Two more trailers added to my fleet..
And my ongoing Arctic trailer
As for suspension, I like to use leaf springs on my builds..
A look under my SWAT trailer..
I usuall use these parts:
For the U bolts I use some 3mm wire clamps that can be found in boat supply store or other stores that deals with wires..
For the axle itself I use a 5mm bar...
To locate the wheel axle in the center of the leaf springs, I use some modified Tamiya HL leaf blocks..
Together they look like this:
For the wheels I find some buggy or 2wd wheels that use bearings.
To secure the wheel to the axle I use some 5mm aeroplane wheel collars, one at each side of the wheel..
Or I modify some hex driven wheels with bearings on each side pluss the collars..
I could have useded a 4mm all thread rod with a 5x4 tube on the utside to secure the wheel with a wheel nut, but I have found the all thread too weak to use this method...
Plenty of ways to do it, find a way that are easy for you, both work wice and easy to get the needed parts.
But I hope I have given you some ideas and help along the way"thumbsup"
Edit: If you can't find wheel collars for aeroplane, you can use the goldish bearings that comes with the most of the Tamiya kits (the ones most people throw away - not me).
Simply drill a hole in the middle and tap it with a 3mm tap and screw in some set screws.