DRILLING PLEXI & LEXAN ?
 

I've drilled some plexi 1" rod for thru wire. played with speed and drills. Used brad points To start and aircraft standard bits to continue the hole. Have to pay attention when to pull back on drill b/4 the heat locks in the bit. Right now the speed of 1500 worked better than 880. Any suggestions on drilling both materials?

If you have ever done any drilling of Brass or Titanium you want to sharpen the the flutes of the drill like that. If you haven't you want to flatten the edge so it doesn't grab. Ideal situation would be a drill with coolant holes the length of the drill so you can have coolant right on the tip. I am building a 4 piece mold for WHOI right now out of acrylic and it needed a 1" dia. hole 9" deep, thru. I roughed out the hole with a drill sharpend like stated above and it worked great, although the clarity is not perfect but I will bore to size and polish it hoping for more clarity. You may want to use a squirt bottle of water to keep the temp down and help in cutting.

Hi Paul. Hope Santa was good to you. I was hoping you'd chime in. I'll give that a try. Any speed suggestions? Also I spun a needle on the dupe out of this material. It cut OK. Should this process ruin the carbide bit?

if you rig a small air jet up to blow into the hole and around the bit, it makes a big differance...keeps the stuff from melting..it's what I do when I make templates on my scroll saw... before I did that, the plexi or lexan would melt or fuse the cut back together.. since I made the air jet...problem solved...

pilot holes give relief depending on the size hole desired

no it won't ruin the bit but it will probably get dull a little bit faster. I'd go a little slower as it will melt like Joe said. If you are drilling deep holes a lubricant, coolant, will help as like Joe said heat causes melting or crazing. If you don't care about the crazing, clarity, problem no biggie. Sharpen the drill with the flute edges flattened and it should cut good. Here is what I am doing at work. Got the bore to a 28 finish but had to go real slow on rpm's and feed. I used a carbide boring bar and a carbide insert. I drilled it thru undersize.

Thanks everyone. I keep you posted on further results.

i find if you dont know how to do the flutes and the diameter is not to big running the drill backwards helps,,,how think is the stock you are drilling? if thin use a wood bock on top

Solid lexan rod. 1" dia. 8 "long.