Just Cuz Robotics RDY-5735 950kV Hybrid Hubmotor

Specifications

Features:

• 49 grams lighter than RDY-5536 with blade hardware
• Through shaft shoulder bolt
• Center or offset blade mounting
• Epoxy battle-hardened magnets

Assembly Notes:

1. Utilizing a through shaft design, you can use the included high-strength shoulder bolt to tie your bot’s frame rails together structurally and support the motor. Torx is the best, so the included custom shoulder bolts use a T25 Torx drive and low-profile heads to save weight and improve repairability.
2. Mounting the motor requires just 3x M5 bolts (not included) and an included 8mm shoulder bolt.
3. Bolt Length Recommendations: The blade mounting flange is 6mm thick, and included M5x12mm bolts will work for any blade up to 1/4″ or 6mm thick. For thicker blades, we recommend longer screws to fully engage the 6mm thick flange.
4. WARNING: AVOID THREADING MOUNTING SCREWS IN TOO FAR! The mounting for this motor is M5 x 7mm depth threads, threading in further than this risks damaging the stator coils. Just make sure your screws are the correct length to clamp the motor to your frame, with 5mm-7mm of thread engagement.
5. CAD download includes blades with the proper spline geometry needed. We recommend offsetting the spline by about 0.010″ (0.25mm) from the actual motor profile for a better weapon blade fit.
6. Update 5/25/25: after seeing feedback from our early adopters, it seems the mechanical design of this first-gen motor isn’t as robust as we had hoped when supported on just one side for undercutter/overhead spinner applications. It should still work well if supported with the longer shoulder bolt on both sides. Improvements will be made in the next batch to improve functionality for undercutters!
7. The first time this motor is spun up it may draw unusually high current even with no load. This is normal and seems to be a result of the big bearings and their grease needing to warm up and distribute evenly. After a couple of minutes the no load current for the motor drops significantly as the motor and bearings heat up.
8. The outside of this motor is like a big heatsink and can get very hot!

For best results, pair with the Just Cuz Robotics Pariah 70A ESC.

This is a custom motor and not a conventional one so a propeller chart is a useless stat to compare this to. You should use a 50A or greater rated ESC.

Actual current draw and torque are highly dependent on your exact ESC and configuration, battery, voltage, and loading. Air resistance and tip speed for your weapon play a huge role in the current draw of your system. Even reducing speed by 20% might cut air resistance in half.

Experimental Bench Test Data: (Using Pariah 70A ESC)

This product is brand new so more testing is required, but some quick preliminary data can be found here. Expect that the motor performance is very similar to the 5536 900kv for the 950kV variant of this motor.

9″ x 1/4″ Blade, 750kV motor:

• 6S 1300mAh LiPo – Peak 70.4 Amps, 1195 Watts on spinup, continuous 36-40A ~600W
• 4S 850mAh GNB 120C LiHV – Peak 38.4A (seems low, likely kv mismatch AM32 settings), Continuous 29A ~260W (severe voltage sag to ~12.1V, recommend a significantly larger battery)
• 3S 5000mAh LiPo – Peak 30.1A (seems low, likely kv mismatch AM32 settings), Continuous 23A ~220W

Hybrid hubmotors vs 5536 hubmotor

ItGresa Robotics is proud to support the builder community by offering and marketing their products. Just ‘Cuz Robotics has quickly become known for both incredible product innovation and technical support for the community through their great videos. We are proud to be one of the very first distributors to partner with them and help bring their incredible products to a broader market.

Warning: combat robots are not toys! They are extremely dangerous. Click here for a safety video.

Testing a robot with an active spinning weapon should never be done while maintaining a line of sight with the robot. Ideally, you should be testing inside an enclosed box or arena with at least 1/4″ thick polycarbonate windows or top to see through, and 1/2” or thicker plywood or MDF construction. Operation (Including testing) outside of a suitable arena or test box could cause serious injury. By purchasing this product you acknowledge that you are responsible for the safe use of this product and that Team Just ‘Cuz Robotics, ItGresa Consulting Group Inc d/b/a ItGresa Robotics or their employees are not liable for any injuries or damages.