Post Crash Test

OK, I am officially in the Crash Club.

I was hurrying to finish a job before Thanks Giving and instead of putting a short countersink tool in, I chucked up a long 3/8" HSS drill (my next procedure) and it plowed right down through my part and broke when it hit the bottom of the vise.
The drill chuck spun apart leaving the TTS chuck collet in the machine and the chuck flew off.
The chuck collet looks to be in good shape but the inside of the drill chuck has several big gouges where it spun eccentrically as is spun apart.
Amazingly the vise has no visible signs of damage.
The drill bent laterally and the chuck came off so it didn't plow into the top of my part.
For those in the Crash Club (or want to be), is there anything I should check before assuming everything is OK?
Besides putting an indicator on the spindle to test if it is ok, are there any other tests/checks I might want to do (besides drinking less coffee and slowing down).
Thanks,
Nathan

lol. I honestly didn't know there was anyone not in the crash club :)

A crash like that should have no effect on anything, other than possibly bending the Jacobs adaptor and tapered bore in the drill chuck.

Regards,
Ray L.

I have bumped my TTS drill chuck on the side enough to drop the chuck off before. It didn't damage anything. I would not consider what I did a real crash though. I just hit the wrong jog key direction. That type tool holder is actually a little forgiving in that way. :)

You can debur some or enough to reseat the chuck and put it back together. Chuck up a large drill and turn it at slow speed. You will be able to see damage or bent parts then.

You didn't hurt yourself too bad there. I would definitely re-indicate the part and vise before rolling again. I have snapped off 1/2" roughers before with no real damage. You can definitely hear the steppers groan when you make a move like that though! Welcome to the not-so-elite club :banana:

Yeah I had a big crash once - I was ploughing down a big steel part with a 3/4" insert mill and the tips were getting blunt. I could hear the spindle slowing so I began the run towards the machine. Only to arrive in time to watch the spindle stall, steppers scream.

I was worried about the spindle bearings but they are still running fine - so they must be well proportioned for the job. I fitted a load meter after that and can see when the motor is getting to its limit now.

Not so keen.

The best way I know to stay out of the Crash Club is to not be in such a hurry. I have learned over the years when I get tired it's time to quit for the day.

Steve has some Sage advice right there! Also make sure to cut some AIR before jogging down to zero on real stock and hitting cycle start with your untested part program! When you do a variety of set-ups you don't always set Z-0 consistently at the top or bottom of the stock. I have been burned by that before and now run all my air cuts after indicating with stock in the vise + total stock thickness + 1" just so I can visualize the first cut motions. Call me a poor CNC machinist, but when I run multiple iterations of CAM to attempt to optimize my runs on multi-sided parts it is just a way conservative way of life for part #1 in real stock :-). Tooling and fixtures are just too expensive for me to do otherwise....oh yeah and titanium stock isn't cheap either :-).

Thanks for everyone's advice and insight. You are right, it turned out to not be too bad. Being the first time it was kind of scary to watch it unfolded in dismay as I hustled to the e-stop.
I took a break to think of my stupidity and how I will not make that mistake again.
I cut some threads on the same part after I took a break and the machine cut very well and to tolerances so that made me feel better.
Yes, slow down and be redundant on checking.

The one good thing that comes out of bad crashes is learning, "I WON'T DO THAT AGAIN!" :)

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Originally Posted by CadRhino

....as I hustled to the e-stop. ....

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Which is why I now have 3 estops to make them easier to get to in a hurry (just having one on the electrical cabinet at the back of the enclosure is a bad idea IMHO). At about $5 each plus a bit of wire it is a cheap investment.

My Estops are all in very convenient locations, however they are never close enough for a faulty rapid move. :)

Since the difference between life and death is 0.25" at 100 ipm (150 millisec), anything outside of arms reach is too far.... and usually, any panic button outside of 3" is too far.... :tired:

Quote:

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Originally Posted by pickled

Steve has some Sage advice right there! Also make sure to cut some AIR before jogging down to zero on real stock and hitting cycle start with your untested part program! When you do a variety of set-ups you don't always set Z-0 consistently at the top or bottom of the stock. I have been burned by that before and now run all my air cuts after indicating with stock in the vise + total stock thickness + 1" just so I can visualize the first cut motions. Call me a poor CNC machinist, but when I run multiple iterations of CAM to attempt to optimize my runs on multi-sided parts it is just a way conservative way of life for part #1 in real stock :-). Tooling and fixtures are just too expensive for me to do otherwise....oh yeah and titanium stock isn't cheap either :-).

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Just don't do like I did and forget to zero Z at the air cut height... My first time ever threadmilling using a very nice (and pricey ~ $150) Scientific Cutting Tools thread mill. My code was wrong and I broke the tool before it even cut a thread.

bob