Academy Notes and Tips
SEPT/OCT
2003
Volume 46/Issue 5
IN
THIS ISSUE
Project
Articles
•
Queen Anne Living Room Tables
• Covered Wagon Toy Box
• Tilting Shelf Sewing Thread Holder
DEPARTMENTS
•
Ask Smitty
• Owner’s Gallery
• Letters from Owners
Academy Notes
Clean
Cuts - Pt. 2 - Lathe Tool Sharpening
Service Pointers
MARK
V Miter Gauge
Safety Tips
Safety First!
What's
New
42"
Filter Hood for DC3300
EDUCATION
• Find
A Shopsmith Woodworking Academy Near You
• National
Woodworking Academy in Dayton, OH
ONLINE
CATALOGS
• Online Accessory Catalog
• Request
Printed Accessory Catalog
• Online
Replacement Parts Catalog
MARK
V INFORMATION
• Find
A Shopsmith
MARK V Demo Near You
• Request
MARK V Information Package
LINKS
•
Links Worth Visiting
•
Free Woodworking
Tips
FEEDBACK
Contacting
Shopsmith
Copyright
2003.
Shopsmith, Inc.
All Rights Reserved
From
the Shopsmith Woodworking Academy
Clean Cuts
-- Part 2--Lathe Tool Sharpening
Printer
friendly PDF copy of article
As
a rule, when a brand-new set of lathe chisels arrives in a woodworker's
shop, both experienced turners and novices alike can't resist taking a
minute, just to look at them. But, while a novice may merely gaze in unfocused
wonderment at the unspoiled ash handles and the beauty of the satin sheen
on the steel, the “old hand” peers critically and carefully
at the thickness of the steel, the length of the handles, and...the cutting
edges of the tools.
Why? Because it's that tiny portion of the chisels that holds the true key to producing “happy results” in lathe turning. But it isn't merely the sharpness of the edge that dictates the results you achieve...the angle, length and thickness of the bevel is equally important to your success. But which bevel works best?
A
Shorter Bevel: Most full-size, standard lathe chisel sets come from
the factory with a 45-degree bevel. This provides a lot of steel back-up
for the cutting edge. As a result, it's a strong, long-lasting bevel for
a utility turning tool that can be used for scraping - a technique that
centers a lot of stress on the tool's edge.
A Longer Bevel: Many “Master Turners” typically prefer a 30-degree to 35-degree bevel for shearing. This longer bevel helps them get a better approach to the workpiece and provides easier control of the cutting tool. Even though the cutting edge isn't as durable (because there's less steel backing-up the edge), it will hold a sharp edge well when it's used for this more subtle kind of work. It is important to note, however, that if you use a tool with a longer bevel to scrape, it will dull quickly. A Bevel Sharpening Gauge is a handy tool for helping you judge the proper angle when grinding and/or honing chisel edges.
Flat
Or Hollow Ground?: Although you have a number of choices on how to
grind the bevel you want, the bevel on a lathe tool is almost always ground
flat. Lathe chisels with hollow ground edges are available
for special techniques, but again, a flat bevel is tougher and longer
lasting if you're using a scraping technique, like most turners.
Benchstones Or Machine Grinding?: You can use an ordinary benchstone to grind your chisels. To save “elbow grease”, start with a coarse stone such as silicon-carbide, aluminum-oxide, India or a coarse Oriental waterstone...then switch to a fine grit Arkansas, waterstone or diamond stone for the finishing touches. It may take some effort, but it will also help you avoid overheating the steel and drawing the temper out of the edge.
Machine grinding is another option. There are three ways of doing this with the Shopsmith Woodworking System.
The Disc Sander: The first and perhaps easiest of these is to use the Disc Sander on your Shopsmith MARK V, in conjunction with....
...Shopsmith's Sharpening Guide. This special device mounts easily to your MARK V's Extension Table with two screws. A template is provided for locating the mounting holes. Once mounted, it can be quickly set to grind your chisels to nine different angles for shearing or scraping...from 25-degrees to 65-degrees in 5-degree increments (See Fig 1).
 |
| Fig. 1 |
