Thread: Need advice on turning Australian hardwoods in metal lathe

Hi, first, as this is my first post here, a short intro. I'm a psychotherapist discovering crafty things late in life as a liberation from being stuck in my and others' heads Feels so good to be creating real things and using my body in the new wonderland of my little workshop.

My main project is that I'm setting out to make Celtic whistles - they're sort of like recorders, without a hole at the back, and come in all sorts of shapes, sizes and materials. I'm in North Queensland, so I want to use the local hardwoods.

So why am I on a metal forum? The design of the mouthpiece for the whistles involves what are basically concentrically sleeved cylinders about 50mm long. Getting a precise fit from sanding them on a wood lathe is painfully tricky, so I just bought a little metal lathe:

https://www.machineryhouse.com.au/L685

When it arrived I took one look at the manual with its complex formulas for calculating rpm, depth of cut for different metals etc and realised I was out of my depth. It doesn't even mention wood (naturally, I suppose, being a metal lathe...).

My thinking (correct me if I'm wrong), is that for what I need the complex formulas are probably overkill. I'm doing very simple, low-load turning. Just reducing the diameter a little on 50mm long wooden cylinders.

I'm hoping, and would be very grateful for, some simple advice on tool type, angle of cut, approximate rpm and maximum depth of cut for a range of Australian hardwoods:

Extremely hard woods: Gidgee, ironwood, ironbark (yes probably crazy using ironbark but I'll probably try it) etc

Very hard woods: Rose gum, Cadaghi etc

Moderately hard woods: Red Mahogany, Kwila etc

Another relevant aspect of this is that in one of the designs I want to try there are three sleeved cylinders with the middle one only 0.8 to 1.0mm wall thickness, so will need to be very delicate.

And what do you think about the need to bolt down the little metal lathe for this very light duty work? I'd rather not bother - haven't bolted down my midi wood lathe and it's fine.

Thanks in advance for any kind help.

Welcome to the forums.

I think you are over thinking it.
As you say what you intend to do will be light duty work for a metal lathe because it sees all wood as wood.
You'll basically have to try things out and see how they go.
I would recommend some soft jaws for your chuck otherwise your thin cylinders will slip or be crushed by a MW chuck.

Hi Matt,
Welcome to our metalworking forum.

Don't let the other guys know this but at times I have turned wood in my lathe. Shhhh! Crude in comparison to what you envisage, I have turned handles for files and other tools out of hardwood.I know what you mean about fine work though as I knew a bloke who could turn wooden goblets you could see light through.

The basic cutting tool-the lathe bit-I would recommend to you would be HSS - High Speed Steel.

I have used HSS 6mm x 6mm as I have a 12" swing lathe but you would get away with 3mm x 3mm .

HSS comes in a variety of dimensions.

The HSS lathe bit will require a holder to mount it in the lathe tool post. The HSS bits work best when razor sharp. For this you will need to sharpen it on a small bench grinder say 150 mm fitted with aluminium oxide stones.Maybe 60 and 100 grit sizes.

As for RPM, start slow and steadily work up until the best result is obtained.

As far as work holding of your timber I know little outside of turning handles but can elaborate on that if requested.

As for depth of cut it will be trial and error. Start on cheap timber until you achieve some control on the finish and go to the more expensive stuff when you are ready.

Truly! it is not difficult as I have got some great finishes just turning poxy old broomsticks.

Hi Matt,
Welcome to the forum. None of the woods you listed would be considered hard by metalwork standards. For metalworking tools I reckon the harder wood the better the finish you will get. Can't help you with woodwind instruments, but these guys probably can: http://www.woodworkforums.com/f186

Have fun!

I actually find it easier to carve (or turn for that matter) harder wood as it does not string or tear as easily. Sharp tools are a must though.

Michael

Originally Posted by BobL

Welcome to the forums.

I would recommend some soft jaws for your chuck otherwise your thin cylinders will slip or be crushed by a MW chuck.

Matt,

Welcome to the forum.

Think I've seen people filling a hollow tube with a close fitting metal or wooden slug to prevent vice jaws crushing them. Haven't done it myself.

This might be a way of holding your 50mm long cylinders
https://www.youtube.com/watch?reload=9&v=beJ1RFTRzuAcU

Are you a member of any Musical Instrument FOrums / associations ....... they can be useful too. Vaguely remember a thing called Aust. Assoc. Musical Instrument Makers and there is a subforum for musical instruments on the woodwork forum here MUSICAL INSTRUMENTS

Bill

One thing that you might want is a collet chuck. It will hold thin round items with less chance of crushing. Examples below. They are sold in most every country. Depending on the spindle mounting size you can get ER40 sized ones to hold larger diameters.

https://www.chronos.ltd.uk/engineeri...iameter-chuck/

https://littlemachineshop.com/produc...5452&category=

And welcome to the forum.
Pete

Forgot to mention that you can turn your own backing plate to mount woodturning chucks on. More versatility.

Originally Posted by Matt NQ

Another relevant aspect of this is that in one of the designs I want to try there are three sleeved cylinders with the middle one only 0.8 to 1.0mm wall thickness, so will need to be very delicate.

Here's one technique for turning very thin walled tube. He uses Delrin, but I can't see why it wouldn't work in wood: https://www.youtube.com/watch?v=hXq_HfwG7dA

Steamingbill,
your YouTube link doesn't work for me.

For spindle speed, if the mouthpieces you're making are recorder sized (I'm assuming 30 to 40mm max diameter, and not overly long), I'd suggest that the metal lathe will need to be close to it's maximum speed of 3000 RPM. Wood generally turns better as the speed goes up, the limiting factor usually being any out of balance, or risk of breaking if it's a long component.

Graham.

Welcome to the forum Matt.

Originally Posted by QC Inspector

One thing that you might want is a collet chuck. It will hold thin round items with less chance of crushing. Examples below. They are sold in most every country. Depending on the spindle mounting size you can get ER40 sized ones to hold larger diameters. .

ER40 could be hard to find with only an MT1 bore. Might be possible with a collet chuck block?

My wood cutters are shaped like this. When sharp they shave really well.
I usually hone the edge with a little stone I got from a toolmaker, about 75x20x3mm in size (stone size not the toolmaker). Can't remember their special name, can't find mine either now. lol

Arkansas stone?

Should I mention that metal lathes are not meant for wood turning and I believe that manufacturers caution against it (my lathe does anyway) due to dust sealing of the bearings.

Originally Posted by Michael G

Arkansas stone?

Dunno....don't think it was that, but could be.
Maybe the name they called it was related to its use. I do remember them saying they're quite expensive.