I would recomend a full size mini van. You never know what other problems occur for safe exit unless you see what is being presently used for such equipment. Room means safety in this situation. Otherwise, you would see more commercially available vans that were smaller. IMO, it’s a mistake to go too small.
I’m not sure why an electric power steering system could not be modified for less effort. It would seem that all it would need is a stronger motor and the controls reprogrammed to allow higher pressure at various speeds. It still uses hydraulics to actually power the steering.
Electric power setting could probably be modified too. I just theorized it would be easier to modify traditional variable assist power steering because, at one time, the systems provided a high level of assistance regardless of speed. I could be wrong though. It might actually be easier to modify an electrical system.
The 1969 Dodge Dart I used to drive was extremely easy to steer. That car could be steered with one finger, freeing me up to put my arm around my girlfriend’s shoulders. In addition to all-time power steering, it had a pretty large steering wheel. I wonder why they decided to make it harder to steer in newer cars.
http://www.creativecontrolsinc.com/products/zroeffort.htm
“We can modify both Rack & Pinion and Gearbox styles of power steering:”
Problem solved.
What you really should be doing is going to a handicap conversion specialist and having them evaluate your particular disability and what they can install to work best for you. Wild guessing about 100% hydraulic steering is going to end up with you getting a vehicle that is not tailored to your needs.
You can even get a joystick to steer with, and that is pretty much 0 effort.
Unless it’s one of those old SAAB cars that came from the factory with it.
I suppose that steering efforts today are more in line with the variability of what manual steering actually is. Increased effort at higher speeds is not only natural do to the gyroscopic effect, but safer.
I know Whitey (and most of the rest of us) would like the option of girl friendly use of that right arm (not in Europe) but I feel it’s not only safer but the way steering should be to increase effort with speed. Programming electric steering to vary with the individual will become standard IMO, when/if enough customers demand it. For now, I agree, with enough money, anything can be done.
At the other extreme…Neighbor has a loader with a joy stick for the track drive and it is absolutely scary how quickly it responds and a potential hazard as it demands constant attention. Text while you drive that thing and you could easily climb up one side and down the other of the nearest parked car.
When I look back, I realize it was pretty unsafe to drive with my arm around my girlfriend’s shoulders. Even if I could, I wouldn’t drive that way today.
well, a 100% hydraulic steering system would be easy to turn, I don’t think it would be a practical solution on a normal car. I don’t think it would be street legal eitfher. I have only seen such systems on heavy equipment, or off road rock crawler jeeps, and buggies. IN those systems there is no shaft or rack and pinion or steering gearbox, just a pump, a control valve attatched to a steering wheel(or a lever/joystick), hydraulic hoses and a hydraulic ram or rams acting on the wheels being steered.
I think the person who said it needs to be 100% hydraulic meant that it should be 0% electric, meaning it would have an engine mounted hydraulic pump, rather than a electro-hydraulic system with an electric powered hydraulic pump, or an electro-mechanical system where the electric motor acts directly on the steering shaft or gear. The only reason they might say this is that the only way of modifying steering effort is by changing the flow valve on the pump of certain model engine mounted pumps.
it is even easier to change the effort on an electrohydraulic system. the same valve modification can be done on the electrically driven pumps. the ones I have messed with, this was just a matter of adjusting the preload on the spring. i.e. turning a screw on the side of the pump.
On the electrohydraulic or the electromechanical systems a module controls the effort, based on speed, and in case of the latter, input torque. most of them have a failsafe when a fault is detected to run at full boost, or light effort. which means that if the module senses a malfunction in the inputs, it will be easier then normal to turn, and not vary with speed. You could disconnect the speed input, or CAN lines to induce this on purpose, but a warning light may come on. on the electrohydraulic system you can alter the voltage of the torque sensor input to make it think you are turning it harder, which will make it apply more current to the electric motor to reduce the effort required to turn. You could do this with a variable resistance potentiometer or actually one for left and one for the right, geared to a common knob, allowing the user to dial in the effort with a single knob on the dashboard. This would probably take about $10 in parts, and an hour of work for a decent fabricator/mechanic to do. well, a little longer,at least the first time to make it a nice professional, user friendly installation.