# 12.5 mm bit



## ed4copies (Feb 20, 2008)

I would like some feedback on this bit.

Mine ate my first attempt at a plastic blank.  I put it aside and went back to my old bits.  

Today, I got an e-mail from a member trying to drill cats and blowing them up (has NEVER happened before), turns out to be the same bit.

I BELIEVE the flutes are cutting aggressively and ANY vibration is leading to "breakage".

Has anyone used this bit succcessfully in plastics???

Thanks in advance!!


----------



## IPD_Mrs (Feb 20, 2008)

Ed I have used it three times on Jr.s in the last 2 months.

Mike


----------



## gerryr (Feb 20, 2008)

I've used it in plastics also, but it has been a few months since I did.


----------



## rherrell (Feb 20, 2008)

I've also made some Jr.s using acrylic and that bit. I drill at 500 rpm clearing every 1/8" and I don't drill all the way through. I make my blanks a little long and trim on the bandsaw after drilling.


----------



## ElMostro (Feb 20, 2008)

Yep, same here.  I was drilling some Texas ebony and blew up the first 3 tries.  It will always happen as the bit was cutting through the bottom end of the blank it would try to lift the blank and SNAP goes the blank.  I tried drilling fast and drilling slow and it was still hit and miss.  So, now I do like Rick, I cut long and do not drill all the way through then I cut off the bottom end on the mater saw (very carefully).


----------



## IPD_Mrs (Feb 20, 2008)

Ed actually come to think of it I did have one half of a Acrylic Acetate #02 - Doodles crack on me as I went through the blank.  I do not remember which end it was, but I think the nib.  

Here is what I think is happening.  When drilling on a drill press using a drilling vise, we might have it too tight in the vice and thus compressing the blank as we drill.  Once you drill through the end of the blank the stability in the material is no longer there and it colapses under the stress.

Anyway just some thoughts on it.

Mike


----------



## pipeyeti (Feb 20, 2008)

I have anew 12.5 from csusa and have done about 30 pens with it and no problems that were not caused by me.


----------



## rixstix (Feb 20, 2008)

It used to happen quite often.  I haven't had the problem when I drill similar to Rick's method.  The only additional step is that when I clear every 1/8", I also cool the bit and acrylic with water and occasionally use spray silicone drylube.  Without the cooling, the acrylic shavings are almost soft enough to form a doughball.

I've had trouble with several CSU bits vibrating significantly more than others, but just assumed it was me and my drillpress.


----------



## mrcook4570 (Feb 20, 2008)

The CATS materials are the easiest to work synthetics I have encountered.  I have drilled a lot of blanks with a 12.5mm bit and can't recall any problems with it in any material.  I did modify it to be a split point with the drill doctor and I sharpen it frequently.  I also never allow the bit to create an exit wound in the blank.

That said, I'll probably blow up the next dozen that I drill with it.


----------



## Hello (Feb 20, 2008)

try drilling a 7mm hole first and bore out the small hole with the big bit.....that's what I do to avoid breakage with soft woods and corncobs


----------



## R2 (Feb 20, 2008)

Ed, sometimes the design of the flutes and the cutting angle of the tip can effect the way different materials cut.
I had a problem with some drillinig and sent an email to Sandvik-Dormer in the UK. they replied within hours with information, including where I could buy the suggested bit at a location closest to my address!
I think there are bits designed for "plastics" so it might be worth a try to email them.
To me, Micah's suggestion seems the most sensible to follow shoul you not find a satisfactory bit.


----------



## DCBluesman (Feb 20, 2008)

> _Originally posted by ed4copies_
> 
> Has anyone used this bit succcessfully in plastics???


Turn wood and you won't have this problem (as often). [8D]


----------



## ed4copies (Feb 20, 2008)

Thanks to everyone, and I hope more will respond.

The one I blew up was enlarging a hole in the first acrylic Eagle attempted.  The 12.5 mm bit was BRAND NEW.  Touched the material with the flutes and splinters all over the room.

Needless to say, Eagle had a lot of time in that blank, so I was very distressed that I had broken it.  Since then, I tried a couple others and again, felt the bit was at least a contributing factor.

However, today's e-mail about drilling the cats reminded me of this problem, so I want to know if I should just be warning people that MY experience with that bit has NOT been favorable.

So, thank you to ALL who respond (yeah, even you, Cav!!)


----------



## Aderhammer (Feb 20, 2008)

> _Originally posted by MLKWoodWorking_
> 
> Ed actually come to think of it I did have one half of a Acrylic Acetate #02 - Doodles crack on me as I went through the blank.  I do not remember which end it was, but I think the nib.
> 
> ...


Shouldn't happen, your making a circular hole, strongest structure and the force would be applied equally, part of the problem is not clearing the bit, the materail can't go up and certainly can't go down so it starts to push out and wants to crack the blank.


----------



## skiprat (Feb 20, 2008)

Ed, there are several things you can try. First is to dull the drill bit. I know this is controversial, but people that drill plastic sheet do it all the time. It tends to stop the drill bit 'grabbing' or 'pulling' its way through the material. Next you can Google 'drilling in plastic' There are some easy ways to sharpen a bit specifically for plastic. Another method I use is to increase the speed of the drill but decrease the feed speed. This way seems to get a nice clean hole, but you need to take your time to prevent heat build up. It is not the cutting edge of a bit that causes heat, it's the sides of the bit and the waste between the bit and the sides of the material.

I really try to avoid drilling 'pilot' holes. Just about all of my blow ups have been done that way. 

If I have a 'tricky' hole to drill, then I will most definately do it on the lathe. My drill press has a lot of slop ( backlash ) between the quill and the handle. If the bit bites, then it will take up the slack and nose dive into your ( or Eagles ) blank and wreck it. Even if it doesn't bite, it often will vibrate and drill hexagonal holes!!!

Even if you only have a three jaw chuck on your lathe, you *can* drill an almost perfectly centered hole in a square blank. 

Yet another method I have used on complex glue-ups is to liberally coat the outside of the blank with CA and saw dust to make a hard shell that hopefully will hold it together while drilling.


----------



## wdcav1952 (Feb 20, 2008)

Ed, thank you for your premature thank you.  My suggestion would be to send your difficult blanks to me to drill.  We veteran turners are always happy to help a newbie.


----------



## ed4copies (Feb 20, 2008)

> _Originally posted by wdcav1952_
> 
> Ed, thank you for your premature thank you.  My suggestion would be to send your difficult blanks to me to drill.  We veteran turners are always happy to help a newbie.



Happy to hear it.  I have a couple hundred to do before April 1.  Watch your mailbox!!!!

oh, They're pretty easy, only a couple are from Eagle.  And there's a few (dozen) tru-stone, some of the metal blanks Dawn has made for me - as I say, nothing challenging!!  Mostly just 5/8" acrylics that I want to make into Jr. Gents!!!

Turnaround time - 3-4 days is no problem.

Thanks!!!!


----------



## IPD_Mrs (Feb 20, 2008)

> _Originally posted by ed4copies_
> 
> Touched the material with the flutes and splinters all over the room.



Ed, might I suggest that you turn down the RPMs.  6000rpms is not a recommended speed.

Mike


----------



## johnnycnc (Feb 20, 2008)

Ed,where is your 12.5 bit from,and what brand?
A good resharpening will help the csusa bit.
And even if it's a Norseman bit,while a very good bit,I will
second Skiprat's suggestions on a different sharpening
technique.
Also,is your vise clamped firmly to the drill press table?

I have had to "dub" or flat a 0Â° rake across the cutting edge
face of several drills to prevent them from hogging in
and blowing up plastics.
This helps slow the "self-feed" tendencies of a sloppy drill press quill.

Check this article,down to page 2,see picture "K" for an example.(The whole article is long,but a good read).
http://www.newmantools.com/machines/drillpoint.html

Hope this helps in some small way.


----------



## follow3 (Feb 20, 2008)

Hey Johnny,

Is this a service you would offer your customers.
I happen to be the guy who blew up tho 2 "cat" blanks. (both halves no doubt)

I think it is the bit. Like one member comented it almost seems as if they are pulling the blank up too hard, which would lead you to think the rake angle is too aggressive???

I would love to try getting that changed before I ruin any more of those awesome blanks.

Let me know,
Steve

PS, got the dead center today...I will soon be trying the mandrel less method.



> _Originally posted by johnnycnc_
> 
> Ed,where is your 12.5 bit from,and what brand?
> A good resharpening will help the csusa bit.
> ...


----------



## follow3 (Feb 20, 2008)

Hey Ed,

Thanks for posting this.

I see a couple of tricks I am going to try.

1. I am going to try a pilot hole first.
2. I am going to stop short and cut the end off.
3. I am going to slow my DP down to 500 rpm.
4. I am going to try to get the angle changed on my bit.

Thanks again,
Steve


----------



## johnnycnc (Feb 20, 2008)

Steve,I'd be glad to help you.
Sorry about the blanks,those are too nice.
I'll pm you.


> _Originally posted by follow3_
> 
> Hey Johnny,
> 
> ...


----------



## thewishman (Feb 20, 2008)

Sometimes I will wrap the blank with black tape, to keep it together through the drilling process. That way when it shatters, I only have to pick up one piece.

Chris


----------



## wdcav1952 (Feb 20, 2008)

> _Originally posted by ed4copies_
> 
> 
> 
> ...



Ed, my computer crashed so I didn't read this post.


----------



## ashaw (Feb 21, 2008)

Ed
I have had no problem with this bit.  Used it lots


----------



## Rifleman1776 (Feb 21, 2008)

All CS bits I have used require sharpening before use. I use a Drill Doctor and put a split point on them. Yes, the 12.5mm has given problems with some delicate woods. In that case, I use an over-length blank, drill just past the tube length then bandsaw to spec.
No sympathy from here with plastics blowing up. They should. [}]


----------



## ed4copies (Feb 21, 2008)

Frank,

We all know you NEVER turn anything but wood, some of it transparent!


----------



## ed4copies (Feb 21, 2008)

I'm really glad  to see Johnny (an expert, IMO) chime in to help Steve.  I did not have a GOOD answer.

I do want to reassert, however, that the one I blew out (Eagle's), I had predrilled and it was being held in a beall collet, on the lathe.  The conditions were as optimized as I could dream up.  

Eagle and I have had SEVERAL LENGTHY discussions about this, since.  We both believe the pre-drilled hole was a DISADVANTAGE in this instance.  The flutes grabbed, there was nothing under the brad point, so no "straight hole guide".

I believe I would have been better off WITHOUT the pre-drill.

REMEMBER, I'M SO SMART I BLEW UP THE BLANK!!!!  YOUR OPINION CAN'T BE ANY WORSE!!!  Feel free to tell me I'm all wet (except Cav, he will be busy drilling for a couple weeks now - as a dentist, this should be right up his alley!!)  I still have more blanks that I will have to drill!!!


----------



## gerryr (Feb 21, 2008)

> _Originally posted by ed4copies_
> 
> The flutes grabbed, there was nothing under the brad point, so no "straight hole guide".



Ed, didn't you know that brad point bits are the spawn of the devil??????[}]

The only time I've ever had problems blowing up blanks of any kind was when I used brad point bits.  I quite using them a long time ago.


----------



## Rifleman1776 (Feb 21, 2008)

> _Originally posted by gerryr_
> 
> 
> 
> ...



Brad points are the berries. For pens, I use twist in only two sizes and that is because my brad points sets don't have those two. Pre-drilling (e.g. guide) holes are a no-no with brad points. We are all guessing as to the cause of this blow-out but the pre-drilling _could_ be the culprit. In this case, we have a plastic that was a glued up segmented blank. That may mean different density materials were used. A grab was probably the cause. And, such a recurrence might be unavoidable when dealing with plastic glue-ups. Woods are more 'cuttable'. Turning plastics is more of a machining operation. qualify: that's IMHO.


----------



## johnnycnc (Feb 21, 2008)

Ed,
I have had poor luck with pre-drilling.
As to why,I will say that a drill cutting solid material
uses a combination of different cutting actions.
The point area does more extruding than cutting.
The outer portion has a more aggresive action.
This all balances itself out in how we are use to feeling a drill cut.
When you remove a portion from the center of a hole,by pre-drilling,
you remove the part that is more difficult,and requires more pressure to drill.
This leaves the outer edges of the drill to cut agressively,as is their nature,
and it will hog into your blank much quicker than drilling solid.
I think this will explain why things happen the way they do,
or at least can happen,as it did with your Eagle blank.
just my 2 cents worth,hope this helps.


----------



## Rudy Vey (Feb 21, 2008)

I don't believe that the size has anything to do with this. My best results are with the pilot drill bits from DeWalt.


----------



## Randy_ (Feb 21, 2008)

Let's take the easy part first.  I don't know what your problem is.  I have a couple of ideas; but they are essentially guesses although I would agree with Rudy that the bit size per se has nothing to do with it.

Twist drills are pretty much taken for granted by most folks, yet their geometry is very complicated and if you get it wrong, they don't work very well.  The average home mechanic runs down to Home Depot or Ace and buys the same 1/4" drill bit regardless of whether he is drilling a 1/16" piece of sheet metal, a 1/4" thick piece of steel angle, a 1/2" thick piece of oak shelving, a 2" block of Plexiglas or a chunk of lead.  Well, it doesn't make much sense that the same twist drill would do a good job on all of these various materials and the fact is that it doesn't.  Fact, also, is that most folks don't understand that you need different types of twist drills for different materials.  Sadly, getting a twist drill that is optimized for a particular drilling task can be difficult and expensive so most folks just buy your standard compromise hardware store bit and do the best they can.

I don't claim to be an expert on twist drill geometry; but have done some reading on the subject.  For a drill bit to do its best work the point angle, lip clearance angle, rake angle, heel clearance, flute angle and a whole slew of other parameters must be correctly adjusted for the material being drilled.  As an example, here is an article that discusses some of the issues related to twist drill geometry.

http://www.newmantools.com/machines/drillpoint.html

I suspect there is no single(one size fits all) explanation for your problem, Ed; but do believe you need to explore the possibility of getting some drill bits that are custom  sharpened for your particular application rather than just using an off-the-shelf bit.  For folks who are drilling relatively mundane blanks, maybe the standard bits are OK and the risk of blowing up an occasional blank is not a concern.  But where drilling expensive or rare blanks is concerned an effort probably needs to be made to acquire drill bits better suited to the application.

Were it me, I would engage in some conversations with professional drill sharpeners and maybe even try to contact the guy who wrote the article I linked to.  An Internet search of "twist drill geometry" will provide you with a large number of resources that should help you resolve your problem.    










.........................
	

	
	
		
		

		
		
	


	



Dallas, TX................................In Their Memory


----------



## 4reel (Feb 21, 2008)

When I bore a larger hole I will put the blank in cut to size but I will use a piece of another blank that was cut off. I put it below the one that I am drilling. It obviously cannot be bigger than the pen blank. The two are pressed together and put in my vise. Then I drill and usually have a successful hole.


----------



## gerryr (Feb 22, 2008)

> _Originally posted by Rifleman1776_
> 
> In this case, we have a plastic that was a glued up segmented blank. That may mean different density materials were used. A grab was probably the cause. And, such a recurrence might be unavoidable when dealing with plastic glue-ups.



I think you need to get some glasses or at least take more time reading.  Where did Ed say this was a glue-up?


----------



## ed4copies (Feb 22, 2008)

> _Originally posted by gerryr_
> 
> 
> 
> ...



I said it is an Eagle blank.  This particular Eagle blank was his first acrylic, other than those he made from Dawn's black acrylic -which went fine but they were drilled with one of my tried and true Harbor Freight bits (IIRC), where I like to go to visit and buy things I don't need, but with the price of gas I don't get there as often as I once did cause the Durango is a real gas hog, but it pulls the trailer well and the trailer has been sitting since our last show in December so I should probably check the tires........(yes, Karl, that was for you)

One of his cross ovals.  So, while there was SOME glue present, it was not structurally significant, since the blank blew up long before I got that far.


----------



## Rifleman1776 (Feb 22, 2008)

> _Originally posted by gerryr_
> 
> 
> 
> ...



Because that is what Eagle does. He cuts up pieces into incredibly tiny and complex shapes then glues them together to make pens that cannot be believed. Below one if his more well-known pens, the Cathedral.

Edit: Sorry, photo didn't 'take', at least on my 'puter.


----------



## Sfolivier (Feb 22, 2008)

I know it might seem counter-intuitive but I got the trick from my dad, who's been a machinist for many decades. When you use large diameter bits that are not brad points... dull them  Most twist bits are way too aggressive and will pull themselves forward with a little bit too much enthusiasm. I had the problem with a 27/64 (I think) and after taking the sharp leading edge very lightly to a disc sander, it stopped destroying my acrylic and punky wood blanks.


----------



## ed4copies (Feb 22, 2008)

Welcome to IAP Olivier.  Would have sent you a PM, but you did not leave an address.

I believe your father is correct.  That is the next thing I plan to try!


----------



## follow3 (Feb 23, 2008)

Hey Ed & Others,

Where can I find pics of these famouse Eagle blanks?

I am dying to see one.

Steve


----------



## Rifleman1776 (Feb 23, 2008)

> _Originally posted by follow3_
> 
> Hey Ed & Others,
> 
> ...



I'll try again to post the first picture. A very complex pen, titled the 'Cathedral'.


----------



## Daniel (Feb 23, 2008)

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 (Feb 23, 2008)

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.


----------



## Sfolivier (Feb 23, 2008)

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.


----------



## IPD_Mrs (Feb 23, 2008)

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


----------



## ed4copies (Feb 23, 2008)

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?????


----------



## follow3 (Feb 23, 2008)

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



> _Originally posted by ed4copies_
> 
> 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.
> 
> ...


----------



## Lathemaster (Feb 24, 2008)

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


----------



## Rifleman1776 (Feb 24, 2008)

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]


----------



## gketell (Feb 24, 2008)

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


----------



## Randy_ (Feb 24, 2008)

> Specially manufactured to produce smooth holes in acrylic. The special Tip Angle allows for gradual penetration of material thus eliminating damage to back side of material. Modified Rake Angle of 0Â° & Cutting Edge Clearance of 10Â° produces the smooth CHIP FREE hole required when working with acrylics.



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_ (Feb 24, 2008)

> _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_ (Feb 24, 2008)

> _Originally posted by gketell_
> 
> You can alway regrind your current bits.....



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 (Feb 24, 2008)

> _Originally posted by Randy__
> 
> 
> 
> ...



How did you know? Actually, it's a .54 caliber. []


----------

