I always new it was the right thing to do!

[Maurice]

This morning whilst waiting for the glue to dry for a pen kit I decided to drill out a couple of slimlines to pass away the time in the shed. I was drilling an acrylic blank with a Colt 7mm drill, (I’ve recommended these drills for acrylic in the past) at 1500 rpm on my record power lathe when all hell broke out.

There were a couple of loud bangs at which point the drill chuck, which had been in the tail stock, together with half a drill had hit the shed wall and continued to fly across the front of my face having first taken the skin off my fingers. It missed my face by a matter of a couple of inches before crashing into the other side of the shed. After stopping the lathe I saw that the other half of the drill was still inside the acrylic blank.

I was withdrawing the drill from the blank in order to wind the tail stock back in before pushing the drill back into the blank to complete the drilling distance. It was at this point when the drill broke and tore the drill chuck out of the tail stock.
Fortunately I had been standing behind the tail stock turning the handle and, this is the main point, wearing a full face shield. We often just work with goggles as eye protectors but if I had been 1 or 2 inches in a different position the chuck and broken drill would have hit me full in the face and I probably would not be writing this ode to you all.

I always have known I should wear a full face shield but at times it’s too much trouble. But not any more I’m convinced it’s the right thing to do.

 

[Jimjam66]

Yup - gotta treat machinery with respect! Glad it was just a 'near miss'.

 

[paulm]

I think we all get complacent at times and its little reminders like this that points out why we do need safety gear.

 

[Terry]

You must ask yourself why did this happen Maurice????
When drilling acryllic keep your speed down to around 400rpm and keep withdrawing the drill to let the swarf clear. This will stop the acryllic from overheating but more importantly it will stop the drill binding in the acryllic which I suspect happened in your case.
I would never ever drill anything at 1500 rpm as it is far too fast!!!!

Glad you got away without any injury.

 

[PhillH]

Good post, I use safety overglasses as I wear specs and find anything else causes misting.

I also stand behind the tailstock if drilling.

I'm with Terry though, 1500 does seem high speed especially with Acrylic, I assume it melted inside and "grabbed" with the results you eloquently described.

 

[Doug]

Yep, got to agree with Terry, you'd be melting the acrylic at that speed & as you withdrew the bit it cooled enough to grab the bit.
Thankfully you have survived fairly unscathed to tell the tale.

 

[turnaround360]

I had the chuck come away in the head stock and had to replace the head stock spindle now i always have a draw bar.

 

[stevenw1963]

I hate drilling on the lathe so only do it if needing to drill a centre hole for hollowing. Pillar drill for all else.

 

[edlea]

Slow down Maurice 1500 is far to fast for acrylics

 

[Walter]

You were lucky Maurice, 1500 rpm is too fast for drilling anything.

 

[Penpal]

Maurice, I use a threaded draw bar in the head stock of my lathe also in the quill of my pillar drill having had a repeat episode on the drill press
I did observe on a 1000 dollar drill press last week there was no provision in the quill to fit a draw bar (very poor in my opinion).

Somewhere in the world of woodturning the previously stressed basic principles of morse taper useage has been thrown out or not explained withdrawing the turning force in drilling can be the very opposite effort used to put it in in the first place, another step I take is to always have on hand a morse taper reamer and every time a taper is removed for any reason I lightly clean, ream the holding part.

I felt very sorry for you having this experience whilst drilling having drilled countless Corian blanks in the past and lots of cast blanks.

Kind regards Peter.

 

[silver]

1500, never.. Be careful Maurice. With that said my dad had one come loose in much the same way as yours and he was drilling a piece of bocote.

After that he made sure the mt was hammered in and when winding out the drill he always made sure the chuck was coming out as well.

Still remember boarding up the window after it decided to leave the shed without opening the door before leaving..

 

[yorkshireman]

Thanks for the advice Maurice and glad you're OK

 

[Neil]

You must ask yourself why did this happen Maurice????
When drilling acryllic keep your speed down to around 400rpm and keep withdrawing the drill to let the swarf clear. This will stop the acryllic from overheating but more importantly it will stop the drill binding in the acryllic which I suspect happened in your case.
I would never ever drill anything at 1500 rpm as it is far too fast!!!!

Glad you got away without any injury.

I suspect Terry that as Maurice was withdrawing the drill, that the drill stayed in the acrylic and the chuck came out of the tailstock, I've often wondered why they cant solve this with some sort of lock? It is bloody dangerous, we've all forgotten to hold onto the chuck when withdrawing the drill at some stage.

 

[Grump]

Holding the chuck is sheer stupidity Neil, use a drawbar if you worry it may come adrift.
I use long drills and don't withdraw the damn thing, drill all the way through in one swift movement.
I drill at high speed and touch wood have not had that problem.
It is all part of the excitement init the odd black eye and cut finger that's what keeps us in the shed is the thrill of what we will create init?
Glad you are Ok though Maurice keep the nut on mate and learn to duck init?

 

[Walter]

we've all forgotten to hold onto the chuck when withdrawing the drill at some stage.

Holding onto the chuck as you withdraw the bit is dangerous practice too. If the bit jams in the work it could rip the skin off the palm of your hand.

Drilling at a sensible speed that is appropriate to the material and withdrawing the bit regularly to clear the flutes should prevent the bit from jamming in the work, but a drawbar on the chuck Morse taper will make absolutely certain the chuck stays in the taper. Clean well maintained tapers also help and for the scale of drilling we are doing on pens that in itself should be enough.

 

[Terry]

I suspect Terry that as Maurice was withdrawing the drill, that the drill stayed in the acrylic and the chuck came out of the tailstock, I've often wondered why they cant solve this with some sort of lock? It is bloody dangerous, we've all forgotten to hold onto the chuck when withdrawing the drill at some stage.

You could possibly be right Neil but only Maurice can verify that but drilling at 1500 rpm is too fast and because the swarf coming off acrylic will be thick it can cause a drill to bind and snap and certainly more so with a colt 7mm colt drill as they can flex(bend) very easily when drilling which can compound the problem !!!!

 

[Terry]

Holding the chuck is sheer stupidity Neil, use a drawbar if you worry it may come adrift.
I use long drills and don't withdraw the damn thing, drill all the way through in one swift movement.
I drill at high speed and touch wood have not had that problem.
It is all part of the excitement init the odd black eye and cut finger that's what keeps us in the shed is the thrill of what we will create init?
Glad you are Ok though Maurice keep the nut on mate and learn to duck init?

You say it is all part of the excitement Brian ???? That is a strange statement to make especially if somebody ended up with a serious injury!!!!

 

[rowdyyates115]

Lucky boy there Maurice, but please slow the lathe to below 500 for drilling acrylic/polyester

 

[Maurice]

Thanks for the comments gents but can I ask you to have a look at this youtube video which I think is provided by the producers of the Colt drills

.

The main selling point is the speed of drilling in all materials including acrylics. Because of the design of the drill there is no necessity to withdraw the drill to clean the flutes or to allow it to cool down. On this occasion I think I had been following the manufacturers instructions on the drill's use.

I have been drilling blanks including acrylics for years without this happening before although I have had normal thin steel drills break but not the chuck flying out.
I have a draw bar fitted to a chuck I used for inserting in the headstock when sanding but I have not used it in the tail stock because of the need to allow the tail stock to travel with the drill into the blank. To allow this, the drawbar on the chuck would have to remain loose, although I do now accept it may prevent the chuck from travelling so far in mid air.

I have tried to include the video link but until I post this reply I don't know if it will work.