Rage3 Brushes

[DrPhill]

Just had to replace them again - one of them wore very fast.

I got an 'aftermarket' pair of brushes. Lots of popping and sparking. It could be that the new brushes are not (as advertised) suitable for this model, or it might be that the commutator (???) that they rub against is damaged.

New brushes from rage are 20gbp, a new (base model) machine is about 70gbp and carries a three year warranty.

What would you do?

 

[sunnybob]

sounds like the commutator is worn. look closely at the segments, they should be clearly defined with no curve or burning.

for the prices quoted, I would bin it.

 

[graduate_owner]

Could the sparking be due to thd brushes bedding in? Perhaps they are not an exact match but will surely wear down to the diameter of the commutator in time. As has been said, check the commutator for damage.

K

 

[DrPhill]

Hi all,

thanks for the replies and votes....

Had a look at the commutator - looks fine through the brush-holes. But then I noticed some screws on the end-cap. Oh-oh. Takes off end cap and three bits fall out. Two plastic and one magnetic. And a screw. Ok four bits fell out. The screw was a pz2 but its recess was filled with plastic. The inside of the end cap was worn immediately over the end of the motor shaft. So the screw was loose, and rubbed the inside of the case until it filled the slots with plastic. There was not enough clearance for the part to become completely dislodged but enough for them to be out of position a little.

I have sort-of figured out how the bits should fit together, and they leave the magnetic bit near to some electrickery with wires headed off into the motor housing. Could this be the the mechanism that detects when or how fast the motor is turning (spinning magnet on the shaft, coil of wire in the electrickery?) Could the magnet being loose be responsible for the motors misbehaviour? or is it caused by the misbehaviour?

The tool has a 'soft start' mechanism - I have no idea how that works, or even if this is relevant.

I will try the motor out, but first I need to find a way to tighten the pz2 screw in the end of the shaft. - maybe some threadlock?

Anyone out there know anything about these motors?

Oh, and those five votes for a different machine - what would you recommend?

This machine, although it cost about 150gbp new easily saved me that (and more) employing an expert to patch-match my wood-block floor, and has done several jobs since then (including lots of rubbish/firewood chopping and the odd nail or screw) so I am not too disappointed. If I can resurrect it that would please my wallet though.

 

[graduate_owner]

Just guessing but those unidentified wires could be to do with blade stopping. My SIP mitre saw went wierd, it wouldn't switch off when I released the trigger and by the time I reached the wall socket there was black smoke pouring out of the saw, then nothing worked. On checking, I couldn't see how some wiring went back so I did a test with a multimeter to assist my 'guesswork' and it worked again, but free wheels to a stop after switching off. I can live with thar. So the device that bings the bladd to a rapid stop was thd culprit.

K

 

[DrPhill]

My blade coasts to a stop in normal operation, but I am sure that the loose bits will not have enhanced its behaviour. Tomorrow I will tighten the bits up, with loctite on the screw and see if it behaves any better. The machine is destined for the scrapheap if I cannot fix it - I am not convinced that a twenty quid set of brushes would be a good investment.

I can probably get through the winter without cutting any more kindling/firstwood, and can defer the decision to the next carpenting task. I might even be able to transplant a working motor from a new (low-spec) machine to the older (higher-spec) base. I can likely salvage the old blade (though that may not be worth it if blades last longer than motors).

 

[graduate_owner]

Rather than scrap it, try offering it to forum readers who might be able to salvage bits for their saws, assuming you can't get it going that is.

K

 

[DrPhill]

Sure, though I am not sure if I would get many takers.....

 

[DrPhill]

Update:

Replaced the loose bits, used a bit of threadlock on the retaining screw. The saw works perfectly now. I guess those bits were not meant to be rattling around loose. Who'd a thought it hey?