Thread: trailer design help

alright firstly thanks yonee for clarifying the rego issue here is were i have gotten so fare i will have override disk brakes the draw bar will be made from 50x75x4 the main chassis will be 50x50x3 and the cross members will be made from 50x50x1.6 the deck will be 2 meters wide and 3.5 meters long do you trailer guys think a trailer made form these materials will weigh less than 250 kgs.

Based on a Draw bar at 3mtrs over all length x 2,
4 x Cross Members,
and a Box Frame made from 50x50x3 ,you come in at around 108Kgs.
Add to that a coupling,Axle,Springs,Tyres,Lights,Brakes,Welding wire or rods,A Floor of some description to go on your base,Tie Down points,Mud Guards if they are used leaves you 142Kgs to play with.

alrigh done some calculating and found out it will be over my weight limit factoring in 20 kg for floor 60 kg for wheels and mudguards and 10kg for welding wire lights etc so what would the weight be if i made the draw bar out of 75x50x3mm and the frame out of 50x50x2 and only made it 1600mm wide also the axle kit weight 160 kgs so i think it my be impossible to keep it under my 250 kg limit

Cant you find these weights out yourself on the net.
You will save about 23.5 Kgs

This Weight Guide from Atlas Metals should help you in working out the weights of the steel, it is an Excel program

thanks for the steel weight converter and all the help also how much do you think a 40 mm square trailer axle with mechanical disk breaks override coupling and springs weigh because somewhere i was it weighed 100kgs and somewhere else for the same thing they said it weighed 160kgs

Andre

while you're doing your calculating, may I suggest that a VERY important consideration is that the tie down points that the tractor will be anchored to need to be strong enough to keep the tractor on the trailer.
I think you may find this factor is a determing one in terms of the section size you need to use

hi guy the trailer has gone up on the list of things that are needed. i have what might be a silly question i have a really long length of 50 mm solid square bar and was wondering if i could use stub axles joining them to this with a sleeve of square tubing. thanks andre

Originally Posted by welder

hi guy the trailer has gone up on the list of things that are needed. i have what might be a silly question i have a really long length of 50 mm solid square bar and was wondering if i could use stub axles joining them to this with a sleeve of square tubing. thanks andre

I dont think you can register trailers in a lot of states that have welded stubs - could be wrong though

Originally Posted by dazzler

I dont think you can register trailers in a lot of states that have welded stubs - could be wrong though

Overlay axles on Caravans and Drop Axles on Horse Floats and Car Carriers have welded stubs...

Originally Posted by welder

hi guy the trailer has gone up on the list of things that are needed. i have what might be a silly question i have a really long length of 50 mm solid square bar and was wondering if i could use stub axles joining them to this with a sleeve of square tubing. thanks andre

I don't think that I'd be sleeving them to join them. You'd be better off welding them up as an Overlay axle, that is sitting the stubs on top of the axle bar. You'd want a pretty good jig though, and a 3 phase welder. You wont get the penetration required for the strength to be retained in the axle with a single phase. And I'd like to see the wheel alignment if it's done without a jig.

well here is were i am at so far i am building the whole out of 3 mm box the draw bar will be 50 x 75 x3 and the main frame will be 50x50x3 will this be adequate also does anyone know where to get cheap axle kits in Sydney thanks Andre

I think I've read enough to be really scared now as I too live in Nowra

I think 50 x 75 x 3 for the drawbar is ample and 50x50x3 for the chassis is an overkill. I made a 7x4 box and the chassis is 30x30x3 SHS and it has handled everyload I've put in it with no movement or deflection. Have a look here for the details - WIP - Trailer