WOOD LATHE TIPS
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The majority of the turning done here at American Furniture Design is for legs for tables and chairs on our Delta lathe. So almost all our work is spindle turning rather than faceplate. We will review spindle turning in this newsletter.
When turning a cylinder the piece is held between the live center and the cup or dead end center and a gouge is used to rough the piece. If your stock is more than 3” square, first cut it to an octagonal shape on the band saw. Locate the center of the stock and mark the center with a punch. If the wood is very hard, drill a small hole at the center and cut shallow kerfs across the corners. Place a spur center in position and strike it with a wood or rubber mallet to seat it firmly in place. It is a good idea to mark the end of the piece on one of the spurs, so that, if you take it out of the lathe, it can be put back in the same position.
Place the work between centers and turn the tailstock handle until the cup center seats firmly on the wood. Release the pressure a bit and apply a few drops of oil or graphite. Adjust the tool rest to clear your work by about 1/8” with the top of the tool rest about the same above the center of the piece.
The speed of the lathe should be adjusted in term of the diameter, using faster speeds for the smaller diameters. Always start turning at the lowest speed until the wood becomes a cylinder. This is the number one mistake that beginning turners make. Turning a large piece at too fast a speed can be very dangerous to your well-being. Imagine a baseball bat being thrown at you and your shop with too high a speed!
Under 2”
900-1300 RPM
2400-2800
3000-4000
2” to 4”
600-1000 RPM
1800-2400
2400-3000
4” to 6”
600-800 RPM
1200-1800
1800-2400
6” to 8”
400-600 RPM
800-1200
1200-1800
8” to 10”
300-400 RPM
600-800
900-1200
Over 10”
200-300 RPM
300-600
600-900
This chart is posted on the wall above our lathe so that as we turn stock we reference it to assure that we do not have flying baseball bats!
There are two methods of holding the gouge. The first is to place the thumb over the gouge and the fingers under it, using the forefinger as a guide against the tool rest. The second is to place the hand over the tool, with the wrist bent and against the tool rest. Both work very well and you may find yourself changing from one to the other as you work.
Once the piece is finished with the roughing to size the finish turning is done with a skew and this can be done with either a scraping or cutting method. Another easy method is to use a small block plane. Adjust the plane to take fine shavings. Set the angle to about 45 degrees to the axis of the work and use the tool rest to support the plane. Start at the center and move to one end as you would any other tool.
In your turning tools there are 6 basic types. Gouges are used for rough cutting stock to a round shape, skews are for smooth cuts to finish a surface, parting tools to cut a groove, diamond tools to finish the inside or corners, flat nose for scraping a straight surface and round nose tools for scraping concave cuts and circular grooves. There are many suppliers of great tools and it is sometimes best to buy a starter well-known set and add to it as your skills increase. We have used Robert Sorby for years and they have performed well for the limited amount of turning that we do.
A lathe can be a tool that will in an evening give you a great deal of pleasure and satisfaction. In a few hours you can go from rough material to a finished product..
American Furniture Design Co
Brian H. Murphy