CNC Projects Built Using Sherline Tools

Shown on this page are projects Sherline owners have built using Computer Numeric Control (CNC) on their machines. As CNC has become a major force in commercial machine shops in the past decade, it is also becoming more popular in the home shop as well. This is driven by the lower cost systems now available, by the greater public knowledge of what can be done with CNC and by the increased number of machinists that already know how to use CNC machines at work. We offer these projects as examples of what people have actually done with their machines. We get questions all the time asking, "Can CNC do this or that?" We feel that seeing actual results is much more informative than listing stepper motor resolution figures, backlash amounts or other statistics that might look good on paper but don't give you a real-world feeling for what you could actually do if you had such a machine. Keep in mind also that the projects shown here are not the limits of what can be done with CNC, just some examples of what has actually been done so far.

Send us photos of your projects

We hope you enjoy these projects, and if you have made something on a Sherline CNC machine that you would like to share here, please contact us and send photos and a description to be added to this page. If you would like to share the actual G-code you used to make the part, that will make the page even more valuable to those wishing to follow in your footsteps. The ideal submission would have a photo of some of the key setups, tooling used, a shot of the finished part, the G-code used and a description of any special problems that had to be solved to make the part. Readers would also probably be interested to know if the G-code was written from scratch or translated from a CAD file, and, if so, which one and what translator program was used.

Send submissions to Craig Libuse via e-mail: craig at sherline dot com (Substitute "@" for "at" and "." for the word "dot" in the e-mail address.)

Table of Contents

1. "Baby Beam" steam engine model by Alan Marconette

2. A spindle drawbar remover by Colin Dyckes

3. A machinist's puzzle—A cube within a cube within a cube by Tom Hubin

4. A CNC church in two parts by Tom Hubin

5. Cutting a helical gear by Joe Martin

6. Counterweight the mill Z-axis by Harry Yingst

7. Keeping chips off your Y-axis leadscrew from Tim Schroeder (A tip rather than a project...)

8. A minibike supercharger by Robert Rosenfield

9. A humanoid robot by Matt Bauer

1. "Baby Beam" Steam Engine Model by Alan Marconette

Two views of Alan's "Baby Beam" steam engine. (Click on either photo to view a larger image.)

The "Baby Beam" Steam Engine is almost finished.  No, the final engine will not have SHCS (socket head cap screws)! It was inspired by the M.E. Beam engine published in '59, which was scaled from the 1914 M.E. article by George Gentry. George did an accurate prototype model of the engine. I've heard that it is of the form of engines designed by William Fairburn in the 1840-1850 period.

The engine is approximately 6" tall, 11" wide and 6" deep.  Shown is a 5" CNC'd flywheel, and the plans include an optional 6" flywheel of an alternate design.  This engine was built using many CNC part files and was entirely machined on the Sherline mill and lathe. This version was built with a brass cylinder, steam chest and beam, although aluminum could be used as well. The base is aluminum, and, although 10" long, was machined on the Sherline mill as well!

The bore is 3/4" and the stroke is 1 1/2".  The design incorporates a slide valve driven through considerable linkage. The piston drives the 6-1/2" beam through the Watts parallel motion and is a joy to watch.

Alan Marconett  KM6VV

http://www.hobbitengineering.com/

Alan (Right) shows his engine at the 2004 Men, Metal and Machines show in Visalia.

The 3D CAD drawing and the above photos help explain how the puller is made. Click on any photo to see a larger version.

Colin didn't send any written explanation when he attached these photos to his e-mail, but the photos pretty much speak for themselves. This part offers another take on the best way to remove a collet or chuck from the spindle without hammering on the drawbolt. Any method that uses slow, constant pressure to push the arbor out of the #1 Morse taper in the spindle helps keep your machine in alignment and saves the Z-axis from developing excess backlash from the handwheel set screw having to support the force of pounding on the headstock.

To use the puller, a split collar is attached to the spindle shaft leaving enough space underneath to insert the base of the puller. To remove the item from the spindle taper, the drawbolt is first loosened. Then the puller is inserted under the collar and the socket head screw tightened against the head of the drawbolt. Tightening the screw pushes down on the bolt, removing the tapered collet or arbor from the spindle.

After seeing this write-up, Colin mentioned that after trying his first prototype he ended up filing a groove in the spindle shaft while it was spinning. It doesn't show in the photos, but the set screw in the split collar goes into this groove. This helps keep the collar from slipping up on the spindle shaft when the screw is tightened against the drawbolt head. He says this is optional.

For those who would like 3D and CNC files for the puller, Colin's drawings are included as links below:

Colin adds: "The IGES file (.igs) and the STereo Lithography file (.stl) should be readable by just about any CAM program (VisualMill, SurfCam, Solidcam, etc., etc.). I supplied those files rather than the original Solidworks file because they are pretty much universally readable. The STL or IGES files will need to be rotated within the CAM package to get the correct
orientation for milling."

3. A machinist's puzzle—CNC nested cubes by Tom Hubin

The photos above show various stages of the machining of the puzzle. It is simply a number of accurate boring jobs in a row. (Click on any photo to view a larger image.)

This is a project done on my Sherline 5410 mill using TurboCnc 3.1a.

Directions for using g-code file 3cubes.cnc to machine 3 nested cubes. (File: 3cubes.txt copyright Tom Hubin, 26 November 2004)

1) Start with a 2 inch cube of 6061 aluminum. This can be a 2 inch length cut from 2 inch square bar stock.

2) Mill or fly cut the outermost 1.950 inch cube from the 2 inch stock. Be sure to machine something from all six sides so that the finish is attractive.

3) Label the six sides as top, bottom, right, left, front, rear.

4) Drill 3/8 inch diameter center holes into top, front, and right surfaces to a depth of 1.5 inches. These three holes will pass
completely through the innermost cube. I used the 3/8 inch end mill holder with a machine screw length 3/8 inch diameter drill bit.

5) Drill 3/8 inch diameter center holes into bottom, rear, and left surfaces to a depth of 0.75 inches. These three holes will not
touch the inside of innermost cube. That way the 3/8 inch diameter center holes through the innermost cube will be seamless.

6) Secure the 1.950 inch cube in a vise and use an edge finder to accurately locate the rightmost surface and the rearmost surface so that the center of the topmost surface is at (X,Y)=(0,0).

7) Load a 3/8 inch diameter x 5/8 inch LOC aluminum roughing end mill. Move it over the topmost surface. Lower the bit until it
just touches the topmost surface. I usually do this by loosening the bit so that it drops down and touches the topmost surface. Then tighten the bit just enough so that it won't fall out.

8) Run the program. You will be prompted to touch the surface with the end mill. You have already done this so continue.

9) The bit will be raised and you will be prompted to tighten the bit and start the spindle at 2800 RPM, which is max spindle speed on a Sherline mill. Tighten the bit securely then start the spindle.

10) Stay near the machine, lubricating and clearing chips as machining takes place.

Here are the CNC files in various formats. Right click on a file to save it to your computer or open it with the appropriate program.

3CUBES.CPP (3cubes.cpp is a plain text Borland c program to generate the gcode file.)

3CUBES.OBJ

3CUBES.PRJ

3CUBES.BAK

3CUBES.EXE

3CUBES.DSK

3CUBES.CNC (3cubes.cnc is plain text gcode for TurboCnc 4.01.)

(NOTE: If you cannot open these files, try downloading the ZIP file that contains all the original files. To do so, CLICK HERE.)

The remaining 3cubes.* files are binary files generated by the Borland C++ compiler but are not needed.

*.txt, *.cnc, and *.cpp are plain text files and can be read and modified with just about any DOS, Linux, or Windows text editor. DOS Edit command can be used. I use the shareware DOS text editor PcWrite. Microsoft Notepad, WordPad and Word are Windows text editors that can be used.
 

Here are some websites to help visualize the nested cubes:

http://www.dakeng.com/gallery.html—Dan Statman's dime sized nested cubes. Small and very very classy.
http://www.grapevineglassworks.com/landscapes/cube.html—Artwork showing nested cubes with no hole through the center.
http://www.geocities.com/barxe/cubering.swf—Animation showing something similar but here just for fun.
http://www.token.crwoodturner.com/magiccube/—Shows inner cubes detached so as to tumble freely within outer cubes.

Tom Hubin
thubin@earthlink.net

This project is an excellent example of how a number of CNC files and fixtures are used to handle all the various operations involved in making a multi-sided part. It's not simply a matter of one G-code file that does everything. The files can be found by downloading the ZIP file linked in the paragraph below.

DRAWINGS

This church is machined completely using CNC. It is made it two pieces—the church and the steeple—that go together with pins. The dimensioned drawings were done in a program called "Vellum." They have a .VLM file extension and can be viewed by downloading a free utility called "Vellum Share" you can obtain at http://www.ashlar.com/products/share.html. There are versions for Windows and Macintosh. In some cases the drawings also show the holding fixtures. The drawing files can be found in the Zip file linked below.

G-CODE

I ran the G-code with TurboCnc 3.1a on my Sherline 5410 mill. After design and making the jigs I made a batch of 8 churches for Christmas 2003. I started the project early November 2003 and finished March 2004. A few months late for Christmas but well received nevertheless. Machining and handling time for the building and the steeple is about 6 hours each when done in a batch of 8. That is about 12 hours per church. The project was inspired by one page of a Home Shop Machinist magazine article that was sent to me by an acquaintance. The files needed to make the parts can be obtained by clicking on the file name CHURCH.ZIP to download a 354 Kb Zip file. One of the zipped files is called "SEQUENCE.TXT." This file will explain the order in which the other files are run and what they do.

CLICK HERE TO OPEN THE CHURCH.ZIP FILES

Designed by Tom Hubin Nov 2003.
Copyright Tom Hubin, 2003 and 2004.
Tom Hubin
thubin@earthlink.net

An interesting side note about the church project...

Neil Knopf of The Home Shop Machinist Magazine adds the following note about the original article on the church project:

"The church was run in the September/October 2002 issue of HSM. It was designed by Walter Yetman of New Jersey and close friend Rudy Kouhoupt. Walter made the church as a gift to his pastor and dedicated the article to his friend Todd Beamer who was Walter's son's Sunday school instructor. Todd was killed in the 9/11 crash of Flight 93 in Pennsylvania. He was the one who declared, "Lets roll," as he and a few others went forth to overwhelm the terrorists."

The setup on a Sherline mill. (Click on photo to view a larger image.) Here, we have used a number of Sherline accessories. The 3701 right angle attachment holds the rotary table vertically while the 3702 right angle adjustable tailstock holds a P/N 1191 live center to support the other end of the arbor the gear blank is attached to. The 3701 and 3702 each sit on top of a P/N 3017 crosslide accessory plate to get a little extra height. A P/N 3231 Gear cutter arbor holds an involute gear cutter on the spindle, which is offset to the appropriate angle. The X-axis moves left/right and the A (rotary) axis indexes for each tooth and rotates as the blank is fed past the fixed spinning cutter. The Y-axis is used manually to adjust the tooth depth or with CNC to cut the gear to the proper depth in a number of passes if needed. (This gear in aluminum could be cut to full depth in one pass.) The Z axis does not move.

In order to help with the calculations on a helical gear, Joe Martin wrote a Microsoft Excel® program that helps come up with the unknowns when you have the necessary pitch and angle information. Viewing this program requires Microsoft Excel. To view the formulas that Joe developed to make the calculations you will first have to unprotect the worksheet by going to the "Tools" menu and selecting "Protection>Unprotect". Then, when you click on one of the cells that contains a formula, you can read the formula in the window above the worksheet. When you are done looking, be sure to remember to protect the file again. Understanding these formulas will require a pretty good working knowledge of Microsoft Excel formulas. Using the sheet just requires that you know the values to plug in to the pink cells. When you change one of those numbers, the formulas will recalculate the values in the orange cells for you. Once you have the values, there is another function included that will write the g-code for you. This clever addition to the program was written by Bill Krobetzcy and his future son-in-law Jeremy.

CLICK HERE to view Joe's Excel Program to develop the values for a helical gear.

The G-Code

Once you have the numbers, writing the program is fairly easy. It is a set of five lines of code repeated by the number of gear teeth. Notice that dimensions and angles are given to four decimal places.  In this case, the 34-tooth program begins...

%
g90g01x0.0y0.0a0.0f15.0
g90g01a0.0f15.0
g90 g01 y-.0895 f5.0
g91x-1.70a-47.0310
g90g01y.05f15.0
g91x1.70a47.0310
g90g00a-10.5882
 
g90 g01 y-.0895 f5.0
g91x-1.70a-47.0310
g90g01y.05f15.0
g91x1.70a47.0310
g90g00a-21.1765
 
g90 g01 y-.0895 f5.0
g91x-1.70a-47.0310
g90g01y.05f15.0
g91x1.70a47.0310
g90g00a-31.7647
 

And so on to the last block:

g90 g01 y-.0895 f5.0
g91x-1.70a-47.0310
g90g01y.05f15.0
g91x1.70a47.0310
g90g01a0.0f720.0
%
 

As you can see, once started only the last number changes in each block of code as it indexes for the next cut. To get the entire 34-tooth program in .txt format, CLICK HERE.

6. Counterweighting the mill Z-axis by Harry Yingst

While not actually a project you can do WITH your CNC mill, here is a project you can do TO your CNC mill for better response on the Z-axis. One of the problems with a vertical mill unless you happen to be working in outer space is that gravity makes it a lot easier to lower the Z-axis than to raise it. The stepper motor must raise the entire weight of the saddle, headstock, speed control, motor and cutting tool each time it goes up. One way they alleviate this problem on big machines is to use a counterweight that effectively neutralizes the weight of the head so that it takes the same amount of effort to raise or to lower it. The Sherline headstock/motor unit weighs about 10 pounds, which can be a lot for a 136 oz-in stepper motor to lift, particularly in 3D projects where there might be a lot of small, rapid up/down movements of the Z-axis. Harry Yingst submitted these photos of a system he came up with using a lead shot-filled tube and a pulley system suspended from the ceiling. You can probably think of some other ways too, but here is one that uses few parts, requires no holes be drilled in the machine and uses easy-to-find materials you may already have lying around. If you come up with another way, please send photos to craig@sherline.com and we'll include it.

Photos of the counterweight system show how it is attached to the mill DC motor using a hose clamp and how the line runs through pulleys attached to the ceiling to keep the weight out of the way. (Click on any of the photos to view a larger image.)

Here is what Harry had to say when he sent in the above photos:

Attached you will find some photos of my counterweight setup. The weight itself is a 9.5" piece of 2" PVC pipe and end caps. I drilled a hole in the center of the top one to put a screw eye through and used a fender washer and a lock nut on the inside and a standard nut on the outside. I filled the counterweight with #8 lead shot and glued it all together. (I still need to paint it.)

I used a piece of Dacron rope and connected the weight to the mill using a 3" hose clamp and a single link of chain as an attachment point. You will notice in the picture that I used a screw-on type chain link on both ends of the line to allow the weight to be easily removed or changed if desired. I may make a second weight some day as I am considering making a second high speed milling head (30,000 rpm or more) for use in engraving PC boards, so I want to be able to swap weights quickly.

—Harry Yingst

7. Keeping chips off your Y-axis leadscrew from Tim Schroeder

Tim Schroeder's solution uses flexible rubber tire inner tube material along with some custom brass angle pieces to keep chips off the Y-axis leadscrew. (Click on photo to view larger image.)

The X and Z leadscrews on a Sherline mill are positioned so that they are protected from flying chips. The Y-axis screw, however, is exposed. On a manual mill, the operator is in constant attendance and can simply brush the chips away periodically, but CNC operations often run unattended for periods of time, and the volume of chips produced with a CNC system can make finding a way to keep them off the Y-axis screw a higher priority. Tim Schroeder came up with a pretty good solution for his manual machine by using some old rubber inner tube material which is held in place with brass angle that attaches to the mill base and front of the saddle. A second piece is located behind the table and is secured to the front of the mill column base. The above photo is pretty much self-explanatory as to how it works. The addition of these parts may mean a slight reduction in your Y-axis travel, but in most cases the extreme ends of your travel envelope are not used anyway.

--Craig Libuse

Robert Rosenfield recently completed a supercharger for a restored 1960's Honda 50 mini trail bike. The parts for the supercharger body were mostly cut on a manual Sherline mill, but the turbine itself was cut using CNC on the Sherline mill. (Click photo to view larger image.)

The Honda Trail 50 minibike fitted with the custom supercharger makes more horsepower. Also shown is Robert's shop with the sheet metal enclosure for the mill. (Click photo to view larger image.)

The above photos show the horizontal mill setup used to cut the round parts on a rotary table. The second photo shows the rotary table offset at an angle on a tooling plate so that the turbine blades can be cut. The third photo shows the 10° tapered 3/8" end mill making the cuts. The 4th photo shows the finished turbine and some other parts in aluminum and delrin.  (Click photo to view larger image.)

The blades shown in these photos were made with a straight cut. Robert has made later models where the tool path is a curve rather than straight, as he feels this should achieve better air movement as well as making for a more impressive looking part.

To view a dimensioned drawing of the turbine in PDF format, CLICK HERE. Drawings of each of the other parts are also available upon request.

A New Version

Robert's latest compact supercharger design for small motors. (Telephone for size comparison in first photo, a 25¢ US coin in final two photos. Click on photo to view larger image.)

According to Robert, "These are the brand new Model SC125 superchargers designed for 50 cc thru 125 cc four-stroke motors used
in pit bikes, super pocket bikes, go-karts, Honda 50's, etc."

Overall dimensions are: 4-1/2" O.D. x 5-1/2" tall x 4-3/4" wide. Original 63 mm (2-1/2") 30º blade with left-hand thread. Design capabilities include 2-1 pressure ratio variable boost, maximum 100,000 RPM shaft speed, 24-34 mm carburetor sizing. Pressure oil feed to plain bronze bearings with VitonT seals for high temperatures.

As usual, the photos show that Robert has also been able to obtain really nice finishes with his manual and CNC Sherline machines. The main body is made from one large billet of aluminum. It can take several days of machining time to get it down to size. Although this could be done quicker on a larger, more powerful machine, it is interesting to note that the hobbyist with time and talent but limited funds and space can still achieve superb results with tabletop machine tools.

Here is an adjustable pulley tensioner assembly made by Robert, again with beautiful finishes.

Matt Bauer found that CNC made many aspects of building the parts for this robot much easier. Not bad for a first project in CNC. The sabertooth skull is a nice touch... (Click on photo to view a larger image.)

Matt Bauer was not a machinist and had never worked with CNC when he purchased a Sherline CNC mill and a lathe. It didn't take him long to get the hang of it, and the robot shown above was his first project. He describes the process best in his own words:

"Shortly after our return from the ROBO-ONE 10 competition in Japan last Fall, I purchased the Sherline model 2010 CNC Mill and 4410 CNC Lathe. Having no previous CNC experience, I was surprised how fast I was able to learn the necessary techniques needed to operate the machines. No longer than a week into it, I decided on scrapping our previous robot design entirely. Before that I was forced to fabricate all the aluminum brackets using a band-saw and drill. The parts created for a humanoid robot are mostly mirror images of its other half, so the CNC capabilities of your machines allowed me to easily duplicate opposing sides and made short work of the intricate designs I was ultimately going for. In a nutshell, this 24 servo humanoid robot consists of 45 aluminum; and 27 delrin parts all done using the Sherline mill and lathe. I was even able to add a little flare by engraving his name in an acrylic backlit marquee located on his chest. Pictures say a thousand words, so here is a pic of our completed humanoid robot dubbed “Rook’s Pawn III”. He stands 19” tall and weighs about 5.0 lbs. He will be attending RoboGames very soon, and we plan on returning to Japan in the Spring to compete against some of the best humanoids in the world. Thank you."

—Matt Bauer, Defiance, OH