Hang on to your chuck!

[jeff]

When drilling deep on the lathe, I bet a lot of you take the same shortcut I do. You advance the chuck with the handwheel, then hold on to the chuck, flip up the tailstock retaining lever, and withdraw the whole thing. I've done that countless times. It seems safe, but maybe with the MT it's not as safe as I think.

Last weekend I wasn't gripping the chuck as securely as I should have been, the bit hung up in the workpiece, and the chuck pulled out of the tailstock. Wanna guess what happened? :biggrin:

The bit bent, and the chuck made several increasingly large orbits around the centerline. The chuck met my thumb on one of those orbits, and finally launched itself across the shop, ricocheted off the drill press, and impaled itself in my dust collector piping. This was the most serious accident I've had in the shop, and it shook me up.

After changing my shorts, I patched myself up, but after a week of pain and lack of healing, I had a little surgery today to clean up the mess. The nerve block wore off a couple hours ago, and it already feels better than it did this morning.

Keep asking yourself "how can this hurt me", and pay attention to the answer! I lost focus for one moment at the wrong time and I got bit. Other than a few bucks and a few lost evenings in the shop, I'm none the worse for it. 18 inches to the left of where I ended up ducking and I might be dead.

There are many dangers in the shop and the only defense is YOU! Be careful my friends.

 

[Dan Masshardt]

That was the first and biggest near miss of my turning career.

I didn't have my hand on it at all.

I do pull the whole thing out, but with most of the pressure on the chuck itself.

And I stand out of the way!

 

[Tom T]

Thank you Sir. Now I know what not to try. Glad you lived to write us.

 

[Jim Burr]

Hmmm...was doing that this morning on some peppermills. Time for a "Watch it" check!!

 

[longbeard]

I think you and Ed Brown been hanging around each other.
Glad your ok Jeff

 

[johncrane]

Not good Jeff,i'm very happy your ok.

 

[ed4copies]

See what happens if you DON'T WATCH the Sunday night movies!!!


Glad you are OK, my friend!!

 

[stonepecker]

Jeff.......Happy that you were not hurt any worse. Accidents happen in a split second. You can NEVER be to carefull.

 

[jeff]

Here's another little tidbit. Do you know what kind of doc works on fingertips and nails? A Podiatrist! Makes total sense, but they ought to advertise that fact. I called mine just for a recommendation on what kind of doc to see and told me he routinely handles injuries involving the finger tips and nails.

 

[1080Wayne]

Have done the same on my drill press , but the only potential hazard there is that the chuck falls on my foot .

The first thing to remember is that tapers are designed to accurately align parts in a compression setting , not a tension one . The second is to frequently withdraw to remove the cuttings , as they are what jams the drill bit . Some woods are more prone to it than others . Don`t keep drilling if the cuttings stop coming out . Low melting point plastics are the worst hazard .

I know I haven`t told you a single thing that you didn`t know before the incident . We all need safety refresher courses from time to time , but I would rather not get them from reading about accidents .

 

[edstreet]

First hate to see anyone have an injury in the shop.


I have read this with interest and a few things does not seem to add up or make sense. So I am going to limit my response to questions.

*) Is this being blamed on using the hand wheel?

*) the first red flag I noted was 'I wasn't gripping the chuck as securely as I should have been' <- by this you mean with your hands?

*) I am assuming the drill bit bent because the tail stock was no where to be found to allow an index reference point. From this is it safe to say you pulled the tailstock out and the drill chuck got caught?

*) was it the drill chuck in the tailstock or the chuck in the head stock that got your finger?

 

[tim self]

Yep, been there, done that. Glad you're live and well.

 

[jeff]

Responses below

First hate to see anyone have an injury in the shop.


I have read this with interest and a few things does not seem to add up or make sense. So I am going to limit my response to questions.

*) Is this being blamed on using the hand wheel?

No. I was advancing the bit using than handwheel. Retract to zero. Lock tailstock with bit at entry point. Advance with handwheel into stock. Hold chuck and retract entire tailstock. Crank quill back to zero, advance tailstock to zero, reposition, repeat

*) the first red flag I noted was 'I wasn't gripping the chuck as securely as I should have been' <- by this you mean with your hands?

Yes, I believe it's very common to put a little pressure on a MT connection to keep it firmly seated by holding the chuck barrel.

*) I am assuming the drill bit bent because the tail stock was no where to be found to allow an index reference point. From this is it safe to say you pulled the tailstock out and the drill chuck got caught?

Yes

*) was it the drill chuck in the tailstock or the chuck in the head stock that got your finger?

Was my description that bad? :biggrin: It was the drill chuck.

 

[SteveG]

TO ALL you pen turners that read this experience. I am talking specifically of this one i.e. withdrawing the drill bit/tail stock during the drilling the blank on the lathe. This one seems to be THE ONE that very very many (self included) have personally experienced. The loose chuck whipping around wildly until it flies off, becoming a dangerous projectile. LET OUR EXPERIENCE BE YOUR WARNING!!! Learn to do this right. Then, do not let your guard down. We have lots of members here at IAP, but do not want to loose even one to a flying TS Chuck!

 

[hard hat]

Glad you're ok! Better a thumb than it sticking out of your neck.

I had the same happen recently but the 3/8 bit didn't bend. Luckily I dove out of the way uninjured and spent the next 15 minutes looking for the bit and chuck to find it neatly sitting on a shelf above the lathe.

 

[gimpy]

WOW, glad all turned out for the best

Time to take it easy for a few days

 

[edstreet]

Am curious, what was the RPM.

 

[MichaelD]

I got spooked with a wobbling chuck too many times so too weeks ago I bought a taper I could use a draw bar with. Not many do that on the tail stock but I feel better myself.

 

[paintspill]

this happened to me a few weeks back. and you are right about the changing your shorts part. luckily i was standing at the end of the lathe and the chuck launched in a different direction.

here's my tip. now whenever i put my chuck in i retract the jaws all the way in and tap the chuck home with a hammer.

 

[randyrls]

If you want to be really safe and your lathe has a hollow tail stock, look for a drill chuck with a threaded (3/8" x 16TPI) end in the taper. These are commonly used for drill presses and milling machines.

 

[raar25]

I have also been there and done that I was drilling a large number of full length acrylic pen blanks last year and had to hang on the the drill check super tight when the plastic chips tried to melt and capture the drill bit 5" down into the hole.

Glad you are ok.

 

[sbwertz]

I've been making peppermills all week. After having the chuck begin to back out of the tailstock once, I now turn off the lathe before withdrawing the bit, then move up the tailstock and restart the lathe. I don't have very strong hands and don't trust myself to be able to hold the chuck in the tailstock if it catches.

 

[sbwertz]

If you want to be really safe and your lathe has a hollow tail stock, look for a drill chuck with a threaded (3/8" x 16TPI) end in the taper. These are commonly used for drill presses and milling machines.

Where can I find one of these? What do I search for?

 

[edstreet]

Ok pics or it doesn't count! Sorry just had to throw that in there.

 

[jeff]

Am curious, what was the RPM.

~500

 

[Dick Mahany]

Glad you weren't seriously hurt. I had the same experience about a month ago. Drilling at 650 RPM. Lost a beautiful Amboyna blank and a nice long drill. It all happened so fast that I couldn't hit the off switch fast enough. No injuries here, just a bruised ego and a lesson learned the hard way.

 

[Old Codger]

Drill Chuck Safety...

I'm a little confused... Maybe I just have never seen one, but I don't recall ever seeing a 'threaded drill chuck'... I have several thread #2 Morse Tapers that drill chucks will fit on, but never a threaded drill chuck...might be that there are lots out there, I've just never seen or used one. My drill chucks compression fit onto a standard threaded #2 Morse Taper but that won't prevent what happened to our friend above even if you're using an all thread rod. The all thread rod WILL prevent the Morse Taper from coming loose, but not the drill chuck as they can and often will separate from the Morse Taper and then you have a serious accident if you're not holding on tightly and are not able to stop the lathe quickly... If there are threaded 1/2" drill chucks out there that will all an all thread rod to keep it in the tail stock, I'd appreciate a source for one as I'll certainly replace the ones I have... I too, almost panic when the drill chuck separates from it's Morse Taper!!! Safe turning to EVERYONE!!!

 

[TomW]

Jeff,

Your description was perfect, judging by the fact that my stomach was upset about 3/4 of the way through it... I guarantee you saved me from the same accident sometime in the future.

Thanks Buddy!
Tom

 

[jeff]

I'm a little confused... Maybe I just have never seen one, but I don't recall ever seeing a 'threaded drill chuck'... I have several thread #2 Morse Tapers that drill chucks will fit on, but never a threaded drill chuck...might be that there are lots out there, I've just never seen or used one. My drill chucks compression fit onto a standard threaded #2 Morse Taper but that won't prevent what happened to our friend above even if you're using an all thread rod. The all thread rod WILL prevent the Morse Taper from coming loose, but not the drill chuck as they can and often will separate from the Morse Taper and then you have a serious accident if you're not holding on tightly and are not able to stop the lathe quickly... If there are threaded 1/2" drill chucks out there that will all an all thread rod to keep it in the tail stock, I'd appreciate a source for one as I'll certainly replace the ones I have... I too, almost panic when the drill chuck separates from it's Morse Taper!!! Safe turning to EVERYONE!!!

You have a taper mount chuck. Mine is a 1/2-20 thread mount but my MT is a tang back. I'm going to switch to a drawbar arbor. So the chuck threads onto the arbor, and the drawbar threads into the arbor.

 

[mvande21]

Glad to hear you are ok. Another big danger I have been finding is the jaw chucks. If the jaws are a little bit open, they are an easy catch on anything in proximity, including fingers. Had many catches that pull fingernails in a bad way. Nothing serious but it definetly does not tickle!!

 

[seamus7227]

Ok pics or it doesn't count! Sorry just had to throw that in there.

yeah Jeff, you know the drill, "no pics, didnt happen"!! LOL. I would love to see the stitching of your war wound if you are able!

 

[nava1uni]

So glad that you were not hurt worse.

 

[Nick]

jeff,
glad you are done better, close call. After reading the posts, some one mentioned using a draw bar. I checked both of my drill chucks and there were no tapped holes. Is it possible to have a machine shop drill and tap a hole in them for a draw bar?
Some where I remember hearing that if you clean off the MT and rub some chalk on the taper it will hold better, but it looks like the draw bar is the best choice.
Take care and have a Merry Christmas

 

[edstreet]

Ultimately this is how you use a drill chuck on the lathe.
Fountain Pen - - YouTube

Also on this one.
Masters of the Fountain Pen - Kiyoshi Kato

 

[sbwertz]

Glad to hear you are ok. Another big danger I have been finding is the jaw chucks. If the jaws are a little bit open, they are an easy catch on anything in proximity, including fingers. Had many catches that pull fingernails in a bad way. Nothing serious but it definetly does not tickle!!

Take masking tape and wrap around the outside of the jaws after the piece is mounted. It protects you from those sharp corners. (DAMHIK)

 

[Powerstroke 7.3]

Had that happen to me - I hang the pieces above my lathe that I get to see every time I use the lathe as a reminder... It has been the only time my wife came running to the garage to see if I was alright... the chuck had hit something and made such a sound it scared her. I also had to change pants...

 

[edstreet]

One thing that I am having a hard time wrapping my head around with this issue is this.

If the drill chuck's taper is inside the tail stock and still supported by your hand(s) then why did the drill bit bed and why did the drill chuck try to give the airlines a good run for their money?

Perhaps the drill bit became bent if the drill chuck was clear of the tail stock and not being supported but that is about the only what that I can see.

 

[sbwertz]

One thing that I am having a hard time wrapping my head around with this issue is this.

If the drill chuck's taper is inside the tail stock and still supported by your hand(s) then why did the drill bit bed and why did the drill chuck try to give the airlines a good run for their money?

Perhaps the drill bit became bent if the drill chuck was clear of the tail stock and not being supported but that is about the only what that I can see.

When you turn the wheel to back the bit out of the work to clear shavings out of the bit, sometimes the bit catches a bit in the work, and breaks the grip of the morse taper on the tailstock. As a result, instead of the bit backing out of the work as you turn the wheel, the chuck comes forward out of the tailstock. When it clears the tailstock, the weight of the chuck and morse taper cause the bit to bend. Since all this is happening at about 500 rpm, it happens FAST. The whole chuck is whipping around in a circle until something lets go and it goes flying across the shop.

 

[Scott]

I'm glad you're OK!

Scott.

 

[edstreet]

One thing that I am having a hard time wrapping my head around with this issue is this.

If the drill chuck's taper is inside the tail stock and still supported by your hand(s) then why did the drill bit bed and why did the drill chuck try to give the airlines a good run for their money?

Perhaps the drill bit became bent if the drill chuck was clear of the tail stock and not being supported but that is about the only what that I can see.

When you turn the wheel to back the bit out of the work to clear shavings out of the bit, sometimes the bit catches a bit in the work, and breaks the grip of the morse taper on the tailstock. As a result, instead of the bit backing out of the work as you turn the wheel, the chuck comes forward out of the tailstock. When it clears the tailstock, the weight of the chuck and morse taper cause the bit to bend. Since all this is happening at about 500 rpm, it happens FAST. The whole chuck is whipping around in a circle until something lets go and it goes flying across the shop.

Still does not fully explain things. I just measured and the chuck that I have has a 3 1/2" grip on the tail stock. That means you would have to be drilling well beyond 3 1/2" deep to get this effect. The second part that of what I said must have been overlooked, that was "and still supported by your hand(s)"

I can clearly see why the drill bit could bend in certain unsafe conditions but going back to re-read the OP the key works that I may have missed in the start was "When drilling deep on the lathe"