The planner heater can be modified to take a bigger in size 8k ohm potentiometer that turns much easier then the original pot.
After removing the original knob and taking the case apart you would find the original very small pot that can be turned with a small straight edge jewellers screw driver.
Basically unsolder the old pot and solder in the new pot.
Build a case , done.
Pictures of the finished product in the near future .
I've had quite of few heaters and I believe this one is the best you can buy mainly because of the power mode that allows you to simply dial the heat at whatever level you want , for example your able to dial to a very small trickle of heat output or up to blasting out massive heat.
8k ohm potentiometer
