All AndyMark gearboxes require grease for proper operation and long life. We suggest using our red tacky grease, am-2768. We also encourage that the user powers the gearbox continuously for 30 minutes without grease to allow the gear teeth to wear in. While we do design with short run times in mind, this 'run in' period for smooth gearbox operation, is recommended. Once this is completed, thoroughly grease the gear teeth periodically to ensure smooth operation.
NOTE: When operated correctly the angle of the worm in the RAW Box allows it to back-drive.
The RAW Box is a strong, compact gearbox utilizing CIM Motors. Steel and brass worm gears are used in order to provide a setup where the CIM Motors are located at a right angle from the output shaft. Since one or two motors can be used as input for this gearbox, and the gears are made of strong materials, this gearbox can provide a high level of torque.
The worm gear shaft is driven by a spur gear. This spur gear is driven by another spur gear located on the output shaft of the CIM Motor. These two spur gears can have their position swapped in order to change the overall reduction of the gearbox. The Standard Ratio is how the gearbox is pre-assembled and shipped. The Switched Ratio is what the user can get, after re-positioning these gears.
This gearbox design is heavily influenced by the two-motor Right Angle Worm gearbox made by student designer Joey Milia of FRC team 192, GRT (Gunn Robotics Team) from California. Joey and GRT came up with this successful design for the 2012 FIRST Robotics Competition. Thanks, Joey and team 192 for providing this design to AndyMark so that the robotics community can utilize this design! A picture of Joey and his initial gearbox design is below.
- Material: 4140 Steel
- Maximum Output Torque: 90 ft-lbs
- Output Shaft Size: 1/2" Hex
- Ratio: 14.2:1,7.1:1
- Weight: 1.39 lbs
These perform well with no issues; removed a star due to motor mounting hole misalignment on one of the two we got.
The RAW Box gets the job done!
I was very impressed by the compact size, solid construction, and easy assembly of the RAW Box. In all of our testing, the RAW Box did not back drive (tested with loads exceeding 60 lbs) while powering a simple single compound pulley system. Well done!
A little expensive!
I was very surprised to see how well built and compact this gear box is. Just wish the price was more reasonable.