So you want to drill your acrylic drums.

   There are a lot of factors to consider before you drill acrylic. The type of bit, speed, pressure just to name a few. I'll try to cover most of them here but beware even the slightest error can result in failure if you are not careful.

   Lets start with the bit selection. The bit used for plastic is quite different from that used for metal or wood. The main differences are the tip and the screw. The tip is shaped with a steeper angle (pointier) and the cutting edge is beveled. A wood bit if used for plastic would grab and tear it as the bit digs into the surface. The plastic bit is more subtle and works a little slower. The screw portion of the bit is designed to remove the debris cut by the tip and has no cutting edge that some wood/metal bits may have.Additionally, starting with a smaller bit and working your way up to the correct size will help in preventing damage. This also allows for greater control and slower RPM on the second or third pass. If you decide to do this, keep the pressure applied to the material light and let the bit do the work.

   Next, the correct speed for the job. This is something that comes with experience. Some say slow is good while others say fast works better. I believe it depends on the bit and material size (see below for recommended speeds) but you might want to get some scrap acrylic and practice before you drill the real thing.

   Pressure. Don't push the bit into the surface of the drum, let the drill do the work. If you have access to a drill press, that is best. If not then be careful not to move the drill from side to side. Be straight and steady.

   Use a slow feed rate (not RPM but pressure put on the material) when starting the hole to allow the bit to enter the material. Also slow the feed rate when exiting the other side (you may want to increase the RPM a little as the bit exits the material). This will help prevent chipping or worse.

   Locating the hole is critical. Measure and measure twice. Nothing is worse than having to buy a hole relocator. You don't want to use a center punch to start the hole but an awl will work well to worry a point in the surface. This will keep your bit from traveling along the surface of the drum when starting the hole. Acrylic can expand and contract as much as 1/16" per linear foot with changes in temperature, therefore holes should be a little larger than the screw, bolt or whatever is inserted into it.

   It is best to back up the piece being drilled with some soft wood or acrylic scrap. Since we are talking about drums here, that may be easier said than done. It is possible to shape a piece of wood with a band saw perhaps or heat up some acrylic on the stove (acrylic will release extremely harmful fumes when heated so I don't recommend this). This will also help to relieve undo stress on the piece as the bit exits the acrylic. Also make sure the piece being drilled is held firmly or clamped to a firm surface.

   If you are drilling a surface that is three times as thick as the bit being used I recommend a lubricant or coolant (water will work fine) to dissipate heat and remove debris. This will also help to improve the finish.

One last note:
A chipped or irregular hole can cause a crack to occur months after the project has been completed. Using a countersink bit on each side of the hole will help reduce any imperfections and relieve stress but use it lightly with just your hand (no drill attached).