Hi everyone! First time here and first time building a robot. I’ve built a remote control lawnmower with wheelchair motors. I dont have any specs all I know is they are from a quantum 6000 wheelchair…
I have the batteries from the wheelchair ( 2x12 volt in series) , hook up to the sabertooth and using r/c transmitter. Off the ground everything is perfect. On flat surface also. I’m able to pick up a good speed, almost to fast. But if I tried to go full throttle from stop or if trying to go slow up a slope it will stop and start making weird noise. If I let go the throttle it start going reverse by itself quick and I have to shut it off to regain control.
Last night I saw the red light coming on when I tried to move it but it was only flickering like on and off the motor. Sorry it’s hard to explain.
Before spending more money like getting a 2x60 sabertooth or getting new battery, I figure to get some help first. Hopefully within this long explanation my problem is clear. Thank you
I have connectors for the original 8 gauge wire of the motor but they are too big to fit the sabertooth. Thats why im running 12 gauges wires for now … anyone knows which 8 gauge connector fit on a 2x25 sabertooth ?
I tried also separating the axis of the control. So instead having the same joystick to control everything I use one joystick to steer and the second for throttle and was still the same results .
First, have the customer check for shorts along the battery and motor lines. Even stray copper wire strands can cause this type of behavior which is exacerbated with higher torque.
Next, make sure the customer reverses their power-up procedure. They have the Saber DIPs set for auto-cal mode. So the transmitter should be powered-up first, before the Saber receives battery power. This ensures proper signal calibration.
The most likely cause for this issue of the inhibition of regenerative current into the battery. What is the capacity of the customer’s batteries (amp hours, Ah)? What is the current rating of the battery disconnect switch? Do they have any other components on the battery lead besides the regulator for the receiver?
Have the brakes been removed from the motors?
These type of motors with that type of wheelbase will draw a lot of current.
I tried to power up the transmitter first and then the Saber still no change.
Now I’m wondering what I should do. Buy 2 new 32 amp AGM batteries ?
Install a 24 volt alternator ?
Run the system on 12 volt and alternator ?
I ordered a 2x60 last Sunday and should be in the next couple days, should it try it ?
I have a doubt on the batteries I’m using since they are old . But I thought low batteries would just make the motor turn slowly before not moving at all. If the Saber I’m using is too small to turn motors over will they move slow or not at all or they will start acting weird like my issue ?
If the Sabertooth has been driving the motors with the brakes intact (depending on how you had them wired into the circuit - how did you have them wired?), then it’s possible that the 2x25 firmware may have gotten corrupted. I would recommended using DEScribe software to reset it. You will need a USB to TTL serial converter.
The 100A switch is compatible with a 2x25, but not a 2x60. Wheelchair batteries typically do not have enough capacity to handle power from a regenerative motor driver like the Sabertooth. And without knowing what the capacity is with these, I would recommend not using them.
I think you would need more than 32Ah to run this application (at least 55Ah). This might be better suited for a 2x60, but that requires even more capacity. Do you have a clamp meter to measure current draw on the motor output?
I’m also concerned about what is happening in the recent video. What exactly are you commanding it to do here? With the stick at “reverse” and the motors not moving, along with what seems to be a turn(?) command on the stick, I’m really confused. Did you power it up this way, with the stick at reverse?
Maybe it is the best to contact them directly on [email protected] ?
