[Frank Woolf]

Since I built this trailer it has become obvious that many people around here have never seen a trailer on a car. So I thought it may be of some value to people if I put some info here.

Some may want to make one and when making anything its always a good idea to see what others did and what mistakes they made so I will post a brief review of the design and building process for those who are interested.

I wanted a trailer that can carry very heavy loads of dirty or rough materials like compost, rocks, etc and be towed over extremely rough roads so it had to be built strong.

For the main frame I used 2" x 1/4" thick steel angle with 2" square tube on the sides. The 2" square tube is not as thick as I wanted but being four sided and supported by the 1" square steel tube side frames it is probably as strong or stronger than the 2" x 1/4" thick steel angle.

In the first two pictures the basic components of the man frame are cut and laid out on the floor. The 2" square steel tube is cut on three sides and bent to get a smooth non welded outside corner.

In the second two pictures I have welded the main frame together with brackets for the suspension made from 2" x 1/4" steel angle. Don't look too close at the welds. My welding is not pretty. I blame my poor eyesight and unsteady hands

[Frank Woolf]

With the main frame complete I made the side and front frames using 1" square steel tube. Originally I planned for the sides to be 18" high but when cutting the 1" tube I realized this was too much so I reduced it to 13" high.

I wanted the front rail to extend up so very long loads could be supported and held higher than the roof of the car.

I made an error in the design here. I made the front high frame as part of the sides. In other words the high corner tubes for the front were also the corner tubes for the sides. This made the center tube align with the corners so the wood at the front needed extra steel tube each side of the center tube to be bolted on and the wood at the front is in two pieces. It would have been better to make the 13" high tube all around then add the high font tubes.

These pictures show the 1" square steel tube sides and front with the red lead undercoat and the black finishing coat.

[Frank Woolf]

The axle, wheels and springs could now be fitted. Fortunately my calculations for the trailer height turned out to be right. With no load in the car or on the trailer the trailer is level.

This is probably a good time to point out that the width of the trailer body depended on the space between the wheels and I wanted the wheels to be the same spacing as the car wheels. Its bad enough on really bad unpaved roads to get the car left and right wheels to avoid the worst lumps and holes. Trying to allow for trailer wheels that on a different track would make it worse.

When I went to buy the axle, wheels and springs they kept insisting that they are a standard width but I insisted that the wheels should align with the car wheels and that's what I got after a couple of days.

I should also point out that the axle should not be in the center of a trailer as this causes a trailer to weave when being towed and can be dangerous. It is also more difficult to reverse. I put the wheels far enough back so that if evenly loaded there would be 15% to 20% more weight at the front than the back.

[Frank Woolf]

Next comes the wood paneling. This trailer is for carrying all the 'orrible stuff I would not want in the car and has to withstand rocks and rubble being dropped into it so I figured there was no point in using expensive wood.

I went to a lumber yard and asked for 8 foot lengths of 3/4" to 1" thick coco lumber. It was cheap at 45 pesos per piece but the quality was awful. It varied from 1/2" to 3/4" (the same board). Some was hard but some was so soft I could push my fingernail into it. I had some other lumber at home so by using some of each I got enough that is "good enough for now". I will replace it with better wood when it gets worn out or damaged. You will notice that some boards have extra bolts. This is because after fitting they warped so much I had to add extra bolts to pull them flat.

[Frank Woolf]

Getting near finished now as I move on to making the tailgate.

I used the same 1" square tube for the frame with four heavy duty hinges and two very large tailgate clamps.

I admit I got a bit lazy here and just welded the hinges and clamps onto the tailgate when I would really prefer them bolted on but my guess is that they will last for a good many years so if they ever need replacing a grinder can be used to grind off the welds to remove them.

The tailgate is done so there is just the jockey wheel to make and add some hooks for tie down ropes along the bottom corners. Yes, in my design I forgot all about needing something for ropes and elastic straps to hook onto.

In the second picture you can clearly see the extra 1" square tube I needed to add for the front wood boards to bolt to.

[Frank Woolf]

On the first trip with the trailer to the beach house I took about 2,000 pounds of cargo. This included 8 bags of cement, 500 ceramic wall tiles, bags of tile adhesive, doors and door jambs, bottled water, canned goods for the workers, etc. I thought the springs I got were too heavy but when I first loaded the trailer the springs went past straight to bent the other way so I moved some of the load into the car. Now the car and the trailer were both at maximum loading.

This was going to be a test of the car getting up hill and brakes going down some very steep hills. If the trailer survives unharmed then I know it is as strong as I intended it to be.

Going uphill was slow as expected but the old lady did good getting up the worse hills without going down to the lowest gear.

Going downhill I was more concerned as on long downhill stretches the brakes do overheat and fade if I don't drop down the gears to use engine breaking. I overcome this by using different combinations of overdrive on or off, and different gears (D, and 2) so I don't need to use the brakes too much.

On the very steep down hill stretches with this very heavy load I stopped and shifted into L (Low) to get maximum engine braking and it was fine. Only once I felt the rear wheel slip and spin for a couple of seconds going up steep unpaved roads so I never needed to use 4WD.

I was also watching to see if the trailer was bouncing because I have not yet fitted any shock absorbers. It was fine but I suspect it will bounce a bit when empty.

We arrived at the beach house after an uneventful trip. I inspected the trailer and could see no sign of and stress or damage so I guess it is as good as I intended.

This picture was taken when it was about half unloaded. I haven't got a picture yet of the jockey wheel or tie hooks and I left the trailer at the beach for moving some limestone later in the week so I will get pictures later.

[Frank Woolf]

The trailer has moved tons of rocks, around 80 sacks of coconut coir, loads of plants, building materials, etc since I made it so it is certainly paying for itself.

At new year we took about 25 members of the extended family to the beach lot for an overnight stay. On the way back some of them wanted to ride on the trailer so I ended up with ten people in the car and eight on the trailer. They said the ride was great even on rough roads but it needs seats and something to stop the wheels throwing mud at them.

So since the last pictures I have added the jockey wheel, seats on both sides over the wheels, extra springs and shock absorbers.

In the first picture the shock absorbers and extra springs are just visible.

In the second picture you can seen the seats also increase the cargo capacity.

[davaodan]

Hi Frank,

That is one fine trailer! I have a 4 door p/u with a 4 foot bed with canopy and that certainly limits my load but your trailer offers much more flexibility and room.

Is it licensed by the LTO? If so, what were the hoops you had to jump through to get it licensed? Is there any extra charge at the Samal ferry?

Later,

Dan

[Frank Woolf]

The box part of the trailer is almost 7 feet by 4 feet. The seats create a lot of extra flat bed space.

I did a lot of checking on laws concerning trailers before I built it. I expected things like a full set of working lights, an "On Tow" sign with registration number, etc. All I could find for private use trailers was that if you use it at night it should have red lights on the rear end.

On the ferry they charge the same as a second car so it costs 540 each way with the trailer. For this reason I try to make every trip to Samal with the trailer really worthwhile.

For the large commercial trailers such as those used for containers you need a different license.

[kleinbaas]

Interesting, I’ve bookmarked this page for future reference.

Anyone thinking of building trailers might also find this website useful: http://www.larringtontrailers.com - they build various trailers from scratch, making all the parts themselves. If you're going to build a trailer yourself there are going to be part you just can’t feasibly build yourself.

Hope this is useful.