gmreeves
Member
I blew out my first two blanks this afternoon at lunch time. Both blew out while exiting the blank. One was an acrylic from woodcraft and the other was a nice piece of cocobolo crotch. The only other blank that the drill bit was used on was a piece of Buckeye burl. These were the larger ends of a Jr. Gent, I beleive a 12.5mm bit and what appears to be a standard jobber bit. The bit came from CSUSA as part of the Jr. Gent. acsessories pack. The Buckeye Burl blank drilled through easily but it was stabilized so that may have had something to do with it.
I'm not sure what happened with the Cocobolo blank other than it was just big enough for the Jr. Gent pen and that may have caused the problem. It drilled fine until exiting the blank and then blew out and cracked up part of the grain. I am guessing the use of a backer block could have prevened this.
As far as the acrylic blank, this was my first attempt at an acrylic. I slowed my drill press down to 620 rpm's, proceded with light pressure, cleared the chips every 1/4" or so, and didn't have any issues until exiting the blank. I'm assuming all I need to do is like everyone mentions here about cutting the blank long, drilling part way through, and then cutting the excess off. Is there anything I might be missing before I attempt to drill the next blank. Again, I don't think over heating was the cause, just the drill bit catching as it broke through the other side.
I'm not sure what happened with the Cocobolo blank other than it was just big enough for the Jr. Gent pen and that may have caused the problem. It drilled fine until exiting the blank and then blew out and cracked up part of the grain. I am guessing the use of a backer block could have prevened this.
As far as the acrylic blank, this was my first attempt at an acrylic. I slowed my drill press down to 620 rpm's, proceded with light pressure, cleared the chips every 1/4" or so, and didn't have any issues until exiting the blank. I'm assuming all I need to do is like everyone mentions here about cutting the blank long, drilling part way through, and then cutting the excess off. Is there anything I might be missing before I attempt to drill the next blank. Again, I don't think over heating was the cause, just the drill bit catching as it broke through the other side.