In the manual it says not to open the machine, but how can I check the blades etc?

Not opening the machine refers only to the body of the machine. Do not open this body and if this is broken you need to contact us.

The upper part of the BLSTRsander can be opened to replace, check, clean etc. the rotating parts. You can compare these parts as the replaceable parts of a grinder

Unscrew the 3 black screws at the top and you have acces to the impeller (=the 2 aluminium plates that keep the 6 blades in place), the metal topcover (with the slider inserted in it) and the plastic topcover with the tube.

Make sure that when you assemble the tool again , the tube goes well through the metal topcover, that the slider is well in place and opens/closes correctly and that the slider- end is well inserted into the "fork" that guides the gritflow.

N "MANUALS" YOU CAN FIND PICTURES HOW TO OPEN THE TOPCOVER