Rifleman1776
Member
I'll try again to post the first picture. A very complex pen, titled the 'Cathedral'.
12.5 mm bit
- Thread starter ed4copies
- Start date
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I'll try again to post the first picture. A very complex pen, titled the 'Cathedral'.
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Daniel
Member
My problems with drilling plastic, any plastic, has been when the bit exits the material. have you ever tried drilling plexiglass without it cracking at the last second? using a piece of wood under the material for the bit to drill into as it exits helps some but not always. compaire the problem to the same thing you get when drilling through metal. as the bit exits it makes that last deep bite. in metal it will actually stop the bit, but in the case of plastic the material will give by breaking. The solution. high speed and slow gentle feeding as the bit exits. just enough to let the bit chew away at that last burr. easier said than done and probably much easier to do on the lathe than the drill press. or as others have suggested. don't drill all the way through and cut the blank to length after drilling.
Rifleman1776
Member
OK, after much fussing, I found that the file name had an apostrophe in it that prevented proper uploading.
Here is an example of a very complex Eagle blank/pen.
Here is an example of a very complex Eagle blank/pen.
Sfolivier
Member
Hi Ed, thanks for the welcome. I opened my profile a little bit more now 
"as the bit exits it makes that last deep bite. in metal it will actually stop the bit, but in the case of plastic the material will give by breaking"
This happens when the bit is pushed too fast through the end of the blank. The flukes create a "butterfly" opening and the twist part of the bit starts screwing itself into it. As you stated, it's a function of the forward / rotation speed. I drill at pretty low speed (750 RPM) so I go VERY slowly when I reach the end of the blank. I often put masking tape on the depth gauge of my press drill so I know when to slow down to a crawl. I also make sure that I hold the drill handle in a way that doesn't allow it to move forward on its own (as opposed to pushing it only).
I have never drilled blanks as delicate as the cathedral, but I have drilled some seriously spalted wood and I don't seem to tear them appart anymore.
For plastic, you can also make sure that your chuck is not too set in the drill. I know it's a horrible practice buy this will allow it to slip on the axle instead of destroying the plastic. In a way, you'll end up with the situation you described with metal.
"as the bit exits it makes that last deep bite. in metal it will actually stop the bit, but in the case of plastic the material will give by breaking"
This happens when the bit is pushed too fast through the end of the blank. The flukes create a "butterfly" opening and the twist part of the bit starts screwing itself into it. As you stated, it's a function of the forward / rotation speed. I drill at pretty low speed (750 RPM) so I go VERY slowly when I reach the end of the blank. I often put masking tape on the depth gauge of my press drill so I know when to slow down to a crawl. I also make sure that I hold the drill handle in a way that doesn't allow it to move forward on its own (as opposed to pushing it only).
I have never drilled blanks as delicate as the cathedral, but I have drilled some seriously spalted wood and I don't seem to tear them appart anymore.
For plastic, you can also make sure that your chuck is not too set in the drill. I know it's a horrible practice buy this will allow it to slip on the axle instead of destroying the plastic. In a way, you'll end up with the situation you described with metal.
IPD_Mrs
Member
Ed,
I just drilled a Acrylic Acetate (AA-44) Silver, White Black with the 12.5 for a custom order. I set my stop on the drill to just start to come through the bottom then took it back to the drill press and too about 1/16" off to make the hole complete. Drilled slow clearing out the shavings every 1/16" to 3/32" When complete the bit was warm but not hot. Could easily handle the bit. Still can't get a centered hole even when I center the dummy bit on the vise that I use. Checked and the vise is at 90 all the way around the bit. The dummy bit may be the problem as a dummy is using it. Also when I drill I have a peice of wood under the blank so that it has some support in the bottom. I have blown out this blank before on the 12.5 but have had little to no problems once I got the Norseman bits.
Mike
I just drilled a Acrylic Acetate (AA-44) Silver, White Black with the 12.5 for a custom order. I set my stop on the drill to just start to come through the bottom then took it back to the drill press and too about 1/16" off to make the hole complete. Drilled slow clearing out the shavings every 1/16" to 3/32" When complete the bit was warm but not hot. Could easily handle the bit. Still can't get a centered hole even when I center the dummy bit on the vise that I use.
Checked and the vise is at 90 all the way around the bit. The dummy bit may be the problem as a dummy is using it. Also when I drill I have a peice of wood under the blank so that it has some support in the bottom. I have blown out this blank before on the 12.5 but have had little to no problems once I got the Norseman bits. Mike
ed4copies
Local Chapter Manager
I originated this thread because I wanted a thorough answer to Steve's (Follow3) question about the cats. As usual, I learned a lot from the answers.
One additional input was received from Eagle who recently got an "intro set"-bushings and 2 drill bits that included the 12.5mm bit. As we discussed my reluctance to drill his blanks now that I have blown one up, he reassured me that this would act no differently than my other split point bits. SEEMS HIS SET HAS A SPLIT POINT BIT IN IT. Mine was a brad point bit. I thought there would only be ONE 12.5mm bit, but perhaps CSUSA has realized there is a problem using the brad point (although I believe my method was a significant contributing factor). So, we may be talking about different "beasts" in this thread.
Who'dathunk there'd be more than ONE 12.5 mm bit?????
One additional input was received from Eagle who recently got an "intro set"-bushings and 2 drill bits that included the 12.5mm bit. As we discussed my reluctance to drill his blanks now that I have blown one up, he reassured me that this would act no differently than my other split point bits. SEEMS HIS SET HAS A SPLIT POINT BIT IN IT. Mine was a brad point bit. I thought there would only be ONE 12.5mm bit, but perhaps CSUSA has realized there is a problem using the brad point (although I believe my method was a significant contributing factor). So, we may be talking about different "beasts" in this thread.
Who'dathunk there'd be more than ONE 12.5 mm bit?????
follow3
Member
Hey Ed,
My 12.5 mm bit came from one of the accessory kits that CSUSA offers and it is a split point. I didn't know you guys were discussing brad point bits. I also did some thinking and realized that after loosing 2 of the cats, I decided to try on one of Dawns freebies that you sent me and had no problem. The difference is that Dawn's blank is a bit larger. I think maybe the cat blanks may be too small for the large bit. It is making the walls too thin and there is no strength left???? Just another guess.
Thanks everyone for all the great info, this has been very educational.
Steve
My 12.5 mm bit came from one of the accessory kits that CSUSA offers and it is a split point. I didn't know you guys were discussing brad point bits. I also did some thinking and realized that after loosing 2 of the cats, I decided to try on one of Dawns freebies that you sent me and had no problem. The difference is that Dawn's blank is a bit larger. I think maybe the cat blanks may be too small for the large bit. It is making the walls too thin and there is no strength left???? Just another guess.
Thanks everyone for all the great info, this has been very educational.
Steve
Lathemaster
Member
Great discussion all
My son who is in the trades swears by these drills for drilling plastic and acrylics. Have yet to try them personally but I do trust his judgment.
Note: I have no affiliation with this company and no financial interest.
http://www.thefabricatorssource.com/products/06drills.htm
My son who is in the trades swears by these drills for drilling plastic and acrylics. Have yet to try them personally but I do trust his judgment.
Note: I have no affiliation with this company and no financial interest.
http://www.thefabricatorssource.com/products/06drills.htm
Rifleman1776
Member
Oh, goodie, goodie! Now, we need a new weirdo drill bit style to drill acrylics. [:0] I'm so happy.
Nebber mind. I just remembered, I only do wood pens 99.999% of the time. [8D]
Nebber mind. I just remembered, I only do wood pens 99.999% of the time. [8D]
gketell
Local Chapter Leader
You can alway regrind your current bits. The trick with acrylic is that it is brittle so taking an aggressive bite is a shattering experience. By regrinding your bits to a steeper angle you make for much less aggressive cuts and therefore better chance of success. This would work for most woods too but not for metal because the bit edge is thinner.
When cutting flat acrylic sheets one trick is to run your blade backwards. Either that or buy a Reverse-rake blade.
GK
When cutting flat acrylic sheets one trick is to run your blade backwards. Either that or buy a Reverse-rake blade.
GK
Randy_
Member
Mike: Thanks so much for that link. You have re-emphasized the precise point I was making in my earlier post!! Glad to know I was incorrect about availability and that the special grinds can be bought off the shelf.
Randy_
Member
Originally posted by Rifleman1776
Oh, goodie, goodie! Now, we need a new weirdo drill bit style to drill acrylics. [:0] I'm so happy.
Nebber mind. I just remembered, I only do wood pens 99.999% of the time. [8D]
I'll bet that if we check Frank's gun cabinet, there is only one rifle in it......a 458 that he uses whether he is hunting elephants, whitetails or squirrels!!
Randy_
Member
Not exactly sure what you mean by this; but with the exception of Paul and a few others, folks here are not going to be doing that themselves and having a Drill Doctor won't help, either. This is a job for a professional drill sharpener.
Dallas, TX................................In Their Memory
Rifleman1776
Member
Originally posted by Randy_
Originally posted by Rifleman1776
Oh, goodie, goodie! Now, we need a new weirdo drill bit style to drill acrylics. [:0] I'm so happy.
Nebber mind. I just remembered, I only do wood pens 99.999% of the time. [8D]
I'll bet that if we check Frank's gun cabinet, there is only one rifle in it......a 458 that he uses whether he is hunting elephants, whitetails or squirrels!!
How did you know? Actually, it's a .54 caliber. [
]