How come the drill bit always jams and then the chuck spins? ARGHHH

[tehfunk]

I am just so confused with drilling (and painting, but that's another post), I'll elaborate. I got a new drill just recently and when drilling the first box I couldn't use the uni-bit I bought because I couldn't have it sticking through too far, but anyway, I'm really worried I've badly injured the keyless chuck in the drill because whenever I'm drilling the bits catch, jam, and the chuck spins but not the bit, then I have to back it out and so on  . First, I do a pilot hole and then I go up a bit at a time--first area of confusion: some people say you just do a pilot hole then do the size necessary, for instance 3/8 inches, and others say do pilot then 1/8 then 1/4 then 3/8 and so on??---- How long is it supposed to take to drill through an enclosure with one bit?

uni-bit question--I used a uni-bit and it worked great last time, but I only did two holes, but they were extra tough because they were on a wah enclosure. My worry is I didn't oil it like some people say is necessary. I'm only drilling aluminum btw. Why do you oil a bit, what happens if you don't? Also, I had read that you should oil while drilling, then I just read, "make sure to oil your uni-bit when you're not using it", now I'm just striking out with drilling. Really, searching the forum on everything about drilling and painting and clear coating frustrates, confuses, and causes me to worry to a degree where my head is going to explode. I really try my best to read all this stuff, but right now it's only making my confusion worse, I just don't want to ruin a brand new drill or, in the case of painting, an entire paint job because I wasn't 100 percent sure before I went into it... and then what's worse is to think I was sure and to find out afterward that I didn't do something right. Sorry for all that rambling, hopefully you masters can help me. Thanks.
-Sam

[Ripthorn]

I'm no master, but if the unibit has a round shaft, then when it grabs and the chuck spins, you aren't doing much damage, if at all.  What I would check is your torque settings on your drill.  Not every speed or torque setting will work well on every project.  That is why there are adjustments that you can make.  Also, in terms of oiling a drill, you do it to reduce friction and thus heat.  If your bit gets too hot, it can warp and/or lose its sharpness making it nigh unto useless.  As in all metal work, the lubricant is usually applied a little first and then if the cut (or drilling) is of a prolonged time, you also oil while it is doing its thing.  This is just so that it cuts smoother and stays sharper longer.

As far as using standard bits, the way I drill metal (and most of this is structural steel, but the concept is the same) is punch where you want the hole.  Then use a small-ish bit (for really heavy stuff I start with 1/4"), then go up to an intermediate value (if the desired size is really big, use two intermediate values) and then drill the final hole.  Make sure the bits you have a split point (they help keep the bits centered) but not brad point (mostly for wood).  And make sure to take your time, if it takes an extra several seconds to get a good clean hole, it's worth it.

[Tantalum7]

First off take a deep breath and relax, it's only a drill and an enclosure.  I can only speak for most of the unibits we get in the states, but the shanks on them are usually ground triangularly so that they don't spin in keyless chucks (because keyless chucks don't usually get as tight as their keyed brethren).  If the shank is round and it's spinning in the chuck, you'll see damage on the shank of the unibit where the hard jaws of the drill are spinning on the softer metal of the unibit.  If you don't see any damage then it's probably just that the clutch mechanism is set too low.  If you don't have a clutch on your drill, and you're sure that the unibit isn't spinning inside the chuck, then it might be that the internal gears of the drill got damaged.  If that happened see if you can bring the drill back, because using a unibit in aluminum is not extremely strenuous use for a drill.

Now the the oil thing.  It's not the end of the world if you don't have any kind of cutting fluid to use while you're drilling.  One or two holes in an aluminum enclosure are not going to harm a decent unibit.  You already have the advantage of being able to step drill by using a unibit in the first place, which makes everything easier.  You will have a slightly easier time if you can use a few drops of cutting fluid during the drilling process, and the holes might have a slightly better finish on them, but it's not that critical--especially if you don't try to use a really high RPM.  Oiling the bit after you're finished is only to prevent rust on the bit, and unless you're storing your bits somewhere wet, there's not much risk of that either.  So don't panic.

[tehfunk]

ok, thanks for the advice, the oil info helps. But, I guess I must have been unclear about the "bit catching in the hole causing the chuck to slip" in that it happens with normal drill bits, not the uni bit, these normal ones have round bases--like mentioned my unibit has flatted sides, it's actually hexagonal or something (I didn't check exactly), so it's impossible for the chuck to slip on that. But, when I was drilling a big 1/2 inch hole with the uni-bit I did feel it somewhat jam and the chuck slip but only for a second because the flat of the shank don't allow it to slip as I already said.

But, my question is, why are my normal HSS round shanked drill bits always getting jammed in their holes, and then causing the chuck to spin and slip helplessly, it's beyond aggravating and makes finishing a hole nearly impossible without filing; it's ridiculous, I mean aluminum isn't that hard, so can someone tell me what I am doing wrong.

Also, how long does it usually take you to drill a, say, 1/2 inch hole with normal bits--from pilot hole to the final size, and how long does it usually take you for a 1/2 inch hole with a uni-bit. Thanks.

[Tantalum7]

It IS true that aluminum is soft, but it is also a gummy metal, which is to say that it doesn't make nice clean small chips that drop away from the drill bit.  The metal wants to grab onto the flutes of the drill bit and stick there--especially if you don't have a cutting fluid or some sort of coating on the drill bit to prevent this (TiN, TiCN, and even Ziriconia) are used for tools in high speed machinery to help combat this.  What happens with a standard fluted drill bit when it goes through a relatively thin sheet of aluminum, such as the top of an effects enclosure, is that as the point of the drill starts to break through, there is nothing underneath to support the burrs of aluminum.  So instead of shearing off, these burrs just push down and catch the flutes of the drill.  The drill then tries to thread itself into the hole like a screw.  You try not to let it do that, the burrs are too strong to break, so the only thing left that can happen is for the drill or the chuck to spin.  There are two ways I've found to help with this scenario.  One is to clamp something (a hard piece of wood, plastic, thick piece of aluminum) underneath the surface you're drilling to help support the drill as it goes through the thin top of your enclosure, or ease up on the pressure a bit as the drill starts to go through.  Sometimes I increase the rpms of the drill as well as easing up on the pressure--this makes smaller chips that are less likely to grab the drill.  Also, if you aren't going in perfectly perpendicular to the surface, your chances of the drill bit catching and binding are higher since at any angle other than 90deg, the drill bit is presenting an oval cross section to the hole (picture cutting a cylinder with a plane at some angle to its axis and looking at the surfaces produced).     
If I were using a hand drill to put holes in a box, I would find a nice hard piece of wood that fit just inside the enclosure and was just a little taller than the enclosure so that the top of the enclosure was supported by the wood and not by the sides of the enclosure (I hope you can picture this).  Clamping this whole thing down to a bench or in a vise will greatly improve your chances of good results as will keeping as perpendicular as possible.  Hope this helps some.

[tehfunk]

It IS true that aluminum is soft, but it is also a gummy metal, which is to say that it doesn't make nice clean small chips that drop away from the drill bit.  The metal wants to grab onto the flutes of the drill bit and stick there--especially if you don't have a cutting fluid or some sort of coating on the drill bit to prevent this (TiN, TiCN, and even Ziriconia) are used for tools in high speed machinery to help combat this.  What happens with a standard fluted drill bit when it goes through a relatively thin sheet of aluminum, such as the top of an effects enclosure, is that as the point of the drill starts to break through, there is nothing underneath to support the burrs of aluminum.  So instead of shearing off, these burrs just push down and catch the flutes of the drill.  The drill then tries to thread itself into the hole like a screw.  You try not to let it do that, the burrs are too strong to break, so the only thing left that can happen is for the drill or the chuck to spin.  There are two ways I've found to help with this scenario.  One is to clamp something (a hard piece of wood, plastic, thick piece of aluminum) underneath the surface you're drilling to help support the drill as it goes through the thin top of your enclosure, or ease up on the pressure a bit as the drill starts to go through.  Sometimes I increase the rpms of the drill as well as easing up on the pressure--this makes smaller chips that are less likely to grab the drill.  Also, if you aren't going in perfectly perpendicular to the surface, your chances of the drill bit catching and binding are higher since at any angle other than 90deg, the drill bit is presenting an oval cross section to the hole (picture cutting a cylinder with a plane at some angle to its axis and looking at the surfaces produced).     
If I were using a hand drill to put holes in a box, I would find a nice hard piece of wood that fit just inside the enclosure and was just a little taller than the enclosure so that the top of the enclosure was supported by the wood and not by the sides of the enclosure (I hope you can picture this).  Clamping this whole thing down to a bench or in a vise will greatly improve your chances of good results as will keeping as perpendicular as possible.  Hope this helps some.

sounds interesting, but does that mean drilling through the wood too?

[Tantalum7]

You do drill a little bit into the wood, and you have to keep moving the wood around so that you're not drilling into empty space if you drill a hole in the same place again.  Drilling aluminum plate with a hand drill is never a satisfying experience, but it doesn't have to be as hard as you've experienced in the past.  One last thing is that if you are drilling a large diameter hole it helps so start with smaller sized drills, just like on your unibit.  This puts a limit to the size and strength of the burrs. 

[maze]

I don't contribute much here because I'm pretty much a noob at building effects
I read more than I should but  I can say I am no stranger at drilling holes in metal
so here is some tips that I hope will help
For starters there is no way you are going to hurt the drill it will hurt you first  if its a cordless drill make sure its fully charged and on the highest torque setting
the key to drilling is a sharp bit and the right speed if you go to fast with steel it will over heat and trash the drill bit  for drilling enclosers you don't need any oil it only contributes to the mess if its a good drill bit it will last a long time if you don't over heat it  I have a unibit that's 20 years old and has never seen a drop of oil and is still usable
never try to start a hole with a unibit start with a regular bit first the same size as your smallest unibit step if your not using a unibit then go in steps first 1/8 then 1/4 and then 3/8 and 1/2  that's why unibits are so usefull you don't have to keep changing bits   allways center punch your starting point buy the best drill bits you can they will last longer and do a better job  if your dill is veryable speed your home free start squeezing the trigger until the metal starts to produce like cork screw shavings that's the right speed stop squeezing
if they are turning blue slow down your about to trash your bit blue means its over heating depending on what your drilling you will get chips insted of cork screws
as long as nothing is turning blue drill bit included your at the right speed if you go to slow that will cause your bit to grab and slip in the chuck

[tehfunk]

if you go to slow that will cause your bit to grab and slip in the chuck

So, you think it could be in part that I am going to slow? Also, the uni-bit I have is self-starting and probably sharper than my normal single size bits, and it goes through that first step faster, so you think it's okay to start with it?

[Tantalum7]

Unibits are extra nice for gummy metals because they don't have a helix to them, and the sections going through the metal are too short to be able to twist off axis much.  With a big enough center punch you might be able to start with the unibit--in a drill press, I'd definitely go for it, but by hand, I'd agree with the info posted above.  My suggestions before were more for standard jobber length drills.   

[maze]

well its all about the the type of drill
the unibit is designed to start holes but because of the fact its not a twist drill (now its getting technical)
starting with a regular bit gets you better accuracy
I am assuming your are tyring to do this with a hand drill and that is fine but from your post
i am getting the impression your going to slow that's why its grabbing
you need speed to blast threw the metal  think of it this way did you ever see one of
those samurai guys cut off a guys head with a sword with lightning speed it would never happen otherwise

[Tantalum7]

I also agree with Maze's last comment.  In a drill press with your enclosure clamped down securely so that it can't move, a unibit should stay accurate.  By hand this is not always so.  If you compare the way the unibit's point is ground versus a std or split point drill bit you can see that it's kind of rotating around the center rather than cutting at the center like a split point.  If you're just holding your box down by hand pressure, the unibit can wobble a bit.  One of the most important things to know about machining is rigidity--the more rigid your set up is, the more accurate everything becomes.  Clamp things down whenever you can, use short stiff drills when you can, center punch and center drill first, and it will show in the results you have.  Maze is also correct about the speed thing--too slow and your chips will be large and ungainly, prone to grabbing the drill bit.  Too fast and you could overheat the drill and ruin the hardness of it (it's much worse for steels and refractory metals though).  You'll get a feel for it in time. 

[Cliff Schecht]

Soapy water is the best (and cheapest) solution for drilling aluminum. I'm not sure how many people actually put any kind of lubricant down when they drill their enclosures but it's good practice and makes the holes come out very clean. Plus your drill bits last longer because they aren't constantly overheating and dulling themselves. The soap water isn't as much of a necessity when using a Uni-bit with a hand drill but for a drill press, it's almost essential to get those nice pigtail-curl style aluminum cuts.

[Tantalum7]

The funny thing is that most high-priced, environmentally safe industrial cutting fluids are just glorified soapy water--with a few anti-microbial additives and some fun colors.

[petemoore]

  Punch...don't have one handy
  So I drill fast or slow doesn't matter at the entrance of the hole, one way or another the bit is very slow at removing much until the flutes are below the surface.
  In the middle portion, fairly slow drill speed and high pressure [don't break the bit] seem to cut and remove the most material the quickest.
  As the tip exits the bottom of the hole, [BTW the 'acts like a screw analogy is a good one] it can remove very large chunx of material or get stuck in them, I've found greatly reducing pressure [right at the end of the cutting] and increasing speed seems to keep the bit from 'biting off more than it can chew', and it tends to exit much more smoothly.
  Having the bit precisely aligned helps to make an even 'ring' at the bottom, during the exit, the bit won't create a 'large burr' and 'small burr' side, there will be an even thickness of ring shaved through, all edges of the cylinder being equal means the bit can't punch through easily on one side, and grab a thick burr on the other.
  Drilling cold soft aluminum...bit heat shouldn't be a big problem, the material is cut fast enough that the bit is always finding new material to cool itself in. I would rather have a bit slowly dulled a little faster than get oil and shavings all over the wah. I don't use oil either...I know it's bad, but we get by, I've seen it used and not used, basically you get an idea what does and doesn't eat drill bits real fast [such as stainless steel].

[LEON.01]

I dont rate them uni bits at all!!!

Someones already said about the torque settings, thats why your chucks spinning! If you turn up your torque though, watchout for the hand holding the enclosure as this will spin rather than the Chuck!

I use a Magdrill with the enclosure clamped in a vice! straight through in seconds and no bit changing! Might have to de-burr, but that only takes a couple of seconds!

As for Lube! Lube EVERY cut (hole)! Cleaner cuts, longer lasting bits, A bit more messy but worth it in the long run.

I dont drill pilot holes due to the drill i'm using, but one pilot then your right sized hole should do. Another reason for your chuck spinning! If your pilot holes are too close to the size you drill next, the bit will just jam up.

[David]

My experience has been that you need a good Vari-Bit or Unibit, a good drill, lubricant if the material is stubborn, and speed, not torque.

[LEON.01]

My experience has been that you need a good Vari-Bit or Unibit, a good drill, lubricant if the material is stubborn, and speed, not torque.

Your experience has served you well! Speed isn't the answer to a spinning chuck though! not enough torque! 

[caress]

man i just drill pilot holes, then go at it dry with a unibit in a hand drill.  has worked well for me and i've been using the same bit for over 2 years...
i always get little curly shavings and i've drilled MANY boxes that typically have >4 holes (most of my effects...)

i tried to get into using a drill press, but i'm more accurate with the hand drill.

[LEON.01]

Every one to their own preferences then?!