there will need to be some angle on the 3rd wheel bracket, maybe only 5-10 degrees inclined towards the centre of the chassis, But that'll allow it to self centre and hold centre when moving forwards.
Its going to be a real pain in the ass to turn while moving forwards because of all the front overhang of the auger, you'll probably find that all the turning will have to be done while moving backwards.
I would suggest maybe use the neck from a bicycle frame, Maybe even have a look at a little kids bike because it'll all be quite compact and you can probably just modify the forks to hold the wheel.
That'll give you bearings to hold everything in place, as well as a shaft sticking out the top that you can turn.
As for turning it, you can either use a lever style system or perhaps use a gear and chain system. If it were me, I'd reuse a gear from the pushbike welded onto the steering shaft, then run a chain between that and a motor with a gear on it. Maybe you could utilise an old windscreen wiper motor? they are quite powerful with a lot of torque and easy enough to adapt with 12v.
I suppose that depends on your control system though. To use that, you'd need to feed it 12v to turn one way, then swap the polarity to turn the other way. It'd turn when there was power but otherwise be a 'dumb' system, so no self return or centering unless you added position senors or contact switches. Alternatively a servo would be much better, but probably more expensive once you factor in the power needed for it and the control module to run it. That'd likely be easier to adapt to the signal coming from your remote control though.
I'd try to keep all your weight, battery, electronics etc, over the 3 wheels, it'll prevent it from bogging down in the front, give grip over the drive and steer wheels and give better overall stability.
That or try to move the drive axle as close as you possibly can to the inlet scoop of the auger, maybe right behind it. that'd improve the mobility and steering immensely.
Its going to be a real pain in the ass to turn while moving forwards because of all the front overhang of the auger, you'll probably find that all the turning will have to be done while moving backwards.
I would suggest maybe use the neck from a bicycle frame, Maybe even have a look at a little kids bike because it'll all be quite compact and you can probably just modify the forks to hold the wheel.
That'll give you bearings to hold everything in place, as well as a shaft sticking out the top that you can turn.
As for turning it, you can either use a lever style system or perhaps use a gear and chain system. If it were me, I'd reuse a gear from the pushbike welded onto the steering shaft, then run a chain between that and a motor with a gear on it. Maybe you could utilise an old windscreen wiper motor? they are quite powerful with a lot of torque and easy enough to adapt with 12v.
I suppose that depends on your control system though. To use that, you'd need to feed it 12v to turn one way, then swap the polarity to turn the other way. It'd turn when there was power but otherwise be a 'dumb' system, so no self return or centering unless you added position senors or contact switches. Alternatively a servo would be much better, but probably more expensive once you factor in the power needed for it and the control module to run it. That'd likely be easier to adapt to the signal coming from your remote control though.
I'd try to keep all your weight, battery, electronics etc, over the 3 wheels, it'll prevent it from bogging down in the front, give grip over the drive and steer wheels and give better overall stability.
That or try to move the drive axle as close as you possibly can to the inlet scoop of the auger, maybe right behind it. that'd improve the mobility and steering immensely.
