My trailer design- Long, and I tend to ramble :) (small pics

[fasttimes]

I've be doing some preliminary design for my off-road trailer and would like to know what you all think. It has a rear outside kitchen and does not have standing room like a teardrop trailer, but is box shape like a travel trailer. I guess it's a hybrid then? The design calls for carrying enough supplies for at least 30 days, be completely independent in electricity, and have air conditioning.

Here are some pics. The scale is 4 pixles per inch.

Frame:

At this point, I'm really faking it with this frame design. It's basically the same as the Outback Teardrop with the four leveling jacks, corner bracing gussets, and a tongue long enough for jackknife turns.

Of note, is the rear hitch on the trailer. This will allow me to carry a dirt bike. This also help get more weight behind the trailer axle.

Body:

The body will be of composite construction. The main room will be 1/4" ply 7" iso. foam insulation - 1/4" ply composite on all sides (floor ply will be 1/2" instead of 1/4".) To get the large 1/4" plywood sheets I need throughout, they will be glued up from sheets of 1/8" ply with staggered joints. Instead of using standard lumber for the framing, I'm thinking of making wooden "I" beams out of 2x2 (ripped down 2x4s) and 1/4" plywood. This would reduce the thermal bridges caused by the lumber between the insulation, and should be even stronger and lighter than using standard lumber.

The kitchen area will be either un-insulated 3/4" ply (as shown), or a 1/4" ply - 1/2" iso. foam - 1/4" ply composite. The kitchen door can also be seen, and this copies the door design used on DANL's trailer.

I don't know yet what I'm going to use to finish all the walls/roof. One thought was to use GAF that rubber roofing product they have for buildings seen at http://www.gaf.com/Content/Documents/10571.pdf

The water tank shown will hold 75-85 gallons. It's partly under the bed base and partly under the closet next to the bed. Having the water in the insulated section allows the water thermal mass to help the 1000 BTU air conditioner maintain the temp during the hottest parts of the hottest days. It takes about 3100 BTUs to raise 75 gallons 5 degrees.

Lastly, the twin 20-lb propane tanks are shown on the trailer tongue. If I find that I need more propane to get through the winters, I can always swap out one or both of the 20-lb tanks for the taller 40-lb tanks.

Interior:

We see the bed base with part of the water tank, and the closet next to the bed with the rest of the water tank under it. There is also overhead storage above the foot end of the bed, next to the closet unit. This will probably where I have the electronics, like satellite TV receiver, satellite radio receiver, and surround sound system. TV viewing will be done through a laptop.

The composting toilet vents through the roof, and above the toilet a cabinet hides the vent pipe (actually, I'll probably use hose) and gives extra storage.

The entry door is in the only place it can be in this layout, and the side opposite the hinge side is tapered so the deep door can open.

I have not made a decision as to where the single window will go, but it may be in the door.

I have two possible problems with this layout; one is the location of the entry door may be partially blocked by the wheel; the other is how to access the under bed storage with ease.

As under-bed storage is a good fraction of total storage, it has to be as easy to get at as possible. The storage over the foot side of the bed complicate getting at the under-bed storage as well.

As The floors are about 8 inches thick, plus the additional 2 inches due to the frame thickness, plus more height from the axle springs, the door may be partially overlap the wheels, but still not be blocked by them due to the height differences. I guess I won't know until I can calculate the proper location for the axle.

Another decision I have yet to make is what to use to finish the interior. My first thought is to use plastic laminate (aka Formica) as it's easy to apply and take care of. The down side it it's not cheap, and can look bad if it gets worn.

Also, where to put the 4 Surrette S530 batteries? At 508 lbs total, I want them as close to the axle as possible. They fit perfect under the bed, just in front of the water tank, but this places the weight forward of (but still close to) the axle. The alternate location would be in the back kitchen area. The places the weight at or behind the axle but exposes the batteries to the temp extremes. It might also complicate maintenance access.

The evaporator assembly (cooling unit) of the air conditioner will probably be mounted at the top of the closet, facing the toilet.

I'm still trying to come up with a good heater. With the insulation, I would need only about 1500 BTU's max, even down to 20 degrees F outside. But, the only heaters this small are un-vented catalytic types-- the Coleman SportCat Perfectemp (1,500 BTU). I fear using an un-vented heater in such a small trailer, but maybe I'm paranoid. I could use a carbon monoxide detector and vent as recommended. Of course, with venting I would now need more BTU's; probably in the 3000 BTU range. There are several RV un-vented catalytic heaters in the 3000 BTU range.

A small company also makes a vented catalytic heater in a 3000 BTU size, seen at http://www.omnicast.net/~arnie/. With this unit, combustion air is still taken from the inside, but it have a built-in vent fan that is supposed to remove the combustion gases and also bring in fresh make-up air. Sounds good, but now we have the power requirements of the fan (1/2 amp) and the igniter (5 minutes @ 5 amps), so probably works out to about 1.5 amps total power usage per hour (assuming a couple cycles per hour.) Price if this unit is also an unknown at this time, and a carbon monoxide detector would still be a must, IMO.

Another possibility is to build a hydronic heating system like the one described at http://www.solarhaven.org/HPArticle.htm. This is ideal, in the sense that the combustion is outside the living space, but would also probably be too bulky.

I haven't worked out the kitchen area, but will include stove, small sink, refrigerator, air conditioner condenser assembly (section with the compressor), solar charge controller, maybe the batteries, and the remaining space used for storage. It's going to take some thinking to use this space with maximum efficiency.

Exterior:

This shows the 6 solar panels in their stowed (stacked) travel position, and the toilet vent.


Finally, this is with the trailer in use. Awning attached, back door open (not seen), satellite TV dish out, and solar panel array deployed (array depicted tilted at a 45 degree angle in the picture above.)

The most interesting feature is the solar panel mount . It's a little hard to describe what I have in mind, but I'll give it a shot. First, the entire stacked array of panels slides out half way over the edge of the roof on drawer slides. Then, the top two pairs of panels deploy out to opposite sides of the bottom set, similar to the way some small tool boxes have the extra trays that deploy out the sides and give access to the bottom section of the tool box. Lastly, the array is tilted to the correct angle. I'm not sure yet how I want to lock the array to the correct angle.

[fasttimes]

Here is the latest update.:

The water tank is still under the foot end of the bed base and the closet next to the foot of the bed.
I've been working on the kitchen area.

A floor-to-roof frig/freezer takes up the right side of the kitchen. 4 inches of insulation is used all around. The frig/freezer saves some space by sharing the main section's 7 inches of insulation as its rear insulation. I don't know yet where the fridge compressor is going to be placed.

I've decided to put the batteries under the kitchen counter, surrounded on all sides with 2 inches of iso. insulation to protect it from cold weather. Maintenance access will be accomplished either by a removable section of counter top, or by mounting the batteries on a drawer that slides out after removing an access door (as shown above.)

The compressor section of the air conditioning is under the kitchen counter. There is a vent through the outside wall, and plenty of venting holes will be drilled in the surrounding under-cabinet 1/2" plywood dividers, and venting through the under-counter cabinet doors. The cooling section of the air conditioning is placed high on the wall above the bed.

I've decided on using the Platinum Cat vented catalytic heater. Although expensive, it's small in size and BTU output (perfect), controlled via thermostat, and is the only vented cat heater. This can be seen in the door, and will be located below the window (if I put the window there.) I will be using an armored hose to supply the propane to the heater for safety.

The thermostat for the heater, battery monitor, and indoor/outdoor thermometer is mounted high on the over-the-toilet cabinet, facing the bed.

Under-bed storage access finalized. The foam mattress will be spilt at the foot end, so the bed platform to avoid the problem with the over-bed cabinet. The bed platform is then hinged about 5 inches from the wall and can then be opened for access under. The access door should easily clear the thermostat, battery monitor, and thermometer without any problems.

Well that's it for this update.

Still to add: Add kitchen counter, stove, sink, solar charge controller, 300 watt inverter, surround sound speaker placement, lighting, Carbon Monoxide/Propane/Smoke Detectors, and electrical breaker box. Then I have to calculate the proper axle location.

[angib]

Wow! That's what we Brits call 'a quart in a pint pot' - is that '10lbs of potatoes in a 5lb sack' in America?

You've got up to 700 lbs of water, 500 lbs of batteries and at least 300 lbs of dirt bike, so the basic trailer and body is going to end up at something like 1500 lbs to hold that lot up - that's 3000 lbs total without even thinking how much a composting toilet weighs (sounds wonderful, though...).

Unless your truck has 'Mack' written across the front, you should do a weight and centre of gravity estimate to keep the hitch weight within sensible limits (unless you propose to use a weight-distributing hitch). Taking the dirt bike off the back will probably make the trailer untowable as the hitch weight will then leap up.

At 75 gallons, you might want to think about dividing your water tank into two, so you can position the two tanks either side of the axle so that the balance of the trailer isn't affected too badly by how much water is onboard. Indeed you might think of integrating at least the water tanks, and maybe battery boxes, into the trailer frame itself.

Be sure to post your design as it progresses - it is interesting, if unusual!

Andrew

(PS What future use?)

[BrianB]

Satellite TV, composting toilets, dual 40lbs propane tanks, 680lbs of water and 500lbs of batteries... You forgot the 40inch plasma TV with 3000watt surround sound speakers.

I don't think you understand the idea of teardrop trailers. Minimization is the key. You're trying to fit a coach motorhome onto a teardrop footprint and it's simply not feasible. If you're really after a teardrop, try scaling it down...a lot.

One thing I just don't get, if you're going to be spending your time watching satellite TV, what's the point of going camping?

[fasttimes]

Wow! That's what we Brits call 'a quart in a pint pot' - is that '10lbs of potatoes in a 5lb sack' in America?

You should see my current (self-built) van conversion I full-time in now. I have the roof covered in 350 watts of solar panels, and a crank-up 1.5 meter satellite dish for picking up c- and ku-band TV. I always get mistaken for a news van! Why build it, if it's conventional.

You've got up to 700 lbs of water, 500 lbs of batteries and at least 300 lbs of dirt bike, so the basic trailer and body is going to end up at something like 1500 lbs to hold that lot up - that's 3000 lbs total without even thinking how much a composting toilet weighs (sounds wonderful, though...).

Unless your truck has 'Mack' written across the front, you should do a weight and center of gravity estimate to keep the hitch weight within sensible limits (unless you propose to use a weight-distributing hitch). Taking the dirt bike off the back will probably make the trailer untowable as the hitch weight will then leap up.

The composting toilet is the Envirolet non-electric found for about $1000 at http://www.envirolet.com/enwatsel.html and weighs 75 lbs / 34 kg.

I do plan on doing the weight and center of gravity estimate after I have a better idea of how the kitchen will go together. I'm hoping the axle will be right under the water tank, or at the back 1/3 point of the tank.

I'd prefer not to have to use the weight-distributing hitch, but will use if needed (could be a nice additional passive anti-theft measure in favor of the trailer.) I found some plans on the net for building a weight-distributing hitch, so I am equipped if needed.

I do plan on using the bike to push the COG back further.

At 75 gallons, you might want to think about dividing your water tank into two, so you can position the two tanks either side of the axle so that the balance of the trailer isn't affected too badly by how much water is onboard.

If this trailer balances where TDs tend to balance, that places the axle right under the water tank. Placing the batteries in the kitchen area should also push the COG further back if needed. I won't know for awhile. I'm mainly wondering how the weight in the under-bed storage will effect things. This will tend to be stuff used the least, like tools, ect.

Indeed you might think of integrating at least the water tanks, and maybe battery boxes, into the trailer frame itself.

Why? Getting the weight lower for stability, or are you referring to a structural issue? The trailer wheels will have a wide stance, at about 7 feet center to center, so I didn't think stability would be a problem with all the heavy weight as low as it already is. I'm I incorrect in this assumption?

Be sure to post your design as it progresses - it is interesting, if unusual!

(PS What future use?)

Thanks. I have a lot more designing to do. I'm going to have plenty of questions to ask.

PS I was thinking so I could add important new info or additional new pictures without having to edit the original top post.

Satellite TV, composting toilets, dual 40lbs propane tanks, 680lbs of water and 500lbs of batteries... You forgot the 40inch plasma TV with 3000watt surround sound speakers.

A small surround sound is planed, as I already have one in my van coversion... can't find room for the plasma... Only kidding. I guess I shouldn't even bring up my satellite Internet connection.

I don't think you understand the idea of teardrop trailers. Minimization is the key. You're trying to fit a coach motorhome onto a teardrop footprint and it's simply not feasible. If you're really after a teardrop, try scaling it down...a lot.

One thing I just don't get, if you're going to be spending your time watching satellite TV, what's the point of going camping?

:BE
Because it's for full-time use, not just occasional camping. I'm really designing more of a TTT than a TD. The kitchen is of TD inspiration, but the shape will be an ugly box, more TT inspired. I already full-time in a van conversion of my own construction, so I'm used to the small size (the trailer is about the same size as the van conversion.) I hope the trailer fills all the holes the van conversion can't: Always comfortable in any weather, long-term independent dry camping capable (30 days), nice but basic kitchen, secondary transport so I have transportation when the main vehicle is being worked on, just enough storage to carry the important stuff I need on at least a monthly basis, off-road capable.

If I wanted to make a 150 mile round trip every couple days (I like camping way off the beaten path,) I could really cut down on the requirements for things like water and propane, but that gas adds up real quick (not to mention being a pain in the rear.)

What I don't need is more room than I have now in my van conversion. I love the cozy size of small trailers. If I need space, I sit outside under the awning. A larger RV is just too much for my needs, and can't go where I want to go anyway.

[angib]

Getting the weight lower for stability, or are you referring to a structural issue? The trailer wheels will have a wide stance, at about 7 feet center to center, so I didn't think stability would be a problem with all the heavy weight as low as it already is. I'm I incorrect in this assumption?

I was thinking of weight saving, but that's probably not worth worrying about. I can see no stability problem with such a massive track.

Andrew

[fasttimes]

Updated message Wed Dec 29, 2004 5:18 am. Go to the message here: http://tnttt.com/viewto ... 6075#16075

[Guy]

Dear Whateveryournameis.

I usually do not post to people who do not even use a first name. However, you are great about posting some useful info. Please note your link to the hydronoc artlicle contains an extra " . " at the end. The correct link is http://www.solarhaven.org/HPArticle.htm You already have a great supply of water so why not go for a full open radiant system? Teardrops are perfect for them. Here is a link with some great design layouts for retro radiants http://www.radiantcompany.com/system/open.shtml This gives you both heat and on demand hot water in cold weather and on demand hot water in warm weather.

Thanx for the initial link and idea.

[fasttimes]

Dear Whateveryournameis.

I usually do not post to people who do not even use a first name. However, you are great about posting some useful info.

OK, OK. I've added a sig now so I could add my name, OK?

Please note your link to the hydronoc artlicle contains an extra " . " at the end.

Fixed. There was also another link with the same problem. The "auto-hyperlinking" feature is what did it.

You already have a great supply of water so why not go for a full open radiant system? Teardrops are perfect for them. Here is a link with some great design layouts for retro radiants http://www.radiantcompany.com/system/open.shtml This gives you both heat and on demand hot water in cold weather and on demand hot water in warm weather.

Thanx for the initial link and idea.

I like the radiant water heating system idea. My only issue with the radiant system is the need to now have a bulky water heater. Every additional piece of mounted equipment takes away more storage space, and I don't have lots of extra space in my current design.

I had planed on just using solar heated black bucket of water has my hot water source (only used for showers anyway,) backed up by an infusion of stove heated water as required.

One possibility that might make the radiant water heating system more practical is to build a small water heater box that will fit on the stove-top.A small gallon size box, with a pressure valve, an some sort of small expansion chamber on the top. This would save some space, but you would have to remove the unit when cooking. As a practical matter, you would have to use some quick-disconnect type fittings that allow the hoses from the heater box to be removable, and "trap" the water that remains in the lines from spilling out. You would have to experiment to find the proper stove burner setting that's just right, but it should be possible, as long as the stove has fully adjustable burners, not just a hi/low setting.

[Guy]

Love it Gerry,

I am in LA, too. GuyMazzeo is my name.

Wonder if we could work on sourcing the system together. On a typical tear you would only need about 4 gallons of water. It would be drawn from your cold water. BTW zodi.com makes a unit just like you suggested, stove top.