Wheels for a gantry hoist?

[astro_al]

Hi guys, I'm building a mobile gantry crane with a 5T capacity. I'm stuck on finding a set of cheap wheels to put on it.

The floor is pretty rough, so they need to be pneumatic or maybe on pivoting 'bogies' to give some flex.

I'm not sure if lots of little ones or a few big ones is best. But they need to be cheap, either way. Any solutions I find need some hubs machining, but I'm not getting into that.

Answers on a postcard...?

Ta, Al

 

[rtbcomp]

Will the wheels be required to move the gantry + load or just the gantry?

 

[Drains]

Al, you're unlikely to find pneumatic wheels that can take a load like that without sagging (unless you're less frightened of tyres overpressurised to about 200 psi than I am). You can't allow the tyres to do that as it can potentially destabilise the load if it's off centre.
Solid tyres might suit you better and will tend to give less, although they still flatten with load.
There are plenty of forklift tyres going on ebay which might do better - http://www.ebay.co.uk/sch/i.html?_sacat=0&_nkw=forklift+wheels&_nkwusc=forlkift+wheels&_rdc=1
also some heavy duty PU wheels there but only rated at 1300 odd kg each, so you'd need four at each end of the gantry. (at least, as you'd need to factor in the weight of the gantry too)

 

[Drains]

Will the wheels be required to move the gantry + load or just the gantry?

It's bad practice to move a loaded gantry on anything but smooth level ground and/or tracks, unless the gantry is specifically designed - usually powered and with a large footprint, or with a facility for taking the load off the winch and onto some sort of solid base. It can be really dangerous if the load starts to rock. Ideally loads will be put on equipment specifically designed for moving, not lifting - like a pallet truck/ bogey etc.

 

[rtbcomp]

^^
That was my concern - having moved an engine on an engine lift!

Landrover wheels, hubs and stub axles might be an option.

 

[Drains]

Al - one way around the wheels problem - as long as you only intend to use the gantry for lifting, not moving, is to rate the wheels for the weight of the gantry only and to fit screwjacks or similar to the gantry to take the load off the wheels when lifting.

 

[astro_al]

Ok, points taken, a little clarification.

The base of the gantry will be pretty large. The floor isn't really bad, it just isn't showroom smooth.

If I need to move anything, it can just be raised an inch off the ground and rolled. This is for rare times when the forklift won't cut it, or for lifting machines off trailers etc and dropping them directly to the ground (drive the trailer out from underneath).

I have one single operation in mind for the next few months of installing my powerhammer, most of which is straightforward, but at one point I need to lift the whole hammer about a metre off the ground and wheel it forwards, say 2 foot and lower it over the anvil. For this one, I can ensure the ground is level, if necessary by having steel plate for the crane to roll on.

Drains, the screw jack idea is good, I might do that anyway as a safety feature for whenever I can use it.

By the way, does anyone know a source of 5T beam trolleys? Cheap! I scored a good lifting hoist on eBay, use need to hang it.

I have been wondering about electric wheelchair motors or similar to propel it. Might be more stable being pushed by wheels (REALLY slowly) than being pushed by hand further up the frame?

I think forklift wheels are ideal, but the used ones never have hubs with them...

Ta, Al

 

[Hitch]

Wonder what the load rating is on wheelie bin wheels al...



Seriously though how about machining/fabricating up your own steel rims, and fitting press on tyres, not sure on the cost of these, but can be got from the likes of decent castor makers like Brauer or Blickle...

Or get some of the cast iron wheel types with the PU tyres, and make your own bracketry incorporated into the legs....

 

[pidgeon chit welder]

I've got four locking castored big 9 inch x 1 inch wide one tonne industrial rubbish skip wheels on solid tyres that I have lashed up with a welder to slip my 12 foot high 4x4 plantform on. They have axle bearings in them

If memory serves me correct each castor is rated at 600 kg each
I got them on line on ebay for nine quid each brand new inc P&P .

Here is an ebay number for cast iron bodies and orange polyurethene rims @ 200 mm dia to consider ...then search for a better price perhaps , though as these are inc vat they do seem much cheaper than many other places that will add VAT .
Item number: 120915666812

Just found a 5 tonne push beam trolley in the same place
item number 280118734728
They also have geared ones in their shop.

 

[wheresmejumper]

what about trailer jockey wheels and assembly

 

[madkayaker]

Unlikely to have the weight capacity

 

[wheresmejumper]

found one capable,but the price is pretty substantial to say the least!
jockey wheel

 

[MattF]

I have been wondering about electric wheelchair motors or similar to propel it. Might be more stable being pushed by wheels (REALLY slowly) than being pushed by hand further up the frame?

Wouldn't think those motors would have enough poke, personally. Plus there's also the jolt factor when you use any electro-mechanical drive. There'll always be a little kick when it starts. Why not just put hook rings on the bottom of the frame and use a block and tackle or similar for moving it when loaded. You can move things with a lot finer control when you're physically controlling it.

I think forklift wheels are ideal, but the used ones never have hubs with them...

Trailer wheels? You could try and drop on some old trailers or indispension units and just use the hubs from those. Good old cast irons wheels are always another, though obviously without any frills, option.