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Author Topic: cs70eb saw with motor problem  (Read 718 times)

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Offline eestibob

  • Posts: 1
cs70eb saw with motor problem
« on: June 25, 2020, 11:08 AM »
Hi, I have a customer with this cs70eb saw at a window factory, I have replaced the brushes in the motor, checked the bearings wich seem ok but I still have a problem with the motor speed and power being unstable. set on full power  it will run full speed for a 15 to 20 seconds then start to slow then speed up a little then slow. the armature is a bit worn where the brushes contact and that is the only thing i see as a problem. how can I check the speed control and power supply pcb.
Any help would be appreciated.

Cheers from Estonia

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Offline Alex

  • Posts: 7782
Re: cs70eb saw with motor problem
« Reply #1 on: June 25, 2020, 11:47 AM »
Mine does that too. For all the years I have had it now, which is 8 or 9. And I don't think it is a problem, but by design. The saw has an electronic circuit that keeps the saw at a constant RPM, and to achieve this the saw changes the power output to keep the RPM constant.