am I turning to big

[TYLER WOOD]

I agree with the taking up a mentor. It will allow you to learn what is safe on a lathe, as well as help in understanding the limitations of the lathe. The motor may be able to turn it, but you are wearing the bearings out in the motor. Putting strain on the spindle like that may not break it today, but it will break eventually. It could be on a large piece or a small piece. Misdesigned buildings do not fail typically when the building is built, but later on after it has been straied for a while. Take the advice from the people here.

[alex carey]

Alex Shanku you have me salivating.

alex

[Paul Atkins]

Jeff, RPM is revolutions/min. I know you know this. Feet /min is what he needs to know. 12" diam. at 50 rpm=157fpm =about 33 mph. 500 rpm @ 12" = 1572 f/min = 335 mph.
Alex, If you want to turn this piece of wood, drill, carve, chisel, or chainsaw out the middle and get the weight down - dry it a little, too. ( Or save it in a plastic bag till you have more experience or more cast iron.)

[john l graham]

This lathe while not as big as some may be closer to your price range and give you some options for heavier pieces. Using Paul's estimate you could turn a 50# piece of wood. The spindle size might still be a little light. Just another option out there. John

http://www.vegawoodworking.com/2400%20Bowl.htm

[Harvey Schneider]

Looking at the photo of the rough blank, I am guessing that it is about 14" in diameter.
I am rather surprised that nobody has pointed out that 450 RPM is a speed more reasonable for finishing that piece rather than for roughing it. With that much mass and it's momentum at that high a speed, broken tools are very likely.
I have a Jet 1642 and I have worked close to it's limits on both diameter and mass (15.5" diameter, 60 lbs initial weight), but my roughing speed is more like 150 RPM.

[alex carey]

@Paul Yeah I got all that. I keep all of my stuff in a bag and wait for it to dry. This eucalyptus for some reasons disintegrates after a few months. Small holes start to appear everywhere and it looks terrible. It kind of crumbles. No other wood has done that to me.

@John I was just looking at that lathe. I am also thinking of doing some longer spindle work which that vega can't do. I am also seriously considering the powermatic 3520B. I talked to the guy over at toolnut. 2959$ and it comes with the 18" extension. Free shipping and all. After I sell my lathe I think I'll have enough to go with this lathe. I probably won't turn bigger than 18" for quite a while so this will do fine and I will be able to be inbetween centers which is much safer especially for a younger more reckless person like me.

@Paul I would rather be roughing at 150 but my lathe doesn't go that slow. The reason I went to 450 I was trying to up my torque. I don't actually have it turning at 450 consistently. I set the dial to that speed but as soon as I touch the tool to the wood it slows down. I am more turning at 200. I wait for it to speed up then make some cuts and it slows down. It's like flicking the switch on and off.

Alex

[Leo Van Der Loo]

Somebody needs to get his school money back I think

A 30 CM bowl (about 12") is 3.14 X 30 = 94,2 CM circumference = .942 Meters
At 500 rpm 500 X .942 meters = 471 meters a minute
60 min in an hour, so 60 X 471 meters = 28260 meters = 28.26 KM = 17.56 miles per hour

You can use inches, 12"x3.14=37.68"
500 rpm x 37.68" = 18840" per minute
60 minutes x 18840 = 1130400' = 17.84 MPH

[Leo Van Der Loo]

Alex as you have heard from most here, you should get a larger lathe .
It might not be so much the weight on the spindle as the power required to spin that size of a piece of wood and to be able to cut on the outside of such a large piece of wood, as you will certainly shorten the life of that motor if not burn it out anytime you overwork it like that
I've turned on a lathe like that, and it is a sweet turning machine, but made for smaller pieces than you are attempting to do on it, more like the piece I'm turning on it .

[Paul Atkins]

Leo, Boy! My brain must have been really cold this morning! -Sounded pretty fast but I was just thrown by the 600 rpm thing. (measure twice - speak once)

[M Toupin]

remember 50rpm at the spindle translates to: 1" spindle at 50 rpm outside diameter of 12" equals: 50 x 12 = 600rpm at outer surface of turning blank.

How does the rim turn at more RPMs than the shaft without twisting it's self into a knot?

Mike

[Leo Van Der Loo]

Yup we all do that sometimes , just wanted to correct it

[Jeffrey Fusaro]

How does the rim turn at more RPMs than the shaft without twisting it's self into a knot?

Mike

isn't that how a black hole gets started?

[M Toupin]

isn't that how a black hole gets started?

Just might be... but I bet the grain is really cool!