Wtf? How to open a Hacker motor?

[suicideneil]

Slottless:






You can see that the windings are essentially 'stuffed' inside the stator, and are smooth inside, forming a nice hollow tube for the rotor to sit inside.

Slotted:





Basically, the slots on the stator focus the magnetic field, causing the rotor to align to the field as it rotates - thats the notchy feeling you notice as you spin it by hand. Depending on the specifc design and brand, the notchy feeling can be greater or less pronounced.

With slottless motors, the field isnt focussed in the same way, so you dont feel the notchyness as it spins. As a side note, slotless motors are usually 2 pole so they spool up faster, but produce less torque compared to a 4 pole slotted stator motor (that spools up slower, and has a higher natural drag-brake effect).*

*correct as required..