welding

[HobbyMan]

Some searching on the internet yielded this

How expensive would this be to build?

[DiverRay]

The diamond plate floor will cost about $300, as a guess. Northern Tool and supply has most of the parts you will need for a trailer, and plans for sale as well. For two bikes of the XS size, I would go with the 2500Lb springs.
My dad and I used 3" channel steel to build utility trailers. That was the outer frame rails, from the tongue too the back, and then a slightly smaller cross section for the cross rails. I would put on at least 4 cross rails, one front and back, and one at each mount point for the springs.
Just my $0.02

[HobbyMan]

Thats the frame design that I was thinking. I found some strong box beam that is light enough to work with. If the diamond plate is that expensive, I might scrap that idea. My welding teacher's son has a metal shop and he gives students good prices on metal. I should know what it will cost in the next few days. Now that I know what I am going to do(for the most part), I am going to start collecting materials. This means that I need the suburban which is in use by my sister these days. The hardest part about gathering materials is where to hide them in the shop so that other people won't cut them to bits for fun. I am probably going to mig weld it since the welder is available.

[DiverRay]

Do have the bike rails BOLTED to the frame. That way, you can have just one or two, and keep the weight centered just in front of the axle.

[mro]

Axle Alignment Tip

When I am ready to set the axle (s)
I have the trailer frame, tongue and hitch all in place/welded up
Turned upside down... with the springs/axle resting in place.
I tac weld a piece of steel cable right behind the hitch and pull it tight to each side of axle to make sure each side is XSactly same distance from hitch. Your trailer will track the way it should even if your frame is not square........


mro
btw
Can also mount each axle spring to a piece of angle iron. Make it about 12 inches longer than spring and center spring on it. Drill holes and bolt to frame. Can now adjust axle position by drilling new holes in frame to move axle either forward or back should the need arise w/o having to cut and re-weld. Works very well on small trailers.


mro

[HobbyMan]

I am going to have 3 rails bolted down. Actually, that is how I was going to alighn the axle. I use the same cable technique aligning wings on RC airplanes.

[HobbyMan]

Do you all think that 11ga 1.5x2in rectangular tubing would be strong enough? It looks like it would hold two bikes. It is priced just under $1 a foot. Ohh and BTW: That trailer pictured in the photo up there cost about $6000 USD WOW! It is completly custom to haul around HDs.

[DiverRay]

If you use the rectangular tube, I would use mro's idea, and weld the spring hangers to a 3 foot section of STRONG angle iron. That way, the force is spread over a greater area on the tube, and you shouldn't have any problems. That is how my boat trailer was built, from a factory.

[mro]

something you should know

When you make a trailer......
Should it come to pass that an accident should occur and the design/material/workmanship should be found at fault...
You can not only be sued but held "criminally responsible" for damages/injury or death.

I'm not trying to dissuade you from making something as simple as a bike trailer, but you have to do it right the first time.

Go see a few different trailers similar to what you want to make. Check them over critically.

I prefer to "over build". I always use slightly heaver thickness steel and just a few more reinforcements than commercial built trailers. All trailers I've made are still in service (6 from scratch, 2 redesigned/remade from boat trailers and a couple that I've remade from parts)

11GA ??? is light. I'd use something considerably heaver duty at least for the basic frame.


mro

[HobbyMan]

I do agree that I should overbuild. I have spent much time in the past few weeks and have looked at many MC trailer frame designs. The materials I am using are at least if not better than what is in the "Lowes special" as I would put it. Should I just go to maby one or two thicker gauges for safety? As far as experience and liability goes, I have done more than my fare share of towing on long haul trips. I have experienced plenty of mishaps and equipment failures. My only inexperienced part is actually building the trailer. Ever since I could drive, my dad made sure that I knew how to tow. Partly so that he didn't have to as much. I am basically taking the design of my boat trailer with a little modification and downsizing. Keep in mind that the boat and trailer weigh in at about 5 tons. It uses large rectangular tubing. I will be using basically a smaller version with no bends in the tube and a shorter toung. If my welding teacher's son can't get me a good deal on a deck plate, I will go without it. I have decided to get the axles and springs from a Redneck Trailer Supply store. I have bought a variety of things from them before and their prices are usually reasonable and they carry good quality. NTE has basically a bunch of junk that I would not trust. I talked to a guy that bought a drop down axle from them and the spindle was misaligned. All of the stuff in there is really cheap quality. Even one of the sales clerks said that most of the products they carry are not very good quality! Can you believe that? I just bought a bunch of cycle parts so my cost must be at a minumm right now. I think I could have the frame done by next Friday (hopefully) and the axles and springs on a little later. Maby the school auto shop wil paint it for free. One final question, what is the best way to jig the metal while I am welding it together? I have a level that I will use to make sure that the parts are not warped when assembling.

[mro]

My shop floor (where I did my welding) near perfectly flat/level.
The four pieces of steel used to make the basic frame, spend a little extra time to make the front and rear XSactly same (I clamp em together and cut/grind to smaller of the two)

Lay the pieces out and can measure the angle with a tape measure. Want to form an Equilateral triangle.

Example, top right corner measure 48 inches down one "side" and mark it, measure across "top" exactly same from same starting point. The distance between the two marks, adjust so it is 48 inches also. You now have "squared" that corner. Clamp in place, and can clamp a spare piece of steel across these two to hold angle while tac welding. After tac welding these four pieces together can measure diagonally front right to left rear and opposite side which should be same. BIG hammer is my favorite adjusting tool.

Front of my trailers are near perfectly square. Steel parts won’t be perfectly straight and the rear may be off but close enough. This is why I use a steel cable to set hitch instead of just measuring it.


mro
btw, trailer traveling on highway, hits pot hole, amount of the force transmitted through spring to trailer is substantial. Have had springs break, but my frames and cross members were unaffected.

[mro]

Fenders

Fenders can be a PITA.....
If you weld em to frame even with heavy duty "brackets" they will eventually fatige from vibration and crack/come loose.

Have found making a bracket welded to fender and then bolted to trailer frame to work best for me.

mro

[Dragonrider]

Re: something you should know

Originally posted by mro
When you make a trailer......
Should it come to pass that an accident should occur and the design/material/workmanship should be found at fault...
You can not only be sued but held "criminally responsible" for damages/injury or death.

This is true of getting out of the bed in the morning. It is not a concern in the rational man's world.

[mro]

rational man's world.

Would like to live there


mro