The Sparedrum Drum Drilling Layout helps to trace easily on the shells the drilling points where you will insert the lugs, snare throw-off, butt-end, air vent... For drum shells from 6 to 26 How to use : - On a rigid and flat surface, position the layout - Position then the shell on the corresponding size, the black line should be slightly visible. This will help to check that the shell is correctly centered - Hold still the shell in position (it must not move) - Use a square to draw lines with right angle on each colored visual mark (the choice of the color depends on the number of lugs your shell will be composed of) - Draw marks where your the snare throw-off and butt-end will be positionned using the graph paper sides - To check that the lines you drew are correct, you simply need to return the shell and check the squareness of the lines using your square angle - Once all the vertical lines traced, you need to trace horizontal lines to finalize the drilling points according to the size of your hardware Our advice: - Before drilling, check several time your work - Check that you are using the right drills (right diameter, adapted to the shell material) - Measure and check carefully the dimensions and center to center dimensions of the hardware you want to install Great drum building!