Kapex blade brake

[Woodhack97]

So I'm reading the manual and get to the part where it say's the Kapex has a gizmo that stops the blade in a second or two upon releasing the trigger. It goes on to say the saw will basically NOT work when this gizmo wears out. When do I need to think about replacing this and is it a repair I can do?

TY
Brian

 

[GPowers]

Is it a field replaceable part?

 

[WarnerConstCo.]

I am not real sure I would worry about it.

I think it will take a long time for that to happen.

 

[Rick Christopherson]

It's a shunt brake (electrical) not mechanical. It doesn't wear out. Unfortunately, the person that wrote that manual didn't understand what the engineer told him. If the brake fails, it means the whole motor failed.

 

[Woodhack97]

It's a shunt brake (electrical) not mechanical. It doesn't wear out. Unfortunately, the person that wrote that manual didn't understand what the engineer told him. If the brake fails, it means the whole motor failed.

Whew...that's a relief.

 

[TomGadwa1]

I used to work on linear motion servo actuators. This consisted of a bobbin wound with a coil of wire. The bobbin rode on rails between a set of magnets. When a voltage was applied to the bobbin the magnetic lines of force created by the current passing through the bobbin would cause it to move in a desired direction with a servo driver board for precision control. Sometimes the units would fail due to the bobbin winding having an open circuit. Heres where the braking function comes in. To test if the bobbin winding was an open circuit or not all one had to do was short the bobbins connecting wires together. While the short is applied one will feel the resistance of the magnetic force as the bobbin is rapidly moved along the distance between the magnets. This effect can also be used for regenerative braking such as on trains and in this case the KAPEX as well.

 

[TomGadwa1]

To further explain the test I described above is very much like the shunt braking principle. What the engineer was implying was that if the brake ceased to work it would be due to an open winding on the KAPEX motor. This would cause the saw to not spin the blade as well. Clever use of the basic principles of magnetism and the cutting lines of force by the FESTOOL engineers. My curiosity is do they apply this to the other tool braking setups within the product line?