My drum sander broke down after 7 years, has ordered a new one but it will take some time before it shows up. Getting something shipped from the US now takes months. Meanwhile, I need to be able to thin down various small details. Preferably flat and perpendicular as with a drum sander. Details like the segmented saddle, thin spruce shims and nut blanks. Have my shelf with self-adhesive 80 sandpaper that I use to thin it down, but the difficulty is to make it just as thick over a larger surface. After some quick thinking about it,I did a jig that does the job well, albeit with more work and time.

Using my shelf with sandpaper as a base, the new one is a "sled" with self-adhesive 80 sandpaper and four machine screws and a stop. The slide in MDF had holes drilled slightly smaller than the diameter of the machine screw. The screws then had to thread themselves into the MDF.

To set the height between the two flat surfaces with sandpaper, I use loose feeler gauges. I add a tenth of a mm or two to the thickness so as not to thin out too much.

With the feeler gauges under the sled and two clamps that hold everything in place, I use a 0.05 mm feeler gauge to screw down all the screws to the shelf. The feeler gauge should just be possible to move. Now the sled is adjusted so that it is parallel to and has the correct distance to the shelf.

A thin piece of spruce is thinned from 2,5 mm to 1,5 mm. Takes a while to grind down a larger surface like this.

Became absolutely perfect 🙂

With thicker material you can lock the piece to be thinned between two thin sticks attached with clamps on either side, here an nut blank that needed to be thinned down.

To fine-tune the thickness of a semi-finished segmented saddle after an initial sanding, I use thin feeler gauges.