trailer questions

[Lawnmowerboy]

hi all, i hve recently been given a 6x4 trailer by a freind in return for some work to his fergie tractor over its pretty rusty but quite solid i am using the original axles but have done the wheel bearings and tyres as there mini wheels
the hitch coupling is a good ol' Bradley cast one but i intend on completely rebuilding it using the old body as a pattern
first i intend on making an a frametype thing made from 2mm 40x40mm box to carry the hitch running all the way under the trailer then again using the same metal toconstruct a 6x4 rectangle with a few crossmembers then weldthe a frame to the bottom of that then fabricate the sides 1ft high all from the same guage material then plywood the base in 12 mm and the sided in like 8mm

any thoughts
will

 

[Lawnmowerboy]

COME ON anyone ?

 

[madkayaker]

what are you wanting to know? as we have no idea what your wanting to put in the trailer or what your wanting to tow with then the possibility of comment is nill

 

[KemppiFrog]

All right then..
One of the loads that get forgotten in trailer design by DIY types is the pitching forces. So your centre spine should be deeper than it's wide. And there is also the side flex from bumps that puts a sideways load at the point that the spine leaves the rectangular box frame. Indispension type units are very stiff and accentuate these loads. So if you use a single tube for the spine, some smaller diagonal braces will spread the load. It is a pretty small trailer, but worth bearing in mind while you are setting it out.

I just built one, so here is the general plan.

Bought the rear axle and springs off a SEAT Marbella. €80 at the local dismantlers including as new tyres. This is one of the few cars that has a simple tube axle and semi eliptic springs. Cut the axle and add some tube to get the width needed (box is 1.3mt x 2.1mt)
Maine frame is out of 30x60x2 box with a couple of cross members in 30x30.
The spring shackles are attached by tubes welded through the frame to allow for the rubber bushes that reduce 'towing clatter'.
The rest of the box frame is 30x30 with the corner posts open topped so I can drop in an H-frame for carrying long stuff that extends over the car.
Two more bits of 30x60 form an A frame from the middle x-member to the hitch, welded under the frame. They join to a short bit of 30x60 that the hitch is bolted to.
Plywood floor and sides.
This is a very strong construction as I use it to collect firewood. A cu.mt of oak weighs around 6/700kg, which is way over the springs capacity. There is a guy near Cambridge who is the agent for Aeon rubber springs, so between the axle and x-member are two off his list that I chose to up rate it. £55 the pair. (They look like two do-nuts stacked up)
There is actually a 500kg gross limit on non-certified trailers here, so the plate says Max Load 500kg.
One plus of the system: The axle has the hand brake bits as well as hydraulic, so if I want it braked, most of the stuff is there.
KF

Nuff info?

 

[Lawnmowerboy]

great thanks, it will be mostly for firewood and carrying round my walk behind tractors and rotavatos and motorbikes

 

[KemppiFrog]

Ah,
Forgot to mention, the width was chosen to carry the ride on mower that I share with a friend. So close to home for you......
KF

Edit:Couple more thoughts, A 50x50x2 should do for your (single) spine. Much stiffer than 40.
For your use, a tipper? Hinge the spine/a-frame at the middle x-member and locate it with cheek plates and pins at the front of the frame. Means you can keep it secured to the car while loading or unloading.