This little tool helps to set the quartering of steam locomotive driving wheels. You will need to print two of each inside and outside plates. You will also need two 2mm screws of 40-50mm long plus about 10-12 nuts for the same. Assembly: Place the 2 screws through the holes in one of the outside plates and secure with 2 of the nuts. Next slide one of the inside plates over the screws and secure with nuts. Thread on another 2 or three nuts on each screw (the distance between the inside plates must be less than the wheelset to be quartered back to back measurement) and slide on the second inside plate. Secure with two more nuts. Lastly, slide on the 2nd outside plate and secure with nuts. (The same amount of nuts on each screw must be used as between the first outside and inside plate.) The jig should now be perfectly square and all surfaces parralel to each other. How to use: Screw the crank pins into the wheelset to be quartered. Place the axle into the round slots with the wheels sitting between the inner and outer plates. Next, rotate the wheelset that the right hand crank pin touches the 45 degree angle on the right hand side when looking at the wheel square on. Now, gently twist the left hand wheel till the crankpin touches the left hand 45 degree angle plate and the quartering is done. Secure the wheels in this position and do the next wheelset till all the wheelsets are done.