Planning to convert a 6x12 cargo trailer.

[flboy]

2,000 lbs will be a challenge. Do you know what the empty weight (unmodified) will be?

What is your tow vehicle. I can see it has a manual transmission and has 4wd from your dashboard picture.

My build ended up being 3,680lbs totally loaded with KTM-690R on board, full water tanks, food, and etc.. , but I have a 5,200lb GVWR on the trailer and tow with an Ford F250, so no problems there. I have not weighed it unloaded, but I suspect it would be close to 3,000 lbs.

Sent from my SM-N970U using Tapatalk

[rebelrider.mike]

The trailer as it is will be 1,100 lbs. My truck is a 99 Ford Ranger with the V6 3L engine. From what I've read, the clutch is the weak point, limiting the towing capacity to 2,400 lbs. They did have a 6x10 trailer, but that's only 150 lbs lighter. Not worth it for the loss of 12 sq ft, at least in my opinion. I can't think of any one thing that will be really heavy, so I just need to make sure all the parts I add don't add up too high. I've also been trying to think of a way I could weigh it as I go. The bathroom scale doesn't go quite high enough...

[Grummy]

>>I've also been trying to think of a way I could weigh it as I go. The bathroom scale doesn't go quite high enough...

By all means.. DO Keep track. A simple spreadsheet or document capable of using self totalling columns can let you record everything and you will always know where your at.

The trick is to get your base trailer concepts established first... things that when it comes to weight, are best considered as a "base trailer weight" before many of the little details are added. Then the bathroom scale can be used to record everything else that goes in after the base weight and items involved are recorded.

You have to decide exactly what base weight means in your case. For me, I waited to scale the trailer until after I installed all my insulation, walls, cabinets, wiring, etc. Then my first entry in the documents table listed that scaled weight AND a detailed description of exactly what was included.

From there on, everything gets weighed and entered in the document, which BTW, also has a field that shows the balance of weight that can be added to reach the 2990 lb limit. This makes it like a "live view" of where you are at.

Ill admit that I have changed my "base weight" more than once to get things right, but that just meant unloading everything I did not want in the base weight, scale the trailer and update the list. Each items line has a notes field, where for example if the item is a BIN, I can list everything that is supposed to be in that bin and the weight with all of those items and the bin, than not have to worry about each individual item. One can always EASILY adjust in or out items in that bin that you deem unnecessary as you go.

I include 2 weight columns in the list so I can put known weights into "currently loaded" or "not currently loaded" so I do not have to look far to recall what something I occasionally haul weighs. For example, sometimes my Scooter is loaded and sometimes it is not. I just replace the ZERO in the loaded column with the Scooter weight and then check the totals to see where I am at with the current load.

Other "Optional Objects" also change from column to column such as: When I rough camp, I may take my portable solar panels so those weights get added... Perhaps the dorm fridge gets removed and the Iceco 12v unit gets added Etc.

Doing things this way allows me to track exactly what I am hauling right down to clothes because they are also binned.

[rebelrider.mike]

Good idea. Assuming the listed weight is accurate, that should work well. I'll give it a try.

As I've been shopping around for parts, and working on the floor plan, I've been able to refine my wiring diagram quite a bit.


I removed some information that doesn't need to be there, and changed around hardware. Also figured out what will get its own switch, and added a battery cutoff switch. Almost everything is going to be in the electrical cabinet, so most of these wires will have a very short length.

The longest by far will be the power from the truck. I don't know exactly how far, but I know it's going to have to go from the engine bay in the truck all the way to the electrical cabinet. Plus the various corners it will need to get routed properly. I've played around with a DC voltage drop calculator, and I think the best thing to do is increase the wire gauge. The efficiency gained by boosting the voltage before it leaves the truck would be eaten up by the inefficiency of the converter. So for now I'm planning on 14 AWG wire. Might actually have a spool of that in the basement somewhere. I think that will still fit the connections on the trailer plug. And the negative wire could be grounded to the truck's chassis, so that wire would be significantly shorter.

The switch for the relay is already installed in the truck. I've got a whole assortment of grommets if I need to drill holes in the firewall. Hopefully I can just find some that are already there to sneak a couple small wires through.

[hankaye]

rebelrider.mike, Howdy;

The trailer as it is will be 1,100 lbs. My truck is a 99 Ford Ranger with the V6 3L engine. From what I've read, the clutch is the weak point, limiting the towing capacity to 2,400 lbs. They did have a 6x10 trailer, but that's only 150 lbs lighter. Not worth it for the loss of 12 sq ft, at least in my opinion. I can't think of any one thing that will be really heavy, so I just need to make sure all the parts I add don't add up too high. I've also been trying to think of a way I could weigh it as I go. The bathroom scale doesn't go quite high enough...

Tongue weight of your trailer "should" be somewhere between 10 - 15% of the gross weight of the trailer.
Surly your scale goes to 165# (15% of 1,100#s). Best to know so on the way home I'd weight it at a commercial scale.
There are 'ways to' build a set-up to weigh the side to side using a bathroom scale. I'm confidant that Google can
provide several examples. chuckle.

hank

[Grummy]

>> Assuming the listed weight is accurate, that should work well. I'll give it a try.

Well, no, I wouldn't rely on that... Just scale the trailer at a nearby Cat Scale, WHEN you have it built to a 'selected point'. You do this in this way so that you do not have to weigh each and every build material (and believe me, it all adds up from the weight of hardware.. even Velcro used).

Then you have a good start point to log all the smaller things you add as time goes on.

Remember to disconnect the trailer when it is on the scale so you get the full trailer only weight, and you can easily get a weight on your tongue at home with a bathroom scale if you use a lever... look it up on line for details. You MUST know where you are at to tow safely.

[rebelrider.mike]

So assuming that the trailer is level, the axle weight plus the tongue weight will be the total trailer weight?

I've read about the bathroom scale technique, but couldn't visualize it until I found this nifty illistration:


If I understand it right, the weight on the scale can be reduced by increasing the length of the lever on that side without changing the length on the "brick" side. I'm having flashbacks to college physics lab, LOL. "When are we ever going to use this crap in real life?"

Kind of speaking of levers, I have an idea for the cell booster antenna. I'm not sure it's a good idea yet but here goes:


I'm thinking on the side of the trailer I could put a pole that pivots near the back, and so could be laid flat while stored, and swung upright to be used. I figure that having a length below the pivot point would give some extra rigidity (if that's the right word) and a place to latch it once upright. Things are pretty crowded in the picture, but I'll have to have a box for the solar cables, so may as well run the cell cable in through there too. The inside part of the booster would hang right on the other side of the wall from the box. The cable from the antenna would run down to the pivot and then across to the box. That would put the antenna up to 9 feet above the trailer, or shorter if that height would cause problems for some reason.

I also figured in where the wall studs would be if they're 16 inches on center. I know the side door is about 32 inches wide, so that puts it nicely between a couple studs. I'm pretty sure that's where the studs will be. If not, I'll find out soon enough and make adjustments.

Pretty sure I know how all the wires will be routed now.

A lot of it will be inside the cabinet so I don't really have to worry about that yet. The rest will be mostly in the ceiling, with a couple runs down the walls. I've also moved the exhaust fan so it will be up near the ceiling instead of below the kitchenette upper cabinet. I don't have the wire from the truck yet, but I'm pretty sure that will run underneath the trailer somewhere. Routed through the frame hopefully to give some protection from the elements.

[Grummy]

>>> So assuming that the trailer is level, the axle weight plus the tongue weight will be the total trailer weight?

Well, yes, IF the axle (both wheels essentially) is on one scale and the bathroom scale is NOT on that same scale.

Seriously, just build the bulk of your interior. Get the walls, Cabinets, Bed and Bed frame etc. established. Scale the trailer at a truck scale for $10 with it disconnected and fully standing on the scale (just do this all before you call the guy on the two way jabberbox found at most scales).

Then you can weigh all the rest of the things going in as you go, and somewhat monitor where your at with tongue weight via the bathroom scale method.

I will point out that your drawing will be very helpful in visualizing how weights are affecting you as you go by using a copy to write down the weight of something right on the drawing where that weight is. By doing this you can start halving / quartering your drawing, add the totals up in those sections and get a rough idea what you've got and where.

This way you can also address things that may not have popped up initially. For example, one issue you may fight with down the road is that back bed. Not so much the bed, but what you STORE under it when you find out exactly how much stuff you "think you need" to have with you (THIS is often underestimated, especially if there is a woman involved in traveling). Visually from your drawing, your bed and under bed storage area is 40% of the floorspace and also in the rear, meaning obviously, you need to compensate with things up front to keep necessary tongue weight. Think too about the potential for any future wall cabinets of any size above the bed that might happen when you find out that crawling under or raising the bed every time you need some thing from under it gets rather annoying.

You've mention solar panels. I may have missed where they will be going exactly, but I know that 2 100w Rich Solars round up to 30lbs less mounting hardware. 30lbs on the front verses 30lbs on the rear makes a difference. Gotta plan for those now as well, even if they are portables being tossed under the bed.

You have done an awesome job so far with the forethought of what you want, and now you may have to lay out on the floor, all the things that might be stored under that bed and get a weight total on them so that you can see if, what appears visually to me at least, your more minimal amount of mass in cabinets and storage space up front will be enough to do that. Oh, BTW, get your exact axle position on that drawing for a visual reference as well.

In my case, I even have things hanging on my back door that adds even more weight back there (Table storage, Spare Tire, Etc)... so you have to really think ahead. It would be a shame if you have to always load arbitrary loose goods in that empty floor space up front just to keep adequate tongue weight because that can be annoying too.

Sure, there is always the ability to get more tongue weight if you need it (front storage box or underframe water tanks), but your trying to hit that 2000lb mark if I recall.

Now, with all that said, reconsider my point of doing a great deal of build out, THEN scale the trailer with those things already included. Make good notes of what that weight includes because if you need to, you still can adjust it up or down as minor things change. Keeping the weights of all your items in a self totalling column will always let you know where you are in this regard, and frankly, on these conversions in particular, it can be a challenge to get it right.

[Grummy]

>>> I'm thinking on the side of the trailer I could put a pole that pivots near the back, and so could be laid flat while stored, and swung upright to be used.

A vertically mounted aluminum extendible paint pole (upside down) can be your best friend here. The swing up concept can too easily get caught in the first tree branch you park under, but pushing your antenna straight up will weave it's way thru easily.

Tip: Use Marine Bimini hardware for creative mounting methods.

[rebelrider.mike]

Yeah, a lot of that stuff I won't know until I get the actual trailer. I think the axle is about 1/3 of the way from the back. I didn't think to ask the the trailer folks, but I'll know soon enough. I don't plan to build it in a weekend either, LOL.

Once I have the trailer I'll pull out all my camping stuff and put it in there and see where they might go. You're right about the solar panels. The ones I'm looking at are about 15 lbs each. I'm reserving the whole roof for them though.

I came up with a quick and dirty list of stuff and what it might weigh based on my floor plan, and stuff I've got in various wish lists across the internet. The things in yellow are only estimates based on the ads.


Like you said, once the basic stuff is installed, the stuff that's going in no mater what, I can take a look at the numbers and see what I've got left to work with. Looks like the electrical cabinet will be ahead of the axle, but it's definitely going to put extra weight on the passenger side. Maybe I can compensate with shelving and stuff on the driver side. Does side to side balancing matter too? I've also got bins of stuff that could be moved to the front of the trailer, or put in the back of the truck if it's not needed for tongue weight. Won't know until I try.

[Grummy]

A whole roof of solar will not change your balance much which is wonderful. I wish I had a whole roof of solar ! Maybe by next year.

>>> Does side to side balancing matter too?

Well, in an ideal world, yes. "Ideal" in a converted cargo trailer might mean a "balanced" use trailer with no intent to haul anything along the concept of "Toy Hauler". In other words, just a fixed "living" environment that does not change much. Most would consider my build to be quite lopsided, but frankly, I have not had any issues.

My own trailer is by design heavier on the drivers side, I assume quite a bit heavier because I have kept the ability to load any "toy" that fits in a 48+" width up to 12 feet long. This would include early ATC's, A dirt bike or scooter, or even a garden tractor (which I often need to haul and camp). So, I compensate when toy is not loaded by filling my underfloor water tank which is on the passenger side with more water, and, I have a cabinet with fridge that gets mounted on the passenger side as well. Any loose extras get put on the passenger side as well. (I do three different fridges depending on what and where.... One is a 110v Dorm, the other two are Iceco 12v units that often ride in the TV when necessary).

But, I can't say it has been a problem, visually or towing. With both tires filled with the same psi, I do not have any additional tire squat, and best as I can measure, I only measure an eighth inch difference from side to side. When I load a 700lb Garden Tractor, Trailer still seems to be level from side to side, though I do end up at about 3200lbs. Yes, I know... Trailer is Rated for 2990 with a 3500lb axle... but at least I added brakes. Brake controller is an AuTowBrake unit... really nice to not have to have anything more than the 4 pin harness so I can tow with anything.

My latest concerns have been tongue weight as I recently added 40lbs of A/C in the nose as well as on the last trip, carried a 52lb Pulsar Generator in my new tongue box. I found that it is nothing that putting 10 psi into my recently installed rear air bags can't adjust for. They sure work slick.

As you can see.... it IS a real balancing act especially if you simply can not do everything your going to do right away.

The one thing I should have had the patience to deal with was drawers... I really wanted drawers, but to build them LIGHT takes time. I had a deadline and used premade cabinets. Even though I cut as much off the back as possible (they had at least 4" of air behind the drawers) and mowed out large sections of MDF in the sides and skinned them with veneer, they are way, way heavier than the cabinets I always built for van conversions, which were Luan panels glued and stapled to very thin pine corners and covered in vinyl or fabric.

One really needs to utilize the lightest possible options for each necessity to keep weight under control.

[Grummy]

Oh,, I LIKE that quick and dirty weight sheet. I hope you already see its value !

Note that you can add yet a second column for weight for each item.... the first column is what's in the trailer the second is for what is not. By switching the number from the 'not' to the 'is' column, you can utilize that for things that do not always get loaded for every trip, and more importantly store the weight instead of losing it and having to reweigh it because you forgot.

For example, depending on my trip, my lawn chairs, or a 12v fridge (or two) may end up in the Van and not the trailer. Easy to do a quick study so I know where I'm at.

[hankaye]

rebuildmike, Howdy;

One of the 'other' folks that normally haunts this page is named McDave. This is a link he supplied
a while ago; https://www.engineersedge.com/calculato ... alance.htm
It's a plug in the numbers type of program that will help with the head scratchin'.

hank

[foxontherun]

You're right about the solar panels. The ones I'm looking at are about 15 lbs each. I'm reserving the whole roof for them though.

Is that 154 lbs solar panels correct? Seems like a lot of 15 lb panels for a 6x12 roof.
Harry

[rebelrider.mike]

Looks like a useful calculator Hankeye, thanks.

Yep, 10 solar panels at 15 lbs each is 150 lbs. I found these panels at Home Depot, and they are shaped just so that they fill up almost the entire 6x12 area:
https://www.homedepot.com/p/Grape-Solar-100-Watt-Monocrystalline-Solar-Panel-for-RV-s-Boats-and-12-V-Systems-GS-Star-100W/204211365



I had figured that I'd only be able to fit six on the roof, but these have different dimensions than the others I've seen. With 10, I can even leave gaps in between panels for better air flow. I'm also panning to have them on a rack of some sort so they're not sitting directly on the roof, but an inch or two maybe higher. That way I can be sure the weight is on the frame of the trailer. Gotta remember I live in the PNW, so I'll be lucky some days to get 100W out of a 1,000W setup, LOL. Still, you can do a lot with 100W if you're careful.

One advantage I think I'll have as far as weight goes, is that I don't plan to reinstall the plywood walls. I'm thinking I'll go with something lighter, like paneling or something. I also plan to build the shelves and cabinets myself, and hopefully I can build some descent light weight ones. I've never made my own drawers before though. So that will be interesting to learn. The wall cabinet in front will have to be sturdy enough to hold water and the microwave, plus whatever ends up in that third space. And the counter top and folding table I'd like sturdy too. but everything else should be fine being made out of lighter materials. There's also the fridge and air conditioner to support too I suppose.

Just occurred to me that I don't know if the Generator I'm looking at is pure sine wave or not. The description says: "Designed to mirror a pure sine wave, this generator limits total harmonic distortion to under 0.3 percent at no load and under 1.2 percent at full load, making it safe to run laptops, cellphones, monitors, tablets and other sensitive electronics." I don't really know what that means. Here's the generator: https://www.amazon.com/dp/B07XZX5FTR/?coliid=I1E337G1N1Q94X&colid=1E6B1UUZBLNWO&ref_=lv_ov_lig_dp_it&th=1 I'd think if it were pure sine, they'd plaster that all over the ad. Maybe it's a step up from the cheep modified square wave? Anyway, it's highly recommended.

Well, I'm hoping not to need a generator. I'm thinking if it's not sunny enough to charge the battery from solar, maybe it also won't be hot enough to need the air conditioner. In which case, the battery would last a lot longer.

I do love me some spreadsheets! To get an idea of the size of the battery I'd need, I counted up what I think I might use in a day. Keeping the theme that stuff in yellow are things I haven't bought yet, so I only know the power needs from the ads. I've already had the CPAP on it's own battery and Watt meter, so I'm pretty familiar with its power needs. So it gets to be green.

I factored in time as well as power since not everything will be going full on all the time. How long each device is used makes a big difference, and is hard to guess since it would vary from person to person. Also, it's hard to tell how often the fridge and air con will cycle on and off during use. I did my best based on the KWh/year ratings.

I've also been a battery nerd for a few years. I made myself a standardized table for designing batteries based on power requirements and cell characteristics. This one is for the trailer battery:



First block is the power requirements of the thing I'm using. In this case, I know the Wh I want from the table above. And I know the time and voltage I want. The rest is worked out by math.

Since I'm buying a specific make and model of LiFePO4, I can get the specs for it and add that into the second block. Though I'm a little confused on this one as they have both a maximum depth of discharge, and a recommended discharge of 80%. I don't know if they mean the same thing, or separate things. So to be on the safe side, I've assumed both. Anyway, with that information for each cell, I can put the info from the first two blocks and make the third block which is the battery's size and configuration. I was hoping to get away with only buying 8 cells, but it looks like I'll be wanting 16 if I want to run the air conditioner.

The last block is what the battery will actually be able to do based on cell characteristics and usage. So I can see that even if the fridge and air conditioner draw their peak amps at the same time, and everything else is on too, I'd still be at less than half the battery's maximum current ability. Also, I'll get my 24 hours, and if I leave the air con off, I'll get closer to 55 hours. And that's without any help from solar, which in 55 hours, there must be some coming in, right?

Not the most complicated battery I will have built (that one goes to the ebike project) but definitely the largest in terms of power storage.