Spur gear motormount with integrated encoder

[Create3D]

Hi, I have been developing this new motormount for a while(1-2 months) and i decided to make a topic about it.

What has been done?

• Truck adaptor plate, fits trampa cnc machined trucks.
• Motor baseplate, designed for 63mm motors with 44mm bolt division.
• Spur gears designed and ordered.
• Stress analysis for mechanical parts.
• 3D printed prototypes(Alot).
• Designed magnetic encoder.
• Cost optimization for parts.
• Design cover with integrated encoder.

To Do :

• Finish magnetic encoder design and order.
• Finish baseplate, truck adaptor design and order them cnc machined.
• Design wheel adaptor and 3D print it.
• Machine spur gears.
• Test.

Old version:

Current version:

[onloop]

Great work so far!

So do you need a magnet on the motor shaft?

[Create3D]

Yes. I have tried attaching 3d printed “magnet holder” on the shaft. That worked fine, but i think it could be more compact. For this i am trying to embed magnet inside the spur gear so i could save 3-5 mm of cover height.

[onloop]

What is the advantage of encoder compared with hall sensor inside the motors?

[Create3D]

Normal esk8 motor has 7 pole pairs and 3 hall sensors, so it generates 42 pulses per revolution. 42 pulses / 360 degrees. 1 pulse equals ~8.57 degrees of resolution.

Encoder generates 4000 pulses / revolution ( 4000 pulses / 360 degrees), which equals 1 pulse / 0.09 degrees of resolution.

Higher resolution is important for FOC mode.

Increasing resolution, increases dramatically low speed torque and efficiency of motor, removes coqqing.

[b264]

Are the gears steel or not steel?

[Create3D]

Wheel spur gear is made of POM plastic and spur gear on the motor shaft is steel. It’s pretty common to use soft and hard material in drivetrain.

[ShutterShock]

Interesting design, I don’t think I’ve seen anyone with encoder integration quite yet.

Mountainboards and encoders mix really well, and I agree, I think embedding it in the spur gear is a good idea. Need some kind of retention though so it doesn’t break off and get in the gear teeth

[Create3D]

That’s good point to make sure magnet can’t get in the gear teeth.

[b264]

Do you have any plans to use steel gears in the future?

[Andy87]

@ShutterShock

Interesting design, I don’t think I’ve seen anyone with encoder integration quite yet.

Etoxx approximately 5 years ago. Ready available since years.

[Create3D]

It’s possible. I am making wheel gear assembly modular so material of teeths can be changed.

[Approachinglogic]

Great project!!

[Create3D]

Encoder wire is attached to cover plate. I designed there 1 zip tie, but i think i go for 2 zip ties just to be sure.

Motor attached, motor shaft will be cutted correct length.

[Create3D]

Update :

Spur gears arrived :

Encoders arrived :

I got cnc and have been learning to use it

[Create3D]

3D printed bracket for milling

[Create3D]

Finally its working I made 10S6P Samsung 30Q batterypack for this project. Vesc is limiting peak power to 3200 watts. Thanks to encoders torque is very high and constant.