Lathe Speeds & Chucks

Sounds like a goofy answer, but my turning speeds are relative to the size of the workpiece.
I start slow when roughing, faster for shaping basic form, then speed up more for final finish turning.
My speed range on the lathe is 500 to 2700 rpms. I rarely use the highest setting.
Bill

-- bill@magraphics.us

You do not mention using tailstock support obviously longer lengths/widths need extra support.

Not aware of a rule of thumb as far as length/width to use or not use tailstock support or lathe speed. I use tailstock support until it gets in the way whether spindle or bowl turning. Lathe speed depends upon what am turning, more than size.

Boils down to common sense, confidence, and experience.

-- Bill

I’ve seen this formula posted in several places. Diameter x speed = 8000 to 9000

Take the diameter and divide into 8000 to 9000 = speed

I usually divide into both 8000 and 9000 to get upper and lower speed.

I don’t usually follow this on small turnings but do with larger things like large bowls.

-- Dewayne in Bainbridge, Ga. - - No one can make you mad. Only you decide when you get mad - -

In addition to the other advice… turn as fast as you feel safe. A faster speed often means a shorter completion time and a cleaner cut, but also more of a chance for something to go wrong. I start roughing pieces really slow. Once I’m sure they are balanced, I turn it up. If at any point I start to feel uncomfortable with the wood or the cut, I slow it down again.

Also, since no one else mentioned, turn the speed down low when you are sanding. High speeds generate heat, which can crack or burnish the wood, and also can cause the adhesive on the sandpaper to weaken, shortening its life.

-John

My understanding is that you turn the speed up to sand, otherwise it takes forever. If you don’t press too hard, heat build up can be avoided.

When turning pieces that are out of round or out of balance, I start at low RPMs and turn up the electronic speed dial until I get some vibration, then back off a bit. This is where electronic variable speed really shines.

-- Dwight - "Free legal advice available - contact Dewey, Cheetam & Howe""

+1 for Bill White.

-1 for speeding up to sand cuz it’s faster.

-- I dream of the world where a duck can cross the road and no one asks why.

I have a delta 46-460 with variable speed. I have the belt set on the medium pulley and I haven’t needed to change it for anything.
I can have a range of 500 to 1900 on that setting, and I’ve never had to go faster than that.

I’ve noticed that sometimes turning the speed up negatively affects the cutting, plus there is more risk of accident.

-- Mom always said, "you can do anything you put your mind to." The older I get the more I realize she was right.

Turn fast, sand slow.

The formula Dewayne provided is a common, and good one. The other rule of thumb is “turn it up until it gets scary, then turn it down a bit”. Obviously this one is not without its hazards, but is also common and used at your own risk and based on comfort level and experience, use of the tail stock, etc.

As far as your tenon, make sure it has the correct taper for the jaws, and does not bottom out.

-- Robert --- making toothpicks one 3x3x12 blank at a time!

When starting your lathe, just make sure you are NOT standing in front of the workpiece. Stand off to the side so if the wood comes undone and comes off the lathe, it won’t hit you. It may take out a window or something but not you head or eye. Emergency rooms and mortuarys are not fun places to visit.

Be safe and have fun.

Thank you for all for your thoughts and suggestions.

My NOVA chuck’s instructions suggest no higher than 600 rpm which just didn’t seem right relative to what I’ve seen on TV or YouTube. After having experimented on my own and from discussions like this, I’ve come to the belief that those manufacturer numbers are for their own liability more than anything.

THANKS…

Were they talking about the cole jaws? 600 rpm is the recommended max RPM on those, and I would follow that.

But for standard use of the chuck and jaws that is really slow for a max speed. I may have to dig out my manuals now! (granted my experience is with the G3 and the Super NOVA 2, so some of the others may have different instructions)

-- Robert --- making toothpicks one 3x3x12 blank at a time!

Robert spot on concerning cole jaws. I say save your money and just use a jam or donut chuck for reverse turning bowl bottoms.

I scanned the manual and think it is well written with sage advice for someone with experience or just starting out. Other than how to install threaded insert & jaws or cleaning not sure what manual has to say for my Oneway chucks.

CAPACITY: DO NOT USE THE SCREW FOR VERY LARGE WOOD BLANKS. Its use is intended for small bowl and screw chucking work. The maximum capacity which should be mounted on the screw – 250mm (10 inches) diameter x 100mm (4 inches). DO NOT EXCEED 600 RPM FOR THIS OPERATION. Use tailstock support.

DOVETAIL OPERATION
This is a strong holding method, using the standard 50mm jaws bowls up to 310mm (12 inches) in diameter can be turned. DO NOT EXCEED 600RPM WITH THIS OPERATION. OUT OF BALANCE STOCK MUST BE TURNED AT THE SLOWEST SPEED POSSIBLE.

They should have omitted RPM’s and mentioned tailstock support what most folks do any way.

-- Bill