Backing 4 down?

[wrench]

   Who would find it handy to be able to backup 4 down?
   Who would be willing to shell 400. - 500.?
      Testing been put on hold when fuel went above 4.00,  I may resume now.
          wrench

[Nick Badame Refrig/ACC]

Hi Wrench,

I have backed up 5ft at times to get myself out of a predicament. 5ft seems to be the "BIND UP" point when I start to see my

front tires skip across the tarmack. With proper judgement, you should never need to back up your toad.

What do you have in mind?

Nick-

[white-eagle]

i backed straight back about 20 ft when i turned into a flying j line that was not marked, but was shut down.  thankfully, some real understanding trucker let me over.  that was a real slow, careful backing.

yeah, wrench, what did you have in mind?

[wrench]

  Well it's pass the mind status, I got a controller built ed, bought a testing car, I am at the installation state.  Don't want to elaborate too much, but it would allow one to backup in a driveway from the street without stress on the toad's steering comportment. The request on the 4-500 is to help in determining what to use, (cheap or top of line).  So I need some input, Pls just say what you think.
             wrench

[Lin]

Could backing work better if someone is steering the toad?

[white-eagle]

  Well it's pass the mind status, I got a controller built ed, bought a testing car, I am at the installation state.  Don't want to elaborate too much, but it would allow one to backup in a driveway from the street without stress on the toad's steering comportment. The request on the 4-500 is to help in determining what to use, (cheap or top of line).  So I need some input, Pls just say what you think.
             wrench

if the price difference is $100, i think i'd go toward the top.  if you are talking about a complete tow bar setup that fits into the receiver and attaches to the vehicle tow assembly, even $500 is cheap.  mine is a 10,000 lb cap tow and cost about $800 total i think. 

i know, i know, some of you built your own for $60 and a couple hours work.   

[blue_goose]

There is a hitch on the market that you can back with.  The Co. that makes the M&G brake makes one.
Jack

[Sojourner]

Backable Towing System (left click)

Quote "If a towed vehicle has 2 degrees or less caster, it can even be maneuvered like a trailer" unquote.

FWIW

Sojourn for Christ, Gerald

[TomC]

Especially with power steering, you have to watch out for using too little caster (2 degrees is pushing it).  You usually need more caster on a power steering vehicle for steering wheel snap back to center (that feature is also what causes the steering to wonder off center when backing).  With less caster, you would have to steer the car back to center.

Since we have air systems on the bus, I would think it would be relatively simple to install two large casters mounted to two pneumatic rams on the front of the tow arm that could raise the front of the car off the ground permitting trailer like backing of the towed.  The air cylinders would be activated by the backup lite circuit and be completely automatic.  You'd just have to wait for the car to come up off the ground an inch or so to make backing possible.  Using two 1500lb rams would be sufficient, I would think.  Good Luck, TomC

[rv_safetyman]

Wrench, I would be quite concerned about the market for your invention.  I can tell you first hand that a good idea (I think my system is a good idea and most folks tell me it is), may not make the market line up at your door and can get you in a whole lot of financial trouble (first hand experience ).

There are two issues when it comes to backing.  Putting a strain on the towed vehicle, and putting a strain on the tow bar.  I would think most vehicles can withstand REASONABLE "abnormal" loads, since this is a safety related system that is over designed to at least some degree.  What worries me is the tow bar. 

When I built my own tow bar (quite a bit more than a couple of hours), I did not worry about the strength (typical engineer - over designed a bunch).  However, the commercial tow bars are a different matter.  Even the 10K units are not at all robust in my opinion.  They are designed so that the bars are almost always in tension.  If you start backing up, they go into compression and that can very easily lead to buckling of the arms since they have very little "column strength", plus you will also be applying a bending load to the small column.  As an engineer, it scares the bejeebers out of me when I back up even five feet (and then only when perfectly straight).

Jim