And now a message from the makers of gauze

[funkychicken]

I was finishing off a little Jacaranda bowl when I thought "I'll just put the speed up to 3000rpm", "And Now I'l just turn it on - Wham! Gdgdgdgdgdgthunkdgdgdgdgdgdg - Owee...

Wham - the sound of half a bowl breaking loose from the rest at 3000rpm and hitting me in the stomach. (and drawing blood)

Gdgdgdgdgdgthunkdgdgdgdgdgdg - The vibration of half a bowl spinning at 3000rpm and the lathe falling off it's perch (Pic 2)

First thought: Augh!
Second thought: Owww, my tum tum!
Third thought: The lathe is going crazy! Turn it off!
Fourth Thought: Noooo! The bowl is ruined! (pic 2/4)
Fifth thought: Hey my hands are bleeding.... (Pic 3)


The wood had a crack in it but I didn't know it'd do that!

Be safe guys!


Funky C

[Chesand]

Ouch!!!

[tea lady]

Dang!! Cool sound effects though.

[Caveman]

:o Bad luck, but maybe also lucky - coulda hit you in the head/face:oo:.

3000rpm:oo: - for me that's a pretty scary thing - I hardly ever find the need to go much above 1,000.

Also using the chuck in compression mode gripping a tenon is my preference. Looks like you've got yours in expansion mode - I tried this once and in tightening the chuck caused a hairline crack (also using Jacaranda) - haven't used this method since.

Good luck on your next one:2tsup:.

[Calm]

Guessing that bowl is in excess of 6 inches diameter i think even in good condition that would be a bit quick.

Anyway i had the same thing happen to me one day (i never got hit though) and immediately thought i dont think i will do that again.

Now you can change your avatar to suit Steve "thebleeder" :D:D You two might start a trend but i dont thnk i will copy you.

[dai sensei]

I can really relate to that unfortunately - see here (http://www.woodworkforums.ubeaut.com.au/showthread.php?t=39044). Nothing goes to waist though, I cut mine up for pen blanks, is there any wood of yours salvageable?

[funkychicken]

:o Bad luck, but maybe also lucky - coulda hit you in the head/face:oo:.

True!


3000rpm:oo: - for me that's a pretty scary thing - I hardly ever find the need to go much above 1,000.

Nothing over 1000rpm?? Whaddyou only turn wagon wheels for a living?? What about for pens/miniature stuff?


Also using the chuck in compression mode gripping a tenon is my preference. Looks like you've got yours in expansion mode - I tried this once and in tightening the chuck caused a hairline crack (also using Jacaranda) - haven't used this method since.

Good luck on your next one:2tsup:.

Hmm...how do you finish your work? Jam/bowl chuck?


Ouch Neil! Good thing you were wearing a shield!
Nah the walls were 5mm thick max, only thing I could make from it is modern art :D

I'm wondering...a bowl 95mm radius, spinning at 3000rpm hitting me 2 feet away... How fast was it going?

[artme]

You are both lucky and unlucky.
I would advise that you don't work anything of that diametre at that speed. :no::no::no:At 3000 rpm tour rim speed is pretty frightening and any flaw in the timber will cause big problems as you have just discovered.

[Calm]

I'm wondering...a bowl 95mm radius, spinning at 3000rpm hitting me 2 feet away... How fast was it going?

well lets see if i can remember

95 x 2 pie r = 596.6 mm
circumference x rpm = 1,789,800 mm per minute
convert to km per minute / 1,000,000 = 1.7898 km per minute
convert to km per hour x 60 = 107.38 kmh

So if you were 1/2 a metre away it took .016762 secs to hit you.

I guess you had no chance of ducking.:D:D:D

ps. the maths are there to be corrected.

[Skew ChiDAMN!!]

Hmmm... short Km in your part of the world, Calm? :innocent: (but ya made a mistake that corrected it. Serendipitous. :;)

Anyways, that's the absolute fastest a piece could spin off that bowl - if it was a chip off the very rim. The parts of it closer in to the axis of rotation are moving much slower... down to 0Kmh at the middle. So, in reality the velocity would be closer to that obtained by using half the radius and the rest of the angular momentum would go into making the piece spin. ie. it'd come flying off like a frisbee...

Want to take a stab at the maths now? :U

Even so, it'd be well over the speed of hurt. Ya have my sympathies FC, been there, done that, won't do it again in a hurry! I bet you won't either!

[ss_11000]

:rofl: unlucky dude

why is it i laugh at ppl getting hurt?

[China]

The speed is not the problem it is the fact that the bowl contained a flaw, I seldom run my lathe below 3000 rpm

[weisyboy]

outch

that is way to fast

but atleast we can all have a good laugh

look i found a vidio of you

:brick:

[China]

Been doing it for thirty five years just as I was taught at trade school

[funkychicken]

The speed is not the problem it is the fact that the bowl contained a flaw, I seldom run my lathe below 3000 rpm

Yeah from now on I'll check thoroughly for cracks (except this one was obvious:doh:)


And theoretically the last bit to break off would be the rim and therfore the piece would be going top speed when it came off.... Just a thought...

Did I mention it made a big lump and drew blood where it hit my tum-tum. And yes I was wearing a shirt.... And yes it hurts..

[ss_11000]

Did I mention it made a big lump and drew blood where it hit my tum-tum. And yes I was wearing a shirt.... And yes it hurts..
you forgot to where the bullet proof vest:wink:

[funkychicken]

you forgot to where the bullet proof vest:wink:

That's actually not a bad idea... kevlar turners jackets also with groin protection - Now there's an idea!

[joe greiner]

BTDT; in compression mode too, and before hollowing the bowl. But I've always stood aft of the headstock when starting high speed or odd-ball blank. Near the tailstock may be a good switch location for emergency shutoff; not so good for cranking up the speed.

stirlo, for the same reason you can buy a T-shirt with the legend, "It's only funny until someone gets hurt. Then it's hilarious."

Joe

[Caveman]

Nothing over 1000rpm?? Whaddyou only turn wagon wheels for a living?? What about for pens/miniature stuff?

Hmm...how do you finish your work? Jam/bowl chuck?

Wagon wheels:D - only done a couple that size!
Very rarely do any spindle work. Not into pens - do turn some larger stuff, but mostly in the 10" to 20" range.

Saw a nice formula somewhere but can't recall where exactly it was that I saw it:

Diameter x rpm's should equal between 6,000 to 9,000

i.e. 6inches diameter x 2,000rpm = 12,000. (This was in reference to bowl turning.)
I always turn at whatever speed feels comfortable, but have written that formula on my wall as a quick refernce just to check now and then.


For finishing the foot I have a homemade compressions chuck
67838
and a set of 'cole' jaws that I use to reverse the bowl
67839
or simply reverse it with tailsock support and finish off by hand.

[OGYT]

Cracked wood is a dangerous thing... 'cept in my case, maybe a cracked turner is worse. :D I routinely turn bowls up to about 9 or 10 inches dia up to about 1200 - 1500 rpm for making the final smoothing cuts. At that, I'm always using the bowl steady. But if it's got any cracks in it, I slow it down a lot.
Glad you're still with us! :U

[wheelinround]

So instead of Funky Chicken we should now call you Ruffled Chicken some bruising on the stomach I suppose by now and those fingers at least you had the camera handy :D

:2tsup: Glad you ok FC and finaly we see that lathe

:oo: Lathe falling :doh: better secure it FC but then again it may be in line now and centres meet up.

[hughie]

in compression mode too, and before hollowing the bowl. But I've always stood aft of the headstock when starting high speed or odd-ball blank. Near the tailstock may be a good switch location for emergency shutoff; not so good for cranking up the speed.

Yep! that pretty much my modus operandi as well. Goes back to when I was a little tacker using my Dads lathe. Had a lump of Jarra fly past my head. It weighed around 2kg, took me a couple of weeks to get back into it and a change of clothes........


Still this probably is another twist on how speed can kill....:U

[oldiephred]

Been there , done that and that's why I love the foot sw. When I move away the lathe stops. Of course it also has it's problems but they are "livable" Sure hope there was no permanent damage to hands , body or confidence. 3000 all the time??? wow.

[DavidG]

Brings back memories of a red gum bowl.
Threw on a gum line and hit me in the head. :o

Thank goodness for the triton respirator. It bounced off and hit the wall.:C

The vl300 did not move and the big red bar was useful. :U

[Calm]

FC i like the new avatar.:2tsup::2tsup::D

[funkychicken]

Glad you're still with us! :U

So am I!:D


So instead of Funky Chicken we should now call you Ruffled Chicken some bruising on the stomach I suppose by now and those fingers at least you had the camera handy :D

:2tsup: Glad you ok FC and finaly we see that lathe

:oo: Lathe falling :doh: better secure it FC but then again it may be in line now and centres meet up.

You already got to see the lathe in this (http://www.woodworkforums.ubeaut.com.au/showthread.php?t=65608&highlight=my+new+toys) thread...remember...

Yeah I think I'll screw it to the bench now... And maybe bolt it to the house frame...


FC i like the new avatar.:2tsup::2tsup::D

:B

[wheelinround]

:doh: oh ah :B even commented on it too:doh:

[Tony Morton]

Hi Funkie

With a blank that size and speed its a wonder it didnt take off lathe and all after all it is a JET.

Think Safe and have fun Tony

[La truciolara]

What an experience! But you were lucky.
Did you want to fly over the lathe and take off that you tuned the speed up to 3.000 rpm's ? :U
I have done a file which gives you some indications on what would be the lathe speed in function of the diameter of a BALANCED piece of wood.
In you case the turning speed should have been around 2.000 rpm. But I guess, even at that speed, because of the crack, it might have blown up all the same.

If you want to test the very simple program you can enter the diameter in the left columns of the tables.

http://www.la-truciolara.com/forum/Turning%20speed.xls

[Elbow]

FC sometime back Skew posted a chart or suggestions for recommended speeds. I think I still have a copy somewhere or he may post it again if he reads this. If not pm him
Allan

[funkychicken]

Thanks guys,

I don't think I'll be as cavilier with the speeds from now on...

[Alastair]

In your case you knew the speed, and a fault came and bit you. Normally with a pulley drive, you are still at the switch if you have mistakenly set too high a speed, and can kill it quick.

Another scary scenario happens with VFD varible speed drives, where the speed control is a knob. This can be bumped, or twisted and forgotten. If combined with a 'soft start' where speed ramps up, this can happen while you are moving away, and catch you by surprise.

Happened to my instructor at TAFE. Before he knew it, a MDF "cole jaw" had exploded, fortunately missing him, but taking out a window and light fitting.

I often turn scary pieces: too big, too fast, out of balance, out of round, segmented. My final check before turning on is ALWAYS pulley speed. I have also perfected the art of turning while standing out of the firing line. This has come from much experience of wearing my art in the past!

PS: Bloke at our guild developed a voice activated switch, which he demonstrated, wired into the lathe circuit. And sudden loud noise woud kill the lathe. We referred to it as the "SH*T SWITCH!!!!"

regards