Fieldmaster trek 4x4

[ArfurD]

Hi
Has anyone heard of, got one, or field tested one of the Fieldmaster trek 4x4 chairs, reason is I like to go on field trips, painting and photographing landscapes, but has yet not found ANY other UK wheelchair maker that will go off road, I don't mean mountain climbing in a chair, but a chair that can be used on grass, gravel paths, slopes etc.
A chair that has independent 4 wheel suspension, and has a very good motor on each of it`s 4 wheels, and is not made and sold solely in the US of A.
Because if anyone on this forum knows of such a chair or someone in UK who can help me build such a chair I would be over the moon.
I have some s of my own for making leg guards and roll-gages with all weather covers for manual and power chairs, I am just looking for someone local to me that has engineering skills and are prepared to work OUTSIDE of the box to develop suitable OUTDOOR going chairs.
There must be loads of guys and gals that have skills and experience enough to design and build chair loads better than the stuff various companies make for us then have the cheek to say their chairs are better than sliced bread.
Lets rise up and rebel, well perhaps not rise up, against chairs that simply do not do the job the companies that make the chairs SAY they do.

Arfur Rebel

[ex-Gooserider]

I'm sure that BM will be along shortly to point at his own chair as something that has a lot of off-road capability...

Also, I'm not certain, but I think he's done some talking with the folks that make those chairs - I know he's mentioned dealing with some maker of UK off-road chairs.

The question is how well ANY kind of 4WD chair will do with battery life, as the design is inherently going to be a power-hog, just from running 4 motors (plus whatever it does for steering - the photos don't show) plus the drawbacks of tank steering...

No dimensions, but I wonder about how long / wide the chair is, and whether it would be useable at all indoors, and even if it will fit inside a standard mobility van - a problem with many "outdooor" chairs.... Also it looks pretty tall, which isn't good for your center of gravity.

Really, what we suggest as the best "outdoor only" vehicle is to adapt a low cost petro powered ATV or UTV, as this avoids all the problems with power and range that are impossible to avoid with a lead acid battery setup...

ex-Gooserider

[Burgerman]

That chair is ok OFF ROAD, (even with skinny tyres that sink in soft stuff).

But batteries and any kind of off road don't play well together. Expect good range on smooth surfaces, bad to pretty much unusable for long, off road. It also lacks power for off road. 4 motors doesn't matter much if the limiting "torque" factor is the battery Amp capability, or the max Amps that the controller used is capable of isn't also bigger than a 2 wheel drive powerchair.

The real problem is of course that to most users is useless as you need to be able to get out, and swap the complete front end from casters to wheels/motors when you want to go off road. And back again to get into a vehicle or house... And as an indoor powerchair its pretty rubbish with masses of weight over the front casters.

If you can stand, don't want to use it indoors, and the hopeless range and battery life OFF ROAD doesn't worry you then it might be OK.

GR It isn't 4 wheel skid steer, it steers like a scooter with a low seat and a joystick. There's also a Tramper, which is about as good off road only. And a few others. But none can really be called wheelchairs. They are off road "buggies" limited by speed/battery range and torque when the going gets to the point where they work better than my own powerchair.

[Sully]

This Trek 4x4 is an OK +/- 4 WD but it is hardlly fully or even close to being independently suspended, it is horizontally articulated but that appears to be all. It needs to be somewhat vertically swiveled as well, to do what you described as what you would like. Otherwise you stand a real chance of overturning this buggy.

4 equally powered motors that might have 250 -350 output watts and an reduction output revolutions of 90 -115 would be a minimum you could use to possibly propel such a buggy. Weight Balance on all four wheels is also pretty important, for traction purposes. But the bottom line as always is getting the Amperage to the motors independently as well as in quantities enough to make them perform. You are asking a lot of a total storage capacity of 80 Ah @24 volts. And even at that you'll only get a piece of that 80 Ah at any given moment and it diminishes fast (peukert). So that seems to require LiFePO's as a power source. Then a better than just good controller and skills (yours) that can maximize the distribution to any pair of the four DC electric motors, at any given moment.

They make such a thing here in the states and other countries for harvesting logs in the woods, a skidder, that uses a couple of hundred horse power, and what you want to do in theory with maybe 3 or 4 HP Maximum. It's not impossible, but it will take a few minutes longer to make.