mdf is actually quite a workout for a router. A couple of causes of your over heating could be:
1. too heavy of a cut (either too deep or too fast)
2. bit too far into collet, conducting heat directly from bit into router shaft.
3. mdf dust clogging air passages, preventing proper cooling (especially if in a table mounted operation)
4. You not taking a coffee break halfway through and giving the motor a chance to rest (only kidding)
5. bad bearings (how free does the motor turn when unplugged?)
Try blowing out the housing with clean dry air, just to make sure your router isn't clogged with dust. You could also check how much air the motor fan moves by running your router without a bit in it and feeling the airflow. If is still gets really hot, their might be a bearing issue.
1. too heavy of a cut (either too deep or too fast)
2. bit too far into collet, conducting heat directly from bit into router shaft.
3. mdf dust clogging air passages, preventing proper cooling (especially if in a table mounted operation)
4. You not taking a coffee break halfway through and giving the motor a chance to rest (only kidding)
5. bad bearings (how free does the motor turn when unplugged?)
Try blowing out the housing with clean dry air, just to make sure your router isn't clogged with dust. You could also check how much air the motor fan moves by running your router without a bit in it and feeling the airflow. If is still gets really hot, their might be a bearing issue.
