Start Date: Fall 2003
Duration: apprx. 2 months
I needed a trailer to
haul around a snowmobile so I decided that I might get better use out of
a general utility trailer instead of a snowmobile trailer. I
checked the local trailer retailers and found that the going rate for a
5' x 10' utility trailer was around $1,300 Cdn. The trailers
weren't very strong and were made mostly from light angle iron.
Always looking for a good project, I decided to build one instead.
The objective was to build a better trailer for about the same
cost. I also wanted to build in a tilting feature to make
loading easier. Using rectangular tube instead of angle for
the main frame would make a stronger trailer, but would add steel
cost which would hopefully be offset by free labor.
I bought some inexpensive plans from ebay to
get some guidance. They didn't offer much value at all.
They included a drawing of a frame but stated that there were too
many axle types to include those in the plans. I was hoping
that they would answer questions I had about axles and tongue weight
but they really only showed how to build a frame.
I ended up drawing my own plans in AutoCAD
that you are free to
download for reference if you like. They are not totally
complete, but I used them to get a weight estimate, a steel
materials list and details on some pivot pieces.
Steel Shopping List
Trailer Budget Plan
The axle kit shown below was
purchased locally from Intruder Trailers
. Key decisions for choosing an axle kit are weight
capacity(3,500 lbs here), type of suspension (leaf spring, torsion
bar, etc.), width of frame, and height of the hitch. This kit
was pretty much the stock 5-foot wide trailer kit, although custom
widths can be ordered.
The steel was ordered from a local supplier.
I found that it is well worth it to comparison shop when purchasing
steel. The most expensive retailer was over 2x the cost of the
The first step was to cut up the main
frame pieces and weld it up. Make sure that the axle will fit to
the plans before cutting and welding. I used an abrasive cut
off saw and a stick welder for most of the cutting and all of the
It is important to make sure things are
square and flat at this stage of the game. 3-4-5 triangles
will ensure that things are square, and for flatness, I tied
two strings diagonally from corner to corner (like an X). I
made sure that the strings were just touching each other at the
intersection of the X to check for flatness.
Positioning the axle depends on a few
factors. Since I was building a tilting trailer, the axle
typically goes pretty close to the center of gravity to allow for
easy tilting. Most trailers that don't tilt seem to have the
wheels positioned slightly more towards the rear. The main
thing is that you end up with some tongue weight when everything is
done. I figure that you probably want about 5% of the gross
weight of the trailer as tongue weight. My axle is only about
6" behind the center of the frame. I was thinking that if I
needed to add more tongue weight, I could add a toolbox to the front
of the trailer, but it turned out not to be necessary. I ended
up with about 30lbs at the tongue when it is unloaded and it tows
The other critical item at this point is to
make sure that the axle ends up square and centered on the
centerline of the frame (centered with the hitch). The
distance from the hitch to each wheel has to be the same to ensure
straight tracking. As long as the tongue is square and
centered to the frame, then the axle can be square and centered on
In the photo below, the frame is upside down.
I'm mounting the tongue to a crossbar that is just ahead of the
axle. The tongue is a square tube which has a 1" solid round
bar through it at the end. Gussets reinforce the round bar.
The round bar is sandwiched between two 1/2' mounting tabs with 1"
holes. This arrangement provides the pivot action for trailer.
Since this crossbar is taking all the pulling and braking force, I
used a 2" x 3" rectangular tube instead of lighter material which
was used on the other crossbars.
latch shown below is widely available at trailer part
suppliers. I prevents the trailer from tilting when it's not
supposed to. Just weld it in place, and weld something on for
it to latch to.
The fenders were a bit difficult to weld with
a stick welder without blowing holes. I used smaller rods and
low heat. I found when welding the sheet metal to heavier
metal that if I struck the arc on the heavy metal first, then worked
the molten pool onto the sheet for a short period of time, I could
get a strong weld without blowing a big hole. Later on, the
fenders are reinforced by some angle iron that also serves as
mounting points for the lights and license.
|The side rails are just angle iron. I attached the
top of the fenders to the sides to strengthen everything up. At the
back of the trailer, the vertical side pieces were made from
two angle iron pieces welded together to make a C-channel.
This allows me to drop a board across the back of the trailer if
I need a 'tail gate' for any loads.
The whole trailer got the wire cup treatment
to remove any surface rust or weld spatter, and then was primed and
|Remember to make provision for a good ground connection
through the pivot to prevent dimming tail lights.
Here the trailer has its wood decking
installed and final paint. There are many more pictures
showing the step by step progression in the photo album linked