The Sherline Miniature Machinist's Newsletter

Number 44, October 17, 2011

http://www.sherline.com


Customer Project

Miniature Scale Replica Fire Apparatus/John A. Ackerman

  

A United-Kenworth fire truck scratch built in 1/32 scale is one of many that John Ackerman has built.

John A. Ackerman, a retired publishing company owner, has made an outstanding collection of scale replica fire apparatus. Many members of his family were firefighters, and he started building models of fire equipment at age nine. Some of his models reside at his home, and a number of his LAFD models are on display at the Los Angeles City Fire Museum. Principally working in 1:32 scale, John uses a variety of hand and small machine tools, including his favorite Sherline Model 5400 mill to fabricate parts and special fixtures (to facilitate making various parts) for the models. The bodies are made from plastic and brass with details turned from aluminum. John is a stickler for accuracy in the overall look of the vehicle and placement of the details. John is among the founders of the LAFD Historical Society, a life member, former Board member and former Apparatus Committee chair. He continues his participation as a member-at-large, as he now lives in Tucson AZ. As a noted historian on fire apparatus, his knowledge and advice is in demand among other researchers and model makers.

 Some of his apparatus models are displayed at his home.

 More of his LAFD scale replica apparatus are display at the Los Angeles City Fire Dept. Museum.

An example of one of his models is a beautiful 1:32 scale 1941 LAFD United-Kenworth he recently completed. It is primarily made from sheet styrene plastic while the fenders and front end are vacuum-formed on forms he made using his Sherline mill. He cast his own rubber tires and machined aluminum and brass parts for the small details. The ladders are made from basswood with spaghetti for rungs. He used the Sherline mill to make the half-round shapes on the bars in the grill. He also uses the mill to make a variety of fixtures, such as one to hold the small pieces of brass for soldering in order to make the stanchions that hold the railing in place. 

 This 1955 Seagrave Triple in 1/32 scale features a detailed Hall-Scott engine. It won a prize for best engine in a model vehicle contest.

 A simple milled soldering fixture helps align the many stanchions needed on the handrails of most fire trucks—typically 12 to 20 per vehicle. Time invested in making fixtures pays off in more consistent parts and time saved later in assembly. (Photos: John Ackerman)


Shop Tip of the month

Turning Tapers on a Sherline Lathe/Joe Martin

(Information obtained from Joe Martin’s book, Tabletop Machining, P/N 5201)

On most large lathes, a compound slide is used to turn tapers. On a Sherline you still have that option, but many tapers can be turned without using a compound slide. The Sherline lathe was designed with a headstock that can be rotated, giving you the ability to turn tapers using just the basic machine.

Turning Simple Tapers Without a Compound Slide

Basic taper turning (shown with optional P/N 3001 power feed at left)

Short tapers—Short work can be held in a 3- or 4-jaw chuck and turned as shown in the first figure. In this case, the engraved angle markings on the lathe base can be used for reference. A greater degree of accuracy can be obtained by measuring the angle between the face of the headstock (the side that the spindle nose protrudes from) and the edge of the crosslide table. The lathe tool and crosslide handwheel can also be used to measure and mark off small movement when offsetting the part. With part held square to the lathe, bring the tool up to barely touch the part. Rotate the headstock to move the part away from the tool and move the tool using the handwheel to obtain the desired amount of offset. Then rotate the headstock to bring the edge of the part up to lightly touch the tip of the tool and then lock the headstock in place.

Figure 1—Turning a short taper by rotating the headstock

Long tapersFor long tapers, the part can be held between centers using a faceplate and drive dog on the headstock and a live or dead center on the tailstock. The drive dog acts as a “universal joint” as the drive pin slides in the faceplate slot to accommodate the angle of the offset. (Keep in mind the calibrations on the base have no meaning when cutting a taper between centers. That taper must be established by trail and error.) See figure 2.

Figure 2—Turning a longer taper with a part held between centers and offset with a faceplate and drive dog. Note slight offset of headstock compared to the lathe base.

Remember that the tool must be on center for these settings to work. Tools set above or below center will cut less of an angle than is set. Also, don’t be ashamed to bring a taper to final size with a good, flat, single-cut mill file.

Turning Tapers Using a Compound Slide (P/N 1270/1280)

On the Sherline lathe, the compound slide is designed to be used on the “back” side of the part with the cutting tool upside down. While this might not be practical on a large lathe, it is easy to reach over the smaller Sherline lathe to operate the compound slide handwheel. The base plate is held to the crosslide table with four T-nuts in the two table T-slots. Mounting it on the back side of the part eliminates interference with the crosslide handwheel. The ¼” cutting tool can be mounted in grooves on either side of the slide or across the groove at the end of the slide. An additional advantage of this setup is that less tendency for the tool to “chatter” when it is being lifted in the slide rather than being pushed down toward the table. Gravity also helps clear the chips more easily as they are going downward rather than upward. One final advantage of using the compound slide is that the lathe need not be taken out of square to use it. Once done and the slide removed, the lathe remains squared up, saving you the time of re-squaring the headstock.

Short tapers—Short tapers can be turned as shown in the 3rd figure. Angle marks at 1° increments help determine the angle of the taper once the base of the slide is lined up square with the crosslide table. The part can be held in a 3- or 4-jaw chuck and the cutter is advanced using the handwheel on the compound slide.

Figure 3—Turning a short taper using a compound slide.

Unusual tapersCutting a taper like the one shown in the final figure would be difficult without the use of the compound slide. This particular example shows a taper being cut on an oversize section of a long part held between centers, but other situations can arise that make use of the compound the only way a taper can be cut.

Figure 4 (above)—Another way to cut a taper. Note that the compound is held off the side of the table and fastened with only two mounting screws in order to reach the part. N unusual setup like this will require lighter than normal cuts but will get the job done when there is no other way.

 The P/N 1270 Compound Slide.

More can be learned about the use of the compound slide if you read the instructions that come with it. See http://www.sherline.com/1270inst.pdf.


Product Spotlight

Sherline adjustable tailstock tool holders

(This feature is repeated from newsletter #14. So many new people have joined the newsletter mailing list since it was run in early 2009 that we felt it was worth repeating.)

1201 1202 1203 1204 1206

P/N 1201-Adjustable Live Center, 1202-Adjustable Drill Chuck Holder (1/4" and 3/8" Chucks), 1203-Adjustable Tailstock Tool Holder, 1204 Adjustable Drill Chuck Holder (5/32" Chuck) and 1206-Adjustable Die Holder. (Click on any photo above for more information on each product.)

An advantage of the Sherline lathe is that the headstock can be rotated to cut tapers. The disadvantage of this adjustable design is that perfect alignment with the tailstock is more difficult to achieve. The solution for those who need perfect headstock-to-tailstock alignment is to make the adjustment at the tailstock end using these special purpose tool holders. They all have a rear plate with a #0 Morse taper for the tailstock spindle. The front plate can be adjusted in relation to the rear plate to achieve perfect centering. A witness mark on top of the rear plate makes it easy to return the holder to the aligned position when used in the future so it doesn’t have to be re-aligned each time. P/N 1201 replaces the standard live center with an adjustable one. P/N 1202 allows the attachment of a 1/4" or 3/8" Jacobs drill chuck. P/N 1203 accepts tools you make yourself that are held in place with a custom turned split collar and set screw. P/N 1204 has a #0 Jacobs taper to press on the small 5/32" drill chuck, and P/N 1206 holds 1"diameter tapping dies. A 13/16" bushing is included for smaller dies. For centering, drilling or tapping small parts where perfect centering is critical, these adjustable tool holders give you new options.


Did you know?

• If you have made something using Sherline tools that you would like to share with our newsletter readers and/or on our web site, please send us photos and a description. Also, if you have a handy tip for using Sherline tools in your shop, send that too. We are always looking for shop tips as well as fun projects to pass on to others. Send them to craig@Sherline.com.

• If you can’t get by the factory in person to visit our showroom or get a factory tour check out the “Photo Factory Tour” at www.sherline.com/factour.htm.


Upcoming Model Engineering Shows

2011…

Vista Antique Steam and Gas Museum Fall Tractor ShowVista, CA, October 22-23, 2011. See http://www.agsem.com/ for details and a map. Although not all about miniatures, there is always an interesting gathering of running model engines on display—miniature and full-size. They fire up and run the huge steam tractors too.

2012…

Cabin Fever ExpoJanuary 14-15, 2011. (Auction January 13th), Toyota Hall, York Fairgrounds & Expo Center, York, PA. See http://www.cabinfeverexpo.com.

North American Model Engineering Society (NAMES) ExpoApril 21-22, 2011, Yack Arena, Wyandotte, (Detroit area) Michigan. See http://www.modelengineeringsoc.com. Sherline and the Joe Martin Foundation will be attending this show.

Send us your show details and we will post them here


Joe Martin Craftsmanship Foundation News

• Earlier this month the museum was visited by our board of directors member Paul Knapp. Paul brought with him twelve additional engines to add to our display. It’s hard to pick a favorite, but the ¼ scale winged sprint car with the DOHC V8 Novi engine is by Jim Riggle is hard to beat. In addition, we added four new Gasparin CO2 engines—a 3-cylinder radial, a 9-cylinder rotary and an 18-cylinder radial plus a 1-cylinder engine billed as the “world’s smallest” in the Guinness Book of World Records. This engine has been installed in a tiny high-winged Taylor aircraft model that is unbelievably small and light at just 3.5 grams for aircraft and engine. Another favorite will be the new “Stinger 609” supercharged V8 built by Gary Conley. Also added were a rare New York radial and a Seidel radial prototype engine. This brings to 208 the number of Paul’s engines that can be seen by visitors to the museum.

• Tom Boyer and machine shop volunteer Dave Belt have begun work on our latest engine project. It is a 5-cylinder Kenner radial engine based on plans recently published in Model Engine Builder magazine. The crankcase is now almost complete. Dave will be using our Deckle pantograph mill to machine the connecting rods after making an oversize pattern.

• Tom Boyer and Craig Libuse gave a presentation on October 13th to a large woodworking club at the local Ocean Hills Retirement Community in Oceanside. We explained the purpose of the foundation and brought along a few examples of the displays including an engine or two to run. This was our second visit to Ocean Hills, as apparently our first presentation to the “Woodchucks” club in 2008 was a big hit. See our Club Visits page for photos of this and other museum events.