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Posted: 1/25/2009 11:53:27 AM EST
Ok i need your help,  when drilling the front piviot pin  detent hole i  broke off my  drill bit in side the  hole about a 1/4 inch down,  how can i get it out????????? i think the hole sidze is 5/32  so its  small

i tried compressed air to get  it , i tried tapping  on the lower,,,  can i  try and drill out the Drill bit?>
Link Posted: 1/25/2009 12:02:53 PM EST
[#1]
I you talking about the hole for a spring you could drill the vent hole at the level of the end of the drill (tip) and try to push it out from there using also the heat gun. If you try to drill the broken drill out it will push the new hole out of alignment.
Link Posted: 1/25/2009 12:23:53 PM EST
[#2]
If nobody has any good ideas for removing it, my suggestion is to mill off the whole area and turn it into a slabside lower.
Link Posted: 1/25/2009 12:28:04 PM EST
[#3]
yes its for the spring   but how will  drilling a  vent hole  do the job and i would have to drill 4 inches then from the opposit direction to make it work
Link Posted: 1/25/2009 12:32:17 PM EST
[#4]
Hate to say this but unless you can have someone EDM it out I think your screwed.


Maybe someone else has a better suggestion
Link Posted: 1/25/2009 12:34:35 PM EST
[#5]
I was thinking perpendicularly to the broken drill channel and use the pick bent 90 deg
to push broken drill out
Link Posted: 1/25/2009 12:39:39 PM EST
[#6]
It might look a little different but having 2 vent holes wont do any harm, just like Stag said, drill a right under the bottom of the broken bit and use a bent pick to try to twist it out.
Better than scrappin a lower.
Link Posted: 1/25/2009 12:39:42 PM EST
[#7]
Leave it in there. Cut the spring and detent down. 1/4 of an inch might be enough room to work with.


Did you try whacking it really hard on a hard surface?
Link Posted: 1/25/2009 12:47:30 PM EST
[#8]
Can you take the flat end of another bit with some epoxy or JB Weld on the end and run it down the hole to attach to the broken bit?
Link Posted: 1/25/2009 12:49:46 PM EST
[#9]
Magnet?
Link Posted: 1/25/2009 12:56:07 PM EST
[#10]
Disssolve the steel out of the aluminum.  Acid will eat the bit, but not the aluminum.
Link Posted: 1/25/2009 12:59:36 PM EST
[#11]
You can use a screw extractor. You drill in the center of the broken drill bit and use the screw extractor counter clockwise to remove.

http://www.sears.com/shc/s/p_10153_12605_00966196000P?mv=rr
Link Posted: 1/25/2009 12:59:47 PM EST
[#12]
What Kinda acid can i use to disolve the bit? and how long will it take?

if that dosent work i think that the 2 vent holes might be my next best  chance.

what do u guys think about getting a carbid  tip and like grinding  it out?   an the  hole is  3/32" in Dia
Link Posted: 1/25/2009 1:03:29 PM EST
[#13]
if you live in florida, I can EDM it out for you.
Link Posted: 1/25/2009 1:03:34 PM EST
[#14]
Acid????   i wouldn't go there yet.  try a quick heat with a heat gun and tap with a soft mallet.  or a dap of JB-Weld on the end of some welding wire and try and glue it to pull out.
Link Posted: 1/25/2009 1:21:19 PM EST
[#15]
I think JB weld is the best idea so far.
Link Posted: 1/25/2009 1:21:28 PM EST
[#16]
Might try and find a tap extractor online. They're made for fluted taps but you may be able to modify it or make your own to go in and grab the flutes and twist it out.
Link Posted: 1/25/2009 1:43:41 PM EST
[#17]
Quoted:
I think JB weld is the best idea so far.


+1   nice trick
Link Posted: 1/25/2009 1:46:06 PM EST
[#18]
Quoted:
Hate to say this but unless you can have someone EDM it out I think your screwed.


Maybe someone else has a better suggestion


EDM

Link Posted: 1/25/2009 1:46:25 PM EST
[#19]
Quoted:
Disssolve the steel out of the aluminum.  Acid will eat the bit, but not the aluminum.


acid will still eat at the aluminum but not as fast as it does for the steel


if you still have part of the broken bit sticking out, have a welder weld a nail or somethign to it so you can put that back in the drill and try backing it out
Link Posted: 1/25/2009 1:57:31 PM EST
[#20]
what id JB Weld  and can i  get it at like Home Depot?   the prob is that its  a 3/32" hole  and its broken off  1/4 deep into the hole.  will the JB weld  attach itself to the alum also and then i have a pluged hole?
Link Posted: 1/25/2009 2:18:43 PM EST
[#21]
You should be able to get it at home depot but auto parts stores will have it also.  I would put a tiny amount on the end of the bit that broke off in the drill. Enough to make contact with the other end of the bit but not enough to squish out and touch the sides of the hole. Once you have the bit in one piece pull it out.



ETA: I know the hole is small so I am talking a tiny amount on the bit. It can supposedly be used to weld tractor axles and hubs so it should work with a tiny amount.





 
Link Posted: 1/25/2009 2:26:14 PM EST
[#22]
how long does the JB weld have to sit for and  will it stick to the alum  since its sucha small  hole?>
Link Posted: 1/25/2009 2:29:41 PM EST
[#23]
next time buy good drill bits.


Link Posted: 1/25/2009 2:31:09 PM EST
[#24]
Quoted:
next time buy good drill bits.




Will do , but to late
Link Posted: 1/25/2009 2:31:48 PM EST
[#25]
I would think that it shouldn't take very long but it may be worth it to wait the full 15-24 hours so you don't have to do it twice. But I would probably get impatient and try it in 8








I think the whole key to it working is that you use such a small amount that it won't touch the sides of the hole only the middle of the broken bit.





 
Link Posted: 1/25/2009 2:34:04 PM EST
[#26]
The Ram EDM is the way to go. Any Machine shop either has one or can direct you to someone who has one.

Link Posted: 1/25/2009 2:36:47 PM EST
[#27]
what is the Ram EDM?  an can they do it to a lower  since it is gun part?
Link Posted: 1/25/2009 2:55:34 PM EST
[#28]
Nitric Acid will dissolve the high steel dril but not so much on the aluminum.
You can get it in small amounts from a hobby store.
Just follow the safety precautions

Nick

Link Posted: 1/25/2009 3:00:36 PM EST
[#29]
My brother in law has been doing edm work for 25 years, It's the way to go. Take these guys up on their offers
and you'll have it back in a week if the jb doesn't work. Pm if you need my in laws phone number, he's in so. ca.
Link Posted: 1/25/2009 3:10:48 PM EST
[#30]
What is EMD?>  and bc its an  80% build how would i transfer it?
Link Posted: 1/25/2009 3:11:45 PM EST
[#31]
Since your drilling the detent hole I'll assume it was/is an 80% lower, in which case you shouldn't have any concerns with having somebody do work on it or for you to ship the item out of state.  Of all the ideas I'd say the EDM one is the best.

The JB Weld idea might work on other applications, but with a 3/32 hole you have too much a chance of getting epoxy on the sides of the hole.  Even if you were extremely careful and only used a tiny amount to make contact with the drill I doubt that such a small bond surface will be able to extract the stuck bit.  

But before you ship it off, try this...

Soak the hole with Kroil, WD-40, or some other super-hero style release fluids for about an hour or two.  Then pop the lower in the over at 120 deg for about 20 minutes.  That should be enough to expand the aluminum a bit.  Put on your wife's oven mits and hold the lower in one hand while you give the lower a few good raps with a rubber mallet.  You might get lucky.

Oh, and cheap bits or solid carbide, failing to clear the chips frequently and/or not using enough cutting fluid is usually how they break.  Unless, God forbid, you were using a cordless drill.
Link Posted: 1/25/2009 3:18:59 PM EST
[#32]
Quoted:
Quoted:
Dissolve the steel out of the aluminum.  Acid will eat the bit, but not the aluminum.


acid will still eat at the aluminum but not as fast as it does for the steel



Huh?
Sulphuric acid that we use to anodize a receiver does NOT eat the aluminum.  It forms a layer of aluminum oxide, which makes it impervious to further attack...
Ir will eat steel...
A saturated solution of Alum (yep the stuff made for pickle-making) will make mush of the steel without damage to the aluminum, too.
If you have an EDM, then do use it.
Link Posted: 1/25/2009 3:28:27 PM EST
[#33]
imo k.i.s.s.! screw going to extremes. leave it alone and use a factory colt 2 slotted  head takedown screw/pin. .
Link Posted: 1/25/2009 3:53:54 PM EST
[#34]
Obviously going the EDM route is the best but he should still try some other stuff first. It could be a quick fix, there may be no need to send the lower off or worry about legalities of doing so.





Try all the options that have been offered here. If they don't work do the JB weld if that doesn't work it won't be much harder to remove the whole bit than just the one piece using the EDM.





As far as the amount of JB weld being so small it may not work: like I sad it is sopposed to work on tractor axles. If it ain't enough to pull a broken bit out I would be surprised.

 
Link Posted: 1/25/2009 4:30:29 PM EST
[#35]
You could forget about it and buy one of these KNS front pivot pins.  Probably cheaper than shipping the lower to/from someone.

http://www.knsprecisioninc.com/Gun%20Parts.htm
Link Posted: 1/25/2009 4:53:54 PM EST
[#36]
There's probably an EDM-equipped machine shop somewhere in the OP's area,  within easy driving distance.  No need to ship it, probably.  (Which can have its own legal hassles, if it's completed enough that the ATF says it's now a firearm.)

Sinker EDM with the right electrode.  The bit is dissolved by electricity while the whole receiver is submerged in an electrolyte bath.

CJ
Link Posted: 1/25/2009 5:08:25 PM EST
[#37]
I would have to agree with the KNS pins, for the price, easy install and no waiting, you will be on the range fast.
I am going to order some for myself for a couple of 80% lowers I have on hand.
Link Posted: 1/25/2009 5:21:02 PM EST
[#38]
the  new pin is a great idea. i just  am curious so will pickle juice  disolve the bit ? will it take  weeks?
Link Posted: 1/25/2009 5:50:45 PM EST
[#39]
Do a Google search on using powdered alum to remove a broken bit.  Alum is a commonly available pickling additive found in any grocery store,  that will dissolve a drill bit but not harm aluminum.


Link Posted: 1/25/2009 6:10:18 PM EST
[#40]

Try a reverse drill bit, it's exactly what it sounds like, if it doesn't drill through the stuck bit it will twist it out.
It is much more likely to twist the stuck bit out than drill through it.
Link Posted: 1/25/2009 9:42:14 PM EST
[#41]
If you want the lower completely normal in operation and you intend on anodizing it just complete all the other operations except retainer hole. You then either have it anodized or do yourself (easy) the anodizing procedure of desmuting (nitric acid [Drano] desmuting is the process of cleaning all other metals off aluminum (steel) will eat the steel of bit but not damage aluminum. search the net for a site on anodizing it will verify what I'm (and several others have said) after bit falls out finish drilling hole. BTW deep hole drilling take real care you must pull bit every 1/8" or so and clear chips, use some WD40 for cutting fluid. IT WORKS I PROMISE. JB Weld is wonderful product but will not not work on this problem it's either acid or EDM only.
Link Posted: 1/25/2009 10:31:15 PM EST
[#42]
Since you're open for suggestions, I'll take a stab.  You say it broke 1/4" in, take a

dental pick and see if you can get it loose or can move it.  If it moves alittle, make an

electromagnet out of 5/32 drill rod and wire and a battery.  You can make them pretty

strong.



EDM is like majic.
Link Posted: 1/25/2009 10:47:26 PM EST
[#43]
Quoted:
You can use a screw extractor. You drill in the center of the broken drill bit and use the screw extractor counter clockwise to remove.

http://www.sears.com/shc/s/p_10153_12605_00966196000P?mv=rr


Drill bits are too hard to drill into them.

JB Weld will just result in bonding the bit into the hole - permanently.

Is the bit loose or stuck into the aluminum?
Link Posted: 1/26/2009 4:33:22 AM EST
[#44]
its  stuck solid, i have tried the dential  tool and it wont budge, ill just have to leave it or try and  get it anodozied  some where,    if not then  ill just paint it and get  a better front take down pin
Link Posted: 1/26/2009 4:53:29 AM EST
[#45]
Do the job right or why bother doing it at all? Call some local shops & see who has a EDM

After you pay to have it done right, chalk it up to a learning $$$ experence!
Link Posted: 1/26/2009 5:51:51 AM EST
[#46]
As others have stated, save yourself the hassle and order the KNS push button pins. Might as well get a pivot pin and a take down pin so they match.

KNS pins
Link Posted: 1/26/2009 6:07:47 AM EST
[#47]
I did something like this similar working on a slide. I used a AlTiN endmill to chew it up and drilled the hole.
Yes, they do make 3/32 endmills - I have one...
Only problem is, there usually short, and reduced shank, but there might be enough to get that drill bit out...

BTW: Drano's active ingredient is Sodium Hydroxide???

Ron
Link Posted: 1/26/2009 7:29:25 AM EST
[#48]
Heat?
Link Posted: 1/26/2009 7:32:25 AM EST
[#49]
Just find a local Machine Shop they should be able to remove the drill bit.
Link Posted: 1/26/2009 7:48:23 AM EST
[#50]
I think if you anodize it, the steel will dissolve during the anodizing process.
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