{Ultimate Camping} Trailer - the mobile kitchen/power plant

[AlienSKP]

Remember, the trailer will act as a see saw. if the frig is 500cm behind the axle, and the batteries are 2M in front of the axle, then the 100lbs of batteries would need something like 800lbs of food in the frig to make it balance. And, the weight of the metal/wood in the trailer body is also in front of the axle, so you can put a lot back there before its a problem. The excel link works, I just tested it ( it downloads a zip file that needs to be unzipped). Its slow, but it works.
Tom

Ok I see. I'll need to do the math. I'd rather have the kitchen at the back so you're bringing back some hope. I thought it would not be possible.

open.jpg

The "door" I was talking about was this thing I pointed at with the arrow. What is that? it looks like it is in the way?

This is the 2nd version of the design. I'm building the 3rd version of the design right now, so this design is outdated.
And what you're pointing is an open drawer, not the door. You should try to see it in 3D with Google Sketchup, I posted the skp file.

I plugged in the numbers you gave, and made a few guesses. Here is what it calculated
Basically you have 200lbs of tongue weight in this model, and any camping gear in front of the axle actually adds more weight. 200lbs is a lot for a trailer this small.
If you send me new numbers I can plug them in A=? etc.
Tom

Thanks dude. much appreciated. I dont have the real numbers here right now as I still don't know the weight of my drawers (and drawer slides are heavy!).
But you guesses it good. I can't have more than 100 lbs weight on my hitch (10% of 1000 lbs) so for sure I'll have to figure out how to balance all that sh** correctly.
I'll try to estimate this more precisely and run the numbers. I'll send them to you to review if you want.

I have questions :

• what is X ? LCG ?
• are W1 and W2 the weight applies for everything FROM THE AXLE or just at the end of the trailer ?
• is it true that the axle should be at least from 3/4 of the total length from the hitch ?

Some numbers I can give you :
* frame weight : 110 lbs + a 1/4 inch plywood sheet (48 * 72)
* axle + wheels : 75+20 lbs
* fridge 35 lbs
* water pump 10 lbs
* gas stove ~ 15 lbs
* batteries + boxes 108 lbs
* solar panel " 15 lbs (will be at the front of my current design, above the cargo space)
* charge controller + inverter : 15 lbs
* I will weight all my gear ASAP and estimate the weight of drawers (including slides).
* oh ! and I shouldn't forget about the spare tire (~10 lbs). I can install it either at the front if the cargo is at the front or at the back if the cargo is at the back


MERCI MONSIEUR !

[Socal Tom]

I have questions :

• what is X ? LCG ?
• are W1 and W2 the weight applies for everything FROM THE AXLE or just at the end of the trailer ?
• is it true that the axle should be at least from 3/4 of the total length from the hitch ?

Some numbers I can give you :
* frame weight : 110 lbs + a 1/4 inch plywood sheet (48 * 72)
* axle + wheels : 75+20 lbs
* fridge 35 lbs
* water pump 10 lbs
* gas stove ~ 15 lbs
* batteries + boxes 108 lbs
* solar panel " 15 lbs (will be at the front of my current design, above the cargo space)
* charge controller + inverter : 15 lbs
* I will weight all my gear ASAP and estimate the weight of drawers (including slides).

MERCI MONSIEUR !

LCG = Loaded center of gravity
x-LCG is the number of inches from the rear of the trailer to the center of gravity ( the balance point of the trailer)

W1 is the total weight of the stuff at the back of the trailer. We also need to know the average distance from the back of the trailer. ( if your kitchen cabinets are 18 inches deep I would just call it 9 inches)
W2 is all the stuff at the front of the trailer ( we also need to know how far that weight will be from the back of the trailer. since this is far forward of the axle, we want to be reasonably precise, if its inside the cabin, then its less than 72 inches, if its in a tongue box in front, then we would add a few more inches)

I'll total up the weights you have, and try and estimate the lengths from the back. We can also add additional weight inside the trailer for camping gear etc.
Tom

[Socal Tom]

Here is the next estimate,
I assumed the solar panels and charge controller were in the cabin area, I moved one of the batteries to the back with the kitchen.

tb2.jpg (157.82 KiB) Viewed 2798 times

[AlienSKP]

Here is the next estimate,
I assumed the solar panels and charge controller were in the cabin area, I moved one of the batteries to the back with the kitchen.

I can't split batteries unfortunately, they have to be connected together (they are connected in parallel). good thing is : drawers are on each side and more or less balanced one with the other. Both gear boxes will be beyond them. At the center, there will be the fridge and then in the space after there will be the water tank and the electric parts and the batteries.. So I can balance my trailer with the batteries to move the center of gravity and W2.
I haven't posted the Interior design yet, but here is a picture of it [Warning : spoiler ! lol]

trailer_setupsmall.jpg (77.16 KiB) Viewed 2796 times

so everything after the fridge can be arranged however I want. I'll place everything on the trailer to find out its the gravity center, then arrange these item to find the right spot to put the axle (water tank, batteries)

Do you think I can manage to have the kitchen at the back then ? It would be a great news. Like... Champagne!

[Socal Tom]

Absolutely the kitchen can go in the back. My suggestion would to be that you use the tool to try and pick a tongue length and axle location. Place the water tank as close to the axle as you can, then it will have less impact on the tongue weight. The 108 lbs on batteries on the front will mean your tongue weight will probably exceed 100 lbs, unless you can move them into the cargo area. If that is possible, then you can just pick the battery location last and use it to give you the desired tongue weight.
Tom

[AlienSKP]

Absolutely the kitchen can go in the back. My suggestion would to be that you use the tool to try and pick a tongue length and axle location. Place the water tank as close to the axle as you can, then it will have less impact on the tongue weight. The 108 lbs on batteries on the front will mean your tongue weight will probably exceed 100 lbs, unless you can move them into the cargo area. If that is possible, then you can just pick the battery location last and use it to give you the desired tongue weight.
Tom

Tom you're my hero ! lol
I totally can move batteries inside of the cargo space, water tank as well. And the water tank is 10 gal = 80 lbs of water, but I will be draining it before long drive

Thanks. I've sent you a PM

cheers

[AlienSKP]

{Ultimate Camping} Trailer - Building of the drawers

On each side of the frigde, I designed two long drawers to arrange my kitchen stuff.

Last week-end I started building the drawers.
* bought 2 Baltic Birch plywood sheets 1/4 " and one 1/2" (4ft by 8ft)
* had it cut
* applied 3 layers of Ebony on it, result is great (see below)
* received drawer slides. I'll install 200 lbs 36" slides found here

DSC_0132.JPG (36.95 KiB) Viewed 2702 times

TO-DO list :
[*] Still have to do some cutting
[*] Glue and nail the boards together
[*] Attach drawers to the slides and to the trailer

[TO BE CONTINUED]
I'll take more pictures, sorry. I'll try to give as much details as possible.

[Socal Tom]

Are you going to show us the V3 design? Looks like you are moving along nicely.
Tom

[AlienSKP]

Are you going to show us the V3 design? Looks like you are moving along nicely.
Tom

Hi Tom !

Thanks for your message

I will more focus on building it and writing this build journal. I have some sketches I can post, but apart from that and the frame Sketchup file I don't have much on the V3 design. All I have is in my head. And the V3 has the same features than the v2 : solar panels (but bigger, 3 in stead of 2), battery, small kitchen. The biggest addition is the 12V fridge instead of a 12V cooler and the addition of the sink.

The overall design of the V3 is very flexible anyway, It will mostly depend on how I can thermoform the Divinycell H80 foam that I will use to make the shell out of it (using fiberglass or carbon fiber + Epoxy to make sandwich composite material).
For the moment, I'm dedicated in building the inside. There is so much to do that I try to focus only on it. Yesterday I started to make a 1/10 scale drawing of the inside, I'll post it as soon as I can. It will give you an idea of the overall design.

Thanks for following my thread.

Cheers
A

[AlienSKP]

{Ultimate Camping} Trailer - Interior Design

Design of the inside of the trailer was painful, and it's still a kind of work in progress.
Inside the trailer should fit :

• A 12V 49L fridge, encapsulated in insulating foam and enough space around for a correct air flow. I will have to install a couple fans to improve the flow. Hopefully I found on ebay a nice electronic board with a temperature sensor that will trigger the fans only from a certain temperature
• drawers to store all my cooking gear
• a propane burner (stove) for the times where I can't have a fire pit, or to make a fresh coffee
• two huge type 27 deep cycle batteries (100 AmpH each)
• a 10 gal water tank
• all the electrical parts, including cables, switches, terminal blocks, fuse blocks,..
• a nice countertop with a small sink and a tap and a small panel to switch on/off the lights
• the 12V pump

After a lot of time spent on my book with a paper, an eraser and a ruler, I came up with this design (Left is the front view, right is the top view) :

trailer inside design SMALL.jpg (55.05 KiB) Viewed 2642 times

It should look a bit like that :


For the drawers slide correctly, I'll use angle (L shaped) aluminium rails where I'll attach the drawer slides.
I wanted to find undermount drawer slides but I couldn't find 36 inch ones..
Here is a sketch of it :

drawerslides_design.jpeg (32.9 KiB) Viewed 2639 times

[Socal Tom]

a couple of considerations....
Since your plan is to travel with your water tanks empty, why not just use jugs?
I have a water pump and faucet, but I don't have a permanent tank. I made a tube from PVC, that connects to a hose that connects to the inlet of my pump. THe tube drops into the top of my jug and boom, I have water. I don't have to drag my trailer somewhere to fill the water jug ( unless I want to). Its also a lot easier to dump. You can also find jugs that have provisions for pipe fittings in the cap, then you just screw the cap on, and tilt the jug and you have the advantage of gravity, and you don't have to worry about your tube getting dirty.
Tom

[AlienSKP]

a couple of considerations....
Since your plan is to travel with your water tanks empty, why not just use jugs?
Tom

Hi Tom
I already bought the tank and the flexible tubes to plug it.
Thanks

[AlienSKP]

{Ultimate Camping} Trailer - Electrical diagram design

To power the trailer, we'll have :
* 2 huge 100 Amp batteries. This will give the trailer a lot of power. Because this trailer will NEEDS a lot of power
* 3 x 100W flexible solar panels. I went for flexible "marine" solar panel because they are way more light than aluminium framed ones. I bought a round Analog AMP Panel Meter Gauge and a Volt Meter gauge to monitor the current coming out of the panels
* A 30 Amps MPPT Charge controller will get the juice from the solar panels and power up the battery with a clean current, will power the circuit, and will ensure that the batteries don't overcharge or go below 50% charge.

We'll have all these items sucking some juice :
* The fridge - 15A - 40 amps in 24 hours
* The water pump - 7.5A
* a couple USB outlets (I will surely go for these ones
* a couple 12V car outlets
* 3 flat "COB" LED around the countertop
* 2+1 LED lights included in the kitchen door, so they can light from the top when the door is open
* one flat "COB" waterproof light on each side of the outside of the trailer, with their own waterproof switch so you can provide some light on the outside of the trailer. I'm not sure exactly where I'll put them, on the bottom or on the sides.
* a couple powerful fans will cool down the inside of the trailer and make sure that the fridge doesn't blow up. The fridge will be encapsulated in a foam casket, and air inside it must flow to keep it cool.

All these stuff will be of course all regulated with their own fuse, and we'll have a lot of switches to choose whatever we want to power on or off.
To make sure that we don't draw too much power, a relay will switch off the fridge anytime the water pump is turned on.- removed, see Edit below.
A thermostat will check the fridge area temperature, and will trigger the fans at a given temperature.

After spending a lot of time drawing it on paper, I used Digikey ShemeIt online tool to make a nice wiring diagram.
Here it is :

wiring_diagram_final-small.png (203.93 KiB) Viewed 2536 times

Don't hesitate to ask any question about it. If you're a pro and you notice a big mistake, please give me your advice! Let me know as soon as possible then I'll update it.

Thanks for reading

EDIT

• I removed the relay that switch off the fridge when pump is on after Dale and Chas comments. I also wired the Voltmeter in parallel and made better representation of the batteries. Thanks guys !
• tried to use more conventional diagram terminal blocks and replace the voltmeter to a better spot

[GuitarPhotog]

A design question: why is the 12 VDC power to the pump wired in series with a relay coil that controls 12 VDC to the fridge? The way it's wired, every time you turn on the water pump, the fridge goes off.

That's not a good idea especially if the fridge is a real compressor-type fridge, not a peltier cooler. The constant cycling of the compressor power will unduly wear on the compressor and motor.

And the voltage drop created by the relay coil may be such that you haven't enough voltage to run the pump with enough water flow for your use.

For better understandability, you should use conventional schematic/wiring diagram symbols for things like terminal strips. It's difficult to evaluate the design as you've drawn it.

It also looks as though the negative side of your batteries are not connected to your common ground except through the charge controller. That is not good wiring practice. Your grounds should all tie to one common point or bus. That way if your charge controller fails, your entire electrical system doesn't go down.

My $0.02 worth after 10 minutes of looking at it.

<Chas>

[Dale M.]

Also your volt meter is in series with out put of charge controller (in +PV lead) ... Volt meters are a parallel arrangement meter, one side need to be tied to PLUS (positive) side of circuit and other side to MINUS (negative) side of circuit...

Ammeter is wired ok at this point....

And why at least 6 ground bars.... Technically you only need one large one.... And everything (12 volts and ground) should source from a single point not multiple bars scattered around trailer, these cause multiple (excess) connections and each extra connection is a additional failure point...

You are also somewhat indication your batteries are in series, are you using 2 6volt batteries in series to get 12 volts or are you using 2 12volt batteries for 24 volts..... Think you want to indicate 2 12volt batteries in parallel...

Its a pretty picture but way over engineered and several unnecessary steps/items in design ....

And I agree with way cut off relay for fridge is wired.... The winding of the relay are not designed to take current flow water pump requires...

You have one light (LED) circuit going through 4 switches and 3 fuses ... "WHAT?"

wiring_diagram_final-small.png (178.41 KiB) Viewed 2555 times

With your zeal to have awesome design software you have made it over complicated and quite a few mistakes....

Kind of wonder what else is wrong if one takes a hard look at your schematic...

Dale