I've been wanting to compare a couple drill bits on how well they drill cast acrylic. And I finally had some time to do it tonight. I had some blue cast acrylic that I cut into two blanks 3 inches long each. One blank was drilled with a 5/8" Abbeon drill bit specifically designed for plastics and the other blank was drilled with a 5/8" jobber bit. I used ATF as well while drilling. The bits weren't brand new, but had probably only been used 20 times or less. One thing that I have learned with drilling cast acrylic is to let the drill bit work itself into the acrylic rather than forcing the bit through the blank. You get a much cleaner hole if you do it that way. I also drill a depth of about .30" to .40" a time, depending on how the acrylic ribbons are coming out of the drilled hole. If the ribbons don't have any ATF on them, then the bit will get really hot and you will start getting some crazing. I was able to drill a bit deeper each time with the Abbeon drill bit, since it seemed to hold the ATF around the cutting surface longer. With the jobber bit, the first ribbons that were drilled would lift away all of the ATF from the cutting surface very quickly, leaving hardly any fluid left in the hole.
Here are the drill bits on top of each blank that they drilled. The jobber bit is on the left, and the Abbeon bit is on the right.
And here is a bit more closer view of the two holes in each blank.
The two holes have relatively the same smoothness, but the Abbeon just might be a little bit smoother. The smoothness doesn't show up very well in the pics, but to my eyes, I have to give the nod to the Abbeon. Another thing I like about the Abbeon bit is the fact that you can drill a bit further at a time, and it doesn't sling oil all over the place. The jobber bit ribbons lift all of the ATF away from the cutting edge, and when they surface at the top of the hole, they sling the oil all over the place.
So, that's my opinion on these two drill bits used for drilling acrylic. If anyone else has tried both bits on acrylic, I'd like to hear your opinions as well.
Brian
