A problem for all the budding engineers

[walker]

I am just planning the build for my off-road trailer. It is going to be basically a 6x4 box trailer with lid but I am also building a rack above it to mount the Howling moon roof top tent I have.

Now the problem:

I have an annexe with the roof top tent which I would like to use when we stop for longer periods. This means that the base of the rooftop tent has to be above head height. (about 1900 to base). I don't want the tent up this high when towing as it would be higher than the roof of the Disco. I would like to be able to lift it up when we are stopped but keep it all as simple as possible.

My first thought was to have supports/legs in all 4 corners and have a smaller piece of square tube run down inside a larger tube and put bolts through to hold it in place when lifted up. I am a bit worried that doing this will cause too much movement when sleeping up there and that it might be too hard to lift up. the tent weighs about 60kg but the tube would have to be a fairly tight fit.

Any ideas?

[harro]

I am just planning the build for my off-road trailer. It is going to be basically a 6x4 box trailer with lid but I am also building a rack above it to mount the Howling moon roof top tent I have.

Now the problem:

I have an annexe with the roof top tent which I would like to use when we stop for longer periods. This means that the base of the rooftop tent has to be above head height. (about 1900 to base). I don't want the tent up this high when towing as it would be higher than the roof of the Disco. I would like to be able to lift it up when we are stopped but keep it all as simple as possible.

My first thought was to have supports/legs in all 4 corners and have a smaller piece of square tube run down inside a larger tube and put bolts through to hold it in place when lifted up. I am a bit worried that doing this will cause too much movement when sleeping up there and that it might be too hard to lift up. the tent weighs about 60kg but the tube would have to be a fairly tight fit.

Any ideas?
If you carry a high lift jack, a base plate and slot for raising if it is within the range of the jack.
For stability, drill holes and weld nuts so the bolt can be tightened against the far side of the inner tube.
And weld a small piece of rod to the bolt head so you can do it by hand.;)
Just some thoughts!:twobeers:

[dobbo]

If you carry a high lift jack, a base plate and slot for raising if it is within the range of the jack.
For stability, drill holes and weld nuts so the bolt can be tightened against the far side of the inner tube.
And weld a small piece of rod to the bolt head so you can do it by hand.;)
Just some thoughts!:twobeers:

I was thinking along the same lines,
Another would be to use a pulley system on each corner a cable boat winch on the trailor and locking pins on each corner.

[walker]

I think you would need 2 high lift jacks to lift either end at the same time.:o

But I reckon you are right about welding on nuts and then use a wingbolt.:D I just onder if the whole thing will have too much flex/movement in it. I guess just use big heavy tube.

[walker]

I was thinking along the same lines,
Another would be to use a pulley system on each corner a cable boat winch on the trailor and locking pins on each corner.

Not sure I understand that, but then I'm no engineer. To use a pulley, wouldn't you need a solid fixing up high to "pulley" off?

[rovers4]

Not to knock you down.... but I have found that a neat to slightly loose fit will give you problems for several reasons.

Firstly, moisture will get in and cause oxidation which will jam the sleeves onto the poles.

Secondly, even if you could lift the thing on one side, it will cause the posts to go off vertical. Overcome this by mounting with bolts so that they pivot? Then the whole thing lays over without any vertical support whatsoever!

If you make the sleeves a loose fit, it will rattle, move in the wind or when you roll over in bed, and still be too heavy to lift.

You could try some heavy duty gas struts but then there would be a problem when trying to pack it up.

How about some wind up support legs, same as they use to stabilize the factory made campers?

I do not suggest cable or electric ones as there can be problems with batteries, cables/pulleys etc.

A couple of portable hydraulic rams to do the lifting and then a physical pin/ latch arrangement may work.

[dobbo]

Not sure I understand that, but then I'm no engineer. To use a pulley, wouldn't you need a solid fixing up high to "pulley" off?

Yes you would four poles with pulleys on top and cables running,


I forgot height is your enemy.




Hydraulic or Pneumatic rams would be expensive but would do the job.

I'll go back to sleep now.

[harro]

I think you would need 2 high lift jacks to lift either end at the same time.:o

But I reckon you are right about welding on nuts and then use a wingbolt.:D I just onder if the whole thing will have too much flex/movement in it. I guess just use big heavy tube.
A couple of attatchable angled bracing rods should do the trick.
They can be light gauge and should not much trouble to carry.:twobeers:


Even box, say 20mm x20mm and use the wingbolt as a one of the mounting points;)

the bracing could even be male- female like those cheap tent poles
for minimising carry space.

[walker]

Now it's all just getting too hard. :(

The top legs will have to slide out about 500-600mm. I think we could lift it ok with 2 people...maybe. I wonder if I could coat the poles in plastic or teflon so they dont seize up. Or use something else other than tube for the posts....I just don't know what.

[harro]

Not to knock you down.... but I have found that a neat to slightly loose fit will give you problems for several reasons.

Firstly, moisture will get in and cause oxidation which will jam the sleeves onto the poles.

Secondly, even if you could lift the thing on one side, it will cause the posts to go off vertical. Overcome this by mounting with bolts so that they pivot? Then the whole thing lays over without any vertical support whatsoever!

If you make the sleeves a loose fit, it will rattle, move in the wind or when you roll over in bed, and still be too heavy to lift.

You could try some heavy duty gas struts but then there would be a problem when trying to pack it up.

How about some wind up support legs, same as they use to stabilize the factory made campers?

I do not suggest cable or electric ones as there can be problems with batteries, cables/pulleys etc.

A couple of portable hydraulic rams to do the lifting and then a physical pin/ latch arrangement may work.

Now that sounds like a good idea!
You will end up selling the bloody things.:twobeers:

[Blknight.aus]

its easy enough to do with a small winch some steel cable, turnbuckles and some clever mounting and teflon slider pads

If you look at the way old pop top caravans used to lift its just a remake of that.

[walker]

its easy enough to do with a small winch some steel cable, turnbuckles and some clever mounting and teflon slider pads

If you look at the way old pop top caravans used to lift its just a remake of that.

Yes. I did have a bit more of a think about it and realised would lift the bottom of the inner pole from the top of the outer pole. But I don't want to go down the winch/pulley road.

[dobbo]

its easy enough to do with a small winch some steel cable, turnbuckles and some clever mounting and teflon slider pads

If you look at the way old pop top caravans used to lift its just a remake of that.

Thats what I meant but it didn't come out that simple

[Blknight.aus]

No rope and pully, easy, immitation sissor lift.

make two pair of diagonal braces anchor the front of the top and the bottom, fit roller guides and attach a long threaded rod with a crank to the front of the top of the frame then into the cross member of the top frames rear roller. Wind it in and up she comes.

get lazy, match up a cheapy 500lb winch drive to it and wire it off the aux feed for the trailer or the trailer battery.

make up some drop down bars to releive the weight from the screw if your going to be really cheap and make it from threaded rod from bunnings It will lift it but I wouldnt want to rely on it for support.

or cheaper again........(and still no ropes or pullies)

If theres going to be 2 of you to lift it a pair of long screw lifts fitted centerally at the front or the rear and wind up in sync.

or be lazy, take handy dandy 500lb winch drive make up a chain drive out of a pair of bike chainwheels and hang that under the center of the frame to drive each end...

then insert the main stay poles.

And for the super dooper how cheap am i version....

a ratchet pawled sissor lift

much like the first one but you lift the whole lot by hand and as it rises a one way ratchet will stop it from dropping while you reposition to lift it. (you can also mechanise this one but then you have to use the rope and pully things again)


IF youd like Pm me and I'll draw up some basic Tech drawings of said lifting mechs.

IF any of them take your fancy I'll spec em up and if you happen to be down my way with the parts and a carton of my fav neck lube I'll even build it up for you. (minus the winch drive, Im not that lazy...... yet)

[Graeme]

How about just temporarily or permanently shortening the bottom of the sides of the annexe? Perhaps you might have to shorten your own legs as well, though.

[walker]

Hi Graeme, I did think of this but it really has to be at min 1900 or you cant stand up.

I like Daves ideas. I am now thinking maybe a scissor action to lift it but make this out of a light section and only use it to lift the tent up, not hold it then have heavier supports to place under.

[dobbo]

Electric motors, similar setup to electric windows just uprated motors on each side operated by the one switch therefore they run together. A hand brake or locking mechanism when the tent is erected.

[tombraider]

Adam..

Consider 4 cheapo hydraulic rams (or 2 on a scissor lift arrangement)

Cost - Sub $95.00 each

Cheap hand pump on draw bar....

Pump up to height, pin in position/fit mechanical locking device

Easy as....

Tombraider

[matbor]

I have been collecting pics of custom camper trailers over time, never know when i'll build mine :) , there might be some here that answer your question...

http://disco.bordignons.net/trailers/

Matt.

[scrambler]

Adam,

Just thinking of some other options.

Had you considered raising the entire trailer? Could be as simple as ramps you carry in the trailer to go under the wheels or complex as hydraulics at all 4 corners. Means you can have the fixed height bars and fully enclose under.

Maybe a swing-up arrangement with a fixed height bar to the side and a shorter arm inboard that attaches to the tent base, swing it up and put a lock bolt in to hold it.

Buy a "dead" Jayco camper and attach your rooftop tent onto the roof of the Jayco.

Use lower height rack but carry a large hole to put under the annexe to give extra head height. There may be some spare in the roads around Sydney following the rain.

If I think of any more I'll post.

Steve

[scrambler]

OK. What about this one. Trailer has wheels close to the rear. Uprights are angled forward - for argument's sake at 45 degrees. When stopped, unhitch and raise front of trailer using, again for the sake of argument, a Hi-Lift. Lowers top of trailer for towing, gives full height for camping. Does create havok with the storage function but I'm sure there's a way around that too.

Steve

[walker]

Your just full of ideas aren't you.:p :p

I now have it sorted........I hope. Sorry I did not end up going with any of your ideas.

There is going to be an arm attached to the 4 corners of the rack holding the tent. The other end of each arm is attached to the side of the trailer. (obviously a structurally braced position). All 4 arms run in the same direction and all mave together so the tent lifts up and back.

Is that clear as mud! ;)

Ok, so I can't explain it well it really needs a pic but is should work.

[scrambler]

Damn. And I thought for sure the hole idea was a winner :D

[George130]

Damn. And I thought for sure the hole idea was a winner :D

Yea I liked the idea of a portable hole:D
The goodies definatly found plenty of uses for them.

[dobbo]

Exhaust jacks, setup in sync with eachother once inflated locking pins are extended to secure the tent into position.

Just watch out for over inflation and carbon monoxide poisoning in the tent after inflation

Works for the hovercrafts

[sschmez]

I have been collecting pics of custom camper trailers over time, never know when i'll build mine :) , there might be some here that answer your question...

http://disco.bordignons.net/trailers/

Matt.

I like this design:D
http://disco.bordignons.net/trailers/Michael_Bishop_Oxwagon.jpg

you might find one with bigger wheels and not even have to build anything
:wasntme: Stevo

[Buggerluggs]

Hi Adam,

I can think of a number of ways to do it. It all depends on how much you want to spend and or how easy you want it to be. You can use screw jack sissor lift systems, you can lift each end independently and pull out cross braced legs (rather like a trestle table), you can use air powered rams on each corner with a mechanical lock at either end. Lots of ways of skinning a cat. You want some help let me know.

[walker]

Thanks Ian. I have been thinking about it more and I have alomost come to the decision that I won't lift the tent up!

I had a look through all Mat's great photo's and there are quite a few trailers which are running roof top tents...and none try to lift the tent up and I reckon there is probably a good reason the experts dont do it...other than cost.
When you are doing trips like the Simpson and Cape York you want things to be as simple as possibe. Most of the money in the trailer is being spent on the axle/hubs and suspension. The only reaoson i needed it to lift up was to attach the annexe....which would only be used rarely....so I decided to save the trouble and just carry my centre pole tent, which we can set up as a change room if we camp for more than a couple of days.

PS. When is the next trip? I am busy all September but will be hanging out for a trip in October.

[loanrangie]

I was thinking along the same lines,
Another would be to use a pulley system on each corner a cable boat winch on the trailor and locking pins on each corner.

The same sytem used on wind up camper trailers, you can buy a kit to convert from liftup to wind up from here - www.caravansplus.com.au .

[Michael2]

How about a couple of blocks of timber (or ramps) you can drive the trailer onto when you need the height. One under each wheel. They can double up as chocks. That way everything stays in it's fixed position (no rattles / wobbles).

A bit low tech I know, but also very cheap, non time consuming & versatile.

[walker]

I like the way you think Michael:D :D

The main problem I can see is that it would have to be about 500mm which might be a bit high/unstable for blocks of wood......but I do have a set of ramps which would easily fit inside the trailer, I will have to see how high they are.

As I said earlier I have decided to KISS and will have the tent fixed in position. The axle/hubs/brakes and suspension has been ordered as has all the steel. Will post on some pics...or start a new thread when i start the build.

[scrambler]

I like the way you think Michael:D :D

The main problem I can see is that it would have to be about 500mm which might be a bit high/unstable for blocks of wood......but I do have a set of ramps which would easily fit inside the trailer, I will have to see how high they are.

As I said earlier I have decided to KISS and will have the tent fixed in position. The axle/hubs/brakes and suspension has been ordered as has all the steel. Will post on some pics...or start a new thread when i start the build.
You like the way he thinks but when I have the same idea you don't even notice?!

Mind you, I did follow it up with some slightly crazy ones so perhaps it got lost in the mess.

There's the reverse type of design in the 4WDM mag this month (arrived today) - a bike trailer with raised tent that's dropped to make camper - you could do the reverse if you want to give up the KISS thing.

Steve

[mr_sav]

Hi, I empathise with you. I am currently dealing with the same issue. I am getting my heavy duty 6*4 being revamped with longer drawbar, electric brakes etc etc. Hubs already match my 110 with same/rim-tyre setup. Like you I am wanting to fit a frame, however, I need to creep a bit higher, as I have a galvanised Lid which hinges open to the left.

I need to open it enough to get things in and out. The Lid slides of to the rear, which doubles up as solid Table. I am putting a frame up for the rooftop tent, however, I am going to fix it by flanges rather than the tube in tube to prevent the jamming effect. The idea is, that the whole frame can come of with rooftop tent, so I have my box trailer back in the big smoke, or even drop the frame to the ground if I need the trailer whilst away.

I am aiming to put a large box in front of the trailer on extended draw bar, to cater for my 60l Engel.

I have the Anderson plug kitted up on the truck rear, fitted with welding cable to hold the charge, to run it to the trailer to charge the Deep Cycles. This will allow me to hook up a 3phase charger by mains to charge the trailer batteries, and push it back to the deep cycles in the 110.

All fun and games. I need to make a quick decision whether to proceed with my trailer, or start afresh with a Chopped Up Land Rover. Likely though I will proceed with the trailer because it is a tangible item.

It will be good to see how you progress. PM me if you like, I would certainly like to exchange ideas.

Regards.

[walker]

How long are you making your drawbar and what size steel are you using?


I was looking at a few makes and they have whopping big ones!!!:D

I hope I have big enough steel for my drawbar. I am using 75x50x4mm and it will be 1800 long. I am going to make the drawbar become an integeral part of the frame, it will all be one piece on each side with just a notch cut out to bend it to the right angle then weld it back up

http://www.lrocv.com.au/gallery/displayimage.php?album=35&pos=14[/URL]

http://www.lrocv.com.au/gallery/displayimage.php?album=35&pos=16

[URL="http://www.lrocv.com.au/gallery/albums/userpics/10024/frame%201.doc"] (http://www.lrocv.com.au/gallery/albums/userpics/10024/Trailer.doc)

[mr_sav]

Hi Adam,

Had a look at your word.doc's. I will have new draw bars welded which will be approx 640 longer than current, haven't got the actual length in front of me at the moment. So far as to say, from all my homework, the ideal length of a trailer is: Hitch to Axle = Length of wheelbase of tow vehicle.

Interestingly for me this equates to about the 640 above, which incidently is the size in width of the box I will need to put on the Aframe for my Fridge. Tube Size at the momement is 50*75 and my Trailer Guy "Back Yard" though he works contract for Treg as well, suggesting 50*100. Thickness to 3 or 4mm.

Regarding your drawing, I would suggest extending your drawbar underneath the trailer to just in front of the springs (if you have not already planned for this).

Your trailer looks great - purpose built ground up. I am simply working with an old but proven Trailer that I already have. I need a bit of room, as I am not only camping, but need to cart my dive gear around as well.

Where abouts in Melb are you. I am considering coming over for the long weekend and a few days around. I may head to Queenscliff for some diving. Also I might book into LR automotive for Springs/Shockers.

Regards,

Steve.

[walker]

OK, well that doesn't give me a lot of confidence. I guess I will have to hope the 75x50 is big enough. :o One thing in my favour is that the trailer is not going to weigh more than 700kg fully loaded.

The long rails on the chasis actually form the drawbar. Does this make sense? So the 75x50 tube drawbar will be cut and bent where it becomes the chassis and welded back up.This means that the drawbar actually extends to the rear of the trailer and also sits up higher.

I am hanging out to start but have to wait till the axle/hubs arrive. I dont want to go making up the frame and find it is too wide.

[fernockulated]

have tried to make sense of the last two pages, sounds like the red stars thread,no sense,have just made up my trailer for camping and the base unit was the trusty 6x4 box ,then swung the axle under the springs for extra height ,then fitted 15 inch commodore rims with31x10x15 tyres ,more lift:eek: ,the top is made from discarded canopy from old moby,with the steel frame roof rack that to me looks like it had a roof topper fitted by some previous owner bolted on top,the sides and top will simply unbolt should i need the standard trailer,and front and rear doors as well,right rear corner i have welded a support leg for stability,and on the left front side there is a sink arrangement (not shown ) that simply folds down ,so that we even take the kitchen sink!
https://www.aulro.com/afvb/images/imported/2006/09/186.jpg

[scrambler]

Can't speak for the other contributers Ferno, but I was brainstorming some ideas to get a raised bed with a low towing height. When I puts me money down and buys it I'll post a photo of my mate's camping trailer - think 5x7 converted to a mini-caravan. It looks like yours only tougher and, if possible, uglier. I don't own a rooftop tent and wouldn't put one on a camping trailer if I did, but I did try to help with some sensible and silly ideas to get the creative juices flowing - and they seem to have flowed rather well, which probably had nothing to do with me.

Stars thread indeed. Humph and double Humph.

Steve

[walker]

have tried to make sense of the last two pages, sounds like the red stars thread,no sense

You big whinger!!! It all makes perfect sense......well except for the portable hole. :p

[fernockulated]

I suppose the only sense that some made was that like the land rover they all seemed over engineered,sheesh hydraulic rams of all things ,i thought going camping meant at least some degree of roughing it:D :D :D :D :D ;)

[Gavo]

Why not have the rack for the tent fixed ?

You say you will only use the annexe sometimes, why not have a hing pivot arrangement to move the annex up to the correct height?

If the tent folds to the side the does not have the annex sail track this would work.

I would need to see the tent top you are using to help.

[mcrover]

A couple of car ramps and extended axel stands would be the easiest, cheapes way to lift it about a foot, if you want to go a little expense, use alloy to make the ramps and stands.

If you make the ramps with holes for the wheels to fall into, and make them extra wide at the base, this will make the trailer more secure.

An axel stand with a ball welded on top of it (or treg coupling) can secure the drawbar.

I used to use this sort of equipment when I was towing vans for a caravan hire company and I used to put tri axel 5 tonne vans on stands and ramps as well as camper trailers.

The only problem is that your kitchen will be higher and you will need a skirt for the back of the trailer.