it s not because the can is from Tamiya that ur motor is a 23T .
one can holf whatever a 9t or a 27t armature
a lot of small motor brand use other manufacturers can, armature and/or endbell to make their own .some just modify existing ones
you can (have to!) open any motor to pull out its armature, you can change it or just clean inside of the motor, before pulling it out, check the position of the enbell with the can (use a pen to mark its position) the endbell is setted up to have an angle (timming) that u can set with the can...my english become too bad
this text is from Balak racing, it is important to read it for understanding motor read the page too there are pics http://www.balakracing.com/commcutting.htm
Cutting Your Commutator
By Bryan Balak
For those of you that have been out of the hobby for a while, or maybe are new, electric motor care has become more and more complicated over the past few years. Some of us remember when everyone just ran that trusty 540 that came with the car. The thing was bulletproof. No diodes, capacitors, or serrated brushes. Just bolt that sucker on, and off you go. Nowadays, things are much more complicated. If you want to be competitive in the modified class, A comm lathe (or a buddy who has one) is a must have tool. Even the stock class has changed drastically since the debut of the first ROAR legal rebuildable stock motor. So why is it necessary to have the commutator cut on your electric motor every few races? Before we go any further, lets get some terms defined for those of us that may not know a lot about electronics and electric motors.
Armature – This is the part of the motor that actually moves. It is made up of the commutator, laminations, shaft and winds. When electrons are passed through the winds, an electric field is created that acts against the field the magnets in the can are generating. Since we have two forces pushing in opposite directions, movement is created.
Commutator – The part of the armature that comes in contact with the brushes. It is made of copper, and is usually divided up into 2-6 sections.
Laminations – The part of the armature the winds are wrapped around. These are usually about half a millimeter thick, and are stacked on top of each other. The laminations are sometimes shaped to provide a stronger field. They are usually made of iron ferrite.
Shaft – The part of the armature that rests on the bushings or bearings. I will refer to the shaft in two parts. The long end is the part of the shaft where the pinion gear is bolted on. The short end is the part of the shaft which the commutator is attached to.
Can – The outer part of the motor. It is usually made of steel or some other metal that can contribute to enhancing the magnetic field. The can contains the magnets. A lot of the newer cans, like the Trinity D4 will allow you to remove the magnets. The can holds the bearing that supports the long end of the shaft.
Bushing or Bearing – These are in the can and the hood of the motor. The shaft rests on these. Their sole purpose is to reduce friction. Bushings are made of copper and are found in ROAR legal stock motors and some budget modified motors. Bearings are always found in quality modified motors.
Magnets – These provide the opposing force that the armature’s magnetic force pushes against. If you don’t have magnets (or more specifically, an opposing magnetic field) then you don’t have an electric motor.
Shims – These are placed on both ends of the shaft. They reduce any unwanted space between the can/endbell and the ends of the armature. They are usually made of steel or Teflon.
Endbell – The part of the motor that consists of the brush hoods and the tabs. The endbell holds the bearing that supports the short end of the shaft.
Brush Hoods – These hold the brushes in place and keep them at a perpendicular angle with the commutator. The hood holds will sometimes contain hood springs that keep the brush from vibrating inside the brush hood.
Springs - These keep the brush in constant contact with the commutator. They are sold in different weights. You can change the motor's performance by adjusting spring tension.
Spring Post - These are what the springs are wrapped around.
Tabs - There are 2 tabs per side (positive and negative) on the motor. You can use both sets for soldering leads, diodes, capacitors, etc...
Timing Ring - This is used to advance the timing of the motor. In a stock motor, the timing ring is fixed, and cannot be moved. It is also what the endbell screws into to keep it attached to the can.
Shunt - This is the braided wire that comes out the end of the brush. Some shunts have eyelets on them so you can screw them onto the brush hoods. I prefer to solder them, as this gives maximum electron flow, and better efficiency.