Makita ROS issues?

[graduate_owner]

Hi all,
I have a Makita random orbit sander which takes 150mm sanding disks. I noticed recently that when I apply even very light pressure, the rotation slows almost to a stop. I have not noticed this before and indeed it might have been like that from new. Does anyone have a similar sander, and could tell me if this is 'normal' or is my sander faulty.

Thanks.

K

 

[Bingy man]

I’ve not had this issue but it’s not supposed to stop . Do you have the manual for it . Hopefully it’s just a drive belt rather than a motor issue..maybe post the model number and other members can help you who may have the same model..

 

[ChaiLatte]

What sort (speed, power) of rotation are you expecting?

On a ROS, the disk should be free to rotate in the sense of not being restrained against rotation, but is not actively driven to rotate by the motor. When in use, any rotation you see is passive, a consequence of other active parts of the drivetrain. You could think of it as akin to the front wheel of your bicycle.

The freeness-to-rotate coupled with the oscillation when powered is what produces the random orbital motion. Contrast this with how a traditional orbital (without random) sander works - the traditional 1/3 sheet is constrained against rotation.

If you power it up in mid air, you should see the disk rotate just from vibration but if you grasp it in that position, you can stop it rotating without straining the motor. When switched off, if there is appreciable resistance to rotation, something has gummed up and needs investigating. It is difficult to describe how much resistance is acceptable. The spinning is not free running, like a bike wheel in a bearing. Best thing I can say is go to a shop that has one and feel how a new one rotates.

As above, tell us the model number and go and look at the exploded parts diagram. That wil tell you how the leg bone is connected to the hip bone and show you what part to focus in upon if you determine there is a problem.