ThePog Builds a Caravan

[ThePog]

Been cracking through this as my main project since Feb, its been a good time.

Background; I have been designing this with some friends for a long time now after I built them a caravan a few years ago that was good but had a couple of limitations, mainly size and weight. This is the 547th design iteration since then, it is just time to crack on.

It is a hard side lifting roof, and the methodology will become apparent with the pics. The reason is that it gives plenty of standing height while remaining reasonably compact, plus way less frontal area when packed down for towing, and hopefully some smart packaging will allow nice space usage.

Firstly I went to Chch and grabbed this kit while I was there, altho the steel bits you see have been laser cut and folded locally;

 

I ordered some steel and cracked on;

 

Stand by for Part II....

[ThePog]

This is where it gets tricksy, I have various things that make using a timing belt for the lift a sensible option, mostly availability and prior use in various designs I have done.

That main driveshaft lifts all 4 corners at exactly the same rate, it works well so far.

Then there is much random shite I have added

A doorway

Stabilisers

Towing accoutrements

Tail lights

Flooring

A modified ATV winch for the lift mech that works perfectly but is pretty noisy, I may replace this if it is a problem. Many thanks to @datlow for that sweet idea.

Some water tanks, 120L - set low and central so as to not screw up the weight balance too much

A pressure activated water pump to suit

 

The bed needs to lift away from the seating area during the day, this is my first cut at it which was a hilarious failure as at the horizontal transition point it went terribly wrong. I have found a better way now, more of this in future episodes.

 

[ThePog]

I towed it out to see how it looked in the light of day, looks about right to me;

 

That was to make room in the shed for this stack of secret stuff, all will be revealed in a later episode.....

 

[Willdat?]

Much fizz for this. I have a project I want a student to do involving making a lightweight, low drag caravan. But they don't seem as excited by the prospect as me...

[ThePog]

6 minutes ago, Willdat? said:

Much fizz for this. I have a project I want a student to do involving making a lightweight, low drag caravan. But they don't seem as excited by the prospect as me...

So you want a lightweight, low drag caravan for yourself then....?

[tortron]

12 minutes ago, Willdat? said:

Much fizz for this. I have a project I want a student to do involving making a lightweight, low drag caravan. But they don't seem as excited by the prospect as me...

Bit snug

 

[Willdat?]

8 minutes ago, ThePog said:

So you want a lightweight, low drag caravan for yourself then....?

I have no disposable income for such a venture at the moment (maybe 2024...). I'd like to design one for my folks as sleeping in the backseat/boot of a sedan seems like something you shouldn't do in retirement

[Sc@ Chi]

Looks like you've hit a hot topic, 'cause I doodle heaps during boring meetings at work for my next project, a camping trailer. My thoughts are for the roof to flip 180, like a roof top tent, so the 'roof' forms the sleeping platform but you also have decent standing room in the bed of the trailer. Current plan is for an aluminium tube frame with ali panel infill but I need to ask the OS hive mind about adding a spool gun to my welder.

Anyway, following this like a hawk. Love the roof raising mech so far.

[ThePog]

Yea there are so many potential layouts that pack down. We very nearly did it with a kindof accordion type structure but the sealing was probably going to be difficult with so many hinged seams. There were a couple of really great ideas that were stymied by lack of manufacturing capability in nz, and reluctance to take a punt on a rando chinese factory to make what we wanted.

I have not had a heap of time to carry on with this but there should be an update after the weekend...

[sidewaysickness]

Is this still carrying on from the canvas skinned caravan or is it a different customer?

[ThePog]

2 hours ago, sidewaysickness said:

Is this still carrying on from the canvas skinned caravan or is it a different customer?

Same same, they pay materials and I pay in time and design, we'll both use it...

[sidewaysickness]

At the same time? wow you are getting friendly with your clients.

I do like this design more than the original, I also did like the weird looks I was getting when towing it with a shitty e30

[ThePog]

11 hours ago, sidewaysickness said:

At the same time? wow you are getting friendly with your clients.

I do like this design more than the original, I also did like the weird looks I was getting when towing it with a shitty e30

Maybe not that friendly yet....

This one is way smaller, lighter and lower profile for towing, but should have about the same usable floor area.

[ThePog]

Yea so that pile of stuff is extruded PVC, 35mm thick. The theory is that it is light and stiff, plus the air trapped inside will give reasonable insulation. There are cappings and corner joints etc to go with it... here is a bit I have left outside for a few months just to see how it copes.

 

TBH I am not 100% sure this is the right material for a couple of reasons, the first is that is kind of brittle. It is not bad and no worse than other caravan materials but I would like it to be a wee bit more robust. The second is that it was supplied with many defects and dings from poor handling that I am having to work around. Again not a killer and it may be a case of getting the supplier to check the panels before sending out.... We may just have to rework the cover in something else if it ends up with too many patches.

 

Anyway I have been cracking on with cutting the panels to size and seeing how it goes together. The windows and doors will get cut later, this is just a dry fit without glue.

 

Altho first I stripped it down and finished all the welding. This meant tipping the whole thing over on its side to help with access, which was pretty fraught but doable with my forklift. Forgot to take pics that day.

I also added some steps, as it is a bit of a hike up. These were kindof tight to fit in and needed a judicious trim on one internal leg to get them to sit in far enough. They seem to work pretty well though.

 

Then just adding panels and checking the fit etc

 

That last pic is the start of the lid proper, I reckon it looks pretty nice, with some clean lines. Obviously there will be windows and such but that is later.

It is going to be a mission to assemble that lid and get it on, I will have to rig some lifting points.

 

I also thought I should sort the lift control system which is what I have been up to today. Mostly translating this;

 

Into this;

 

Which surprisingly actually worked..

I may just bite the bullet and get a winch contactor unit as this will be much tidier, but I needed to get the wiring right in my head.

So I at least need to get the lift limit switches in place before I can continue with the lid, that will be tomorrows job I imagine.

 

[ThePog]

Yea so I have been chunking away at this slowly. 

First I made a bed/seating area on the router and biscuited it together. I used the router to add much lightness as you can see;

I sized the bit underneath to take a mattress so kids can sleep in there if they want which has had a lot of positive feedback. Otherwise the mattress can go up top to be half of a double bed if needed. One mattress will be the back seat base. That probably makes no sense but whatever it should work IRL.

I then fucked around for ages with the bed lift, printing many variations of the lift gears and housing on the 3d printer before giving up and ordering some actuators off AliX.

I also wasn't happy with the roof, it was going to be a pain to assemble and if anything got damaged the whole thing was a throwaway. So I rejigged it to have a light steel frame with small panels that bolted in, and this weekend got to it.

It is pretty compact when down and quite big when up which I guess is the whole point.

I ran into an issue with the lift mech, basically the motor has to lift the whole weight which it can without too much drama (after tightening some belts) but you cannot use the manual lift as it just drops straight down again. I will try to solve this with preloaded springs of some type...

This will relieve the load on the motor as well, we'll see how that goes later.

[fletch]

When I was living in Oz they were building box trailers with this honeycomb kind of plastic stuff that looks similar to that stuff you have.

It was strong as shit and they were just gluing and pip riveting aluminum angle to the joins. I forget what it was called but could be a good weight saver and more resistant to denting?

I forget the name of it, but the camper trailer crowd were all over it

[ThePog]

Sweet, I will investigate.

[HumberSS]

I have lots of very strong torsion springs destined for the scrappy...

[ThePog]

Oh yea dredge time.

I have been pretty broken for a while with ongoing gall bladder issues, +10x ER visits and 3x ops but I am kindof cured now. All of which is my excuse for why this shit is dragging.

But the last couple of months have been pretty productive, although i was chipping away when I could muster the energy over the last year.

The belt lift mech was a bit shit, jumping teeth under load etc, I tried linear actuators but no joy, then finally went to a cable setup which appears to work pretty well. Altho the ATV winch motor is pretty noisy, I will find a reduction box and a better motor at some point.

 

After considerable detailing and tidying up i got the frame zinc arc sprayed

 

And started assembly with the water tanks

 

All the steel bits I got zinc plated

 

Installed the seats after a couple of coats of polyurethane.

 

Made a frame underneath that holds the batteries and started wiring things up, this has gotten a lot messier so may be taken out and redone once everything is in there

 

Then I had to remind myself how the router worked so i could make the kitchen

 

The bed is set up on some long linear servos so it lifts out of the way during the day, once this was working ok I made a ply base, altho it was kindof heavy so I reamed a bit of weight out of the parts on the router with a pretty blunt 25mm Mitre 10 bit.

 

So this is where it sits right now, nearly time to sort the panels and bolt them on. The fridge/water pump/bed lift/roof lift are all wired up and live, I just need to remember to wire in the solar panel and charge the system up every week or so.

It is so nice to work on it from the outside TBH, makes things a shitload easier.

 

Still so much to do IRL.

[kiwitones]

Hi, This is a cool project!

I have a bus project with a pop up that isn't working too well and I wanted to improve it/add another.

I'd love to pick your brain. I'm in Christchurch...