makita router rpm constantly reving up/down any one had this problem?

[senor J.]

So I see above I have a couple of opinions that a makita/ porter cable router, even the 3/14 hp supposable "industrial" routers are going to start having major problems at around 120 hours? Thats simply pathetic to put it plainly. I have a dremel tool that I beat the crap out of. It has 100's of hours on it and is still going strong. I would think a heavy supposable "industrial" router would give 100's of hours of use with out major parts going bad...... Any way about that speed control would it maintain constant rpm ,more or less, under load? Im not sure But I think how the speed controls in the makita router work is that applies more current under load to maintain the rpm. Would a harbor freight special do that? I'm pretty sure at this point that its the speed control unit thats going bad . I took the brushes out and they look fine, lots of brush left.

[Madclicker]

Originally Posted by senor J. ...... Any way about that speed control would it maintain constant rpm ,more or less, under load? Im not sure But I think how the speed controls in the makita router work is that applies more current under load to maintain the rpm. Would a harbor freight special do that? I'm pretty sure at this point that its the speed control unit thats going bad . I took the brushes out and they look fine, lots of brush left.

Don't waste your money on the HF "speed control". I have one and it's useless. All it is is a glorified light dimmer.

Proper speed control is done with a feedback circuit. When the speed slows it applies more torque (current) to get the speed back up.

I, also, think the problem is in the speed control circuit(s?). If it were my router I would do one of two things:

1. If I could live without VS, I would bypass the circuits and hard wire for full speed.

2. If I really needed the VS I would replace the circuits.

[iswidcat]

You will probably find that the ring magnet that is sandwiched between the comm end bearing and the commutator has come loose on the shaft, or the magnet itself has cracked within its plastic moulded holder (normally the red band below the bearing with Makitas). This means that the sensor coil withing the electronic section is getting the wrong information, so it cannot tell what speed the motor is actually running at.

If the magnet isn't obviously broken, pull the comm end bearing off and resecure the magnet with a drop or two of anaerobic adhesive, such as Loctite studlock. This is also a common problem with many of the Dewalt (Elu) routers and the big Freud. The manufacturer's difficulty is in moulding a hole through the magnet material that is tight enough to grip the shaft without putting so much stress on the brittle material that it cracks. Use only a very small amount of Loctite and wipe off any surplus, else you run the risk of an electrical short between the commutator and the shaft. Preferably get a qualified tool engineer to flash test (Hi-pot) the tool for electrical safety after you have done this.

[tsalaf]

This is a defect in some earlier Makita routers and was repaired on both of mine free of charge, even after the warranty had expired.