drill

**zoomzoomzoom** · 18th July 2006

hi folks.

i got a drill of ebay (with a impact wrench to) made by marksman, there brand new.

But when i use the drill, when i trigger on then off, a blue flash comes from the motor.

is this normal? im not up to date with power tools so havent got a clue. the impact wrench does not do it...

cheers

**blacksheep** · 18th July 2006

yeah happens with loads of totary power tools - some of my dewalt stuff does it

**zoomzoomzoom** · 18th July 2006

well i put my tounge by it and didnt get a shock

lmao

just hope it doesnt burn the motor out, what is the spark for? any reason

**chubblies** · 18th July 2006

Its just from the brushes that contact the rotor, when you press the button, there is a surge of power going to the motor to start it turning, hence the big sparks- you will probably see small sparks when it is turning full speed too, perfectly normal

**zoomzoomzoom** · 18th July 2006

good, thanks for that, thought i had a naff drill.

**Shambles** · 18th July 2006

Ozone release.. my favourite smell

**kracken** · 18th July 2006

New brushes tend to "chatter" and cause larger than normal sparks due to the fact they need to "bed in" to the profile of the copper armature of the drill. Sparks will be reduced once the drill has run for a while.

**coin-op** · 18th July 2006

Originally Posted by kracken

New brushes tend to "chatter" and cause larger than normal sparks due to the fact they need to "bed in" to the profile of the copper armature of the drill. Sparks will be reduced once the drill has run for a while.

Not wishing to be a pedant, but I will

:
It's actually the brushes bedding into the commutator that causes the flashes. The armarture is the wound part in the middle of the motor.

The flashes can be worse if the motor is sill under load when the drill is turned off, eg when the bit is still in the hole you are drilling.