Thread: Trailer for long loads.

100x50x5 RHS for the drawbar

Thats pretty heavy. If it was me I wouldnt bother going over 3 mm wall for your intended purpose.

75x50x3 RHS for all the main frame

Given the specs u have provided I wouldnt go over that

Remember its all weight at the end of the day. Before I even think about building anything I look around at what others have done before me.

Whow I think all those Bourbons I had just kicked in......the text is getting fuzzy .......... better stop now.

Have fun. Of course fotos are a must.

Firstly, Welcome Buildspacetrain. Hopefully we can give you some assistance.

The size of the trailer is the first area I'd suggest a change. If you've got somewhere to store a trailer that size, then an extra 400mm shouldn't be an issue. To save yourself some cutting, flat floor sheet comes in 8'X5', and therefore if you make your chassis 16foot long (4880mm), then you wont have to cut anything, just buy two sheets. Similarly, if you design your cross rail spacing to match up with the join, you'll save yourself some headaches later. Also the extra length wont cost you extra in RHS either, because if you cut 4880mm off an 8 metre length, it leaves you 3120mm, or 2 x 1560, perfect for two cross rails. Bigger trailer, less waste, no extra expense. (More on that later)

I agree with Jatt that the size of steel you mentioned would be way overkill for the weight of the load you intend to carry. If you intend to have sides on this trailer, then this will be the area where the longitudinal strength lies and the chassis could even be made lighter/smaller again. But I too like over engineering, so here's what I would suggest;

2 x 8M lengths of 75x50x3mm RHS:
Each one Cut:
1 x 4780mm (Two main side chassis rails)
1 x 1425mm (Internal cross rails)
1 x left over 1795mm (Front and Rear cross rails)

1 x 8M length of 100x50x3mm RHS:
Cut to desired lengths for drawbar. You'd have more than enough to tie right back to the front spring hanger. But this is up to you.

For the rest of the internal cross rails and the four corner uprights I'd use 40x40x3mm RHS, but you could go 50x50x3mm.

I'm not too good at 'sketch-up' just yet so I'll describe what I'd do the main frame.
Laid out on the workshop floor (all measurements from front cross rail);
2 x side rails 5 foot apart
2 x front and rear rails either end
7 x internal cross-rails every 2 feet (this would place one in the middle for the sheet join, and evenly spacing the rest.) Where you place the two 75x50's is your choice, but I'd place one at 4' and one at 10'
Centre spring hanger should be at 8'8" (2640mm), and the rest of the hangers placed accordingly. (Yes you'd got your homework correct)
If you intend running the drawbar to the front hanger, then a straight line would make it quite narrow where it supports the front cross rail. I would mark a point on the side rails 3 foot from the front and run the draw bar to there, then continue along the chassis to the front hanger.

Once tacked, squared, checked three times, and then welded we can turn over.
I would place uprights at each corner, then one in the middle of the guard, one at 5' and another at 12' and then a rail on top of these front to back. To mount the gaurds, cut out the square bit in the middle for the upright, and tuck it up under the top rail and sit it against the chassis at the bottom. Another rail across the top at the front and we're pretty much done for the main frame. How you do light boxes, tie-down rails, tailgates, number plate, etc. is up to the individual.

Over-ride brakes have their place, particularly if numerous different tow vehicles are in use. I would go 4 wheeled brakes, either Hydraulic or Mechanical drum brakes. In all cases if the budget is tight to start with, get the brake mounts added to both axles, even if you only start with one set. It makes the upgrade a 'bolt-on' application.

Ford "Slimline" bearings are 1.4 tonne axles, not 1 tonne, but I highly recommend using Slimline axles, just to have that capacity.


This should get you going for now. Good luck and have fun. Take lots of pics too!!

I see you're in Melbourne too. If you need a hand, or some advice in person, let me know.

Cheers,
Yonnee.

Firstly welcome.

This link will take you to what I made, it may help. The inside tray size is 3m x 1.5m, drawbar is 2m, the unit weighs 600kgs. I was an Owner Builder and the trailer worked a treat for me and still does.

https://www.woodworkforums.com/f184/trailer-21592/

Wow, what can I say! Thanks for all your help and suggestions.
Firstly, Jatt - thanks for the steel size suggestion. I see your from Bendigo. I have property in Heathcote where I keep my 4 sheds, 3 wheel-barrows and 2 other trailers. Can a man have too many of these? Keep an eye out for the new trailer some time in the future in the streets of Bendigo.

Rod, nice trailer. HEAVY DUTY STUFF! Always get good ideas from photo's.

Yonnee, thanks for your time and effort to reply. It must have taken some time to figure it all out and put finger to keypad. I really appreciate it.

I'm much more confident now that the steel size will be ok and that I'm heading in the right direction. I will post some photo's of construction, but Im a slow worker. Might post a few photos (if your interested) of big new shed I'm building (over engineering) to house a model railway. (my future retirement hobby).
Again, many thanks. Cheers, Richard

Hi Chaps, Just a few photo's and update of the trailer.
Construction is going well but slow due to time (not enough).
Spent a lot of time setting up for squareness prior to and during welding and has paid off with a nice square and level frame.
I am keeping track of material costs and weight which I will write up later as it might help another trailer builder later.
Cheers.

Its not fair.

where do you guys get your nice clean workshops from!

keep the photos coming.
cheers
Frank

It's looking great BST. Look forward to seeing more as you progress. Also interested in how much it will end up costing you.

Richard, Something to be aware of, when I welded my draw bar on to the front rail of the trailer body it pulled/bent the draw bar hence to mini truss on the underside of the draw bar.

Your's is looking good

Another reason never to weld across the top of the drawbar where it meets the front cross rail.

I just welded the drawbar and coupler plates on today, most pleased with the outcome, then read your comment 'rod 1949'. Bugger I was just enjoying a cupper too! So out I go back to the workshop, grab a straight edge and say a little prayer. The drawer bars are 100 X 50 x 3 and 2700 mm long and yes they have pulled about 4mm over the whole length, with I think is acceptable. I've taken Yonnee's advice and not welded across the top of the drawbar too. Hope to weld the hangers on tomorrow and turn her over.
Sorry Franklin, I'll do better and make the workshop a bit messy for the next photo's.
Cheers for now, Richard.

Not much to show for the past few weeks, but the hard work on the frame is done. Drawbar and coupler is on and frame is nearly complete. That's it now for 6 weeks till I come back from holidays with the good wife. Will buy the mudguards and axles if i got any money left over!
Cheers for now.

C'mon, youve got another thread where you're painting it, where's the updates??

Not a lot has changed since the last photo apart from the addition of the mudguards. It took longer to paint than to weld it up!
Put the fancy white wheels on today but still have to wire it up and put the lights on, also still to do the brakes.
Sorry, Mr Yonnee, will take a few photos next weekend and list detailed prices and weights of individual components for future reference.

After 9 months the trailer is finished and ready to haul all my corrugated iron, timber and steel for the new hobby shed and house extension. The deck is treated pine screwed down to the frame (separated by rubber strip) and will make tying down the load soooo much easier.
I already have another trailer for loose material like sand and dirt which is why I built the deck this way. Total cost for all new materials was $2650 and weighed in at 600kg on the weigh bridge. It is 6 metres long and 2.1 metres wide.
Here's a few photos. Thanks for all your input during this project.