Do I need a 2nd motor controller?

[kailef]

So I’m using a Sabertooth Motor Controller as well as a Spektrum DX6e Controller with AR610 receiver. I’m building another remote control lawn mower. I’ve already got this mostly build and both powerchair motors are hooked up to the Sabertooth motor controller. It’s a 2x32.

I’m wanting to add a linear actuator, just one for now, that will allow me to set up the raising and lowering of the height of the mower. Do I need a 2nd motor controller to hook up a linear actuator and to link it to the AR610 receiver so I can control it from the transmitter or can I use the same sabertooth motor controller I’m using for the power chair motors? I was thinking I might be able to use a Battle Switch from Dimension Engineering since it’s a relay switch.

Also, do I need to add an actuator control board or do I only need the actuator? I would think if using a battle switch, then an actual control board wouldn’t be needed.

I do intend to add on a 2nd linear actuator later once I create a way to attach weed trimmer that can extend out to weed trim along edges and the house.

I was thinking a 2nd motor controller would be needed since the left and right powerchair motors are taking up the others on the first motor controller.

Same question for other accessories…such as if I wanted to add lights and maybe a ptz webcam with some a/v gear to stream it to a monitor. Would a 3rd motor controller be needed or no?

[geraldinebc15]

Hello @kailef and welcome to the RobotShop community!

Do I need a 2nd motor controller to hook up a linear actuator and to link it to the AR610 receiver so I can control it from the transmitter or can I use the same sabertooth motor controller I’m using for the power chair motors?

It depends on the linear actuator, the Sabertooth has a 5V/1A output that can be used for o devices such as receivers, potentiometers, microcontrollers or servos. But if you have an actuator that can be controlled with an analog 5V signal you could use it for that (Actuonix I series for example). There are also actuators that can be controlled with R/C signals (Actuonix I and R series) so you simply need to power it and connect a receiver.

do I need to add an actuator control board or do I only need the actuator?

Again, it depends on the actuator, some can be controlled with what I mentioned earlier and some can’t, for example, Actuonix P series actuators can only be controlled with 6V or 12V (This can be accomplished manually
with a DPDT switch or relay, or using an H-Bridge circuit) but if you add a LAC board it can also be controlled with Analog 0-5V or 4-20mA, or Digital 0-5V PWM, 1-2ms Standard RC, or USB.

I would think if using a battle switch, then an actual control board wouldn’t be needed.

You are right.

Same question for other accessories…such as if I wanted to add lights and maybe a ptz webcam with some a/v gear to stream it to a monitor. Would a 3rd motor controller be needed or no?

If you add more motors you need another motor controller, but if you add more accesories/sensors you need a microcontroller/single board computer. But it really depends on the type of camera you want to add so I suggest being more specific. If you want to make it autonomous or you want to use a camera module a good option is a Single Board Computer, if you want to add a plug and play smart streaming camera that already includes the servos and the controller then you don’t need that. If you want a ptz camera that has the servos but not the controller then you need a servo driver, so… again, it depends. Either way I hope you find this information useful and if you have more questions feel free to ask!

[kailef]

So I went ahead and bought and hooked up a 2nd Sabertooth 2x32 motor controller to control the actuator since it’s a 12v one.

I’m running into an issue here i can’t seem to solve on my own.

So I have 2 Sabertooth 2x32 Motor Controllers.

1st Motor Controller = 2 12v Power Chair Motors. Hooked up into ELVE and AILE in the AR610 Receiver. Works fine if by itself.

2nd Motor Controller = 1 12v Actuator. Hooked up into the Aux in the same AR610 Receiver that’s controlling the 2 powerchair motors. This works fine. I have it linked up to my Spektrum DX6e Transmitter.

If I have run power to the 1st motor controller only, it controls the power chair motors fine. If I run power to the 1st and 2nd motor controller, the actuator will work fine, but the other motor controller that controls the 2 power chair motors flashes red and won’t control the power chair motors.

I tried running a complete separate power supply to the actuator so the 2 12v batteries I use only power the power chair motors, but that didn’t stop the flashing.

I’m wondering if it maybe the DIP switches or something else. Currently I have 1, 5, and 6 pushed down on both motor controllers(as in pushed closer to the edge rather that inside towards the middle of the motor controller.) I wonder if this may be interfering with each other because of it or if it’s something else I’m not seeing.

[kailef]

Nevermind. I got it figured out.

Had to remove the red wire from the servo coming from the 2nd motor controller since it was already getting 5v from the first motor controller.

Everything working okay now.

[kailef]

Actually, I am having a bit of a problem. I’m gonna post an image here to show you my wiring. The way I had it wired up, it fried one of the motor controllers. I’m not sure why. I tend to do a lot of research before I try something and when I don’t, I post and wait for answers. Well, I guess I don’t know as much as I thought when wiring up the 2nd motor controller.

So the motor controller with the 2 powerchair motors has special wiring harness connectors for a quick connect system that links the batteries together so the motor controller is getting 24v’s. There is a 125amp fuse between the motor controller and the batteries to protect the batteries.

On the other motor controller, you can see I have only one battery linked to it to provide it 12v’s so the actuator is not getting 24v’s to overpower it.

The servo’s on the powerchair motors are set to the AILE and the ELEV channels on the ar610 receiver. I also have a Spektrum DX6e Transmitter.

Now the servo to the actuator only has the white wire(blue in the image) connected from S1 to the Gear channel. I originally thought the red, black and white would be connected but it caused an error to the motor controller on the powerchair motors. I did some research and found out from a previous post to disconnect the red wire. I contacted Dimension Engineering also during my search and they suggested I also disconnect the black cable from the 0v on the 2nd motor controller that connects the actuator as it could cause, and I quote, “Leaving this additional ground wire creates a ground loop in your circuit (if both Sabertooth share the same main battery). A ground loop can present a potential difference at any time causing damage to the Sabertooth, as well as other devices on the same ground.”

So by their recommendation, I also disconnected the black wire from the servo from the 2nd motor controller so only the white wire was hooked up.

Before I disconnected the black white, I was able to control the actuator from my transmitter at the 2 power chair motors. I disconnected the black wire as they recommended so I didn’t damage either motor controller.

Once I disconnected the black wire and turned everything back on, one of the motor controllers fried. It had a small puff of smoke and lost power. Now I can’t even run power to the motor controller to the power chair motors because it’s the one that fried.

Btw, separate wiring to the 2nd motor controller as you can tell in the image that I ran separate wiring to only provide 12v’s to the 2nd motor controller that runs the actuator.

Also, the batteries I have and the powerchair motors I have are completely different that the ones in the image. The batteries are still 12v on each and the powerchair motors are ones that are brand new that were bought online and are replacement motors for the jet 3 ultra powerchair.

What am I doing wrong?

[geraldinebc15]

Hi kailef!

I’m not sure if your wiring is the same as what you drew because you mentioned this:

So the motor controller with the 2 powerchair motors has special wiring harness connectors for a quick connect system that links the batteries together so the motor controller is getting 24v’s.

On the other motor controller, you can see I have only one battery linked to it to provide it 12v’s so the actuator is not getting 24v’s to overpower it.

However, on the drawing, the batteries are in parallel so they’re only providing 12V to both motor controllers.

Now the servo to the actuator only has the white wire(blue in the image) connected from S1 to the Gear channel.

I’m guessing you’re referring to the receiver to the 2nd motor controller (the one that controls the linear actuator)

About the receiver’s connection, I’m assuming you were using both sabertooths to power it? (black and red wires), if that’s the case then what Dimension Engineering recommended makes sense. As the black and red wires are for powering the receiver you only need to connect them to one controller, the white/blue wires are for the control signals for the motors so you need to connect them to both sabertooths.

Now, as you mentioned this:

There is a 125amp fuse between the motor controller and the batteries to protect the batteries.

I thought I should mention that Dimension Engineering recommends not placing a fuse between your battery and the Sabertooth. Here’s their explanation:

If this is more of a hobby project instead of an industrial product, most people do not use fuses. The Sabertooth has built-in current limiting.

We prefer that you fuse the motors rather than the battery leads, or if for safety reasons you need to fuse the battery that you do it at a much higher current than the motors. The reason is this:

Because Sabertooth is a regenerative driver, it relies on having a battery to put regenerated energy back into when you command a stop (and at other times). If you draw enough power to blow a battery fuse, all of a sudden the Sabertooth has nowhere to put the energy. It will see the fault, though, and try to stop the motor. It doesn’t, however, have anywhere to put the energy (the mechanical energy of the vehicle and the electrical energy carried in the windings and the caps). So blowing a battery fuse will sometimes kill the driver – which we would replace under warranty, but it’s still annoying for all parties.

The better way to do it is to fuse the motor leads. If a motor fuse blows, the motor will freewheel, the Sabertooth will sit there contentedly, and the only thing you will have to replace is the fuse.

I’m not sure if that’s the reason your driver fried but you can check the fuse to see if it is blown. Either way, the fact that your motor driver smoked means that it shorted and needs to be repaired, so I suggest contacting Dimension Engineering Support for repair.

[kailef]

The other motor controller that runs the actuator, I have the red and black cable from the actuator running into the pos/neg terminals on the motor controller(far left part). I then have a pos cable from the +(3rd screw) on the motor controller running to the pos on one of the 12v batteries. I then have a negative cable running from the -(4th screw) on the motor controller running to the negative on the same battery.

Here is the battery harness I use. The red x is to cross out the reset switch as I don’t have that. I have that linked to a toggle switch that is linked to one of the motor controllers. So that way I can cut power off to the motor controller with the toggle switch.

This is so that 24v goes to the first motor controller(the one that fried). As you can tell, the fuses are pre-built into the wiring of the battery harness cables. This came as is on the powerchair. This battery harness is only used for one motor controller. I have separate wiring that links to only one battery that goes to the actuator motor controller.