books on trailer design?
 

Inspired by oil pan 4's post, but not wanting to be on page 11 of someone else's discussion...

Are there any good books on SAFE trailer design, since i've heard of enough people building something shoddy and having problems, or overbuilding it unnecessarily heavy because they didn't do the calculations relevant to have the strength equally matched in each place? Even how to use CAD to model it up to see how it would respond.

Specifically i'm looking for a folding trailer design as I don't have space to put it. I just want to make one stronger than normal, like with a single 5k axle, because I need to eventually move some heavy stuff I cant break up into separate loads. The typical folding trailer doesn't go over 2k. I imagine paying for something totally custom will be expensive so i'm eyeing the DIY option.

I'm aware a 5k single axle will probably be very rough with no load/light load - so I thought i'd actually SWAP axles when needed and haul by pickup. It would be rare enough (a few times per year) that I don't mind turning wrenches for 15 minutes to change it to heavy mode. Yet often enough I don't want to pay to rent a trailer multiple times over several years. When I don't need heavy I go back to like a 2k braked axle. Then go back to hauling by compact car.

I'd further like to make it somewhat reconfigurable - instead of a single purpose trailer, like just a box, maybe set it up so it's easy to remove the box in such a way to haul a couple project motorcycles or ATV's to strip for parts/repair or whatever else I want to do with it at some future date. Something where I can hang the pieces of the reconfiguration on my garage wall, not something permanently attached preventing fold up and taking a parking space.

At some point I also want to build a car dolly. Those are normally darn expensive! : P My ideal plan would be to go unconventional again - working with the above. Use the 5k heavy axle (rarely used on the box trailer) as the normal axle under the car dolly (letting me haul up to full weight pickups) so that i'm not wasting anything/buying things rarely used. The normal car dolly design has a really wide setup - unless it's possible to jack the car up noticibly higher without being unstable I thought I could just make the 5k axle wide (to work with the dolly) and have the 4x8 folding trailer just accept the somewhat wide axle (which would be notably wider than the normal lighter duty axle) since it's more rarely used. Unless someone sees a problem with this arrangement.


Any suggestions on where to start building my Trailer System? : P This seems to be the first part of some of my other projects - since what needs to be hauled comes first, even before the decision of tow vehicle. What kind of trailering system I can set up, that doesn't even take up a garage parking space, potentially changes the vehicle plans about what vehicle to have in town vs the one you leave out of town at the farm with the heavy trailer but have to pick up for every job doubling fuel wastage as it's four trips then to go get it, come back, get your stuff, bring it back out there, then return home.

I would say to start go find some trailers that are close to what you want that you know have been beaten on very hard and take pictures and take measurements on the steels thickness.

1800 or 3500 are common ratings of one axil trailers.

putting a 5,200 or a monster 7,000 under one would be very out of the ordanery.

though i did see one at a rental place that was rated for 5,200 it was used for the small excavators and ditch diggers under about 4K

it was clear it was made with transporting small excavators in mind. made much stronger then the fold up ones Costco/harbor fright sells.



car dolly's are often 8'6" the legal limit. SO LIMIT YOUR TRAILER TO 8'6"!!!!including all lights and tie downs on the side of the trailer, no point what so ever is legal to be wider then 8'6" with out a permit...

I thought dollies were wide to accommodate the track of the towed vehicle.

How about two trailers? A short T-frame dolly and a longer ladder frame trailer with a hitch ball inside the A frame on the front—both with the same track. Then when you have a heavy load you lift the front of the big trailer and slip the dolly in underneath and attach to the hitch ball to double the weight capacity.