Paint?  Powder Coat the thing. 

While you are welding i would just weld some tubing to the underside to run the wire through unless you really need plastic to save weight. White is nice when new on a trailer but trailers rust quickly especially if left outside and leave stains on the paint which is why i have aluminium and galvanized ones. The standard boring black is good and touches up easily with a nice custom stripe to accent it or red holds up well apart from fading if in a hot climate. Try to make the ramps slide in under the trailer , your back will thank you later especially if they are steel.

Cooper tune. I will be "trying" to keep the trailer under 500lbs. We will see. So far i have used approx. 56 ft. of steel. at about 3 lbs per foot, I am around 168 lbs. I feel im right on track to do so. I will be weighing my mini properly tomorrow as well as getting the CG so that I can more accurately place the axel for optimal mini towing! haha. 

Mur, Great write up! These are some things I have thought of. CO is 3000lb limit before needing brakes. I wont always be towing with the BINI (probably not that often anyway) thus im not completely concerned with getting brakes on the axel. The axel I am purchasing just so happens to be a Dexter axel. Good to know they come recommended. 

As for wiring my plans where to make it as clean as possible. I will be using plastic housing/shroud to run the wires. I will also be running the majority of them through the A frame, that is why the ends are not sealed up for now. Obviously I wont be welding them shut, but probably using a plastic end cap and some silicone sealer. I just want to limit wire exposure as much as possible to the underside of the trailer to keep murphy at bay even if they are protected. 

I will definately look into the brakes and break away system because i would like to keep this thing for a long time. thanks for all the help and suggestions. Keep em comin'!

Also.... paint.... I was thinking white. I dont know why. Could be fun. Thoughts?!

If you are towing with a MINI, and the trailer is going to weigh close to 2000 lbs with a mini on it, you had better have electric brakes on the axle you buy, along with a critical mass momentum modulator; or brake control, in the MINI.  Also, you might as well fit a breakaway switch and a battery.

While some provinces/states demand brakes at 2000 lbs and others at 3000, they usually demand the trailer have brakes when the trailer's GVW is more than a specific percentage of the tow vehicle's GVW.  However, what really matters is your own quality of life, and excellent trailer brakes working in concert with the tow vehicle are worth every penny they cost.

Now is the time to consider the wiring harness for the trailer's lights:  You will need marker lights at each corner, three across the back and the Left and Right Signal/Brake and Park units.  Towing with a MINI you may choose to have amber turn signals and Red brake lights on the trailer, which is cool but then is an issue for towing it with other vehicles.

You want to protect where the wires run to the back.  Plastic wire loom covering is an eyesore under the hood of a mini, but it is necessary under a trailer.  Still, giving your wire a dedicated channel to run in is best, however a simple 1/2"flat of steel may be all that is needed.  Get yourself a tie-wrap tool that pulls the tie-wraps tight and cuts them off to give your work that professional look.  Consider fitting a junction box on the tongue to seperate the plug that goes to the car from the trailer wiring harness.  If you want to look really cool, place a plug on the trailer so that you can run a small harness to the car to run the park lights in the mini while it is hooked to the trailer.  On the tongue, make excellent places to fit a jack and to mount the safety chains.

The most common issue with trailer lighting is bad grounds, but with modern LED lamps, which use very little power, these issues are less common.  Truck style lamps mount in rubber grommets and you can build the entire harness with every lamp getting its ground via the wiring harness.  I prefer to do things that way, but then connect the harness ground back to the trailer frame a couple of times.  Redundancy is good.

Some awesome links:

//www.grote.com/cgi-bin/goc/goc.cgi?product_number=82-1000

Find the local Truck/heavy Duty parts place and Grote or Truck-Lite should be all you need.  It is much better than the stuff at the local auto parts store or Harbour Freight, and about the same money.

//dexteraxle.com/inc/sdetail/169/1127

The brekaway kit is less expensive elsewhere.

For your needs, I'd suggest a genuine Dexter Torflex axle, with electric brakes, not a knock-off.

Also, you may already have ideas for fastening the car to the trailer, however, once you get to the Truck/Heavy Duty suppliers you will see an array of load control solutions.  They will also likely know where you could get custom Wheel bonnets made, if you want to go that route.

I hope this helps.  Some disclosure:  My own fleet includes 4 trailers, two tow machines and my work these days has me responsible for a fleet of trailer mounted equipment and tow vehicles.  My own car trailer is a 17'6" Featherlite 3110 and I doubt it will ever depreciate, in fact I could sell it for more than I paid for it. 

Don't want to rain on your parade but I'm thinking you won't make a 2000 lb limit. Do you happen to know what your mini weighs? Do you have a lb per ft. chart for your material? I may be working on my storage shop tomorrow if so I'll pull my trailer out and put it on the scales. It would be hard to get one lighter. Steve (CTR)

Just make the fenders removeable for access with the Moke type rubber bonnet latches. You can buy the stake pocket pieces to use wood sides (removeable) for it if you want to use it for other hauling chores whic also act as good tie down points. With a 2000lb limit you do not want any more than 200lb tongue weight, there is a formula somewhere on placing the axle so it tracks correctly i think it is total length the axle should be centered 2/3 from the hitch point and 1/3 to the rear. What you have to remember is a Mini's weight is mostly up front so that creates a lot of tongue weight and as you are towing with a Bini not a truck or suv it needs to be taken into consideration.

Rails will stationary if weight allows for it. But removeable is a good option. 

I live in CO, DMV says "If your skilled and can build your own, bring a parts list." and registration is easy. 

Bini tow rate is 2000lbs. So is hitch from Mini do more. Should work out if i can keep weight down on the trailer of my dreams. Either way, I can just buy another FJ Cruiser!! haha. 

Ill check into the side mirrors. 

Plans are to tow trailer and weigh it before loading mini to get total weight. Getting excited to get this axel and move on. 

I will keep weight down by using expanded steel surface and just reinforce where the tires sit. And at the same time use the re inforcement for the tie down points for the tires. 

No worries I like the outside input because things I havent thought of will be brought up undoubtedly, resulting in a better overall product in the end. 

For the rails, make them removable like a stake truck or make a section where the drivers door would be like a swinging gate. Will make getting in and out easier.  Install floor tie down areas around where the tires would be. Make sure your ramps are setup to keep from dragging yor exhaust. Will you have room to store the ramps on the trailer or do you plan to have them slide in and out?

I second the idea of extending the tongue for ease of backing up. Weld on some tow chain attachments.

Points to ponder:

Not sure where you are located, but have you  checked with the local authorities/DMV as to whether you can register the trailer?

Not sure what your Bini's towing rate is, but that may be an issue. Tow limits are usually based on stopping power.

What is the tow rate of the receiver installed on the Bini? Another issue to regard.

Expect to add extended side mirrors too. The rear view will be useless.

Not trying to discourage, just things that need to be considered.

Sounds like you are doing your homework and really are putting some good thinking into your build. It looks good so far. Look forward to following the rest of it.

It will be a trailer to haul my mini (one of the two) with my wifes BINI! (countryman all4. ) 

Single axel w/ 3.5k capacity. (because why not)

They reach to the crossmembers and not the side rails because the steel was pre cut by my buddy who works at an industrial truck fabrication place. The idea was to make them reach/ be an equalateral triangle, but the hitch receiver was not a wide enough angle. Yes its off of a reese towbar, and I asked they guys at the trailer place whom i ordered my axel from. They checked it out and showed me how to weld it saying to use the angle i did. That its just as good as one they sell for 5k. 

I though about using torsion bar axels two of them but all in all it would weigh more and not improve anything really. Due to weight of tires and wheel covers. 

Its already going to be a bit beefed up because of the steel size and the shape. So I feel we will be good hauling a mini. 

Thanks guys ill keep you posted as things progress. Especially when the axel is attached. 

Also I hope to do a write up for MM upon completion. Ill need lots of input to make a good write up so have at it. So if wanted people can have a good blue print. 

Another thing I found the center and pulled a string after tacking to find the center and make sure the hitch was centered before welding. Also took the width then subtracted width of a frame where they met the crossmembers. Subtracted the a frame width got left over. Divided by 2 and measured from the Left and Right side to make sure it matched that number. Worked perfect. 

Cheers. 

Josh

One thing to take note of is the restrictions your tow vehicle's manufacturer will make. For instance, my Subaru is rated to tow 2400 pounds but anything over 1000 pounds must have brakes.
If you choose to ignore that restriction and are involved in an accident, I would shudder to think of what a sharp lawyer could do with that information......
 

Brian James trailers seem to be the mutts nutts in the UK. I used one once to tow a Mini to the docks very nice well made and piece of work with a low height to boot.

I would make your A frame longer you will appreciate it when backing up.

Steve,

I don't believe there are laws stating anything over a single axle must be braked. There are something like 30 states that say anything sold in those states must have brakes is the CVW is over 3000 lbs - which almost every single twin axle is of course. That is why you find a lot of trailers with 3500lb axles, and weighing 1000 lbs, are rated to just 1900lbs.

There is a lot to be said for the lightweight twin axles used on a lot of smaller trailers in Europe, but I also like a single axle for the manouverability too. My mini sits on a single-axle tilter when it goes long distances, but I'd swap it for BrianJames minno any day of the week!

Alex, I don't know what the rules are over there. Looking at pictures from racing books there are some very interesting trailers showing up at the tracks. Our rules (DOT) require two axle trailers to have brakes. That alone adds weight and cost to a trailer. Having used the same trailer for 40 years I have been to Denver, Dallas, Ohio some many times I can't count, New York and southern Fla. I have been to most places many times. I suffered one blow out in all those years and only carry a spare when going racing. No time to jack the trailer remove wheel and run to near by tire shop for a replacement then. The blow out was what appeared to be a low mileage used tire. I'm thinking it had road hazard damage or defect, I won't try that again.  

While building my trailer we had our axle assembly and the tow car there. We put the hitch assembly on the tow car, located the axle then placed the runners on the axle. One look and we knew the load would ride to high. We cut the axle and had 6 inch drop plates cut from 1 inch steel plate. Once welded back together we tried again. At that point we tacked the trailer together all but the axle and placed my mini on the runners. With a bath scale under the hitch we moved the axle till we had a tongue weight we were happy with. We squared the axle and tacked it in place. While we had the axle apart to install the drops we set toe and camber before welding it all back together. That alignment is very important to how your trailer will handle and tow. Give some thought to your design trailers are great shin busters. Good luck Steve (CTR) 

It looks like you are using the ball coupling area from a flat tow kit. Are you sure it will be strong enough to support the tongue weight. It was not designed with this in mind when using for a flat tow setup.

Why did the A-frame stop at the crossmember instead of extending it to the longitudinals? I would have done that personally, but it'll probably be just fine.

Single or double axle ?

I will never use a single axle car trailer again as the car on the back is usually worth more than the extra set of tyres.

Drive it.

Is this a trailer to pull with a mini or to haul a mini on. I built a trailer to carry my mini in 1973 took us three days after work and $175. in materials. I'm still using it today and it works as well now as it did then. If you are still hauling minis on yours in 40 years you will have built a good one. Steve (CTR)