@Magda We would need to know the input values. Wheelchair motors are a good and inexpensive option for medium sized robots, but keep in mind that you will most likely need to replace the controller. 8.5Nm is 1200 oz-in, which is quite powerful.
Hi Coleman.
Let me rephrase the question. I’ve input this http://prntscr.com/cj1lm0 and got this http://prntscr.com/cj1lqr and now my question is. What motor should I use? Do I look for the motor ( or motor with gear box ) who has RPM close to 191 and stall torque larger then 105 so that I’m sure that it will handle 20deg slope and that’s it?
Value for the current to use only for controller selection?
Regards,
Magda.
@Magda The tool is intended to give you ballpark figures for torque and RPM. Based on your inputs, you would need a 24V DC gear motor in the 100Kg-cm (continuous output as opposed to stall) range and ~200rpm. 70Kg is a heavy robot indeed and it needs quite a bit of torque to move up a 20 degree incline. The current is an estimate based on power divided by voltage.
Hello Coleman,
I am building a miniature Goliath tank and its track is made of ninja flex. I am thinking about buying a very small metal gearbox motor, but I am having problems selecting the best motor that will provide enough torque to move my rover. Because it is a tracked vehicle, the only drive wheels I have are the two in the back which will move the track. All of the other wheels I have are idle wheels. What would be the best way to calculate the torque needed for my motor?
Kindest Regards,
Sou
Thank you so much but i still have a question that needs a direct answer, am building a robot of about 5-10kg weight and i would like to know the true specifications of motors i should use and the rating of the battery
@Bruce The Drive Motor Sizing Tool is there to provide an initial ballpark figure given the data you enter. If you need something more exact, there is quite a lot more to factor in, which is beyond the scope of this tool. The battery relates to the nominal voltage you chose, and how long you need the robot to operate between charges.
Hi, I have a question, I am trying to build a drone of almost 3 kgs, let’s say 2.9. It must have a speed of at least 1m/s, and the radius of the wheel is 0.04 m. which motor should I choose to avoid of using a gearbox? I would like the efficency to be at 80% at least. Can you help me please? Regards Giovanni
@Giovanni Motors without gearboxes are rarely able to provide sufficient torque (they spin very fast, but with almost no torque). To get a high efficiency, you need efficient gearing - try maxonmotors or faulhaber (they come at a price).
hi…nice to see this tutorial…is this still valid for stair climbing…??
@Omer Very good question - climbing stairs raises some additional questions like traction / grip. You also need to determine how you want to climb the stairs: using traditional tracks or other more “creative” method.
It would be really nice if this calculator had a gear ratio input. What would be an easy way to offset the output for gearing? Could you just divide the actual wheel diameter by the gear ratio before entering it and end up with the same effective torque reduction?
@Nick Consider the output torque and RPM - if you want to find the motor’s specs without the gear ratio, divide the torque by the gear ratio, and multiply the RPM by the gear ratio. We did not include this because we strongly suggest using a gear motor system with motor already connected.
Starting torque of my dc motor is 4 Nm (without using gear). Will i increase starting torque using gear??
Hi, please what type of battery and motor would you suggest given the data from your calculator
Input
Total mass:25 Ibs
Number of drive motors:1 [#]
Radius of drive wheel:1.5 in
Robot Velocity:1 ft/s
Maximum incline:45 [deg]
Supply voltage:12 [V]
Desired acceleration: 0.254 m/s2
Desired operating time: 2 hours
Total efficiency: 65[%]
Output (for each drive motor)
Angular Velocity: 8.0000 rad/s
Torque*:4.7796 Nm
Total Power: 38.237 W
Maximum current: 3.1864 [A]
Battery Pack 6.3728 [Ah]
Thanks
@Chudi With only one drive motor, do you plan to use rack and pinion steering, or was that a mistake? Skid steer requires two drive motors. A 45 degree angle is really very steep, and the equations factor in acceleration up an incline, which may not be the case.
sir i’m working on my project which is solar powered vehicle the structure is around 400kg please tell me which motor is suitable
@coleman. Respected sir, I am going to design a mobile robot for some specific applications. The details are as follows:
- mass= 15 kg
- acceleration = 0.55 m/s^2
- number of drive motors=2
- radius of wheel= 6 inch
- velocity = 2.2 m/s
- incline = 15 deg
- supply voltage = 12V
- operating time = 2 hrs
i would be truly grateful if you could suggest me a dc geared motor which would suit my needs. I am also looking for an incremental encoder to go with that. Kindly help me please.
Thank you.
Nithin