This is the TM3000C, one of two OMTs (the other is cordless) Mak…
This is the TM3000C, one of two OMTs (the other is cordless) Makita introduced this spring.
Remove screw from rear of tool.
Pull housing off to expose the brushes.
A spring-loaded clip holds the brush against the commutator on t…
A spring-loaded clip holds the brush against the commutator on the armature or “rotor”. This is one of two brushes – the other is on the opposite side.
Release brush by moving clip off to the side.
Pull brush out so it won’t be damaged when you remove the arma…
Pull brush out so it won’t be damaged when you remove the armature.
Remove the plastic housing (Makita calls it the head cover) from…
Remove the plastic housing (Makita calls it the head cover) from the front of the tool.
Remove the screws that hold the crank housing in place.
Pull the crank housing and armature assembly out of the tool.
Pull the crank housing off the end of the armature. It’s a tig…
Pull the crank housing off the end of the armature. It’s a tight press fit where the bushing goes in.
This is the armature assembly. Electricity flows through a pair …
This is the armature assembly. Electricity flows through a pair of brushes that ride against the commutator – which transfers power to the windings. Brushes are necessary because the armature spins so you can’t hard-wire the connection.
The armature assembly is on the left and the crank housing is on…
The armature assembly is on the left and the crank housing is on the right. The end of the armature shaft is machined off-center so when the motor spins the drive bearing moves eccentrically – causing it to press one way and then the other against a pair of arms. The arms are connected to the spindle. When the arms move from side-to-side, the spindle does too – one oscillation for each revolution of the motor.
I was working on a story about oscillating multi-tools (OMTs) when it occurred to me I had no idea how a spinning motor could make a spindle go from side-to-side. So I did what I always do when a tool confuses me – I tore it apart.
I went with a Makita OMT because it looked like it would be easier to take apart than some of the other models. And as OMTs go, it’s not very expensive ($160) so it wouldn’t be the end of the world if it didn’t work after I put it back together.
Click on the slideshow above for images of the tool being taken apart (there are 12 photos in all).
By the way – I put the OMT back together and it works just fine (though Makita might argue with the type of grease I used to re-lube the spindle mechanism).
Archived Comment
September 18, 2012
Would it be akin to cannibalism to have used a Makita instead of a DeWALT to take apart the OMT? 🙂
