Trailer Tent for a small car - home build

[Bfg]

I started this in  "what have you fixed lately"   but it's been suggested I continue it as a new thread. . . 

 

My requirement is for a particularly compact trailer-tent, which is of course in direct conflict with me happening to be 6'5" long (sleeping or sitting).  

Not sure how you guys and gals manage when you go to a long weekend classic car rally or a camping trip with your sports car but, whereas 30 - 40 years ago I didn't think twice about clambering about in a small tent, I now have difficulties.  My not being small doesn't help ..and gravity seems to have accumulated my body mass over the past 65+ years, so I was looking for an alternative.  Being on my lonesome a small trailer tent seemed worth investigating but I couldn't find anything I really wanted.  So I'm opting to do my own thing (..again !)

The following is my planning 'work in progress' . . .

My design brief ; 

• small & low profile to sneak-in behind my Triumph TR (when that's back on the road).   The older Triumph car's width are pretty diminutive (48-1/2" in the case of my TR), and of course any sports car's waist line and rear window are likewise way down there.
• lightweight
• inexpensive / able to be made at home
• for just me, whether I go to a classic car rally or go touring for a month.  I'd like to stay in B&B's but in the first instance (something like a national rally) they are "no rooms" at the Inn, and in the second ; B&B's add up to a lot of cost - if used every night for a month.  Also there are a lot of nice out of the way places to stop to be close to nature ..which is after all why I like touring in an open top car ..and camping.
• provision for a backpacker's camp cooker and basic provisions, etc ..and a dry composting "bucket".  This is for camping  albeit inches off the ground ..not the Ritz.
• easy to deploy and use, even if that's just for a lunch break when the weather is being "particularly unfriendly".    
• predominantly for warmer weather and UK use. 

 

^ proposal I've been working through.

• The trailer's box is just 3' 8" wide x 30" high x 4' 6"" long (5' 6" inc hitch & rear lights) so is smaller than most.  As a trailer tent, it's larger than a small box trailer in which a tent, gear, bedding and provisions are carried ..but I feel this size ought to tuck-in pretty well behind a sports car.
• I propose making it out of plywood and fibreglass, quite similar construction to that of a plywood boat. The chassis frame doubles in duty for the telescopic tubes ..for the tail-end to pull out on. Legs can then support it.
• the berth is on suspended cloth (like a camp bed) which allows for a lighter / slimmer mattress to be used and saves the weight in plywood.
• when extended the berth is ;  6'-10" long x 36" wide for the body, and tapering to 24-1/2" wide at the foot.  Then there's a, hopefully useful, 44" x 6" fiddled-shelf space for bit's n' bobs beside the bed. The void space beside the foot of the berth is a step-through (down to a rubber mat laid directly on the ground) so with feet on the ground I'll have another 7" of height ..useful perhaps when getting dressed.?  With the foot of the berth folded and stowed away the foot space area can be used (with due care) for camp cooking etc.
• the lid is hinged along its forward edge , so in blustery conditions the trailer can be faced into wind to help lessen buffeting or driving rain. A fibreglass lid is also more watertight when closed. It should be very easy to deploy, and it saves a good percentage of canopy and most tent poles.  The lid when down overlays the extending tail to lock it all together, as a secondary lock.

 

It's been an interesting challenge to design for someone of my size and lessening dexterity (it's an age thing !) but I think it'll work ..pending getting a well made canopy, and if I can keep the towed weight down ..so it doesn't lessen the fun of driving a 50+ year old sports car.  I guess the only way I'll know is to build it.  

So, its wheels with suspension, the towing hitch and jockey wheel have been bought, and I'm now committed ..to the tune of almost £205.  This afternoon I was detailing / dimensioning the first pieces to be cut from plywood. I'm close to pulling a shopping list together for the 1-1/2" square hollow section tube for the chassis and telescopic legs.  And I was looking today on e-bay at drive-away camper-van awnings, which may be a relatively cheap way to acquire a canopy quickly.  With one of those - I'd just use the trailer inside the awning as a fold out bed ..until I'm sure the trailer bed / accommodation work well enough to have a custom canopy  

Anyway there you go..  Hope it's of interest.  Your ideas and constructive comment are invited.

Bidding you a very good evening,

Pete. 

[Bfg]

Turning circle ;  Interesting question I was asked about on the TR forum ... 

I looked further into it this morning and an on-line calculator suggests that the TR4's 33ft turning circle (between curbs) results in a 31 degree angle to the trailer.  

I quickly drafted that in ACAD and tbh it did not look as though the trailer would follow within that turning circle (..perhaps because the calculator didn't use the trailer ball to back-of-car distance).  So I altered the drawing to reflect the trailer angle I hope to build and the result looks more realistic. . . 

 

 

^ A quick approximation of the car with trailer tucked in behind it ; straight ahead and at full lock (33ft turning circle illustrated) with the car at 40 degrees to the trailer. The TR is a small car, just 49" wide so the above gives a good indication of the size of this trailer.  Still the pine kitchen table I'm sitting at is 6ft x 4ft and much the same height.. and at just 6" longer that's a huge table for this room.  

Anyways up., I'll check the turning radius / lock once I actually have a trailer, and if necessary I'll extend the coupling's length by a couple of inches to increase the angle.

Pete.

[sutty2006]

This may sound daft, but what about getting the back half of an identical car and turning that into a trailer tent. That’d suit it down to the ground. Top designing works there though! 

[dikkehemaworst]

30 minutes ago, sutty2006 said:

This may sound daft, but what about getting the back half of an identical car and turning that into a trailer tent. That’d suit it down to the ground. Top designing works there though! 

My first thought as well...

[High Jetter]

It's a TR. What’s half a TR worth?

[Bfg]

42 minutes ago, High Jetter said:

It's a TR. What’s half a TR worth?

small fortune rather than a large fortune ?

[Mally]

Too heavy using a TR back end.

I like the idea, the extension, and  the fact that you stand on the floor is good.

I may have missed this, but how is the extension sealed? Does the wind flow through, is there a false floor, or awning material down to the ground? It's draughts I'm thinking of.

What thickness of 1-1/2" box are you thinking? We use 2.5mm and it's quite heavy. It's 40 mm now btw, but I measure like you.

You may get away with 30mm x 30mm x 2.5. steel

I'm a little concerned it may be heavy at the front, but up to 100 kg is usually accepted and you should be under that.

Use a good quality jockey wheel, some slip down with weight on.

Drawbar probably needs to be longer than it looks on the drawings.

I'd make it adjustable at first (slide extra length underneath) then cut and weld when you try turning.

Or make a T with wood, attach coupling to bottom of T, top of T same width as trailer. Pivot T side to side,  if hits car lengthen wood.

 

[Mally]

Just read it all again.

Drive away awning would save much thinking, stop draughts, and could give you much more room.

That's a better proposition long term I would think. 

[catsinthewelder]

Looks like an interesting idea but the folded up drawing makes it look like most of the weight will be on the tow ball, do you know if there is a recommended nose weight for a TR4?

Would a roof box be a good source of a lid?

[leafsprung]

https://www.fyneboatkits.co.uk/kits/other/teardrop-camper/

A bit spendy but the kits are precision made and all the design work has been done for you. More durable, warmer, secure and weatherproof than tenting.

[Bfg]

  

On 6/15/2021 at 2:58 AM, somewhatfoolish said:

? There's nothing stopping you towing something that's wider than the tow vehicle.

No indeed, there is nothing (within reason of course) stopping me from towing a wider trailer but, I think for anyone, the driving pleasure of any vehicle is greatly diminished when there's concern or even the possibility of catching a pedestrian, a cyclist, or another motorised vehicle for that matter, because the trailer or just its wheels / mudguard are projecting out of either side.  A well balanced & tracking trailer can at times be forgotten by the driver ..and then the wider trailer is an accident waiting to happen.   Slightly wider trailers are rarely a problem on a motorway ..but the simple pleasures of driving along narrow lanes and navigating through quaint little villages is noticeably lessened - IMO.   Most drivers seem content when their vehicle's wing mirrors are wider, and others are happy when the trailer is no wider than the car's extremities (like the door handles and bumpers of a classic car).  Me.., well I simply prefer to have the trailer tucked well within the tow car's body lines and slip stream. Driving is more fun that way.    

Similarly there's nothing stopping me from towing a tall trailer, a caravan, or even a tear drop.  Extended wing mirrors help when watching out for motorcyclist, emergency vehicles, or other overtaking traffic - but the rear view via the interior mirror is often obscured. That's something I'm not used to.  And my not being fully aware of what's happening all-around is let's say 'just a little uneasy' (..perhaps that's left over from my being a motorcyclist). 

Tall trailers are more susceptible to side winds, either from the weather or when passing trucks. And the lighter the tow vehicle (a sports car in this instance).. the more adverse the effect.  Likewise when the tow car has a long boot / overhang, relative to its wheelbase length, and also sensitive steering.  Centre-of-gravity ought to be kept low whether it's a trailer or a caravan.  A 'classic' caravan with their narrow track, glass windows and relatively soft suspensions, do suffer more than the modern variant.  Trailers with their load above the height of mudguards are less than ideal.               

Of course additional size (in any direction) also translates into additional weight, which again is not conducive to fun driving. That might be more apparent on older vehicles because their engine power-to-weight ratio tend to be less than a modern, with their fuel consumption not exactly noted for frugality.  For a wider &/or taller trailer / caravan,  air drag can be considerable.  Heavier or unbalanced trailers which are like a tail wagging the dog can be fun to watch from another vehicle ..unless they are just about to cause injury or damage.  Gross trailer weight is also detrimental to braking and handling.  Most of the time it's not an issue, but during that one-in-a-thousand everyday driving scenarios - it can be the deciding factor. 

The pleasure of driving is what it's about when I tour in a sports car.  It's simply an important priority to me.  Conversely, I accept having more palatial camping accommodation is more important to others.

Pete

[Bfg]

On 6/15/2021 at 9:50 AM, leafsprung said:

https://www.fyneboatkits.co.uk/kits/other/teardrop-camper/

A bit spendy but the kits are precision made and all the design work has been done for you. More durable, warmer, secure and weatherproof than tenting.

I'd forgotten about those. Thanks for the reminder.

Essential a teardrop camper, but one which both looks good (beautiful timber and build quality dependent) and which would be super lightweight.  I could be tempted, but for the time it would take me to build such a beauty.  Another time perhaps ..if I find myself a little lady who would like that sort of space.

Pete. 

p.s.  reading about this once again and I see the £2835 price is not inclusive of a chassis. That's another £1500..  And even at £4335 it's a kit that you have to make yourself.  Making it is one thing, but home-building it a blemish free finish would be something else all together.    And then its weight is a bit of a shock too  "The Teardrop Camper weighs about 115 kg fully outfitted and accessorised. The basic shell & galley weigh about 80 kg. Trailer weight will vary wildly; the total weight will probably be about 230–270 kg with typical outfitting."   Outfitting would I guess mean fabrics and things like a camping cooker. It is not the all up packed with clothes food and water for a holiday weight.  

To put this in perspective, the 'target weight' for my camping trailer was 100kg  ..although in practice, because I'm using recycled materials and just one size of steel  for the chassis (rather than lighter outriggers), I'm guessing it'll come in around half the weight of Fyneboat's teardrop.

[barefoot]

Not quite the same, but this is an early design for my abortive trailer project. There's loads more, but they don't seem to be on this computer anymore. It was to be built using rotational moulding - like grit bins - and worked out at about £400 each back in 2006/8 ish. 

[Bfg]

On 6/15/2021 at 6:51 AM, catsinthewelder said:

Looks like an interesting idea but the folded up drawing makes it look like most of the weight will be on the tow ball, do you know if there is a recommended nose weight for a TR4?

No, I'm not aware of a recommended trailer nose weight for a TR4.  The information I have simply gives trailer gross weights of 1016kg if the trailer has brakes, and 200kg otherwise. 

Yes indeed, with the axle that far back more weight will be on the two ball. It was done because the longer wheelbase (of the trailer axle from the car) tracks better than a short wheelbase. The design concept was that trailer should be kept to a very light weight, and so the nose weight on the towing hitch would be correspondingly small.   However . . .

Yesterday I went down to my old boat to collect whatever useful sheets of plywood / materials I might have collected over time. Unfortunately that was largely thicker / heavier material than I would have ideally chosen if I were buying new.   Handling that was a bit of an eye opener, and so then I sat down and started a weight projection. .

Trailer weight estimate
	kg	alternatively	buy 1/4" ply
plywood boards - grp covered
plywood boards - varnished & paint
plywood 1/4"  - varnished & paint
wheels, hubs, suspension x2	26.0	26.0	26.0
base of trailer inc inside the back	10.0
base of trailer inc inside the back		7.5	7.5
seat / underboard of berths	5.5
seat / underboard of berths		4.1	4.1
sides of trailer, all around	17.1	17.1	6.4
towing hitch	0.8	0.8	0.8
jockey wheel	1.0	1.0	1.0
	60.4	56.5	45.8

 

As you can see the weights, so far, adds up to 60.4 kg.  A large percentage of this is the suspension & wheels, towing hitch, etc.  Still I guess with a lightweight chassis and when everything is actually made - the bare trailer weight will be more like 80 - 90kg. That pushes my perception of the all up weight being around about 100kg with berth and canopy up, by perhaps 10 - 15kg.  For comparison,a friend's galvanised trailer, towed behind a TR3 is just a little taller and wider is 95 kg (unladen). He then adds a cover and spare wheel before loading his tent and camping gear into that. 

Still when handling that wood I collected - it seemed heavy ..but also robust.  By using alternative 1/2" ply I also have (more work in finishing, but less weight) I could save perhaps 3 - 4kg. 

And if I went out and bought 'the ideal' (1/4" marine / aircraft quality ply) I might save another 15 - 20kg off the total.  But that again would necessitate extra work in local doubling up for stiffness or strength (such as the door opening and the lid's hinge pins).  It would also add a lot to the overall cost.  Design as well as build is always a compromise.  On this occasion (almost as a prototype, but also for expediency) I'm going to stick with the thicker / heavier materials I have in stock.

However, your query is timely and handling those plywood panels does bring me to question whether I ought indeed move the axle forward a bit.  I'll review the design and see what impact it'll make. 

Cheers,  Pete

[Bfg]

 

10 hours ago, Mally said:

..

I like the idea, the extension, and  the fact that you stand on the floor is good.

I may have missed this, but how is the extension sealed? Does the wind flow through, is there a false floor, or awning material down to the ground? It's drafts I'm thinking of.

What thickness of 1-1/2" box are you thinking? We use 2.5mm and it's quite heavy. It's 40 mm now btw, but I measure like you.

You may get away with 30mm x 30mm x 2.5. steel

I'm a little concerned it may be heavy at the front, but up to 100 kg is usually accepted and you should be under that.

Use a good quality jockey wheel, some slip down with weight on.

Drawbar probably needs to be longer than it looks on the drawings.

I'd make it adjustable at first (slide extra length underneath) then cut and weld when you try turning.

Or make a T with wood, attach coupling to bottom of T, top of T same width as trailer. Pivot T side to side,  if hits car lengthen wood.

 

I'm planning on using the trailer tent during the warmer months only.  I envisage it'll have no better draft sealing than a rag top car with big holes through the floor.  Thankfully I'll not be trying to sleep in it at speed

Indeed the priority is to be a water-fast rain shelter more than anything, and so when bucketing down the hole through the floor will be ventilation. That ..other than in flood conditions, ought to be dry inside.  A friend did suggest having a canvas groundsheet / foot bag sewn up just in case, but I'll try it without to start off. 

Chassis box section / telescoping guides I was originally thinking of 2mm thk.  But on reflection, for this trailer's diminutive size and in consideration of the plywood I have in stock for the base of the trailer ..with the chassis attached directly to it - I'm sure 1.5mm will be plenty robust enough.

My aim for the trailer's all up but unladen weight was 100kg.  Even with the axles so far back the nose weight will be a lesser percentage of that.  I am however about to review moving the axles forward perhaps 6". 

Valid points.. yes, the towing hitch length will have to be developed in-build with consideration to the angle at full lock and the ball hitch height (I don't have a tow bar on the car yet, and that's off the road having its chassis swapped).    

Good points, thanks,

Pete.

 

[camryv6]

Google Camp-let, the trailer tent has already been made for you

[Talbot]

On 6/14/2021 at 12:15 PM, Bfg said:

 

 

Something isn't right there.  The extended centreline of the rear axle of the car should pass through the centre of the turn radius.  It dosn't look like it does.

[Bitzer]

I  do not really know how to put this politely... Maybe it is an overkill. Maybe the easiest way out would be normal tent - building a modern one big enough for four people only takes some 10 minutes. Something like this, for Ł100: https://www.decathlon.co.uk/p/arpenaz-4-1-family-camping-tent-1-bedroom-sleeps-4/_/R-p-4123?mc=8378237

Failing that, I think I saw a plan for trailer "shed" made from thin wooden planking in some very old issue of Popular Mechanics. The whole thing was collapsible, unfortunately, I do not recall any details. I believe it would be easier to create something like that than trying to sew a tent from scratch.

[Bfg]

1 hour ago, Talbot said:

Something isn't right there.  The extended centreline of the rear axle of the car should pass through the centre of the turn radius.  It dosn't look like it does.

Don't know.. but this doesn't seem right.   In any case the angle between car and trailer in this illustration is 34 degrees rather than the tighter angle (40 degrees) I'd previously indicated.

cheers, Pete.

[Bfg]

 

2 hours ago, camryv6 said:

Google Camp-let, the trailer tent has already been made for you

Your 'aving a laugh  .. £5,999.00 Inc. VAT ( RRP ; £6,199.00) + kitchenette 

63" wide doesn't work for me ..in a car that is just 49" wide.

Their trailer is 6" higher than my target (ie., to be no higher that my car's rear wings)

And their unladen weight of 272kg is almost three times as heavy as I'd like.  Towing around half a tonne gross weight would be like my fitting the TR with a Morris Minor engine (despite they being a fine engine).  

[Bfg]

 

1 hour ago, Bitzer said:

I  do not really know how to put this politely... Maybe it is an overkill. Maybe the easiest way out would be normal tent - building a modern one big enough for four people only takes some 10 minutes. Something like this, for Ł100: https://www.decathlon.co.uk/p/arpenaz-4-1-family-camping-tent-1-bedroom-sleeps-4/_/R-p-4123?mc=8378237

Failing that, I think I saw a plan for trailer "shed" made from thin wooden planking in some very old issue of Popular Mechanics. The whole thing was collapsible, unfortunately, I do not recall any details. I believe it would be easier to create something like that than trying to sew a tent from scratch.

And I do not really know how to put this politely...  but I think your missing the point.  I don't want to camp in a tent any more. I feel I've passed that stage of agility in life. 

Indeed I could make things very much easier for myself by making a 2m long box with a lid on it.   No that's not after-shave.. it's embalming oil. 

Thanks, Pete.

 

[Noel Tidybeard]

start with a 6'X4' trailer? the drop down tailboard would add extra length for a BFG to lie down

[St.Jude]

Projects and ideas like this give me the horn. Thank you for giving me something to perv over.

Instead of plywood, could you not opt for fibre glass? I'm not sure fibre glass would end up that much more expensive than plywood? Nab some building insulation sheets, use that as the basis of a mould?

Also, in terms of cooking, Ikea sell a hot plate for about £20/£20 which is supposed to be really, really good for camping/campers. It's not big at all. 

[somewhatfoolish]

7 hours ago, Bfg said:

No, I'm not aware of a recommended trailer nose weight for a TR4.  The information I have simply gives trailer gross weights of 1016kg if the trailer has brakes, and 200kg otherwise. 

Given it's a relatively light car and not designed with load lugging in mind I'd assume a tongue weight of no more than 25-30kg, otherwise the tail may start to wag the dog.

A shortcut to your camping delight could be a box trailer; most are pretty, well, boxy but some look not unlike small caravans; then you have no fabrication to do other than the blank canvas of the interior.

[sheffcortinacentre]

What about a rapido comfort-matic? 

Had one for about 5 years.

 

[camryv6]

12 hours ago, sheffcortinacentre said:

What about a rapido comfort-matic? 

Had one for about 5 years.

 

He only wants to spend £2.50 yet is paying for a re chassis on a TR4 !!

[Bfg]

 

On 6/15/2021 at 6:51 AM, catsinthewelder said:

the folded up drawing makes it look like most of the weight will be on the tow ball,

 

On 6/15/2021 at 7:29 PM, somewhatfoolish said:

Given it's a relatively light car and not designed with load lugging in mind I'd assume a tongue weight of no more than 25-30kg, otherwise the tail may start to wag the dog.

 

I reviewed the design, last night and this morning, and have decided to move the axle 4" further forward.  This allows me that much more usable space behind  the axle to position any heavier provisions and a water container as a counterbalance to nose weight. . . 

    

^ Previous version left, revised to the right.  Looking more conventional perhaps because to move the axles forward - I've reshaped the trailer's plan view slightly, to be wider at the front corners because this means the trailer's body is more parallel over the wheels in their new position. I've shortened the front of the body by 15mm, leaving the ball hitch where it was, to ensure a good turning circle (changing its jack-knife angle from 40 degrees to 44 degrees), and I've also altered the corners from R.100mm to R.75mm, so that the trailer now looks a little squarer and less tapered than before.   The change to the radius was because.. that was the inside diameter of an off-cut length of drainage tube which had been dumped alongside my boat . . .

 

^ exciting isn't it ?   ..but therein lies the cornerstone to the new trailer.

^ with 70cm of pipe cut off and then sliced longways, I have two moulds.  These have been gel-coated white.  I think that pot of gel must have been left over from when I was making cockpit hatches for my boat ..a number of years ago.

To the bottom-left of the photo, seen leaning against the patio's low wall on which the moulds are sitting, are sheets of plywood that I had for refitting my old boat.. The bigger plywood panel was dumped in the skip a year or so ago, and the smaller panel I did buy (ten years ago now) for fitting out the boat.  It's GRP covered on both sides and has a white gelcoat finish.  These panels were door cut-outs from a box-trailer manufacturer. I used some for making water holding tanks on the boat, but these are surplus to that task. 

So., cost of materials so far : zilch   

^ laminated with grass-fibre ..well mainly glass-fibre but a piece of grass was picked up and moulded in after that piece of mat found it's way onto the floor.

  I've started

Pete.

[Bfg]

On 16/06/2021 at 10:21, camryv6 said:

He only wants to spend £2.50 yet is paying for a re chassis on a TR4 !!

It's because I have to re-chassis the TR that I have to count the beans everywhere else. 

[camryv6]

1 hour ago, Bfg said:

It's because I have to re-chassis the TR that I have to count the beans everywhere else. 

I understand, but i think a purpose built second hand trailer tent would be a more sensible option, i believe there is a smaller one person trailer tent that can be towed with a motorbike but my google searching is weak

[sheffcortinacentre]

Friend of mine was contemplating using a pair of truckman tops ( one upside down as the base) bolted together as a one man caravan.