Wheeled Robot Overview
This is a robot series that is designed to drive over just about any terrain for use with surveillance, academic research, and most practical robotic applications. It works on any indoor surface and most outdoor surfaces. Below are the links to different configurations and platforms you can select to customize the ATR to your needs. We offer three categories of ATRs: DM (Direct Mount), SB (Single Bearing), and DB (Dual Bearing). The DM ATR is direct drive with the axles mounted directly to the motor shafts so that the motor shafts support the weight of the robot. The SB ATRs are also direct drive but have one outboard bearing that supports most of the robot's weight and takes a lot of the stress off the motor shafts. The Heavy Duty ATRs are chain driven with the axles to supported by two bearings. This allows the chassis to support 100% of the robot's weight. Each wheeled robot includes IG32, IG42, or IG52 at the end of its item name. These refer to the size of the gear motors that are included in the robot kit (for example, the IG32 is a motor with a 32mm OD gearbox). For more on gear motors, visit our Gear Motors Category Page.
|SDR Wheeled Robot Categories
|DM (Direct Mount)
|SB (Single Bearing)
|DB (Dual Bearing)
*This is the maximum weight that the robot can handle. Please note that this weight varies widely upon the robot's configuration and the surface on which it is driven. Read below for more information.
There are a lot of other people selling 4WD Robots. We encourage you to look closely at them and compare.
- 1 Our Frames: Our frames are made of durable aircraft aluminum. They are laser cut then fully welded and gusseted. They can handle virtually anything you dish out to them. They are not light gauge sheet metal or plastic.
- 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. 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.
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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
Softer tires will typically grip better increasing friction. However, softer tires will also squish down more easily and at some point they won't be able to support the weight of the robot. Our 10in. Pneumatic tires are the heaviest duty standard option. They have steel rims and steel shafts but since they are bigger in diameter, the motors need to be geared down so you will have the power to turn. For extreme duty robots we have 13 inch tiller tires (see our snowplow robot) however they are not a standard option due to their size and weight. If you would like to put these tires on an ATR please fill out our custom robot request form. We also offer 4 inch Omni wheels which will eliminate the skidding torque issues with a pivot turn since they roll sideways. The downside is that they are only 4 inches in diameter and are not good on side slopes or in outdoor or dirty environments. Another option is our mecanum wheels, which are comprised of a series of rollers mounted so that their axis of rotation is 45 to the axis of the main wheel. These wheels allow your robot to drive forward and backward as well as vector side to side.
Most of our ATR kits use a single axle that is supported with a bearing, then coupled to the gear motors. See mechanical descriptions below. The DB ATRs use a shaft that is supported with two bearings, then chain driven. Using this method removes all the dead load from weight off the motors.
Another factor to consider is how the robot is going to be used with regards to duty cycle. A robot controlled by an RC controller for fun is far different from one that used for industrial applications. In industrial settings, our robots motors are run 100% and often autonomously. If running autonomously, stalling conditions must be taken into consideration. If a motor is held in a stall condition for too long the motors will burn up. If you are running a heavy duty cycle you will want the robot to be on the lighter side of its limits and use higher torque motors so they will not overheat and wear out prematurely.
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DB (Dual Bearing) and DB Enclosed Heavy Duty ATR
Our DB Heavy Duty and DB Heavy Duty Enclosed ATRs are our most robust wheeled robot kits. Each of the four axles are driven by a large and powerful motors to yield a very smooth and slip free mode of operation. The wheels are chain driven which allows the axles to be supported by two sealed ball bearings. The ends of the shafts are exposed allowing encoders to be easily mounted to them. The Enclosed robot can operate in all weather conditions and can be made water tight and completely immersible. Many more features are available on the item page. Follow these links for more information.
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SB (Single Bearing) and SB Enclosed ATR
Our SB and SB Enclosed ATRs are our medium duty platform. The wheels are directly coupled to the motors and the axles are supported by one sealed ball bearing. The Enclosed robot can operate in all weather conditions and can be made water tight and completely immersible. Many more features are available on the item page. Follow the links below for more information.
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DM (Direct Mount) ATR
These are our DM ATR that are smaller and more economical robots. Like the SB ATRs, these are also direct drive but the axles are directly mounted to the motors meaning that the motor shafts support the weight of the robot.. Use these robots for navigating tight spaces where the power and size of a larger ATR is not needed. Follow these links for more information about the Compact ATR.
ATR Equipment and Parts
We also offer many accessories for our ATR Robots. Some of these include a bumper that can be mounted on the front and rear of the robot and an upper deck which allows more space for mounting sensors and other components. See the links below for further descriptions of these items.
The above descriptions lead you to the mechanical assembly of the ATR Robots, but in order to make the robot run, you need to hook up the electrical power and controls. See these support topics below for more help.
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