broken bit!!! AAAUGH!!

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watch_art

watch_art

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Joined
Dec 21, 2011
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hot springs, ar
I feel like Charlie Brown right now.

I'm feeling good this morning - and like I should be doing something besides the usual morning internet reading before school - so I go out to start a barrel. Got the blank mounted in my 4 jaw, drill chuck in the tail, center bit, starter hole, 1/4 starter hole... then Lucy takes the ball away and I fall on my tail!

What happened?

So my drill chuck is in it's MT2 thingy on the tail shaft. I was sure to bang it in pretty good before I got started b/c the stupid thing has a tendancy to spin on me. Didn't matter. Stupid thing spun out, drill bit broke, drill chuck flies against the wall behind the lathe (thankfully not at me), blank is now bent, and the bit is stuck about 2 inches in. Blank goes in the trash and I'm now on the ground, on my back, screaming AAUGH!!!

:biggrin:

So I cleaned out the inside of the tail shaft thing with a bit of ammonia/soapy water and did the same with the shaft the drill chuck. Hopefully removed any oils and slippery stuff.

Is this going to keep happening?
 
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Shawn,

I have to say that this is the scariest type of post I see. This happens every once in a while - I should try to find the last thread.

A couple of notes from what we've seen/found:

- Make sure not to screw your tailstock to close to the drill chuck... I will allow self ejecting.
- Many of us hold on to the chuck with our left hand while using it. If you feel it spinning/loosening up at all, unlock the tailstock with your right and pull the bit out till you have things reset.

Glad that you are ok!
 
The answer is yes it will keep happening. You have two tapered surfaces that will want to seperate if the drill bit catches and pulls forward. It doesnt have to be a single large tug but a couple of small ones that work it loose can give the same results. Also if it happens too frequently it can wear either on the inside of your tailstock spindle or most likely the mt taper on the chuck causing it happen yet more frequently.
I also hold on to the chuck as I drill. I drop my lathe speeds and try not to aggressivly feed the bit. My lathe is a sherline and is exceptionally prone to it. I replace the mt tape shafts for the chuck frequently. Mostly because it wasnt designed to drill the sizes Im drilling, any thing over .300 should be bored not drilled on my lathe. If the mt taper on your chuck shows galling where its spun in the tail stock replace it.
 
Thanks guys.

I don't know why I haven't been holding the chuck with my left hand.

For the draw bar - the chuck will go in the head stock? How do I hold the blank in the tail?
 
watch_art said:
Thanks guys.

I don't know why I haven't been holding the chuck with my left hand.

For the draw bar - the chuck will go in the head stock? How do I hold the blank in the tail?
Click to expand...

The drawbar can typically go in either the head or tail stock unless your lathe won't accept one. If you have a hollow tail stock you should be able to make it work, you may need a few washers or a spacer but it can be done.

AK
 
watch_art said:
Also thinking I should get a bench top drill press and do all my drilling there. Something to consider? Or a daft idea?
Click to expand...

Well Shawn, I started out drilling on a drill press and ended up drilling exclusively on the lathe. In my opinion, the vast majority of drill presses out there won't drill as true as your lathe will. In my case, I ended up with out of round holes no matter what I did and my drill press just wouldn't run true enough to do the job. Make sure that the both the morse taper on your chuck and the inside of the tail stock are clean and dry. I drill at the slowest speed, which on my rikon is 430 rpm, and I pull the bit out frequently to make sure that the hole stays clear. I also lubricate the drill bit and blank w/ wd40 to keep things cool and slick.

Good luck.
dow
 
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I'm set up as Andrew suggested. I have a piece of threaded rod that goes through the tailstock and into the morse taper holding the drill chuck. Two washers and a wing nut tighten against the hand wheel on the tailstock.

With smaller drill bits, I don't bother set it up, but when I'm drilling for pepper mills, I like the security of this set up.
 
Okay - drilling on the lathe. I'd prefer that anyhow...
As for the draw bar - wouldn't this just get in the way? When I start turning the crank to advance the bit it won't advance because there's a draw bar on there. Hmmm...
 
Wow lot's of good advice in this thread!

When I posted about a similar thing happening to me, everyone told me how I was doing everything wrong and that this NEVER happens. Glad to know I'm not the only one it happened to!
 
No point repeating a lot of what was already said above.

Were you drilling acrylic? If you try to drill too deep into the acrylic all in one go it will start to melt and get sticky - than it grabs your bit and can be brutal to try to retrieve. Drill at only midrange speeds, drill only a cm or so at a time and then pull out, cool the bit. I usually have a wet rag handy for acrylic drilling to cool the bit after each cm or two.

Ken
 
Scooley01 said:
Wow lot's of good advice in this thread!

When I posted about a similar thing happening to me, everyone told me how I was doing everything wrong and that this NEVER happens. Glad to know I'm not the only one it happened to!
Click to expand...

that is why this thread caught my eye. This is the second one in 2 weeks. Glad you are OK. Now that I know this can happen I can't be so casual about drilling.
 
Using a drawbar prevents you from advancing the bit with the tailstock handwheel. Certainly you can do this and advance the bit by sliding it (the tailstock) on the bedways BUT ... I much prefer to steady the chuck in my left hand while advancing it with the handwheel. Slow speeds and backing out to clear shavings every so often ... works for me!
 
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It's not the oil, it's the perfect contact you need. The taper needs to be perfectly clean of any small nicks or bumps. You can do that by carefully sanding or filing them away. The same goes for the internal taper. It should never need to be hammered tight as a simple jam fit should be fine. The trick is that perfect contact. There are morse taper reamers to clean the internal taper if necessary. The parts should be clean and dry.
 
Well - the left hand on the drill chuck works a charm!

I took the blank from this morning, put the part with the broken bit in the 4 jaw and turned down the other end. So far so good. Maybe I'll be able to knock out the bit and salvage that half of the blank.

:)
 
btboone said:
It's not the oil, it's the perfect contact you need. The taper needs to be perfectly clean of any small nicks or bumps. You can do that by carefully sanding or filing them away. The same goes for the internal taper. It should never need to be hammered tight as a simple jam fit should be fine. The trick is that perfect contact. There are morse taper reamers to clean the internal taper if necessary. The parts should be clean and dry.
Click to expand...

+1 on that

I drill really tough metals with my tailstock all the time. It's a MT2 and all I've ever needed is a good hand slap to set the taper. NO OIL (sorry to shout). There must've been some fragment of something in the taper to have it spin out and if it does that repeatedly then there's something wrong with the taper itself or it's dinged up enough not to make good contact. When I see a nick in any of my tapers I take a #6 cut flat file and just tick it off.

Cheers,
Rich
 
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