Hi great forum
Im having problems getting previous grit sanding lines out on pine and think i may need a new drum. Today for example i cut at 40grit lightest setting on a slight angle then want straight 40grit, 60 then 100grit zirconia then 100grit trio and the rough cut lines are a bit evident in a few places.I never have a problem on oak. I never had a problem on my old frank viper sander either.
The floorcrafter is a 2010 model i picked it up 10 months old in pristine condition apart from the drum needing dressed. I think the problem seems to be the floorcrafter drum is very hard and my drum seems quite wore down.

Anybody got any ideas?

Thanks

Are they side cut lines or not ?

zirc paper is sharp but with that progression I cant really see leaving machine marks. If its side cuts (which the floor crafter is notorious for) then its a wheel adjustment. Check the cutting path of the drum and see if its cutting hard to one side and adjust the wheels before you dress the drum (it may need some of both).

It is rough grit sanding lines which are not being taken out by the following medium grit.
The machine cuts very slightly more on the right when i first got it, it cut heavier on the left side of the drum which is why i dressed the drum. The thing is also that the drum is more wear down on the right side i would go as far to say its slightly cone shaped which is also evident on the upper roller which is slightly worn more on one side..
I would dress it completly flat but there is not room to play with as in its getting down to the rubber and don't want to make matters worse.

Honestly, I would rule out abrasives by using some 3M paper and then if the problem goes away, you know it is the paper.

Also, change the paper . I change out my sanding belts between 4oo to 600 feet depending on the situation and floor type