@jakimovska Unfortunately it seems the manufacturer does not have / provide additional information. Note that 800W = 1 horsepower.
Yes, it is quite powerful as I only need around 8 W. Since Power = torque * speed. If the power is 800 W, and speed 140 rpm (15rad/s). Which means I could get a torque of 53.3 Nm.
However, as each motor is almost 1 kg and I would need four per robot that is quite heavy. Do you have any motors that are lighter?
@jakimovska Anything in that range would be here: https://www.robotshop.com/en/planetary-gearmotors.html
Hi, Iâm selecting 20 degree incline and 1hr operation in my inputs. Are the calculation based on the robot having 20degree incline 100% of the time (1hr runtime)?
@gmoney18 For the drive motor sizing tool, that is correct - the tool does not factor how long you plan to be moving up the incline. Itâs simple, to provide an estime.
I have an inquiry from the robot calculations
Its deduced that I need
2 Drive motors
torque/motor = 87.5 N.m
Angular velocity = 4.5 rpm to have a speed of 0.0385 m/s
and based on supply voltage V = any value for instance 12 V
Running time = 72 hrs
How can I find the motor that would provide the specific torque & rpm as well as battery pack
@sh The maximum continuous torque your motors will need will be 87.5Nm at 4.5rpm (which is very slow). If you can only find DC gear motors which list the stall torque, then you might need to consider 4x that value.
https://www.robotshop.com/en/planetary-gearmotors.html
To get those specs, youâll likely need a very high gear down and a fairly beefy motor.
Once you find an appropriate motor, see what the current draw is at maximum efficiency, multiply that value by the voltage to get an estimate of the batteryâs âWatt hourâ rating.
Again, given the info you provided, you might need to tweak the values to get something smaller, keeping in mind the calculator is simple and goes for a worst case scenario - accelerating uphill at whatever acceleration and angle you specified.
I have an inquiry to find a motor.
My required spec is
4 drive motors, robot travelling at 3.5m/s
torque for each motor - 2.01nm
angular velocity - 116.67rad/s
based on a voltage of 24v, mass 60kg and a running time of 8hr
Looking for the best motor for this application, preferably a geared motor.
Many thanks
Hopefully this will explain some of the limitations with the online calculator:
The torque calculation is to obtain the maximum required torque to move the robot up an incline, as opposed to what would be more ânormalâ operating conditions. Most motor manufacturers provide the stall torque for their motors, so look for a motor whose stall torque is 4x higher than the value calculated. The running time is also based on the worst condition - in that the robot is moving up an incline for 8 hours.
To get an idea of the type of motor youâll need a small personal transport robot (like a Segway) can move an adult human up a small incline.
2Nm seems really low for a robot of that size - what angle and wheel radius did you enter?
With this calculation based on the worse case scenario to prevent stalling, is the power also calculated using the maximum force (ie the power up the slope) despite this only occurring of a maximum of 20% of the working time. Would it be wise to calculate the force of a flat slope as well and then scalar this (ie 80% flat, 20% incline) to work out the power?
The maximum slope working on was 13 degrees, and a wheel diameter of 30cm.
Ideally we require the motor to be as light and small as possible.
The issue is that if the robot climbs really should have enough torque available to accelerate up an incline without being pushed to its limits. Itâs really up to you how much to lower that value in roder to save weight and money. 60Kg is a pretty heavy robot and RobotShop does not currently carry any motors with enough power for that range (likely around 1/2 horsepower).
Most of the links from RobotShop staff no longer work.
And regarding finding a motor once you have the specs you need, there is no motor or gearmotor index or filter. So, with the quantity of choices that RobotShop has, it is almost impossible to find the motors you need.
The website was updated last month and corrections are being made. Several here donât have redirects and have been reported. Appreciated!
And regarding finding a motor once you have the specs you need, there is no motor or gearmotor index or filter. So, with the quantity of choices that RobotShop has, it is almost impossible to find the motors you need.
Same issue. We hope to bring back product attributes (i.e. specifications) which are used for filtering as soon as possible. Apologies for the inconvenience.
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