9inch grinder broken

[Am333rcr]

hi

i have a metabo grinder that was working.

so is this where the brushed brushes have failed and can i replace with new?

thank you

 

[The_Yellow_Ardvark]

That grove is from manufacturer, it is the balance it.

The bushes contact the copper segments on one end of the shaft.

 

[brightspark]

look at the copper segments on the end. if they arent burnt you have a chance of replacing them if it sparks when you renew them its shagged out and not worth buying a new one for it

 

[cheb]

You can just see the copper segments on the right hand side of the first pick and they look clean to me. Clean enough I'd say it worth risking a fiver on new brushes anyway. I usually get mine via Ebay.

 

[Am333rcr]

it just woyldnt start up no sparks or anything.

i may have let it labour in metal .i take it that has been the end of it

the copper end

saveable?

 

[Anguz]

if they all look the same, and not any with more marks than the others, i would risk a set of brushes...
but if it just stopped without sparks, i would be checking the lead and the switch first

 

[cheb]

That'd clean up with fine emery paper assuming the other side is in a similar condition. What do the brushes look like?

 

[gaz1]

emery cloth cleans them or in my case a bit of scotch pipe cleaner pad

then try new brushes there cheap enough but its the only way to find out if its no good or not

 

[cheb]

The grooves can be cleaned with a dental pick. I think it's the clag in those coming out that can cause sparking.

 

[Chippie]

The grooves can be cleaned with a dental pick. I think it's the clag in those coming out that can cause sparking.

It is the ‘switching’ action of the brushes on the commutator that causes the sparking….or technically known as commutation….
Dont clean the comm with anything other than glass paper…clean the comm slots out to remove any deposits.
Buy the correct brushes if you want to, but don’t buy any random set…the copper content varies in brushes with application.
If the tool appears dead, and it not the cable or switch, check the continuity of the armature windings between the comm segments for an open circuit. The resistance between segments should be around 1-2 Ohms or so, but they should all read the same…
Looking at the last photo, it appears as though a couple of the coil ends are detached from the comm risers…maybe the light?

The armature can be rewound, but maybe cost prohibitive…or cheaper to buy a new armature?

 

[Seadog]

Use sandpaper, not emery. A ground down hacksaw blade is good for cleaning the grooves.

 

[Am333rcr]

cleaned the copper bit up . both the brushes look the same.

put together nothing . maybe trigger switch unit?

 

[Chippie]

You should have 2 wires coming from the field coils going to the trigger, check with a dvm on Ohms that there is a reading across those wires..( unplugged from the mains! Please…)

 

[Agroshield]

Check continuity of the cable. With rubber cable, one wire can break just where it is clamped inside the handle.

Check continuity through the switch to make sure it is OK.

 

[bricol]

You have checked the fuse - either in it's plug, or in the plug for a 110 box?

I only ask as I have seen a perfectly good lawnmower chucked out as "it didn't work" . . . one blown fuse replaced with a working one later . . .

 

[Hopefuldave]

You have checked the fuse - either in it's plug, or in the plug for a 110 box?

I only ask as I have seen a perfectly good lawnmower chucked out as "it didn't work" . . . one blown fuse replaced with a working one later . . .

At least you didn't drive from Hampshire to the Ford Bridgend works in Wales to swap a fuse...

 

[Pete.]

Don't clean the armature segments they are supposed to be a dark colour. There's nothing wrong with the armature or the brushes from the pic you show. Granted, yours are showing sign of hard work but they still look perfectly healthy.

First thing I would do is remove the wires from the switch and the lead from the clamp. Grab each with on the end with pliers and pull. If it stretches you have found a broken wire where is comes through the strain relief. I have to fix four or five of these a year at work.

 

[Am333rcr]

thanks i will havr another look tomorrow.

i am skunnered with it and everything has went backward today.

 

[Robotstar5]

At least you didn't drive from Hampshire to the Ford Bridgend works in Wales to swap a fuse...

I once had to drive 40 miles to flick a switch.

 

[500e]

Somerset to Falmouth after asking you have checked its plugged in and switched on at the wall
0200 GMT On a Sunday