could be hooked to a trolley even if mounts had to be fabricated. As to the cable, I've seen it done with a series of mini rolling hangers. It would/could bunch up, but it would roll out and roll back just fine. Te real expense if it were used often would be replacing the cords with high flex cord.

------------------------- Angle iron could connect the winch to the side plates of a purchased trolley. I made a low profile trolley to maximize lifting height and log capacity in a nearly full low roofed storage shed. The tapped mounting holes in the winch are under the trolley side plates and wheels, so installing and tightening the bolts is tedious, more so than if the vertical legs could be bolted to the trolley sides afterwards; mine is one compact unit. With the winch level the hoisting cable winds neatly. I've been replacing steel winch cables with synthetic which is safer to handle.

The hanging line cord wasn't a problem on 8' of track. The search term for supporting long electrical cables is 'festoon'.

--------------------------------- I was happy with the hoisting speed and positioning control of a 1 ton manual chainfall. It lifted the track and sawmill components for assembly, positioned and rotated the logs, and moved all the lumber I cut. When not in use the hand chain was stored in the farm bucket, hung from the hook. The 2T chainfall lifted the heaviest logs but got little use otherwise because it is so slow.

I suppose a jogging or inching mode for an AC electric hoist could be added with a variable time delay and SSR relays, as I did for my spotwelder.