Makita 9911 belt sander - belt wandering

[Eric The Viking]

I've not owned one before, and haven't had this one very long.

On wood it's been pretty good, but I'm trying to level-off some badly-done plastering over a fireplace opening that's been bricked in.

The sander's got a coarse belt on and I'm using extraction. I've now found the belt wanders alarmingly when I use it oriented horizontally - so much so that I fear it will come off at times. I'm using genuine Makita belts.

I've found the screw for alignment, but I can't find any actual tension adjustment. There's nothing in the manual about tension adjustment either.

I know it's a fairly common sander, and I was wondering if anyone else had a similar problem, and how you dealt with it.

Cheers,

E.

 

[carlb40]

Pretty sure all the tensioning is done automatically when a belt is fitted and the lever is put back into place.
As the tracking is ok on timber when held flat. I'm wondering if it because you are using the sander in a horizontal position and it's just gravity helping to pull the belt off along with the course grit.
Have you tried using it vertically to see if the same happens?

Also while it might be slower and more work, have you considered using a surform or similar? That would make life easier keeping the wall flat. :wink:

 

[cusimar9]

The Makita 9911 should auto center the belt, or at least mine does! Perhaps yours has developed a fault? I find the belt wanders off centre when not applying even pressure over the belt (often because the belt is running over an edge), but this is sometimes unavoidable.

 

[Eric The Viking]

Thanks gents.

The steer from the Domestic Controller is that she wants the tower scaff up this morning so she can strip ceiling paper. That means I don't get to do any more sanding for a day or two (too steamy, in quite the wrong way!).

I'll have a play with the belt tracking screw next time, to see what effect it has, and try a new belt too, in case the one I fitted isn't true.

I find I can make the belt slide (when it's orientated vertically) by applying sideways pressure whilst it's sanding. given I need to run it this way, that's a bit alarming (I'm trying to feather someone else's bad patch plastering that's probaly 50 years old!).

I've got a reasonably heavy-duty orbital (Makita BO4900V), but it doesn't make a dent using 60 grit paper. I guess I could drop to 40 grit, but it's pushing it a bit - might just go for the Surform option instead :-(