Data Sheet

8/8/2018 All Terrain Mobile Robots | Wheeled Robots
https://www.superdroidrobots.com/shop/custom.aspx/all-terrain-robots/42/ 2/6
 Back to Top
Load Capacity
This is a common question. Unfortunately, there is not a straightforward answer. Many
factors come into play when picking the right robot in terms of capacity. First off is
understanding that our robots use skid steering. This means that in order to turn, the wheels
must skid. So the more weight, the harder it is to turn. Pivot turns are the most difficult (one
side in forward, one in reverse). Frictional force is dependent on only two things. (1) the
weight and (2) the coefficient of friction. If you are driving on a slick surface such as smooth
concrete, hardwood floors, linoleum floors, etc. its easier to turn than if you are driving on
shag carpet, deep grass, etc. The more weight you add the more power you will need to turn.
More power does not necessarily require bigger motors. You can go with smaller wheels
which require less torque or slower RPM motors which have higher torque. Below is a typical
current drain of a IG42 ATR robot with 122 RPM motors riding with 10" tires.
Drive straight concrete: 2.75A
Drive straight grass: 3A
Pivot Turn smooth concrete 10A
Pivot Turn rough concrete 16A
Pivot Turn asphalt 16A
Pivot Turn grass 16-17A
Pivot Turn carpet 14A
Right Turn or Left Turn Asphalt 8A
Uphill (loading dock ramp) 5A
2 Our Wheel mounts: With the exception of the DM ATRs, our wheels are mounted
on shafts that are supported by heavy duty sealed ball bearings. The DB Heavy Duty
and DB Heavy Duty Enclosed ATRs have two bearings per shaft. Our competitors
mount the wheels directly to the motors. The motors, however, are not rated to handle
any significant load or impact when configured like this.
3 Our Gear Motors: We use 24VDC planetary gear motors with steel gears. 24VDC
equals more power at less current. Our gear housings are very stout and can take the
abuse. We tested other gear motors and sometimes did not even get a full battery
charge before the motors were smoked or the plastic or sintered metal gears were
wasted.
4 Our Support: We are not "Fly by night". If you need support,  call us or email us
(https://www.superdroidrobots.com/shop/contactus.aspx). We are here to help you! Our
website has more than 500 pages filled with information about our products. When you
purchase any of the ATR packages you get access to download our highly detailed
manuals.
5 Our Knowledge: We love robotics, it's what we do. We will be glad to help you with
your needs whether its a custom robot or standard kit.