Power Tool Repair Made Easy

Step 4: New Brushes

Body Grinders, routers, and other tools that run at high loads for a long time wear out their brushes quickest.

Brushes usually don't die suddenly.
At first you'll have to shake or twist the tool to get it to start.
Then maybe you'll have to push the wheel with a stick to get it to start.
Eventually it won't start at all.
Brushes are really easy to check on a good tool.

They're under the little "frankenstein neck bolt" plastic covers. Be careful because sometimes the springs jump and throw stuff away stuff you want.

One of these brushes is obviously messed up, looks likethe spring broke, shorted, and lost its springiness.

Don't buy a new angle grinder that costs less than $15. This one was $17 and it's fabulous. It came with spare brushes.

Comments

[The 4th Doctor]

i got that grinder for less then 15 dollars

[charlieb000]

mmmm $15 angle grinder... i got a way to destroy the gearbox on the more expensive ones.. wonder how much the cheapies take? i figured out that using a grinder upside down (edge of disk makes contact only) removes more steel quickly because there is less surface area contacting than if a larger area of the disk is contacting (just like with drop saws) which makes plenty of heat, smearing the metal. the (now) upward pressure does something bad inside the gearbox and the little gear gets eaten out and the larger gear gets a bald spot... this might be due to the bearings not being wide enough. once the gears start to wear out they will self destruct over time even if you have stopped due to vibration because the teeth are no longer meeting tightly. hitachis lasted over a year, metabo lasted only a few months....

other positives of upside down grinding are you are less likely to slip and miss what you really want to hit (because you are pulling it towards you rather than pushing). you dont have to lift the grinder so high (great if you are using one of those massive ones!), you can grind aluminium with a steel grinding wheel (less smearing) easily, and finally, the disk will never come apart because you made it thin.

CB.
dont say i never warned you.