The hard black plastic power transfer plate/wheel is left hand threaded and turned clockwise to remove so that the clockwise blender motor turns a slower wheel tighter not looser.

Both the power transfer wheel and the fan blades at the far end of the motor are held to remove the wheel. The photo shows the wheel clearly, the fan blade is covered with a towel to protect the hand holding it from the sharp metal edges of the blades.

The normal function of the aluminum fan is to move hot air out of the bottom of the housing.

The convention for electric motors is to turn clockwise facing the power output end of the shaft because EE’s prefer shorter words. The motor shaft is threaded by rolling it between two slotted steel plates, it costs the same to thread it left hand or right hand. In industrial quantity the nuts are identically priced and producing the motor to turn counterclockwise wouldn’t change the price either. It does drive tinkerers to distraction, I wouldn’t say that it is an objective.

The aluminum fan at the far end of the motor from the power transfer end is, as described, a simple stamped metal part that was not processed to remove the sharp edges and protecting the hand holding the blades is a very good precaution. The blades are also easily distorted. An alternative is to hold the nut that holds the fan blade on instead of the blades. It can be held with a wrench, socket wrench, or nut driver, without injuring the hand or the fan blade. The fan retaining nut is M5 and it takes a 7mm wrench but it can also be held with a 5/16” wrench. Best practice would thread an M5 nut onto the shaft as a jam nut prevent the fan nut from breaking free before the power transfer plate, but if the factory applied thread lock works as well for others as it did for me, a jam nut is not necessary.

From a PhD EE - The internal charge controller in these shavers seems to keep track of how much running time it can accumulate between charges before the battery voltage drops below 1.00v/cell. It will refuse to allow the shaver to start to run if either the battery voltage is low or the charge controller thinks it’s running time is depleted. This strategy for tracking the state of charge of a battery pack can’t track the self-discharge rate of the battery. When the shaver sits unused the battery self discharges and becomes depleted quickly setting a low running time. A very short time allows the shaver to be turned on just once between charges. Likewise when a battery is replaced the chip still retains the estimated life of the battery that was replaced. One way to get the chip to use a longer running time is to charge the shaver and start it and leave it running until it stops because the battery voltage falls too low then charge it fully.

From a PhD EE - The comment about a device designed for NiCd batteries being unable to charge NiMH batteries is incorrect, all of the charging strategies used for NiCd are equally effective for NiMH cells. The type of smart-charger used in this product delivers a rapid charge using a peculiar property common to both NiCd and NiMH batteries to terminate rapid charging and switch to trickle charging for a fixed time period before stopping completely. As NiCd and NiMH cells are charged the cell voltage gradually rises, but after it is nearly fully charged the cell voltage slowly falls. At this point charged cells start to heat up rapidly so the charge control IC switches to a low-rate charge for a fixed time before switching off all together. Heat was used by early 30 minute chargers for laptops and RC toys. NiCd cells tolerate heating better than NiMH in the sense that a 250 cycle NiCd and a 1000 cycle NiMH both last less than 100 cycles using a temperature terminated rapid charger.