The Sherline Miniature Machinist's Newsletter

Number 17, May 15, 2009

http://www.sherline.com


Sherline Projects

A CNC Cam Grinder for Model Engines/Joe Martin

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.

óSteven Smith, San Mateo, CA

Another SolutionÖ

"Instead 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."

óAlan Haisley, Lancaster, New York

This and more than 50 other helpful tips for Sherline machinists can be found at www.sherline.com/pages/tips.htm.


Product Spotlight

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

The 18th Annual Machinistís Challenge Contest sponsored by Sherline was recently held at the North American Model Engineering Society (NAMES) Exposition in Toledo, Ohio. Overall winner Scott LaBombard was a first-time winner with his highly polished rotary elliptical engine. Weston Bye of Grand Blanc, MI finished second with his Walking Beam Transfer device. Novice machinist Steve Huck who finished 3rd overall with his small Chevrolet V8 (compressed air driven) actually took top prize money because the novice division winnerís prize money is doubled. Youth Division (age 20 or younger) winner Trevor Katona came close when additional winnings from the $500 Joe Martin Foundationís Young C. Park award were added to the total for his 7th place overall finish. In all there were 19 entries from 15 different contestants, making it a popular and successful competition. Sherline paid out $2100 in prize money and the Joe Martin Foundation added another $500 in the Youth division for a total of $2600 given out at the show. Below are some photos of the winners.

Scott LaBombard of Flushing, MI took first place in the voting, which is done by the spectators at the NAMES show. (Pam Weiss photo) His elliptical rotary engine featured a highly polished finish.

Trevor Katona (16 of Rochester, MI won both the Youth Division and the Masterís Choice Craftsmanship award with his 3-cylinder radial steam engine. (Pam Weiss photo)

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.


Upcoming Shows

ï WEME (Western Engine Model Exhibition), July 18-19, 2009, Vallejo, CA. This relatively new show in the Bay Area hosts a large number of fine engines. Emphasis is on internal combustion engines, but many steam engines are on exhibit too. Sponsored by Model Engine Builder Magazine, this show gets better each year. For information see www.wemeshow.com. Sherline will have a vendor booth at this show again this year.

ï GEARS (Gas Engine Antique Reproduction Show), September 19-20, Portland, OR. The other main West Coast show is held at the armory near the Portland Airport each September. For more information see www.oregongears.org.


Joe Martin Craftsmanship Foundation News

ï Two new craftsmen were added to the On-line Craftsmanship Museum in the past month. Szymon Klimek of Poland is featured in the ìMachining as Artî section for his fine work in brass miniatures that could be called models, jewelry or art depending on your viewpoint. Szymon (Simon) is trained as an engineer, but spends his free time making delicate brass automobiles, steam engines, locomotives, gift boxes and other objects that are displayed inside wine goblets. Alec Gerrard of England is a new addition to the ìUnusual Projects and Skillsî section with his giant 12' x 20' model of Herodís Temple. Alec has invested over 30 years and 30,000 hours in the construction of this unique model on his farm in Suffolk, England. We think you will find both of these craftsmen, though far different in their approach to their work, to be interesting additions to the museum.

ï Richard Carlstedt of Green Bay, Wisconsin was presented with his award as 2009 Metalworking Craftsman of the Year at the NAMES show in Toledo, Ohio on April 18th. He displayed his steam engines and explained their function and history to an eager crowd at the Foundationís booth all weekend. The award included an engraved gold medallion, a book on the Foundation and its former winners and a check for $2000.

Richard Carlstedt is presented his awards by Foundation representative Craig Libuse. (Pam Weiss photo)

ï Receiving the 2009 Joe Martin Foundationís Lifetime Achievement Award was Louis Chenot of Joplin, MO. Lou has spent the past 7 years working on what is without a doubt the finest model of a Duesenberg ever attempted. The 1/16 scale model of a 1932 straight-8 Duesenberg features a fully functional engine that is almost ready to be fired up for the first time. He hopes to get it running this year and then complete the paint job on the bodywork once the engine is reinstalled in the car.

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)

ï On May 6th the 60+ Club of Vista, CA brought a group of their members for a tour of the Craftsmanship Museum, and on May 16th we will be hosting the club picnic for the local chapter of the Over-the-Hill Gang vintage hotrod club. Photos of groups and clubs who have visited the museum can be seen if you CLICK HERE.