I used a Gridfinity generator to quickly put together a base blate for my Ikea Malm Desk dtop drawer. My Malm Desk is the (w) 140cm x (d) 65cm x (h) 73cm and full dimensions can be found here. The drawer has a dimenion of (w) 32cm x (d) 39cm. I took 0.2cm off the base to ensure a safe fit and I also run some felt sides in my drawer. You could probably print some small buffer to sit in the corners to ensure an even more snug fit.