I have been using multiple IKEA RÅSKOG trolleys in the workshop for sometime and wanted to try and adapt some Gridfinity storage for them. I liked the concept here by @ArendsoogCarine but wanted to use the magnetic base plates and had a bit of a different idea for the end pieces.

One shelf requires 5 pieces, one 7x7 baseplate, two 5x1 baseplates and two end pieces. The base plates were generated using the Gridfinity Rebuilt in OpenSCAD project so if you need to work with a smaller printer you can regenerate them. The end pieces can easily be cut in half in PrusaSlicer if needed.

The included base plate STL files have screw holes for M3 screws around the perimeters to allow the baseplates to be screwed to each other and the end pieces have holes for M3 square captive nuts to fix the base plates to the ends. The interior sections have 3x2mm rectangular holes to allow you to use zipties to keep the baseplates down on the shelves.

For the end pieces these have their own fixed bins in each corner at the full height of the shelf. Note that the RÅSKOG manufacturing tolerances seem to vary widely so the end pieces might not line up precisely with your unit, however with a bit of persuasion they've fit in all of the shelves I have tried.

NOTE: There has been at least one user for whom the print did not fit at all as the size was out by too much. I’d suggest taking some rough measurements of the unit against the size of the print before printing as a check. It looks like there might be versions of the IKEA unit with much larger variations in dimension than I thought.