Chesapeake Area Metalworking Society

Review of 28 February 2008 Meeting
Fairland Public Library
14910 Old Columbia Pike
Burtonsville, MD

contributed by Charles Keeney

Editors Note: Wheeler Green took all the photographs at the meeting seen here except for the three noted photographs taken by the editor. Our thanks to Wheeler for sharing his photographs with CAMS.

The February 28, 2008 CAMS meeting rolled towards a start with the usual pre-meeting festivities of indoor tailgating, story swapping and folks trying to get an early peek at the various exhibits that would be discussed later that evening. Dave Bluett showed up with his flock of chickens, most of which were disguised as setscrews and cap screws in various forms. Roy Schaffer made good on his message to the CAMS list that he was bringing along some oversize drill bits for sale. Chris Daniel was offering nice assortments of setscrews and knurled thumbscrews and nuts in nice prepackaged compartmentalized boxes as well as metric thread gauges. Chris also displayed his Arduino/Freeduino open hardware micro controller kit as promised on the CAMS list. This subject is considered too important for just a passing reference so for those unfamiliar with such devices, Chris' introductory message about the devices to the CAMS list has been appended to the end of this report.



The display table prior to start of the meeting with some of the items presented at the meeting. From left to right are dead blow hammers; Chris' Arduino/Freeduino micro controller kit shown on the white sheet of paper; Reed Martin's gas engines, proximity fuse, and joltmeter; and a collection of files. (Photo by editor)

Roy Schaffer kicked off the meeting by making the first of the traditional round-robin self-introductions. Thirty CAMS members were present at this meeting including one lovely young lass so there may be reason to hope that both women and the younger generations will find their way to the metalworking community either professionally or as a hobbyist and maybe both. Roy then noted the upcoming March 15th PATINA Annual Show & Auction and for reasons unremembered, the discussion suddenly took a turn to perpetual motion - that siren with a song so alluring to many, and the giant working pendulum exhibit in the Smithsonian Institution - but that topic petered out after about five minutes. It was briefly noted that the CAMS web pages were once again being updated and the meeting moved quickly forward to the first presentation of the evening.

Bill White with the able aid of daughter Sarah presented a folding propeller for a sailboat that worked on the principle of centrifugal force. When the rotary speed of the propeller reached sufficient velocity the two blades opened like the petals of flower to catch the water and propel the boat forward. This was followed by Roy Schafer discussing some dead blow hammers he had brought including two polymer-based hammers where the polymer was disintegrating. This sparked a discussion of dead blow hammers in general and there was specific discussion that some dead blow hammers use lead shot and some use steel shot. It was explained that steel shot has the virtue of not deforming after repeated blows the way that lead shot will deform.

Next Tom Hubin gave an update of his CAD/CAM laser triangulation device. Tom passed around a $150 camera that regularly sells on eBay for $20-$30 and spoke of a laser modification that costs around $10-$15 as well as passing out some drawings of the device. Tom also spoke about some specific polymer needs and discussed the top speed of the device was being limited by vibrations.

Stu Vors next spoke about Kozo Hiroka's center indicator design. Stu is working on a live steam locomotive and has reviewed some of Hiroka's work, which has been published in Live Steam and published into several books as well. One of Hiroka's tools is a center indicator that calls for a small brass ball to act as a gimbal. Stu wanted to make one of these items himself but found he could only find the item available in a bag of 100. Stu passed around the bag of brass balls and invited the interested attending members to take one if they were interested in making their own center indicator. Here is a web page with the particular design: If the link is down, the design may be found in Kozo Hiroka's book "Building the Shay." One member in attendance noted that Tall Grass Technologies markets a similar design, which may be seen here: Regarding Stu's main project, it is a 7-1/2" gauge Pacific H Scale.

Tom Ballard took the floor to tell of his ingenious solution for those who have built small steam engines and now need a boiler to power them. Tom told everyone that his experiment began with a need to use a small steam chamber. While considering the problem he realized that the solution was in hand in the form of a small pressure cooker such as many of our mothers used in years gone by to prepare the family dinner. Tom adapted a pressure cooker by designing a connection that was attached to the lid where he could tap steam pressure from the cooker and channel it to his engine. Per Tom, the pressure cooker-turned-boiler nicely generates steam at 15 PSI.

Charles Lessig spoke next on an ingenious technique to reduce the thickness of a washer. The primary problem is how hold the washer while filing down the thickness. Charles' shop tip was to place a cubical block of wood in a vise with the intersection where three arrises meet pointing upward. Next place the washer atop the intersection and start filing. The intersection will protrude through the center of the washer sufficiently to hold it in place while you file it down to the desired thickness. Charles also discussed die filers, how tapered wire brushes can often produce results superior to flat wire brushes, and that he was now searching for a Type 8 sprocket for his recreation of a childhood motor scooter.

Bill Gibson took the floor just prior to 9:00 PM and began to speak about his ambition to build a clone of the motorcycle used in the television series Then Came Bronson starring Michael Parks. Bill is actually in the process of building the motorcycle but was stymied by his inability to locate a duplicate of the chain guard. Bill, being a skilled metalworker, said he realized that he could fabricate a replica himself. Bill then displayed three prototype guards and one finished guard that he had fabricated himself using .050" 5052 H3 aluminum sheet. Bill told the rapt gathering that the fabrication process took place in four forming stages that were represented by the three prototypes and one final chain guard. Bill used an 800 beats-per-minute power hammer to do the forming. For those interested, here is a web page that shows the chain guard that Bill reproduced:



Bill with the finished chain guard. The golden color is the result of the lighting; the actual color is that of aluminum.

Apparently not satisfied with impressing everyone with such fine work alone, Bill next demonstrated how to cut out a square hole in sheet metal using just a vise, a hammer, and a cold chisel that he fabricated himself out of rebar reinforcing rod. Within the space of around a minute Bill had punched a square hole in some sheet metal that looked to be about 12 ga. The finished hole was extremely close to perfect dimensions and done as accurately as many of us could have done with a bandsaw.



In this photo Bill has begun to cut the square hole. The sheet being cut is held in a vise and sandwiched between two pieces of angle iron that serve as guides for the chisel. The hammer is in Bill's right hand and the cold chisel, which Bill fabricated himself from rebar, is in his left hand.



Almost done. The outline of the hole can clearly be seen.



Finished, and in much less time than it would take to drill holes and cut with a hacksaw. The object next to Bill's right ear is either an electrical connection on the wall or a UFO although it is suspiciously close to size to the cutout.

Bill wound up his metalworking trifecta by relating how he had seen a master blacksmith shear a substantial bar of steel using only a standard blacksmith's anvil, a hammer, and a flatter. Bill then demonstrated the technique by finishing the shearing of a length of 1/4" X 2" flat steel using that technique. During all this, Bill also shared with the club the proper way to dress (shape or contour) an anvil so that it would provide the maximum versatility in use. Succinctly put, Bill advised that one of the longitudinal sides of the top flat be a square 90 degree surface and that the face on the other side have a rounded taper such as a section of a cone. The square face can be used for shearing and making square surfaces and the tapered cone on the opposite face can be used to produce rounded surfaces. Needless to say, all in attendance were impressed by Bill's informative and skilled presentations.



Here we see a photograph of Bill Gibson prepares to shear the bar. The flatter is held in his left hand, the hammer in his right, and holding the flat bar is..., well...



Here we see a photograph where Wheeler caught Bill at the instant just before the strike. After about a half-dozen strikes Bill had sheared the bar. The white dot just below the flatter is the end view of the tightening screw on a pair of lockjaw pliers.

Reed Martin next took the floor and showed some Henry Parohl engines as well as a Bill Brown inline twin cylinder engine. Following that Reed showed a joltmeter used as a tachometer on Knox horizontal engines. Reed also spoke about a proven technique that works to title in Maryland old vehicles manufactured prior to the introduction of titles. Reed observed that the best way is to first title the vehicle in a state that will allow such vehicles to be retroactively titled and then to take that new title to the state of Maryland Department of Motor Vehicles. Per Reed, this costs about $100 but that is far cheaper than any other known approach to obtaining a clear Maryland title for old automobiles.



The Henry Parohl Marine Racing Engines.



A different view of the the Henry Parohl Marine Racing Engines. (Photo by editor)



The Bill Brown inline engine.



Front view of Reed's joltmeter.


Joltmeter_Back view_R1.jpg

Rear view of Reed's joltmeter.

Reed continued his presentation by telling of his experience in trying to assist an acquaintance to duplicate some unique handles that had been found on an antique Spiral Motorcycle. Though in poor and degraded condition, Reed was able to determine that the grips were fashioned from mother of pearl, abalone and silver. Over a period of a year Reed was able to acquire the materials, carefully slice the abalone to shape and size - a process that required tapering and undercutting - finish fabrication of the individual components, and assemble the items together. The grips were truly impressive items as the photos below show and it is easy to see that Reed's service at the Smithsonian Institution served him well.



Reed, entertaining a question from the audience, holds one of the grips.



Grips for the Spiral Motorcycle in protective foam. Disappointingly, the craftsmanship of the work and the quality of materials, particularly the iridescence of the abalone, just cannot be captured in a photograph.

Reed then went on to speak about the glow plug collection that he had brought for examination, noting that glow plugs are a form of diesel engine. Reed's final topic was about the presentation copy of a proximity fuse that he brought. The fuse had an inscription that stated it was presented to D. A. Borsely, who provided significant contributions to its development. Chris Daniel joined Reed on the floor and both spoke about the fuse and the significant contribution that it made to win the Second World War. It was observed that some experts consider the three most significant developments of WWII to be the atomic bomb, radar and the proximity fuse. Also discussed during the presentation was how mechanical fuses were automatically set, that the proximity fuse is different from a V/T fuse, that the proximity fuse contained a simple radar vacuum tube, one type of proximity fuse used a magnetron, and that the spinning of the projectile generated the electricity that was necessary to power the fuses. It was stated that the Historical Electronics Museum in Linthicum, MD is well worth the visit for information on this subject.



Reed's glow plug collection.



The proximity fuse. The green nose cone is a green transparent material.



Chris Daniel speaks about the development of the proximity fuse.

Roy Schafer took the floor next and spoke about the scraper and the dozen or so files that he had brought along that evening. Chris Helgesen spoke after Roy about a web site featuring information about files and then continued with a brief talk about an Oliver die filer and some files he bought. Other items discussed by Chris were rotary files including one inserted in a pneumatic grinder, a whizzer for cutting sheet metal, file cards for cleaning files, a review of various ways to re-sharpen files, and ended with Chris showing photos of a power box on which he had worked.

Fred Schoomacher brought some Chinese-made utility knives that can be purchased at Dollar Tree but that compare favorably to the Japanese-made OLFA brand utility knives that cost about $20. The OLFA brand knives (there are several variations) are constructed of what appeared to be better materials but the Dollar Tree version has some better design features. Fred shared a tip on how to improve the Dollar Tree version by crimping the blade guide to minimize the tolerances . Fred also brought along an audio tape player with a tape of a PATINA meeting where the featured speaker presented 15-minute talk on what it was like for him going through a European country's apprentice system training. Fred then spoke at length about how to determine the size hex key that a socket head set screw will require and then passed around an information sheet on how to make small hex drivers. Fred agreed to share this document here on the web site but asked that it be noted that Kozo Hiroka suggested something similar however Kozo's process called for annealing, silver soldering and rehardening and tempering whereas Fred's approach uses Loctite or similar adhesives.



The Dollar Tree utility knives about which Fred spoke. (Photo by editor)



Fred Schoomacher's handout on how to make small hex drivers is seen above. Because of the need to retain the details on the sheet, the file has not been resized to the normal target goal of less than 30K bytes (the 30K byte goal is used to facilitate downloads by members using dial-up services). The file is approximately 246K bytes and anyone saving the file to their computer should be able to read all the information on the sheet by using the Windows Image and Fax Viewer or almost any graphics package. Unfortunately the smudges at the bottom lefthand corner is a combination of rust and oil that occured during the transport home - an occupational - or at least an avocational - hazard.

Ed Barmeter wound up the formal meeting by speaking briefly on the concept of a space elevator.

After the formal meeting concluded, yet more chickens changed hands and CAMMERS crowded around the various exhibits to get better views of Bill Gibson's anvil setup, Reed Martin's proximity fuse and his Spiral motorcycle grips - which were just beautiful works of craftsmanship, and the various other subjects of interest. Conversations were still going on in the meeting room long after the formal meeting closed and there is an unconfirmed rumor that several CAM's members were last seen in a nearby all-night restaurant discussing metalworking.



A close up of Bill Gibson's portable anvil. Note the wheels for easing transportation and the use of angle iron to secure the anvil to the platform.


The following is Chris' e-mail message to the CAMS list detailing information about the micro controller mentioned above.

Date: Thu, 28 Feb 2008 09:36:01 -0800 (PST)

From: Chris Daniel

Subject: Tonight's meeting

For tonight's meeting, I will be bringing my latest little project, a simple microcontroller kit. So far as I can tell, it only has a vague overlap with metalworking. However, I think of it as am important component, akin to "raw material", especially for anyone interested in CNC, remote monitoring, etc.

It is a simple micro controller board/kit. It is based on the Arduino(TM),

(Apparently the correct pronunciation is 3 syllables, Ar-Dwee-No, and is an Italian word/effort.) which is an effort based on the concept of "Open Hardware", modeled after the Open Software movement. However, it seems this effort's folks are actually looking to capitalize on their name, and are trying to *sell* hardware, despite the fact that you can download schematics, board artwork, etc. They have since disallowed the use of their name on "3rd-party" products.

My board, in particular, is from a splinter faction from this effort, which is renamed "Freeduino"

and I purchased my board as a kit from NKC Electronics,


What it is all about, is a micro controller chip which has digital I/O, and Analog I/O capabilities. Perfect for prototyping, it's a real workhorse that can do just about anything you can imagine, at least in the world of computers that interface with the Real World.

These have been around for a long time. The difference, for the (Ar/Free)duino world is that they have done a few particular things to bring this prototyping capability to the masses:

1) Tiny board with just a little extra circuitry, lends itself to hobbiest prototyping

2) PC Software: They have created a programming environment that is VERY user-friendly. And, released it for all 3 common platforms: Unix, Mac, Windoze.

3) No fancy extra hardware (i.e. $150 programmer/burner) required. Just a serial port, or for their newest design, a USB port. Plug it in, the GUI environment talks to it. Start programming! Click one button for a compile check (i.e. is your code syntax correct) and click another button to upload to flash memory on the microprocessor.


I will probably talk for less than 3 minutes or so. I have pointed y'all at some begin points for info, and this is "just the tip of the iceberg!" I've been delving deep into things, completely immersed for the last month. I can answer questions at the meeting, including the age-old

"Yeah, ok, it's cool, but what are you gonna *DO* with it?"

And some few last tidbits of info/pointers...

Cost? I got my serial-port-kit for about $20 with shipping. The microcontroller chip, bare, is maybe $5.

Other stuff: I've always been impressed with the products from Dallas Semiconductor. They got swallowed up by Maxim. Google image searches for this company will turn up much more silicone than silicon. Yes, there's a huge difference between these two words, and I can't comprehend how people get them confused.

Their website (for those not wishing to be distracted by that "other" term)

Anyway, with a simple import of a library, the Freeduino board implements the Dallas 1-wire system. This is a data (bus? Wire? System?) whereby other slaves (devices, chips, tiny things) can talk and listen on a single wire. (wire, and ground). This includes power! One single wire for power, and two-way communication.

It's way cool. Each device recharges an internal capacitor while the data line is "High", which also needs to be its default (idle) state. So everything talks with low transitions. It's all about timing! And the Freeduino can handle it.

That's all I'm gonna say for now. Ask away at the meeting!