I now have many hours on my DaVinci1.0A printer and I have been very happy with it. However recently I have noticed that mid print the extruder is starting to jam and causing printing issues. After much investigation I found that there is a large amount of heat bleed from the extruder to the stepper motor while in operation. Using genuine XYZPrinting filament this is likely not an issue since the printing temp is lower than that required by cheaper ABS. However the ABS I'm using is typically printing at a temp of ~20c higher than the XYZPrinting filament. 

Solving this issue was not difficult as we just need to cool the stepper motor a bit during operation. I used the following new parts.....

Photo  Part  Reason  Source  Cost 
 nema17 heat NEMA17 Heatsink Removed the heat warning sticker and placed it with the heat-sink. This must be a NEMA17 heat-sink due to the required center hole for motor spindle and correct mounting hole off-sets ebay £2.30
 40mm Fan 40mm 12v Fan Standard 40mm 12v PC fan, this likely to be overkill as the heat-sink should be enough but while I'm modding the printer I might as well add it. left overs from projects ~£2.50
JCTConnector JST Connectors JST (RC Battery) connectors. This replaces the existing white connector for the extruder heater with one more suitable for the task and allows you to add the fan power wires to the heater power WallE project £0.37 (bought as 10 pack for £3.65)
M3 cap head M3 50mm Machine screws Ideally these need to be 55mm to ensure a perfect fit but I was unabel to get those so settled on 50mm. these screws replace the motor mounting screws for the extra length required when heatsink and fan are added ebay £2.50

Step 1 : Remove the mounting screws for the existing stepper motor

Step 2 : Using the new mounting screws re attach the stepper motor with the heat-sink between the motor and the fan.

Step 3 : Use a meter to find the positive and negative wires of the extruder heater (turn on heater in menu and probe the connector to find +12v)

Step 4 : Remove the connector from the extruder wires. Remove connector from fan wires and splice the red fan wire to extruder positive and red black wire to extruder negative

Step 5 : Crimp on new JST connectors and connect

Step 6 : Turn on extruder in menu and see head rise and fan running.

DaVinciNewExtrderFan

DaVinciNewFanTopView

DaVinciJSTConnector

NOTE: In my top view you can see that because I used a left over fan from another project it was in-fact a 3 wire fan, however since the yellow wire is simply a speed feedback we can cut it off. I cut it very close to the fan so it couldnt get tangled in anything.

Just an extra side note......attaching the fan to the extruder heater wires is a very convenient 12v supply however it should be noted that this supply is NOT constant and in normal use (230C) the heater has ~60% duty cycle so the fan runs for around 60% of the time not 100%. I mention this here so that if you follow this post and expect the fan to run 100% of the time you know that the stop and start of the fan is NOT a fault but an expected consequence of using the extruder supply.