Travelling Crane

[Nigel Graham 2Participant @nigelgraham2]

In a brief digression in AStroud’s “Beginners’ Questions’ thread about flywheels, Andrew Johnston suggested a description of my workshop’s overhead travelling crane.

It had to fit below a fairly low, sloping ceiling, and as I do not know stress and strain calculations used a fairly empirical approach and would not try to lift to the quarter-ton maximum of the ‘Clarke’ chain-hoist presently occupying it. Unusually for me I did produce drawings for its main structure first, using TurboCAD in orthographic mode (not 3D modelled).

Although fitted with a commercial chain-hoist I made the suspension-bar for that such that it can form a non-rotating axle for sheaves, giving a rope block-and-tackle option. To facilitate this exchange the bar is grooved to drop into keyhole-slots in the suspension-cheeks on each side of the crab (the cross-travel trolley).

Apologies for the somewhat soft-focus photos.

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Showing how the chain-block is slung from the crab. I did not worry about centralising it particularly.   Lift that bar and it can be withdrawn for adding sheaves, in that conversion. The main beam axle is simple ERW steel tube held to the wheel by a short, internal stub axle with a screw across it. I have to remember to push or pull the beam by itself not the axle! Essentially the main beam is a six-foot gauge bogie.

Nothing fancy in making those two fancy-shaped side-plates, other than milling the keyholes. 1/8″ steel plate, marked out, cut to shape with an angle-grinder, trimmed by file.

Note the rebate in the batten.

That wiggly thing below the rail is not an electrical cable you’ll be pleased to know. It’s a length of tube “stored” there.

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A closer view of the crab. I made the mistake of having the wheels rotate on dead axles, retained by circlips, rather than rigid wheel-sets. Consequently it tends to live up to its aquatic name, yawing slightly and partially jamming if not pulled along parallel to the rails. The string holds some of the hoist chain in control.

The hoist’s operating chain was far too long for such low head-room, so I shortened and rejoined it by a method long established for making ‘C-links’ for connecting together the wire ladders used in caving and by trapeze artists etc. Cut the link on the weld (so as not to risk failure) by two thin cuts at 45º, so the ‘C’ so formed has two chisel-like edges facing each other. The mating link is similarly cut, and the two will now slide together a bit like a “metal puzzle”.

 

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This shows the central stretcher assembly, of 1/8″ steel plate, 25mm sq tube and channels made by cutting along 50mm sq. seam-welded tube. The fastenings are all M8, giving some sense of scale along with the frame members. You will notice the frame tubes do not stretch the full length of the beam, hence the fairly complicated stretcher assembly and the use of the crab rails (25 X 25 X3 angle) as joiners and reinforcing. A simpler stretcher links the sides at the quarter-width points. I had to cut deep rebates in the ceiling-battens along the low side of the workshop to allow the steelwork to pass.

 

 

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A pier on the concrete-block workshop wall forces this stand-off, though also itself provides an anchorage for the track on that side. The column is 50 X 50 X 3mm ERW tube standing on the floor and screwed with self-tapping masonry screws to the blockwork. The screw-heads are inside the tube, reached by access-holes sized for the socket. The ends of the rails beyond this point are screwed down onto aluminium plugs set in columns made from scaffold-tube. That heavy angle-bracket came from some scrapped gymnasium equipment, if I remember correctly.

Note the main beam wheel. These are ex-hoist traveller of the type made for running on H-beam flanges. The holes in the outer face of the vertical square tube are access to the heads of the horn faces, which are short pieces of black mild-steel assembled then faced on a manual Drummond shaper. The horn-blocks are plain cast-iron with a shallow channel as bearing.

The assembly immediately above each hornblock is a slice cut from a rubber roller from an old printer, sandwiched between mild-steel cups. This gives a modicum of springing to cope with any slight track alignment error. despite all care I knew it would be difficult to lay the track to Network Rail standards – in fact the biggest error proved to be a gauge narrowing by about 1/4-inch at one end of the line, some fifteen feet long. (The workshop occupies the full width of the garden and its existence was a key point in buying the house! One has to have one’s priorities right, one knows.)

 

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A general view as best as I could obtain in a shed that seems to be shrink-fitting itself to the machines. The ceiling-slope is a bit exaggerated by the camera angle. Off to the right is the Harrison lathe whose motor occupies a frame above the headstock, utilising the rail itself and a spar between two of the support columns.

The plastic bag by the milling-machine protects the DRO unit, and as it fits only very loosely stays there in use to keep the unit clean from my oily fingers.

The body of the small Denbigh H4 horizontal-mill peering out from behind the Tracy Tools chart, and the Progress 2G drill holding the chart, are perhaps the heaviest loads this crane has handled.

Hidden to the left foreground is a massively-built two-foot square timber bench bolted to the wall, floor and drill bench and topped with a 10mm thick steel plate drilled and tapped in various places to hold moveable tooling like a bar-bender, small fly-press and bench-vice. It also provides for the shaper if I wish to use it there though it seems happy enough on the bench it’s occupied for the past several years. The overhead crane proved ideal for drilling the plate as it could hold its overhang far from the drill-machine’s table.

The Denbigh was made for line-shaft drive and is waiting for me to make a new drive system for it. It came with a curious confection of ancient motor, old car gearbox and chain drive on a crude frame above it, and I did use it like that for a while.

[DiogenesParticipant @diogenes]

Well done – that’s one of the best looking home-built sky hooks I’ve ever seen..

[Anonymous]

Nigel: Thank you so much for taking the time and trouble to post about your crane. It looks great, very professional! I am going to have to have a rethink. I also need to do some calculations too on bending stresses and deflections.

I had planned to use Unistruct U-shaped steel channel and matching wheels. But I am now having doubts as to whether it will be strong enough. My arrangement needs to be more involved as I ideally need to be able to move a short distance in Y as well as X. I think the heaviest item will be the vertical head for the horizontal mill, or possibly the capstan unit for the centre lathe. In an ideal world I would weigh them. But I have operations for cataracts and a hernia repair booked over the next couple of months, so won’t be lifting anything for a while.

I also need to move a ceiling light and re-arrange the assorted aluminium extrusions that are stored on hooks hanging from the rafters.

Given my upcoming operations I won’t be in the workshop for some weeks. I had planned to design the valve gear for my traction engines, but I should add some serious thinking time for the crane as well.

Andrew

[JasonBModerator @jasonb]

Andrew, having bent  apiece of Unistrut a couple of weeks ago you would do well to look at something else. I was using it to try and lift a drain grating, about 200mm one side of a fulcrum block and 800mm on the lever side. Just standing on it caused the sides to beind inwards and the whole thing go a bit banana shaped and I’ve not put on weight since you last saw me.

As for the hoist keep a look out for the Lidl ones which are basically a Barrow host and quite reasonable, I have one under the bench that I got if I needed it to lift the Fowler but have not had the need

[Mark RandParticipant @markrand96270]

It’s a lot tidier than mine!

 

[JasonB]

On JasonB Said:

Andrew, having bent  apiece of Unistrut a couple of weeks ago

Unistrut comes in a lot of flavours. Please look up the P5001T channel next time you wish to open a drain.

There is a Unistrut engineering catalogue available, where every Unistrut product comes with data on its structural capacity. For the channel, this will include the maximum bending moment. For the trolleys, it will include the maximum capacity of the trolley. Hence, if it were proposed for a crane, it is easy enough to do some fag packet calculations, apply an appropriate factor of safety and assess value for money.

FWIW, my recollection is that the trolleys are not so strong, so you need multiple units with a spreader/equalizing bar to achieve a reasonable capacity. My rough guess is that you could achieve 250kg SWL midpoint of a 3m span with Unistrut.

[Colin HeseltineParticipant @colinheseltine48622]

I use a 41mmx41mm unistrut section for a small hoist above my lathe.  The unistrut is coachbolted directly to the roof joists.  It runs diagonally for about 2 metres and is bolted to 5 joists.  I built my own 4 wheel trolley for it.  It takes the weight of a 50Kg capacity electric hoist which weighs around 22Kg and my biggest lathe chuck which is approx 35Kgs

Colin

[Les RileyParticipant @lesriley75593]

Those Clarke chain blocks lend themselves to fitting a very close roller carriage. If you take the cases off and remove the hook bits you can knock up a replacement that fits much lower and gives more headroom.

I have two such hoists, one above the mill and one above the lathe, both on a swinging arm of 40 x 40 box section.

They run on 4 sealed roller bearings.

[Nigel Graham 2Participant @nigelgraham2]

Thank you for the kind comments!

Les – Swinging-arm, or radial, type cranes such as yours are made commercially for serving individual machine-tools, and there was one in the laboratory where I worked, for lifting a very heavy lid on and off one of the test-tools. The main lab cranes were fully-travelling, a 3-tonne and 1.5t ones sharing the same longitudinal rails, with an arrangement to prevent them approaching each other too closely for the load on the structure.

It was that ability to serve the whole area, I need here.

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Mark – I think yours is the simpler and tidier! Probably stronger too. It’s clear though you have the headroom for that set-up. I had to cope with a ceiling not much above six feet up on the lower side; hence the open-frame design with the crab within the frame.

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At the moment my crane is parked above the Denbigh mill, to support a simple plywood and studding jig suspending a Vee-pulley for the machine’s drive I need build. I needed establish its centre-height and approximate position above the mill.

This jig is not on the hook but rests across the rails. It came from thinking of something similar for supporting long material on the band-saw or drill, replacing G-clamping battens to convenient fixed objects.

The last of my photos shows a dark object on the ceiling, to the left. It is a steel bar screwed through to the joists, to hold tackle for lifting and lowering the heavy chain-block itself.

[OldironParticipant @oldiron]

A couple of excellent home workshop cranes there chaps. Well done.

Just an aside if anyone is looking for a large industrial style over head crane there is one available.  The Rolls Royce Heritage Trust is trying to find a good home for their original Sir Frederick Henry Royce  designed and built overhead traveling crane. It was designed by him even down to the electric motors that power it. Has a capacity of 7 tons if I recall correctly. If it is not dismantled and taken away by some time in August it is off to the scrap yard.  Would be a pity to loose such a great piece of British engineering. Just a little to big for my workshop even though it is a freeby. It spans about 10 metres x 3 metres and weighs in at more than 20 tons I estimate. Was working when the workshops were closed after Covid. Located in Derby and would need to be dismantled and removed at your expense.  Anyone with a serious inquiry or know of a company that might take it message me and I can give you contact details.

I have however taken over a hundred items from them in donations to my measuring and calculator collection.

regards

[Anonymous]

Plenty of good ideas, thanks to one and all.

I need to do some basic calculations for Unistruct before deciding upon a design direction. I can see this becoming a rather bigger project than I had anticipated!

Andrew

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