Topic: build a trailer

[dave500]

anyone here built a trailer?id like say a 7x4 box with front and rear hatch,not real deep,using shackle leafs not those stupid rattley squeaking slider springs,how does a basic frame sound made from two 50x50x2.5 side rails with five 50x25x2.5 cross pieces,using an apex sort of draw bar starting at the front spring hanger and 75x50x3,that should all be pretty sturdy?some of the new trailers ive seen for sale look like real crap!pissy 35mm rhs or shs tube and only welded on two sides on the cross pieces,some only had three cross pieces of angle iron,if I can get my welding up to par I could make a better one at home,ive priced the frame steel cut to length at 150 bucks,i already have wheels and axle,guards can be bought for 40 bucks and springs etc.

[Retro Rocket]

Go hard Dave, there's really not much too them... Sounds like you have most of the expensive bits...

[dave500]

I made a space station this arvo!just gotta build a rocket now to launch it,its not rocket science!

im hoping im getting good penetration?ill ask my wife?

[mick7504]

Are you putting brakes on it Dave?
Mechanical O/Ride is the go if you decide to.

[70CB750]

Yes, i did build a trailer. 10 years ago, still holds. The reason was same as yours, store bought trailers are flimsy.

I used rectangular tubing, sizes I would have to check.



It is really tall to match my jeep and it can follow the jeep anywhere - helps with logging in woods and such. The wheels are the same size as my jeep to have only one spare and it is really sturdy. I can pull on it 5000 pounds of sand - done it quite few times.

The main frame is rectangular tubing 3x2" all around, square tubing is overkill for that, you want rectangular positioned on the short side. Cross bars are 1.5" square to accomodate 1.5" boards for the floor. The railing is 2x2" on top, 1.5x1.5" verticals - the half inch difference is for the side plywood. "A" frame tongue and gussets in corners. Front and back gate are on 1/2" hinges and can be removed for long logs or material.

[dave500]

no brakes mick itll be 750 kilo max,that looks beefy 70cb750 and the dogs look proud to ride in it!id like to have a "rescue racer café trailer"for incase of breakdowns or such aswell,easy to rig up a channel section for bikes and a decent ramp.

[Don R]

 I built a Jr. Dragster trailer once, I used a rubber torsion axle. It was easy to install and worked great. With brakes so it would tow behind my 40 chevy street rod easier. The tounge part pivoted near the axle and used a trailer jack to run it up and down with a spring loaded pin to lock it. It could tilt and not unhook from the tow car, so no ramps needed. It's fun gettting it the way you want it. Use your imagination.

[70CB750]

Thanks, Dave. This is how the whole redneck rig stands now. Bike transport - I would keep it lower, doing SUA (spring under the axle) not SOA. The torsion block axles would help lower it too.

[dave500]

yeah I want spring under axle for less height,my old dirt bike trailer had station wagon leaf springs and air shocks it towed so nicely as fast as you wanted,i sold it a long time ago,it was just a crappy angle iron frame really a mate got given for free no axle etc,we dodgied it up and slapped some paint over it,went fine for years and years.

[Retro Rocket]

Those welds are looking good Dave, cut across a couple and see how well its penetrated, they are nice and tidy ...

[dave500]

we got a big hitachi drop saw at work I might do that mick,no good looking good if its only surface beauty?i chalked out the frame to see how itll be,a bike fits in it easy,its a tad under 4 ft wide working with the axle I have and the 14x7 mags,i just had new 235s put on my car and had the best pair of the old 225s put on those mags and the ancient recaps pulled off,im allowing an inch clearance between the frame and tyre.


those old mags cleaned up ok with some charcoal hammer tone paint and a little polish.

[Don R]

 On my dragster trailer with the torsion axle I drilled multiple holes in the frame so the axle and fenders could slide foreward or backward to adjust the tounge weight. I could either haul my front engine dragster or two jr dragsters and a three wheeler tow bike.  The taillight wires were SO cord, like extension cords with lots of insulation on them run inside the frame and the round taillights were armored in 4" pipe sleeves.  I did need to add clearance lights on the sides, a guy came out of his driveway and almost backed into it one night as we passed.

[dave500]

thanks don,i want it heavy dutyish and indestructible as far as obvious things like the lights being protected,once again the commercialy built trailers ive seen for sale aint that heavy duty,the tail lights are just asking to be smashed accidently too easily?even that old bike trailer I had I moved the tail lights to a position within those two rear rails,you couldn't smash them if you tried.

[mick7504]

That's a good point about making the tail lights bullet proof.
Mudguards are another one that mysteriously get reconfigured when the trailer gets lent to your mates to do a tip run.

The standard reply is "Orrr fcuk, it must have been like that when I borrowed it"

Wrong thread I know, but it pisses me off. 

[dave500]

yeah don't lend out chainsaws/trailers or power tools!

[trueblue]

Dave, I've made a few trailers over the years, every one has had this basic design.  If it is a 6x4 I only put in 4 cross pieces instead of 5 for a 7 or 8x5.  I find the piece of box running from the apex of the drawbar back to the centre of trailer unnecessary and only adds excess weight, which you want to keep down on the 750kg trailer.  My current trailer is made of 1 3/4x 3/4 or something like that, you don't need overly wide box steel if you use a steel floor.  You weld the floor to the frame and the sheeting becomes part of the strength.  My drawbar is 3x2, and plenty strong enough and relatively light.  If you want somewhere to put your spare, weld a brace crossways on your drawbar and attach it there.  If you need trailer parts these fellas used to be bloody sharp on their prices and right on your doorstep.

 http://www.activefabrications.com.au/

 

[70CB750]

Dave I doubt you wouldn't know that, but nobody mentinoned it yet. You want the center of mass in front of the axle even on empty trailer.

[dave500]

thanks Andrew and prokop, ive saved that link ill check them out later,i was going to mount the axle slightly behind the centre line of the square frame and no centre bar through the drawbar.

[Retro Rocket]

Dave, my old Telecom trailer had a 1 inch wide flat plate surround welded to the trailer on each side, the tail lights mounted inside, something had to literally go inside the frame to break the lights, guide posts and fences had no chance....

[Retro Rocket]

If it's a concern at all to you, Dave, the farther back you can install the axle the better. It increases the wheelbase and slows the jack-knife of the trailer when backing up. Trailer is already somewhat short, and will want to kink very quickly. Not carrying much weight, so axles rearward is not a genuine load concern.

Thought I'd point that out if you hadn't considered it. I've pulled lots of single, dual and triple axle trailers around. Singles are always the worst for controlling going backwards.

The other option to a good backing trailer Cal is to have a longer draw bar at the front of the trailer, it has the same effect of making it easier to back up without adding extra weight to the front, trailers with the wheels at the back are usually heavy to lift up when coupling to the vehicle, especially if loaded uncoupled, longer draw bar {front rails that mount to the vehicle} don't add anywhere near as much weight to either the front of the trailer or the rear of the tow vehicle......

[dave500]

I checked that site Andrew and I think ill go there for the stuff I need,ive decided to get a longer axle the one I have will be too narrow giving a usable load area of only 1190 wide,i think 4.5 foot wide would be better,probably wont make a start on it until weve sold here and moved,although a trailer would be handy for the move?

[trueblue]

Don't mount the axle or guards until the very end.  Sit the completed box and drawbar on the axle, move the axle forward and aft until you are happy with the down weight on the tongue, I like about 20-40kg down with an empty trailer, depending on the size.  Mark where you want the axel once you are happy, turn it all upside down and attach the springs.  Then turn it right side up and attach the guards.  Remember make sure your frame is square and your axel is square to the frame and the drawbar is also square and centred.  I never use a square to do so, I've always found the best way to do so is measure the diagonals.  If they measure the same from side to side it is square. 

[dave500]

thanks Andrew,i was going to mount the axle rear of the frame centre line by about 75-100mm,ill do your balancing act first though to see how it feels that way,i have a big rafter square ill use to tack up but had intentions of diagonaly measuring for final welds,thanks mate,that link is great,i rang them for a question and they are helpful there aswell,the parts I need to buy from them comes to around 110 bucks,the frame and draw bar steel about 150 bucks,working out pretty cheap so far when a 6x4 new from somewhere is a bloody $1000 and looks light duty.

[trueblue]

No worries mate, I have used Active Fabrications many times, their prices and quality are great and never had a complaint about their service.  When you think about it $1000 for a trailer isn't bad, considering it takes about 8 hours to build a basic one and up to 16hrs to build a decent heavy one.  Multiply that by approximately $100 an hour for workshop charge out rate and it really isn't a bad price.  I wouldn't pay it though. 

[dave500]

I know what you mean about the time etc but not for the flimsy rolling tin box with 13" wheels you get now.