The Velleman provided PCB cover is inadequate as only the top of the PCB is covered and no forced-air cooling is available. Some users have complained about overheating of motor driving components. The two parts make a full cover for the PCB that will accommodate a small 12v cooling fan, the same size as the fan supplied with the printer i.e. 40mm. PLA is the preferred material.
I note that some people have mounted the fan externally but the box was designed for internal mounting with a finger cage on the outside.
Made with the Velleman K8200 via Repetier Host V0.90C using black 3mm PLA; 0.2mm layer thickness can be tried as this creates a more solid box and I print at this thickness all the time now since Repetier Host V0.95F became available with the new Slic3r version. The printer settings were set for solid fill for the full height with the standard linear fill pattern. My preference was for a 200 degree extrude. Before slicing, the cover needed to be rotated to top down. I was using blue tape on the standard bed at 50 degrees. Some minor trimming and hole clearing was necessary. Reset is achieved through the small hole "R" and a straightened length of 3mm PLA was used to fit into the boss as a pushrod on the inside of the case; the reset hole is smaller on the top so that the pushrod does not fall out through the top hole. The pushrod needed to be a loose fit in the boss. The fan power was taken from the PCB, the lower two pins of the unused connector holes near the reset switch are available with 12v. The cover fits to the same bosses as the PCB but the two spacers were discarded as well as the two small plastic washers under the PCB mounting screws. Two 10mm long small self-tapping screws were used to hold the cover to the base on one side but the other side is latched to the PCB. The base was made wider to provide better PCB support. Depending on wiring, some adjustment to the cable entry slots may be needed but I have tried to be generous without leaving finger holes! If the SD-card mod appears I will adjust the case. Solidworks drawings are available.