Festool domino df700 running fast/slow

[Rimski]

Hello, sorry new to the group.
Today while running the domino, it started running slow speed then as I moved it it ran back at normal speed.
Is that the brushes wearing out or some else?
Anybody had the same issue?

 

[alltracman78]

How old/used is your 700?
Has it only happened one time?

If it has I would keep using it and see if you can duplicate it again?

I haven't had this issue with mine.

 

[Rimski]

The machine is 12 years old, I’ve never had any issues with it previously. When you turn it on it’s almost like there’s not enough current getting through so it doesn’t seem to run at full speed continuously

 

[luvmytoolz]

Maybe the brushes need replacing or just sanding back a bit to get a clean straight edge, and check the copper pads on the rotor haven't built up a layer of crud. You can safely give them a very light sand to bring them up like new.

 

[Rimski]

I’ll have a look at that, thanks Still a bit perplexed as to why it’s going slow and fast, if it was a simple loose connection it would cut out rather than slow down surely?

 

[luvmytoolz]

It could even be the control board, a broken pin or dry joint, but cleaning the rotor and brushes is an easy quick job that would at least rule them out.

 

[Rimski]

I guess the hardest thing with these jobs is diagnosing the problem, fixing it is usually straightforward after that

 

[luvmytoolz]

Also once you've ruled out the rotor and brushes, having a look to see if you can see any signs of wear/slop in the mechanism would be an idea in case a gear or bearing has worn to the point it's allowing it to shift in and out of transmission.

 

[RJNeal]

First thing I would check out is the Plug It connection.
Sounds to me like it’s arcing.
Are they black and have soot on them.
It is recommended that you don’t just switch tools and cords with a contaminated cord end. Or the could go to the next tool.

 

[Rimski]

I’ll have a look, thanks

 

[Rimski]

I’ve tried a different cable, same problem unfortunately

 

[C8H10N4O2]

I’ve tried a different cable, same problem unfortunately

Just for troubleshooting sake, have you tried a different receptacle with the different cable?

 

[Rimski]

Thanks to everyone for their input here. It seems to be working ok now!! Fingers crossed So my mate who’s an electrician took the outer casing off and had a quick look at the carbon brushes. They didn’t seem too bad, put them back and tried it again. It started working again, but a bit intermittently (fast/then slow/then fast). He gave it a bit of a shake to see if it was something loose. It started up again ok. Left it and came back to it the next day to show my dad, and it’s like nothing happened! I’m going to change the carbon brushes and give it a clean, but we’re wondering if a bit of dust, dirt, wood chip etc or even a piece off one of the brushes has come off, hit the motor and caused a spark (hence the popping noise and smell I initially noticed) and perhaps contaminated the armature. When my mate had a look it perhaps it came off?