I am working on an the design of an electric wheelchair that should carry a mass of 100kg. Please I need to be sure this wheel and motor-gear specification can suit my design, Thank you.
1)https://www.robotshop.com/en/banebots-p60-gearbox-64-1-no-grease.html
2)https://www.robotshop.com/en/rs-550-motor-19300rpm-12v-6249oz-in.html
3)https://www.robotshop.com/en/actobotics-6-heavy-duty-wheel.html
The one item you’re missing is the hub between the wheel and the output shaft of the gearbox, which needs to be Actobotics and 0.5" diameter:
robotshop.com/en/actobotics- … g-hub.html
However, this setup cannot support 100Kg directly; the output shaft of the gear motor would break, as would the wheel.
If you take a look at which motors and wheels are used in wheelchairs, they are significantly more powerful, larger and the wheels are not being directly supported by the output shaft of the gear motor.
We suggest you input known values into the Drive Motor Sizing Tool to get an idea of the torque and rpm you need:
robotshop.com/blog/en/drive- … -tool-9698
Thanks for the link. I already input my wheelchair requirement to the calculator there. The number of my drive motors are two and two casters to be in front.
Here are my output on each drive:
angular velocity: 15rad/s
Torque: 13.343Nm
Total Power: 195.64W
Maximum Current: 16.303A
Meanwhile, I have done some deep search on robotshop website which I think it’s one of the best to source for the materials for these work of mine. However, my search has been futile since the materials I have seen do not meet my specification. I wouldn’t mind if I get a help on this please. Thanks
Also, I have a question, In order to know the maximum weight my gear motor assembly can support, what I normally do is to multiply the gear ratio by the stall torque of the motor. I need to know whether I will multiply by the stall torque/ max. efficiency.
Thank you
13.343Nm = 1900oz-in
15rad/s = ~150rpm
CIM motor: robotshop.com/en/banebots-fi … motor.html
Torque: 64oz-in
RPM: 4320rpm
You would ideally need a 30:1 gear ratio, which would give you 144rpm.
We can special order a 27:1 or 36:1 gear ratio for the CIM if it is of interest.
Thank you, May I get the cost details of the 36:1 CIM mount gearbox together with other associated components i need like: hub, hub adapter and wheels. Thank you
$133 USD for 36:1 from BaneBots
The wheel you linked to would likely be crushed under the weight - you would likely need much more heavy duty wheels and hub.
Note too that you will not be able to support the weight of the robot on the output shaft of the motor - it is only supported by one ball bearing and meant for rotational loads as opposed to axial or perpendicular.
Please, I need to know the maximum weight this motor-gear configuration can support given the following
gear box: robotshop.com/en/banebots-p6 … rease.html : 64:1 is the gear ratio
Motor: robotshop.com/en/rs-550-moto … tml;RS-550 Motor 19300rpm 12V 62.49oz-in
stall torque:Stall Torque: 4500g-cm / 62.49 oz-in
torque at maximum efficciency of 74.2% is 551gcm
I am thinking of working backward and subjecting my wheelchair design to the constraint of this motor gear box.
Also, Other parts which I am using for this configuration are
1)Actobotics 6" Heavy Duty Wheel
2)Actobotics 1.50" x 0.770" Hub Adapter
3)Actobotics 8mm Bore 0.77’’ Set Screw Hub
4)Sabertooth Dual 12A 6V-24V R/C Regenerative Motor Driver
Please I do need suggestion and comments as I have little mechanical background
Thanks
The maximum continuous output torque of the 550 with a 64:1 gear box would be:
12V nominal
19300rpm / 64 = ~300rpm (no load)
7.65oz-in * 64 = 489.6oz-in max continuous torque
Use this online tool to get an idea of how much torque you need for a robot:
robotshop.com/blog/en/drive- … -tool-9698
Change the weight of the robot and the angle, but you’ll need to lower the overall efficiency.
550 motor efficiency: 74.2%
Gear motor: At most 80%
Overall = 60%
Note that the 550 consumes 10.75A under load, so the 12A Sabertooth will be underpowered when the torque is higher.
You should choose one which can provide at least 20A continuously.
Thank you very much this forum has been so much helpful for me. please , are there stronger wheels available apart from the Actobotics 6" Heavy Duty Wheel especially in terms of diameter and strength, that will be able to fit into the shaft of the aforementioned Rs-550 motor -gear configuration . Thank you
Please which type of hubs or/and hub adapter will fit well between the motor gear box and the wheel.
I am using the 6" tetrix wheel (robotshop.com/en/6-higrip-ru … etrix.html)
Thank you
The following hub would work:
robotshop.com/en/500-key-hub … RB-And-113
You would need a key (which we unfortunately do not offer at this time) as well as two 0.5" shaft collars.
robotshop.com/en/actobotics- … RB-Sct-767
Once again, we strongly suggest not putting a lot of weight directly on the gearbox output shaft.
Please is there no alternative for the shaft collar that I can make use of