The Sherline Miniature Machinist's Newsletter
†The majority of the components for Joeís CNC cam grinder are off-the-shelf parts.
A couple of years ago Joe Martin decided to make a cam grinding machine for model engines using standard Sherline manual and CNC components. The actual machine only took him about a day to make, but the software was another matter. Working out the math to translate a CAD drawing or lift table description of a cam into a program that would grind the shape turned out to be more intensive than he had first thought. After three yearís work and the help of a young man who is a whiz with math he was eventually able to get the program working the way he wanted. Two model engine cams have been successfully ground on it to date.
Cams for the in-line 4-cylinder Seal engine (Left) and Howell V4 engine (right) were ground on the CNC cam grinder. (Tom Boyer photos)
Joe is now considering offering the cam grinder as a Sherline limited production model. We are working on coming up with a price for the whole system including computer and would be interested in hearing from those who would be interested in purchasing one. At this time the plan is to offer the software to run the grinding operation but to generate the G-code in-house for each customer based on a drawing of the desired cam. This service will be included as part of the price.† Let us know what you think.
Shop Tip of the month
Retaining drawbolt washers/Steven Smith and Alan Haisley
Here's a simple, good looking way to keep a drawbolt and washer together.
When you lift a drawbolt out of the mill spindle, the washer can easily slide down the bolt and fall off if you are not careful. The bolt and washer can also become separated while rolling around in your toolbox. If you don't like spending time looking under your workbench or in toolbox drawers for small parts, here is a tip from Steven Smith that solves the problem. He took a short length of heat-shrink tubing and slipped it over the 1/4" shaft of the drawbolt. If the fit is tight enough, you don't even need to heat it to keep it in place. If it fits loosely, just heat it with a match until it shrinks into place to act as a retainer for the washer. On a larger bolt, he also found that the rubber grip from a ball point pen worked to accomplish the same thing. In fact, any piece of tubing of the proper size will do the job. A few wraps of electrical tape will also work, but heat-shrink tubing is the neatest and most professional looking solution we've seen yet.
of heat-shrink tubing, which I didn't have in the size required, I obtained a
small O-ring and found that it works nicely. This also makes it easy to
disassemble the drawbolt and washer at any time if desired."
This and more than 50 other helpful tips for Sherline machinists can be found at www.sherline.com/pages/tips.htm.
Sherline 4" CNC Rotary Indexer, P/N 8700 ($725.00)
†The Sherline 4" rotary table gains a tremendous amount of functionality when coupled to a programmable controller and driven by a stepper motor.
For years the P/N 3700 manual 4" rotary table has been one of Sherlineís most popular accessories. The addition of a stepper motor drive with its own programmable controller makes its use even more foolproof and takes it to markets outside just the home machine shop. A number of industrial uses have been found for this product from indexing operations to inspection of parts to rotating subjects for professional photography. Even on full-size machine tools there are many indexing operations that donít require a large, heavy and much more expensive CNC rotary table. Why bring one in with a forklift when this small unit will do the job fast?
Operation of the unit is quite easy. The electronic readout guides you through most steps intuitively without the need to learn or use G-code. Simple Jog commands can rotate the table in either direction with the touch of a button, or two programs of up to 40 blocks with 4 parameters per block can be entered for more complicated operations. Backlash compensation can also be set electronically if your program requires changes of direction. Click on the linked part number at the top of this section to read more about the rotary table or CLICK HERE to view the complete operating instructions. Everyone from clock makers who cut wheels (gears) to small machine shops have found this rotary table a real time saver that quickly pays for itself.
2009 Machinistís Challenge Contest Results
18th Annual Machinistís
Challenge Contest sponsored by Sherline was recently held at the North American Model Engineering
Society (NAMES) Exposition in
†Trevor Katona (16 of
After 18 years of holding the contest it has been decided that this yearís event was the last. Sherline will look for other ways to promote machining at the small end of the size scale in the future. Complete results and photos of all the entries can be found at http://www.sherline.com/names09.htm.
Did you know?
ï Sherlineís informational web site at www.sherline.com hosts all the information you need to know to make an informed buying decision about precision miniature machine tools. When you are ready to purchase you can call Sherline directly or you can order 24-hours a day from our secure e-commerce site at www.sherlinedirect.com.
ï This month four of our most popular and useful lathe chucks are on sale at 20% off, meaning you can save $22.00 or $33.00. To learn more, see www.sherline.com/special.htm.
ï The handy Fractional/Decimal/Metric Equivalent Chart published in the Sherline Shop and Accessories Guide is now available free on our web site. CLICK HERE to download the 8.5 x 11" PDF file. It also includes handy Morse taper angles as well as common conversion factors.
WEME (Western Engine Model Exhibition),
GEARS (Gas Engine Antique Reproduction Show), September 19-20,
Joe Martin Craftsmanship Foundation News
Two new craftsmen were added to the On-line Craftsmanship Museum in
the past month. Szymon
Richard Carlstedt of
†Richard Carlstedt is presented his awards by Foundation representative Craig Libuse. (Pam Weiss photo)
Receiving the 2009 Joe Martin Foundationís Lifetime Achievement Award
was Louis Chenot
†Lou Chenot receives his Lifetime Achievement award from foundation representative Craig Libuse. The award includes a check for $500.00. Louís world class Duesenberg model can be seen in the foreground. (Pam Weiss photo)
On May 6th the 60+ Club