How not to drill a pen blank or turning your jacobs chuck into a hammer!
- Thread starter Sachakins
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okeydokey
Established Member
wow ..................................no other comment needed
That made me duck watching it at my desk
Terry - Somerset
Established Member
AIUI the arbor is just a tapered interference fit into the chuck. In principle if assembled correctly it should not come apart easily (if at all). A few hundred grams of steel heading towards ones head is not an attractive prospect.
Question - what cause the arbor and chuck to separate - vibration from a slightly off-centre drill, incorrect assembly, ???? Job today - look closely at mine!!
Question - what cause the arbor and chuck to separate - vibration from a slightly off-centre drill, incorrect assembly, ???? Job today - look closely at mine!!
I'm guessing that its a new lathe and chuck and arbour and it wasnt whacked on hard enough to make the tapers grip
i would/do clean with solvent before assembling and wind the chuck jaws fully into the chuck body and whack it with a copper/hide hammer a few times
it could still come out of the tailstock quill however but thats a longer taper so you should notice when retracting the chuck
Ian
i would/do clean with solvent before assembling and wind the chuck jaws fully into the chuck body and whack it with a copper/hide hammer a few times
it could still come out of the tailstock quill however but thats a longer taper so you should notice when retracting the chuck
Ian
Lons
Established Member
My method as well but you should wear a glove on the hand holding the chuck as the other scenario is the chuck comes loose in the morse taper and spins with the work.
As well as not holding the chuck, he was feeding the drill in by sliding the tailstock, rather than by using the handwheel. If the tailstock is free to slide, it's also free to wobble which may have loosened the arbor.
He also drilled in a long way before withdrawing the tailstock to clear the shavings. The drill can be stuck firmly in such a situation.
I wonder if he was wearing a face shield?
Duncan
He also drilled in a long way before withdrawing the tailstock to clear the shavings. The drill can be stuck firmly in such a situation.
I wonder if he was wearing a face shield?
Duncan
I drilled an arcylic pen blank like that once and the drill got so hot it melted the plastic and the two welded together. Both the drill and the blank went in the bin together.
My own thoughts from your video:
I would slow your speed down. It looks too fast for the diameter of drill bit.
I would peck a few times on a deep hole like that with a short rest in between to let the drill cool. That really means for the heat to conduct from where it's working hardest into the bulk of the metal.
Morse tapers aren't designed to be used under tension so yes, hold the drill chuck back against the tailstock as you remove it and doing that with the hand wheel will pull the drill back more slowly and be less likely to provoke the split.
Never wear gloves around rotating machinery, so if the chuck does come loose and you are holding it, you have to let go, might take some minor cuts but less than potentially losing an eye to a flying chuck.
Also, you have the option to stop the drill still in the hole and wind it out with the handwheel while rotating the chuck in the normal direction by hand. Turning the chuck is important if you do it that way.
Thanks for sharing. A lot of us have done it and many of us will do it again even with this reminder.
My own thoughts from your video:
I would slow your speed down. It looks too fast for the diameter of drill bit.
I would peck a few times on a deep hole like that with a short rest in between to let the drill cool. That really means for the heat to conduct from where it's working hardest into the bulk of the metal.
Morse tapers aren't designed to be used under tension so yes, hold the drill chuck back against the tailstock as you remove it and doing that with the hand wheel will pull the drill back more slowly and be less likely to provoke the split.
Never wear gloves around rotating machinery, so if the chuck does come loose and you are holding it, you have to let go, might take some minor cuts but less than potentially losing an eye to a flying chuck.
Also, you have the option to stop the drill still in the hole and wind it out with the handwheel while rotating the chuck in the normal direction by hand. Turning the chuck is important if you do it that way.
Thanks for sharing. A lot of us have done it and many of us will do it again even with this reminder.
Sachakins
The most wasted of days is one without woodwork
It didn't look like a face shield, just glasses, safety ones ?
Orraloon
Established Member
I agree Duncan. There is a lot of movement in the tailstock if it's not locked down. It really is not the way to do it. He is lucky to get away with just a broken drill and dented pride. That lesson will be well and truly locked in.
Regards
John
That is why you hold the drill chuck when drilling. Other wise it may come out of the tail stock when extracting the drill. He also did not clear the drill flutes, by extracting the drill periodically. This was an accident waiting to happen. Was it a video of how not to drill a blank on a lathe ?
There are so many videos on line with unsafe working practices, which new or inexperienced woodworkers watch and think this is the way to do it.
There are so many videos on line with unsafe working practices, which new or inexperienced woodworkers watch and think this is the way to do it.
the great waldo
Established Member
Those safety glasses wouldn't have been much use if that chuck had hit him in the teeth!
cheers
Andrew
cheers
Andrew
We all make errors of judgement, if we are lucky we get to learn from it.
I think everyone who turns has had something come off the lathe at one time or another. Normally down to user error, even if it’s just a change in sound missed or ignored when turning.
I think everyone who turns has had something come off the lathe at one time or another. Normally down to user error, even if it’s just a change in sound missed or ignored when turning.
xy mosian
Established Member
I was taught (1964) to stand behind the tailstock.
geoff
geoff
Sachakins
The most wasted of days is one without woodwork
And one hand on chuck (1978)
treeturner123
Established Member
I knew there was a reason for using a pillar drill and vice, clamped to the drill bed!
Phil
Phil
This proves quite nicely that drill chucks can come loose from a Jacobs taper. And it wasn’t even being subjected to a side load.
The best advice I’ve seen is to scrupulously clean the male and female tapers before assembly. Gently warm the chuck body a little bit (don’t melt the grease inside!) and cool the arbor in the fridge. Wipe both parts clean again and seat the arbor into the chuck body with a swift tap with a copper (or similar) hammer - don’t damage the tang!
I did this with a 3/4” Jacobs chuck I was gifted a while back and it seems pretty solid and I’ve used some fairly large drill bits in it.
I can’t say the same for the 1/2” Jacobs chuck on my drill press. But it’s not my fault, I can’t get the drill press in the fridge!
The best advice I’ve seen is to scrupulously clean the male and female tapers before assembly. Gently warm the chuck body a little bit (don’t melt the grease inside!) and cool the arbor in the fridge. Wipe both parts clean again and seat the arbor into the chuck body with a swift tap with a copper (or similar) hammer - don’t damage the tang!
I did this with a 3/4” Jacobs chuck I was gifted a while back and it seems pretty solid and I’ve used some fairly large drill bits in it.
I can’t say the same for the 1/2” Jacobs chuck on my drill press. But it’s not my fault, I can’t get the drill press in the fridge!
I get the impression that wasn't you, who ever it was just used up a months good luck ration.
Had a similar thing happen at work. Ordered a cheep (>£200) bench top pillar drill, exactly the same as I have had at home for about 20 years with no issues. Had it cost rejected as one available around £120. Drilling with a 30mm hole saw into irregularly shaped plastic, hence a little vibration but not IMO excessive when lifting off having drilled in about 8mm with the hole only full circle for the last 2.5mm away came the chuck. No injury but it did roll flat surface across the back of my hand, did the 5 minute sit down. Very cheep taper with a poor surface finish.
Had a similar thing happen at work. Ordered a cheep (>£200) bench top pillar drill, exactly the same as I have had at home for about 20 years with no issues. Had it cost rejected as one available around £120. Drilling with a 30mm hole saw into irregularly shaped plastic, hence a little vibration but not IMO excessive when lifting off having drilled in about 8mm with the hole only full circle for the last 2.5mm away came the chuck. No injury but it did roll flat surface across the back of my hand, did the 5 minute sit down. Very cheep taper with a poor surface finish.
