Traveling Workshop Lathe Classes Update for Sherline Lathesby Gary Combs (FL)

L et’s start with a controversial question. Which is a better lathe for clock repair: a machine lathe like a Sherline or a jeweler’s/watch-maker’s lathe? I am not going to answer

the question directly in this article because it is too controversial. The bottom line is that with confidence, experience, and training, you can use either for most of the tasks that require use of a lathe. The Sherline comes with a cross slide and lots of accessories are

available, while used cross slides and accessories are available for jeweler’s lathes. I own two jeweler’s lathes: a jeweler’s lathe cross slide and a Sherline 4400 lathe.

When I graduated from NAWCC Field Suitcase Work-shop (now called Traveling Workshop) 201– Funda-mental Skills for Lathe and Clock Repair Part II about four years ago, only eight jeweler’s lathe users were

Figure 1. Projects and/or materials provided during the courses.

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in my class, and the workshop content was strictly handheld graving. Turning with a cross slide was reserved for Part III, TW 202 curriculum. Although common skills such as re-pivoting were demon-strated, we did not actually practice this skill. The two major projects in my TW 201 class were a hand graver sharpening tool and a file rest for the jeweler’s lathe T-rest. Yes, I made them both.

Several years later, I attended an introductory mini-mill class in Columbia, PA, met Jerry Keiffer, and encoun-tered a machine lathe—the Sherline 4400. After turn-ing a wheel arbor with the cross slide and a carbide tool bit, I was hooked. Today, one of my two jeweler’s lathes is a beautiful horological tool display piece and the other is for sale! Actually, I might still use my jeweler’s lathe to polish pivots or manually straighten bent arbors! With only one lathe course completed, I wanted more lathe experience, and I wanted to improve the learning experience for other students.

In January 2017 I coordinated a combined Traveling Workshop 201 and 202—Lathe II for Clock Repair Part III in Shalimar, FL. Nine students (if you include me) participated in the four-day TW 201 course, and seven students continued for another four days to complete Part II, TW 202. The back-to-back classes saved most students the one- to three-day travel time and expense from their home to the class site if the workshops had been held separately. The first class was also sched-uled over a three-day holiday weekend for the working student. One working student did attend.

For the follow-up TW 202 class, students did not require any refresher training, their tools and the class-room were already set up, and the timesaving advan-tages for the students and instructor were huge. The combined classes also netted the NAWCC more funds by saving on instructor travel and student tuition. The most negative critique from students attending both courses was “not enough time to complete all the proj-ects,” even though we started at 8 a.m. every day. At 2 p.m. on the eighth day, some students were still work-ing feverishly to finish projects. From a review of the critiques from both classes, all students’ expectations were fully met. Every participant can now confidently use their lathes for more than polishing pivots!

NAWCC Instructor Bill Knaak and I developed an update to the legacy 201 course to include tools adapted to the Sherline lathe, as well as more tools useful in clock repair (Figure 1). Students were pro-vided material kits of pivot wire, tool bits, and two

damaged clock wheels, and lots of precut project materials. All students were taught unique lathe tech-niques to straighten a bent pivot and arbor using a provided ball bearing tool bit on the cross slide (Jerry Keiffer technique). Did I mention cross slide? All stu-dents practiced a re-pivot of a small (<0.07") arbor (Figure 2) with a less than 0.04" pivot. Students were also provided a damaged escape wheel in which they practiced escape wheel teeth repair or straightening and tool bit tipping with the lathe cross slide. Did I mention cross slide, again? These lathe clock repair techniques were new to the TW 201 curriculum.

For both courses, student project materials were pre-cut. A Harbor Freight portable band saw with metal blade, swag table, and foot control switch (Figure 3) became the class MVTTS (most valuable tool time saver)! As a previous legacy TW 201 graduate, I can attest to the fact that students expended class time hacksawing materials for course projects. For these two courses, a hacksaw was not necessary.

As I mentioned above, the legacy TW 201 course also was centered on hand graving with a jeweler’s lathe and T-rest. For this class, seven of the nine stu-dents brought their Sherline lathes. The instructor also brought an extra Sherline lathe. For all the Sherline lathes a T-rest was available, and the instructor con-centrated on hand graving techniques for only the

Figure 2. John Wagner working on a new pivot for a very small (0.07") arbor with a Sherline 4400 lathe.

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first day. So, on day 1, students were taught how to use hand gravers and turned steps in both brass and steel using hand gravers. Figures 4–6 show students at work on various projects; Figure 7 shows the class participants.

On day 2 of TW 201, students were introduced to their cross slide and tool post as well as making tool bits. Even the jeweler’s lathe students brought out their cross slides. From this point on, students had their choice to use either a hand graver or cross slide to tackle the many projects in both courses. Most stu-dents chose to use their cross slide, even when mak-ing the legacy file rest and hand graver sharpener. Both these projects have merit because they require thoughtful planning to sequence the many fabrication steps correctly. Most students decided to make both the legacy TW 201 projects—even the Sherline own-ers. Some students chose to modify the file rest post

Figure 3. Harbor Freight portable band saw.

Figure 4. Dennis Murphy boring the inside of a mainspring barrel base with his almost new Sherline 4400 DRO lathe.

Figure 5. Sherry Kitts using a jeweler’s lathe to fabricate a winding arbor.

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to fit their Sherline T-rest. Every student in the class had a chance to use a Sherline lathe.

The instructor provided each student with a car-bide-tipped tool bit and taught techniques to make and sharpen other tool bits. For me, there is no going back to my jeweler’s lathe even though I will always have one. In addition, many of the nice accessories that I have with a jeweler’s lathe (3-, 4-, and 6-jaw flat chucks, complete set of WW collets) will fortu-nately function with my Sherline lathe.

Several new TW 201 tool projects were added to the curriculum, including the following: a magic center finder, tool post clamp to hold a verge or other part for resurfacing, another tool post clamp to hold a wheel for replacing teeth, accessory parts for a blue-ing pot made from a mainspring barrel, and others. All the legacy TW 201 tool project materials were also available; if they were not precut, the student could quickly cut them with the MVTTS! Between my previ-ous TW 201 class and these two classes, I have made all the projects except the spade drill. I may never use my hand graver sharpener; how-ever, this project taught me the importance of planning your project sequence and sticking to the plan. In addition, I am proud of the tool!

For TW 202, Part III of the lathe course, seven students including myself were introduced to turning on centers by creating a mainspring winding arbor. Once the lathe was set up with round rod arbor stock properly mounted between the lathe head and tailstock, I think all students chose to use the cross slide and tool bit. All students were provided an AR402 car-bide-tipped tool bit and were instructed on tech-niques to make their

own tool bits. I chose to actually make an arbor for a small French time-only movement missing the square key end of the arbor. This class gave me the confi-dence and skills to make this damaged part a reality!

The TW 202 project to make a spring barrel provided insight on how they are constructed, and students got experience boring inside surfaces with a lathe. We also learned methods to hold an unusual shaped piece, such as glue chucks and wood plug chucks, in a lathe. We learned that work held with a glue chuck can pop off and needs to be re-centered and re-glued—a little frustrating. Wood plug chucks to hold the barrel for surfacing and boring also proved challenging.

Did I mention the blueing pots? I found an interesting YouTube video on making a blueing pot from a spring barrel and thought this would be a good use for the barrel (with no teeth!) we made in the workshop. None of us had time to make this pot during the workshop, but plans were sent home with everyone.

Although the construc-tion of a spade drill was an optional TW 202 project, no one had the time to make one in this class. One student did make a new clock wheel arbor, turning the pivot ends. Others chose to make annealing ovens to prepare hardened arbors for re-pivoting. Future TW 202 courses might consider making these standard projects for all students. Have you ever had a bent or broken clock arbor that was toast? I have! The good news is that I think I now have the skills to make a replacement arbor.

Throughout the classes, we kept a list of sig-nificant or perhaps unexpected skills and techniques learned. A few of these were use of the small stub end of

Figure 6. Carl Dixon using a compound slide mounted on a Sherline cross slide to taper the posts on his steady rest to better fit the small spaces on clock wheels. All the Sherline owners chose to taper their steady rest posts.

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measurement calipers for inside or difficult-to-reach dimensions (only two students were aware of this measurement technique); use of pre-drilled wood blocks for tapping flat and round stock to keep threads in alignment at 90° angles; turning stock on centers to make arbors and small French minute hand clutch and pipe; use of a cross slide mounted on a boring tool bit to cut inside slots; confidence in replacing a pivot on small (< 0.07") clock arbor; con-fidence in repairing escapement teeth with cross slide and anvil tool bit; various lathe techniques to find center of properly surfaced stock; and use of glue chucks to mount and turn flat round stock otherwise difficult to hold for turning.

So, back to the original question concerning use of a jeweler’s lathe versus machine lathe. One student who owns a jeweler’s lathe and used both his lathe and a spare Sherline lathe during the two classes, summed up his perceptions: “The important points I perceived were the modern technology of the Sher-line including 1/4 tool bit increasing the speed of boring and turning over the 3/16 tool bit, better cali-bration of the dials, overall cost savings to a new user

which is very important, the availability of computer control, availability of add-on tools, and overall rug-gedness of the instrument. Having used both lathes in class I can support the superiority of the Sherline if I was a new user.”

If you would like to discuss how you can coordinate a NAWCC Traveling Workshop for your Chapter, please do not hesitate to contact the author at 850-217-5180 or by email at gary.combs@cox.net. He is always available to talk horology.

About the Author

Gary Combs is a U.S.A.F. retired electrical engineer with more than 40 years of service. Gary is currently serving his 19th year as the mayor of the town of Shalimar, FL. He has been an NAWCC member for less than 10 years and has attended and coordinated several traveling workshop courses. Gary and his wife, Nancy, attend most of the NAWCC Nationals and many of the Southeastern Regionals. Gary is the vice president of Florida White Sands Chapter 96 and Nancy is the treasurer.

Figure 7. Class participants, from right to left: Dr. John Wagner, professor from Clemson University; Rod Powell, retired human resources administrator; instructor Bill Knaak, retired chemical engineer; Dr. Al Hartmann, retired pathologist; Gary Combs, retired electrical engineer and mayor of the town; Jack Gilmore, retired financial manager; Glen Kitts, retired mechanical engineer, Y12 Department of Energy, and wife, Sherry Kitts, retired electrical engineer with Tennessee Valley Authority; and Dr. Carl Dixon, retired dentist. Not pictured was student Dennis Murphy, retired military veteran and alpaca farmer.

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