SplineXS Shaft
Last updated
Last updated
The Kraken X44's output shaft is the all new SplineXS shaft. The SplineXS shaft was developed to improve upon other motor output shafts in the FRC market.
The SplineXS has an 8mm OD, which means the shaft fits into a standard 8mm ID bearing. This features allows teams to better support the end of the SplineXS shaft when the application demands it.
When Should You Use A Bearing?
The purpose of using a bearing is to support the motor shaft to prevent it from bending under high loads. Most FRC applications do not require a bearing. However, there are some applications where using a bearing on the motor shaft is beneficial. Some of these applications include those where there's really high radial (perpendicular to the axis of rotation) loads.
The SplineXS shaft on the Kraken X44 has a #10-32 tapped hole at the end. Allows teams to retain items such as pinions and pulleys on the shaft without having to risk deforming the shaft by using a retaining clip like you would on a CIM motor.
The Kraken X44's output shaft is permanently attached to the motor. It cannot be replaced to a different shaft, or replaced if cut. In addition, there are redundant methods to rotationally and axially lock the shaft to the rotor.
These are the parameters of SplineXS shaft.
| Description | Value | Unit |
|---|---|---|
Teeth | 15 | |
Module | 0.5 | |
Pressure Angle | 30 | Degrees |
Splines have many benefits that cannot be matched by the round and keyed shafts typically used on FRC motors. These benefits include:
Splines are known for having less backlash than keyed shafts. This is important for maintaining positional accuracy between the motor and the final output of a reduction. Positional accuracy is important for things like swerve modules.
Keyed shafts transfer all their torque through a single key whereas spline shafts transfer torque through many teeth. This distributes the torque load and allows a spline shaft to transfer more torque before twisting and breaking.
Since keyed shafts transfer all their torque through a single key, it creates stress concentrations in the corner of the key slot. This stress concentration on a thin wall gear can cause the key slot to crack and fail.
Since spline shafts distribute their torque load, the stresses caused by torque transfer are distributed across all the teeth, which helps increase fatigue life and extend the life of the shaft.
There are no keys, which means you don't have to worry about losing one, or having one fall out during the middle of a match.
Press-fitting a pinion isn't the easiest thing to do. There are a number of things you have to worry about when pressing pinions onto round shafts (straightness, supporting the shaft, etc.). With splines, there are no press-fits, so all of these concerns go away.
