Crane for my rear load bed.

[Astro_Al]

Afternoon all.

I'm looking at sticking a crane behind the cab on my Mog 404 to lift at least 500kgs up onto the load bed.

There will be a pretty straightforward 'truck cab'-style roll cage over the cab area (no fixed roof), and when 'lowered' I want the crane to sit below the line of the top bar.

I figure it needs a swivel mounting at the base, as long a boom as possible (the obvious method being to mount the crane on one side and have the minimum length just fit in the space across the bed). A hydro ram for lifting and lowering the boom angle, and probably some kind of small winch to lift the load. Since it is next to the simple cage, I figure the top can also be supported / pivoted which will help with bending loads at the base/swivel.

I'm considering running it all off the hydro pump for the steering / winch (not at the same time ).

Anyone got any inputs on parts to use / fab; design of the structure / mechanisms; hydro ideas; or anything else?

Cheers. When I get a second I'll throw up a crayon sketch of my brain-fart.

Al.

[discojmz]

just watch ebay for a 2nd hand mini-hiab (The type the transit tippers from the hire places have on them. should be able to run that off a modest hydro pump

[Astro_Al]

Thanks for the idea, but isn't it going to stick up vertically when 'stowed' (I'm not sure)? The load bed is pretty damn high once you've got 40" tyres on portal axles. I need it to fold down kinda flattish, as the cab cage will just go into my garage - I don't want anything higher than that.

Besides, where's the fun in buying one...?!

Al

[vinny]

You could pull the arm of a scrap mini digger???

[sotal]

I've got a load bed crane sitting in my garage (not my crane - a friend left it there!)- no idea how good it is etc just thought you might be able to steal some ideas from it if I got a photo or two. It's quite heavy and uses an electric winch

[LandyManLuke]

Is there any reason the boom can't do the lifting, rather than having a winch? - a-la hiab?

I reckon it'd be possible to make a hiab arm-style boom that folded back on itself when behind the cab, then folding out, up, and then down to the ground using a single ram. It would depend on the complexity/ease of use balance you're after though.

[Astro_Al]

Thanks for the inputs guys.

The problem of not using a winch to lift the load off the ground and up to the end of the boom is that the load bed is pretty high and you'll never get the end of the boom down to near the ground, so you'll end up with everything hanging off a long chain / rope, which could give clearance probs when you try to lift it onto the bed. Hope that makes sense!

The kind of things I'm looking at are:

A hiab or similar is also going to weigh a LOT more than something like the above (though I would make mine beefier than those).

Here is my brainfart:

Sorry for level of technical drawing, I hope you guys can keep up!

Al.

[gazelle]

Have you thought of using a derrick arrangement.

You could use the cage as the stay, using both sides of the cage to control the slewing of the arm.

A bit 1960's shipping, but lighter and effective.

Martin

[LandyManLuke]

Thanks for the inputs guys.

The problem of not using a winch to lift the load off the ground and up to the end of the boom is that the load bed is pretty high and you'll never get the end of the boom down to near the ground, so you'll end up with everything hanging off a long chain / rope, which could give clearance probs when you try to lift it onto the bed. Hope that makes sense!

What about a folding arm that works off the one ram still, with a winch. It would mean the arm could be stored veritically, without being swung across the bed, reach would be a function of bed-to-roof height, rather than cab width.

[LandyManLuke]

I've been playing with bits of cardboard, you could make a boom that would stow without swinging, would not require the ram for strength, and would give a reach approx twice the bed to cab roof height.

[steve b]

Hi Al ,

How about a couple of lorry cab-tilt rams, they are usually double action , allowing a 'shoulder' and 'elbow' hinge for low profile folding storage ....you probably don't want to increase the c o g hieght ...could even have a third for a sliding extension . 500kg isn't much and it could all be fairly light ....you've only got to look at a 500kg Sealey engine hoist

Of course the longer the reach the heavier the spec gets....the other thing with mogs is mounting things to the chassis, probably best to do it like the rear load bed on swinging links one side, or even better onto the load bed frame.

Cheers

steveb

[Astro_Al]

Landymanluke - I is a bit fick, innit? You want to furnish me with a Crayola picture so I can invisage your flash of Kelloggs inspiration? I'll PM you my crayons if it helps?

Hi Steve, yeah, I kinda wonder if I'm selling myself short with a 500kg spec... But realistically, apart from machine tools (which would probably be better travelling nearer the ground), I don't see the need.

I hear you on the mountings. My initial thought would be just to mount it on one of the chassis rails, and at the top tie it to the cage - frame flex unaffected. Though I'm reliably informed that frame flex isn't much of an issue once they are stripped down and unladen, so maybe I could just weld it all up and not sweat about it.

Anyone have any input on bearings / pivots for the base mount to allow it to swing round?

Al.

[LandyManLuke]

I've been trying to work out the link lengths to give decent height to the arm whilst maintaining an as-large-as-possible triangle at the bottom.

The ram would lift the red beam, until the pink and green beams are in line, nudging the green/pink joint towards the red beam, followed by lowering the red beam would lock the triangle off - meaning the strength of the ram wrt the load is irrelevant, what is relevant is the size of the triangle, I'm struggling to lower the bottom corner whilst maintaining a decent 'assembled' height for the arm. I reckon it's do-able tho.

The picture shows a reach of about 1.3x the 'bed to cab' height, I think this can be considerably improved.

It's been fun playing with cardboard anyhow.

[Orange]

To throw a spanner in the works...

Are you considering the use of stabilisers and how they might work?? Wouldn't want you to get all excited about getting the crane working only to have the MOG fall over the first time you use it!! I know the MOG is a big vehicle, but.....

The sort of system that street light repair vans/cherry pickers use might be a good way of doing it!! They fold up fairly small, too....

[Discovan300tdi]

how about something like this ??

hiab website

[SteveG]

Father in law has a simple box section crane on his Hi-Lux that fits the design you are after. It uses steel box sections that bolt together so that it can be stowed flat with just the base protruding some 12-15".

Uses a superwinch 1000 electric winch, and a bottle jack to support the arm and change it's angle. I'll ask him and see if he's got some pics if you want some.

Cheers

Steve

[Astro_Al]

Sotal & SteveG - pics would be great, thanks guys.

Discovan300tdi - right idea, wrong price!

Landymanluke - interesting, I'm mulling...

Al.

[OWL]

Hi

What are you hoping to lift with this crane, how often are you looking to lift a load, once a week, a day or hour ?

Perhaps at 500kg you could use a davit as previously suggested, http://www.didsbury.com/didsbury.davit.asp theres a few idea's here.

Cheers

[Astro_Al]

Owl - lifting: materials (lots of steel etc), large gas cylinders, large tools / small machine tools (in the 100 to 500 kg range), car parts - engines / boxes etc. That sort of stuff.

How often? I dunno. How often do I go to Tescos? Hard to say, but I know that stuff which is a pain to use just never gets used, so I want it to be handy, accessible, and quick-ish.

Luke - I'm thinking about your design and wondering what advantage it gives me? The real problem is that the width is much greater than the bed-to-cab height. Usefully, I forget how much, but significantly. Your design uses more mechanisms too. Although I kinda like it. Hmmm.

Cheers, Al.

[LandyManLuke]

Advantages:

- Doesn't rely on the ram for supporting the weight of the load, thus...

- could use a small/short ram to "assemble" it.

- Doesn't need to be swung across the load bed to store

- it's cool

Disadvantages:

- More moving parts

- fixed height when locked off

- the height/width ratio problem

The height/reach problem could be solved with a telescoping section. this also locks off over-centre.

Adding this complicates it more, but actually gives you more freedom as the pivot points on the pink link can be better utilised to give greater boom angle, and triangulation, leaving the telescoping section to give reach.

[jules]

Al

what about a second hand engine hoist/crane with a retro fitted 1or 2 ton winch piggy backed on it and a pulley arrangement for the cable to act as a crane. The original hook and ram would stay for heavier lifts..

I would assume that you could knock up a rotating base arrangement fairly easily

It may not look that flash but I recon you could build that for less than £150

[Astro_Al]

Jules - thats pretty much where I'm coming from, yeah.

I probably won't actually use a real engine crane, because looking at mine I cannot believe that someone who welds these things together all day, every day, can come out with some of the pigeon-turds that are supposed to be good for a couple of tonnes swinging about on the end. Its shocking.

However, I pretty much based my plan so far on the same kind of design, but I'd just buy the steel and make it myself (could probably make better use of the available space if I change the dimensions to suit, as well). Even doing it myself, I reckon it could be cheap and simple.

Then people started throwing other ideas around and my withering brain got confused...

The only real cost is the hydraulics and little winch. Anyone got a nice long ram kicking about...?

Luke - it IS cool. B) But is it worth it?

Al.

[LandyManLuke]

There's an impossible question.

If it was me, I'd be quite tempted to play with the design with some real-world dimensions, and see what it'd turn out like. I've been thinking about what the hinges & over-centre locks would require - but then that beats writing software all day quite easily....

In your shoes, I'd see it as a perfect avoidance project to not risk disturbing any of that vapour you're carefully storing, least it turn into anything like progress. hehe (sorry).

Seriously, it's probably over-engineered, but I reckon it'd work nicely and just imagine the faces of the people you collect stuff from/for as you go 'watch this!'

[SteveG]

Hello Al

Father in law took some pics and here they are..

[Astro_Al]

Thanks very much Steve - be sure to thank him for me.

Nice to see some close-ups of the mount/pivots etc.

I'm pretty set on the design now. Just need to get some steel in and book a little garage time...

I'm basically shooting for the beefed-up-engine-crane type scenario. I'd like to put an extra ram on the top to create an extendable jib. We'll see. Not sure if this means I need to add rollers inside, or just have one tube slipping inside another and keep it greased.

I will defo brace the top of the vertical post onto the cage around the cab. Which should allow for decent load capacities without making it too heavy.

Not sure if I should use another ram at the base to swivel the whole thing, or an electric worm type drive, or leave it manual or what. Also not sure about a bearing at this point, or just a pivot 'pin' running in a tube as per the above pics.

Cheers, Al.