The Kraken X44 is a brushless motor developed by WestCoast Products that has been designed to withstand the rigors of the FIRST Robotics Competition.

The Kraken X44 was designed to be easy for teams to integrate into their designs and has a number of features that set it apart from other brushless motors in the FRC market, including:

• Integrated TalonFX controller

• SplineXS shaft

• Non-replaceable output shaft

• Versatile mounting options

• Robust mechanical design

The Kraken X44 is designed to be a drop in lower power replacement for a Kraken X44. This means the lower weight, lower power but similar rpm.

Diameter

Length

The length of the Kraken X44 depends on the version.

Weight

The weight of the Kraken X44 depends on version.

Mounting Holes

Kraken X44 has (11x) #10-32 mounting holes on a 1.375" bolt circle, spaced 30 degrees apart.

Blind Holes

Each mounting hole is blind, meaning it doesn't go through the mounting plate. By using blind mounting holes, teams cannot lock the motor's internal rotor by using too long of a screw.

Pilot Boss

The Kraken X44 also has the same 3/4" diameter pilot boss that the KrakenX60/CIM/MiniCIM/NEO/Falcon has.

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.

Features

8mm OD

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.

Shaft Retention

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.

Non-Replaceable Output Shaft

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.

Spline Parameters

These are the parameters of SplineXS shaft.

Benefits of Spline Shafts

Splines have many benefits that cannot be matched by the round and keyed shafts typically used on FRC motors. These benefits include:

Low Backlash

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.

Higher Torque Capacity

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.

Uniform Loading

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.

Fewer Parts

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.

No Press-Fits

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.

The Kraken X44 is an enclosed outrunner motor, just like other brushless motors of a similar size. The internal design of the Kraken X44 has a number of features to make it more robust and reliable. These features include:

Larger Bearings

The bearings used inside the Kraken X44 were sized to better handle higher radial loads typically seen in FRC. In addition, all the bearings used in the Kraken X44 are rated ABEC-5 and spec'd to handle the heat that the Kraken X44 can produce.

Integrated Output Shaft

The output shaft of the Kraken X44 is integrated into the motor, and cannot be replaced.

There are also multiple methods of rotationally and axially constraining the shaft to the rotor. This creates redundancy with the idea that if one fails, there's another method to keep the motor running.

Less Drag

The internals of the Kraken X44 was designed to reduce the potential for mechanical misalignment of the shaft bearings. This design yields a motor with less mechanical drag, which improves the no-load performance of the motor and allows the motor to be more efficient overall.

Cooling

The Kraken X44 was designed to keep heat away from the back of the motor where sensitive electronics are mounted.

Motor Performance Parameters

A Note About Peak Power

Referring to the peak power of the Kraken X44 is not an attempt to mislead, or deceive customers. It's a common practice to refer to a motor by its peak power performance, which is why WCP refers to the Kraken X44 by its peak power.

In full disclosure, teams will not be able to use all of the Kraken's peak power on an FRC robot. This is because each motor is limited by a 40A breaker, and the motor needs over (4x) this current to produce the peak power of the Kraken. However, higher peak power is still important in the context of an FRC robot for a two major reasons:

1. The breakers used in FRC are thermal breakers and do not trip at exactly their rated current. It's common that some breakers can allow current well above its rating for brief (less than a second) periods of time. This means that more peak power can have an impact on acceleration. By having faster acceleration, the motor can get up to speed faster when starting from a dead stop or changing directions.

2. By having a higher peak power, the Kraken can operate at a better place on the power curve during an FRC match. This allows the motor to run more efficiently, which means less electrical power is being converted to heat, which means it can run longer before doing permanent damage to the windings.