"waves" on spindle turnings

[Cary Hulse]

I've not done much spindle work. I was recently tasked with turning something (about 18"x1") and found that I was getting a wavy look vs a nice smooth finish. I suspect this was from flex in the piece as I was working it. Is that correct? Any suggestions to minimize or avoid it? Thanks

 

[Brian Gustin]

Sharpen your gouge... sounds like you're pushing too hard on the bevel, which usually happens when someone's trying to make the gouge cut wood when it gets dull. (Been there, done that)

 

[Roger Wiegand]

Finish turning the center first before thinning the ends. Reduce your tailstock pressure to the minimum needed, too much and you will bow the piece. Or hold one end in a chuck and only use the centering pin on your tailstock-- little or no pressure. Gentle cuts with a sharp tool, push too hard and you will bow it. Support the cut with fingers on the back side when working towards the middle. Once the chatter starts change the speed of your lathe-- faster or slower-- to get away from the resonance frequency and take very light cuts. Try a skew rather than a gouge, most spindle turning cuts, deep coves excepted, are easier and cleaner with a wicked sharp skew. All else fails get out the 80 grit gouge. ;-)

 

[Cary Hulse]

Thanks to both of you.
This was mainly with a skew, but I haven't mastered the sharpening of it yet so I'm sure it wasn't quite "wicked sharp", and now I do think I had too much pressure on the tail center.
Much appreciated

 

[Dean Center]

18" is a very long 1" spindle piece that would set any of us up for problems. You'd need nearly perfect technique. And a dull or improperly sharpened skew would not get you there.

 

[R Henrickson]

Finish turning the center first before thinning the ends. Reduce your tailstock pressure to the minimum needed, too much and you will bow the piece. Or hold one end in a chuck and only use the centering pin on your tailstock-- little or no pressure. Gentle cuts with a sharp tool, push too hard and you will bow it. Support the cut with fingers on the back side when working towards the middle. Once the chatter starts change the speed of your lathe-- faster or slower-- to get away from the resonance frequency and take very light cuts. Try a skew rather than a gouge, most spindle turning cuts, deep coves excepted, are easier and cleaner with a wicked sharp skew. All else fails get out the 80 grit gouge. ;-)

All very good advice! 18" is long for 1" diameter. Definitely start from the center then complete toward the tailstock before working toward the headstock. Holding one end in a chuck will certainly help -- I usually use a chuck for lengths >12" for this diameter. Supporting from the back with your fingers will help.

I generally use a spindle detail gouge rather than a skew. A detail gouge has a heavier shaft, so it is less likely to vibrate than a regular gouge, especially for deeper cuts when you have greater length beyond the tool rest.

A spindle steady *might* help, but reduced pressure from your tool and tailstock will likely help more. I rarely use a steady, even for longer spindles, but always a chuck.

 

[R Henrickson]

18" is a very long 1" spindle piece that would set any of us up for problems. You'd need nearly perfect technique. And a dull or improperly sharpened skew would not get you there.

I've turned 29" back posts for Windsor chairs -- maximum diameter ~1 1/2" but as little as 5/8" diameter in the middle. Holding one end in a chuck provides much more support than a drive center. A spindle steady may help, but I've found that finger support from the back is usually enough.

Despite its name, a spindle roughing gouge is good for shaping and can leave a very fine surface when cutting long curves, if you use bevel support. A continental gouge is also good.

 

[Mark Jundanian]

spindle roughing gouge is good for shaping and can leave a very fine surface

And it's relatively easy to sharpen.

 

[robo hippy]

I am not a spindle turner, but a friend is. He commented once that spindles in the 10 to 1 ratio will stay pretty steady. So, 1 inch diameter 10 inches long will be pretty steady. Longer, and/or thinner and you start getting some whipping action. It can be done, but as some one said, "the bevel should rub the wood, but the wood shouldn't know it". Very gentle bevel rub! "Just enough tailstock pressure" is good too. Some even put chucks on the tailstock and put the spindle under pull tension. Sharp tools, of course, and I do strop my skews to remove the burr.

robo hippy

 

[hockenbery]

Despite its name, a spindle roughing gouge is good for shaping and can leave a very fine surface when cutting long curves, if you use bevel support. A continental gouge is also good.

We used to see a guy from the Rawlings company about every year outside Camden yards.
They had a lathe in a trailer with a viewing area.
The Rawlings guy would turn a bat from square to finished bat it about 10 minutes using only an SRG.
He turned the knob with the flute down.
I’m’ sure he was moving a lot slower than his normal speed because he was talking about the process
The only part not totally finished with the SRG was the barrel end of the bat. He had a machine that carved out the end a little.

During the day he worked with the ball players who were Rawlings customers - turning bats for them and tweaking dimensions and weights.

I’m a fan of the continental gouge.