[derikraven]

yesterday I decided to change the brushes on the vac motors on my Ninja. In preparation I watched a video on you tube just to get some tips. It seemed easy to do , just gently leaver the blade holding the wire free from the brush using a screwdriver.
                               Well..............on the first attempt I could not get the blade to shift and ended up breaking the wire from the blade. As there was no need for subtlety now I tried to pull the blade free from the brush.........it still wouldn't come free.
                              To cut a long story short I resorted to cutting the blades free from the brushes using a junior hacksaw. I couldn't help thinking at the time that this action was a bit drastic. Has anyone else experienced this amount of difficulty changing brushes? Perhaps I did it all wrong.Any input from you lads would be most appreciated and, hopefully, a guide fro the future
Derik                                   

[Kinver_Clean]

There is a trick-

If you look at the blade you will see a hole. If you look at what is left of the socket you will see a small tag. This slots into the blade to keep it in place.
The trick is to get a very thin blade to slide down the side of the connector to hold it away from the tag.
I use the tapered end of a small cable tie. Trouble is I can never remember which side to poke it in.

[Paul Redden Countryfresh]

Best to run in brushes to bed them in......connect a wire from each vac together (any one) and  remaining wires to pos and neutral supply.  This will run at half speed, twenty minutes should do then re-connect as before.

As mentioned use a small screwdriver or bradawl to lever spade from brush holder. Try and re solder broken
wire to spade.

good luck

[Kinver_Clean]

Don't beat yourself up over it- the wire break off sometimes no matter how careful you are. As said resolder the wire back on.

[derikraven]

thanks for the advice lads. I have soldered the wire back on. All is well

[Kinver_Clean]

I have a builders 110v transformer to run brushes in with. !/2 hr coffee break and job done.

[Neil Jones]

How often should they be done? I keep meaning to do mine but I've got a feeling ill be there all day

[derikraven]

really depends on usage. There's no harm in checking the brushes for wear every six months say.

[Kinver_Clean]

The old 7.2" vacs needed checking every 350-400 hours. Mostly they ran for 600 or so but some had soft brushes in and only lasted a shorter time. If the brushes ran out that usually was the end of the motor and they are expensive.

5.7"s  should run for 8-900 hrs but need checking at 600 just to be sure.

[Ian Gourlay]

If you are a good boy and change brushes etc how many hours could a motor last?

[Kinver_Clean]

I have had motors last 6 or 7 years with care.
A lot depends on luck- the wires in the windings are insulated with a thin layer of lacquer. This is heated to make it all stick together in a lump so vibration does not affect it. If this wears through then they will short and blow the motor. This can happen at any time and can get quite exciting.
At one time you could get replacement armatures but since they started balancing rotor/turbine assemblies they seem to have gone off the market.