Building a dolly, odd question

[AllanD]

I own a commercially made tow-dolly (a Master-Tow)
that mounts the towed vehicle's front wheels on a platform that is free to pivot.

a dolly without a pivot is much more likely to jackknife with the tow vehicle than a dolly that does not pivot.

Because the dolly and the towed vehicle form a 4-wheeled "Cart" the without a pivot will only want to go it's own way and won't turn and as you enter a turn it will try to push the rear axle of the towing vehicle to the outside of every turn (a strong over-steer effect)

The necessity for brakes on a dolly cannot be overstated, because the weight of a towed vehicle on a dolly also generates an over-steer effect unless it has brakes in which case actuation of the trailer brakes can moderate or eliminate the instability created by over-steer.

If I did not have my master-tow dolly, I would never consider building one, a new tow-dolly is only about $1400 (I paid $1100 for mine, new) Bt if I did I wouldn't base it on a two piece axle from a TIB truck

BTW, that angling of the tires inwards at the top, it called "Camber", "Caster" refers to change in camber as steering is deflected from the center (neutral) position... you want to avoid any self steering n a trailer, it adds unpredictability.

You need towed loads that you are generally unfamiliar with to be predictable, as the "learning curve" is likely to be steep and Expenvive... potentially fatal...

 

[Will]

Allan is totally correct.

Except that you can leave the steering unlocked and the wagon-steer can be done by the vehicle's steering.

That's a towbar. And not every vehicle's mechanics like a towbar.

And a towbar means there is a lot of resistance in the vehicle steering system. If your tow vehicle isn't a lot bigger than the towed vehicle, that resistance can be enough to make for a scary ride. On sharp turns, like on-ramps, that resistance can spin you around and cause a jack-knife. The fifth-wheel of a car dolly is a way better thing if the vehicles are similar size.

If you have a 7,000# E350 like I do, you can pretty much do whatever you want and not worry about it. If you are towing on margin, like using a Ranger, you need to be a lot smarter. it can do it, but you need to pay a lot more attention to your equipment.