and also to help you with motor selection and power supply you need to give us the specifics of approximatley how big the rover would be and wat ud be doing with it
I plan to make a small tank no more than 8 inches long, using the new track system lynx has. I’d like to put some kinda of pan tilt sensor on it, and maybe a laser turrent. It’s not going to be doing any heavy lifting, just traveling around the house and maybe in the park.
haha…that was me. I agree, go with these motors. They have a reasonable amount of rpm’s so your robot speed will be good, and a high stall torque, so your motors won’t burn out driving across grass in your park.
thanks! I’ll go with the ghm-13’s. What do you guys think, 4 moters or 2?
Also, Can anyone help me out with the wiring? So far, Ive only worked with bread boards so I’m nervous about actually soldering wires together.
I plan on using the scorpian moter controller.
4 motors would give you better drive, but 2 would be alright as well as long as you put some ball bearing or small wheels in the front of the chasis to give it better stability and controll.
Since these are relatively small motors (at least in terms of current draw, four is probably the best idea.
Otherwise, you’d need idler sprockets on the end that you don’t have your motors on, since you’ll have no motor shafts supporting them.
I don’t believe LM has idller sprockets, yet.
As to whether or not you should use 2 or four motors - I will soon be testing two on a relatively heavy platform. I will report shortly after I install the motor controllers and start driving it around.
A two motor version is not too difficult to design as long as you get a second set of sprockets, a pair of pillow blocks, universal 6mm hubs from lynxmotion and a 6mm shaft from some alternate source
I am using a two motor setup despite the original concerns i had for power. The motors are the GHM-04s and can easily push around my 2.5 lb setup, not even varying when i put a 7.2 nicad instead of the lipo i plan on using…
My future plans may make it a little heavier so i also have a few questions about motors
the motors i have GHM-4 are 7.2 volt whereas the GHM-12 is a 12 volt motor. If i ran a 12v motor on 7.2-8 volts what would be affected?
would stall torque and rpm be cut almost in half?
or would torque be dependant on the current and rpm on voltage leaving me with only less rpms?
also where can i find/what are all of the dimensions of the larger 12v motors. Im unsure if they’ll fit between my chassis rails lol
Trust me. You have to use the 12v for best performance. I found out only a week ago that I was undervolting my 12v motors at 7.2 v, I should know that it cuts speed (rpms) and strength (torque) down quite a bit. If you dont want to buy a 12v battery pack (expensive) just solder the wires of two 7.2 v batteries in series (red to black) and the extra 2 wires you can use to hook up your motor controller.
do this and you will have a good bot. Its best to run your motors at optimal performance if your only using 2 instead of 4.
Wow, thanks for the quick reply, im using RC speed controls wich can only handle 8 cells/9.6volts, so i’l stick with the ghm-04 motors… for now…
My chassis is built out of some 1’’ al angle and 1/2’’ x 1/8’’ al i picked up at the hardware store. I wanted to add some suspension, but thats a little more planning than i had time(and probably capability) for, so the motors and sprocket idlers are mounted directly to the angle. My treads are a little loose but not enough to come off. some tensioner/idlers will be added later… love this track!
