Inline Sanding Hack
This was a quick experiment to see if one could use a reciprocating saw as a way of achieving a linear or "inline" sanding action.
Using an offcut of 19mm MDF, I cut a kerf into the face of it with a plunge cut using the reciprocating saw, and then flipped the blade over and fixed it in place into the kerf with a screw:
Stuck some sandpaper to the other side (for the purposes of this experiment I did not profile the face of the block, and just left it flat):
Then mounted in the saw:
The saw in question has a plunge stroke of about 10mm. Due to the angle of attack this gives just a bit less than 10mm of stroke of the block, and about 1.5mm of movement perpendicular to the pad.
Does it work?
Yup, you can sand with it, and when using two hands, its controllable, and the pad tracks a decent linear action. You can also get a reasonable amount of weight behind it as well. I used 120 grit sandpaper on it. That proves to be not particularly aggressive, but does sand. If using in anger, a smaller sanding block, and 80 grit would work better.
What does it feel like?
As expected the vibration is slightly worse than using the reciprocating saw just to cut, but would be tolerable for a few mins of use at a time - especially if padded anti-vibration glovers were worn.
(results with a larger mains powered say would probably be better, and less vibration reaction from the mass of the block, but also more weight to hold)
Would I want to do a whole ceiling's worth of beams with it? Nope, I would buy the Festool!