NickPyner:
OK. The penultimate, or possibly ultimate question:
Looking at pic028, you have a bit of white cable to estimate the rpm. Did you just see that cable move momentarily, or did you see it rotate continuously in both directions?
It moved continuously (no stuttering) for as long as I wanted it to be by having the wires in contact with the connection points. By shifting connection points I could make it go the other way. But they moved in different speed. Lets say 80 rpm and 150 rpm. That they moved in different speeds makes me think that there isn't any "low" and "high" connections, changing direction makes the high and low.
Aqualize:
That they moved in different speeds makes me think that there isn't any "low" and "high" connections, changing direction makes the high and low.
That's as good an explanation as any, but it may be reversing just to park.
The reason why I asked the question is that I'm sure the bit of cable isn't wrapped round an "output gear", it's a spline. It looks exactly like the spline for a screenwiper arm, hence my question. If the shaft rotated about a thirty degrees and then reversed, the motor is almost certainly a windscreen wiper motor but not off a car. It's off a train or a bus, hence the size. You often see buses with the wipers going but obviously not connected and thus must have a motor for each. It could still be a wiper motor but, if that is the case, it obviously has a large and vital part missing, the reciprocating gear. Fortunately it is not too vital for you, but the bit that connects to the spline would probably be useful. It could have been that the motor originally drove a hydraulic pump, which might have been nice for your purpose(!)
Aqualize:
That they moved in different speeds makes me think that there isn't any "low" and "high" connections, changing direction makes the high and low.
That's as good an explanation as any, but it may be reversing just to park.
The reason why I asked the question is that I'm sure the bit of cable isn't wrapped round an "output gear", it's a spline. It looks exactly like the spline for a screenwiper arm, hence my question. If the shaft rotated about a thirty degrees and then reversed, the motor is almost certainly a windscreen wiper motor but not off a car. It's off a train or a bus, hence the size. You often see buses with the wipers going but obviously not connected and thus must have a motor for each. It could still be a wiper motor but, if that is the case, it obviously has a large and vital part missing, the reciprocating gear. Fortunately it is not too vital for you, but the bit that connects to the spline would probably be useful. It could have been that the motor originally drove a hydraulic pump, which might have been nice for your purpose(!)
That's an interesting thought. Wiper motors for tractors work similar to how you describe it for other bigger machines (the arm is connected to the wiper motor directly and the motor changes direction).
Well the lack of speed makes me doubt it would be used to drive a hydraulic pump. The tractor hasn't hydrostatic steering (orbitrol). First I was thinking of affected the hydraulic valve on the servocylinder but gave up that. I think it is tightly built together so connecting some electronic valve (which I don't have and they are expensive) may not be possible. Bicycle gears of appropriate size and chain connecting the steering wheel and the electric motor is a way I think this will work, thanks to the power steering. An older tractor we have is without that I know that for such task this little motor wouldn't be enough.
But to sum it up we are waiting for me to take another look it with multimeter and wires, having a printed copy of the wiring diagram I got and see if it corresponds or not. And after that I think I will build it together as I thought with 4 diodes, smaller fuse on the motor controller and an Arduino for a bench test run. I know for sure I will visit the parents around Christmas, we'll see if I go earlier. So don't hold your breath until then!
[...] It could still be a wiper motor but, if that is the case, it obviously has a large and vital part missing, the reciprocating gear. Fortunately it is not too vital for you, but the bit that connects to the spline would probably be useful. [...]
As I don't have this piece my idea use the bicycle gear, somehow centered and then use the welding machine to permanently attach it.
So it is Christmas time and I have a chance to experiment with the motor again. And the connection works as intended!
So now the two input cables, when reversed polarity also reverses direction of the motor. Those 4 diodes was the key.
I will post pictures of the whole thing when I also get the arduino to drive it via the HB-25 controller. What I've done now to test the motor is to connect it to my modded computer PSU (banana sockets on top of it for easy access).
I don't know if I'm doing it wrong with the HB-25 but I will experiment on a small DC motor I have tomorrow.
I thought maybe a video showed it better
Using the servo library I got it to work. I hooked it up to read input from the Y axis of the joystick shield.
I measured the amperage between the PSU +12V and HB25 controller's positive connector, when the motor runs at full speed with no load it uses ~2.5A. Peaks higher, especially if changing direction suddenly.
So thanks everyone for the help, the objective I needed help with by starting this thread has been archived.
