Fabricating a stillage, advice needed

[BrianCork]

Hey everyone, first post here, looks like ye have a wealth of info in this forum!
I need to fabricate a stillage at work to be able to load a piece of machinery onto an artic trailer. Its a small self propelled machine on 4 wheels, weighing about 1.5tons. Im not a professional welder by any means, but having worked with agricultural machinery all my life im a pretty confident welder with arc and mig, and have recently dived into the world of tig.

Anyway, Its going to be a straight flat rectangular frame (no need for folding ramps). It will measure 190cm x 310cm. I was planning to use 80x40x5 hollow section steel.

View media item 9077
The plan attached shows how it will look as you are looking down on it. Red is the bare frame, black will be tracks for the wheels and blue is for support bars welded in for rigidity. All will be made from the 80x40. My questions are do ye think this frame will support 1.5t? It will be loaded with a forklift, wil be welding 2 more runs of rhs underneath for the forks and also 4 corner legs to keep it steady while loading.
What welding set up would ye recommend? I personally would prefer to arc weld it as im more comfortable arc welding. Would 3.2mm rods do this? Plan on welding the joints all the way around.

Like i said, im not a professional fabricator, so please feel free to throw any advice/comments my way!

Thanks, Brian.

 

[colnerov]

Apparently we don't have permission to view the pic.

 

[BrianCork]

Sorry, must've clicked something wrong in permissions, should be sorted now.

 

[Kent]

Big way verticle even not seeing drawing I should say the steel will hold
The design? Dunno can't see the drawing

 

[BrianCork]

Sorry lads, ye should be able to see it now?

Apparently we don't have permission to view the pic.

Big way verticle even not seeing drawing I should say the steel will hold
The design? Dunno can't see the drawing

 

[Bill Edwards]

I find the exact details hard to picture but I'm quite sure it's able to take the 1.5t, plus a bit...
3.2mm rods are ideal for the job.

 

[BrianCork]

I find the exact details hard to picture but I'm quite sure it's able to take the 1.5t, plus a bit...
3.2mm rods are ideal for the job.

Yeah im afraid the design had to be done in MS paint! Its basically just aload of 80x40 sections joined together on the floor with feet underneath. I figured it may be good for slightly more than 1.5t, but its an expensive bit of kit going up on it so better safe than sorry! My main concern was would it flex, but in reality i suppose it probably wouldnt if properly welded at the joints.

 

[Kent]

What a weird drawing. You could likely Park three of them on that if they are all 80 up. Just doing a leg on each corner these will be the weakest bit if the mystery object shuffles

 

[BrianCork]

What a weird drawing. You could likely Park three of them on that if they are all 80 up. Just doing a leg on each corner these will be the weakest bit if the mystery object shuffles

Haha the mystery object is just a self propelled zamboni ice resurfacer. I know its weird, but when it comes down to it i want something that will last. Along with the legs there will be another 2 lengths of rhs running underneath for pallet forks so should be sturdy enough id hope when its all strapped down on the truck.

 

[wilbur]

By my reckoning you have roughly 25-28m of RHS there, which in 80x40x5 is something like 8.4kg/m, so the stillage is going to weigh about 200-250kg. Are you prepared for that?

I think we might have guessed you'd spent a lifetime with agricultural machinery even if you hadn't said...

I think it will be very strong - but you could make its lift easier by not putting the legs right at the corners, or by arranging fork pockets which share the load with the feet when it's on the back of a wagon.

You will 100% want some kind of fork-pocket/guide because steel stillage on steel forks is hellish slippery, and a 3mx2m load on the forks is a bit of a beast anyway. The easiest thing for the fork-driver is to have big RHS tubes across, so that as long as you can get the tips of the forks in, you'll get the rest in. If you want to make life painful, have three sets of rings - one of each long edge and one in the middle (which you can't see from the seat), so that you have to blindly stab around in the dark with the fork tips under the load, hoping that you're straight enough.

Anyone who's done much Heras fencing from stillages will know what I mean...

 

[BrianCork]

By my reckoning you have roughly 25-28m of RHS there, which in 80x40x5 is something like 8.4kg/m, so the stillage is going to weigh about 200-250kg. Are you prepared for that?

I think we might have guessed you'd spent a lifetime with agricultural machinery even if you hadn't said...

I think it will be very strong - but you could make its lift easier by not putting the legs right at the corners, or by arranging fork pockets which share the load with the feet when it's on the back of a wagon.

You will 100% want some kind of fork-pocket/guide because steel stillage on steel forks is hellish slippery, and a 3mx2m load on the forks is a bit of a beast anyway. The easiest thing for the fork-driver is to have big RHS tubes across, so that as long as you can get the tips of the forks in, you'll get the rest in. If you want to make life painful, have three sets of rings - one of each long edge and one in the middle (which you can't see from the seat), so that you have to blindly stab around in the dark with the fork tips under the load, hoping that you're straight enough.

Anyone who's done much Heras fencing from stillages will know what I mean...

Well I'm only 22, but the ag machinery bug kicked in as soon as i could walk haha!
Yeah was planning on rhs for the fork pockets too as il be the fork driver and trying to get the forks into a set of rings at 2 in the morning with worse than useless work lights is a bit of a non runner.
I do understand the sheer weight of it, but i think it should be managable seeing as it will always be loaded with either a 3.5t forklift or 3t loadall, although i know those loadalls do get a bit tail-happy alright to say the least. What would you suggest in terms of lightening it without detracting too much from its sturdiness?

Thanks again for the replies lads, yeve been more than helpful!

 

[wilbur]

What would you suggest in terms of lightening it without detracting too much from its sturdiness?

I'm no structural engineer, but it's pretty clear that it needs much more strength the vertical direction than the horizontal, and that also turns out to the the direction that it's thinnest, which doesn't help. Probably the more rectangular (i.e. less square) you have your steel section the better.

If you were really keen on making it light, you would probably build the two long sides as some kind of truss, with a top and bottom chord spaced apart by something lighter. The bottom chord is in tension and the top one in compression, and the bit in the middle does very little work. You might not actually want these at the edges of the platform, because then only one will be on the forks at any one time.

Do a Google image search on Steeldeck for possible inspiration.

Think about the fact that the whole load may mostly end up sitting on the very tip of the forks. And also that rough-terrain forklifts are often spec'd at 0.5m load centre and only have stubby-little forks, so if you're 1m out then you need to think about derating the forklift.

 

[BrianCork]

Was thinking about the fork issue last night alright. The idea to counteract the possibility of a stubby fork issue in places where extensions arent available is to have a length of channel running vertically up from the ground at the side of the stillage, with a chain attached at the top which can be looped to the headstock of the forklift or loader, effectively creating a 3 point linkage like youd see on the back of a tractor. Would this suffice? To my mind it would, but then again im open to all ideas. As regards to vertical strength, what exactly do you mean?

 

[zzr1200]

At nearly 2 tons with a 36 inch load centre you would need a very large forklift to lift/shift it safely.

Most standard size forklifts are only rated at 24 inch load centres, container handlers forklifts are rated at 48 inch load centres.

Using a chain as a third anchor point makes no difference to the load/front wheel (pivot point)/ balance weight ratio, the extended load centre will cause a ratio imbalance, causing the forklift to lift the steer wheels or worse case, self unload at height.

http://www.globalmachinebrokers.com/forklift-maximum-capacity-calculator-s/2086.htm

 

[outofthefire]

Personally I'd do away with the middle red box, but put 2 more cross supports in the middle and use a suitable sized channel for the wheels to run in

 

[colnerov]

The black bearers are the only ones that need to be strong to take the weight of the machine through the wheels. The fork boxes underneath and a cross bracing at the ends the same height to strengthen the main frame. the red material round the outside can be smaller section but enough to take a nudge from the forklift carriage to prevent contact with the machine.

 

[octo0072000]

why can't it be put on a low loader or trailer if it's got 4 wheels and self propelled
sounds a more sensible idea

 

[wilbur]

why can't it be put on a low loader or trailer if it's got 4 wheels and self propelled
sounds a more sensible idea

I suspect they're trying to pack an entire ice-rink and all its gubbins onto standard flat-bed wagons. Once you get bitten by the 'let's stillage absolutely everything and fork it all on' bug it's quite addictive...

But a trailer with ramps would be a lot easier, except for needing another vehicle/driver, etc.

 

[BrianCork]

Thanks Colnerov, got a very good price on the 80x40 as the supplier has some he's looking to shift so would ideally be mking it entirely out of that, a good point though. I have thought of the trailer Octo, and we have used one in the past, but organising someone to shift it from one end of the country to the other at a certain time is messy in a small business, most places itd be going would have slots for our trucks and deliveries to arrive and it just isnt feasable, having it arrive on the truck along with its ancillaries and kit makes it easier for us. It may also go overseas at times, so being able to load it onto a truck would save on costs. As you say Wilbur, we've stillaged awkward things in the past and its been a godsend it certain situations. Hoping to get the steel organised next week and crack on with it when time allows.