An Interview with Max Hetzel
Max Hetzel - 1944
In June 1999, I was privileged to have some Accutron questions answered by Max Hetzel himself, the inventor of the Bulova Accutron watch. I prepared a list of questions, and these were taken to Mr Hetzel by his daughter - Barbara Young-Hetzel - on one of her trips to Switzerland visiting her father. His actual answers were recorded on tape, and are presented here for you to listen to. All files are in mp3 format, which are playeable on Windows Media Player, or any of the many audio players which support mp3 format.
- Introduction to the questions, by Barbara Young-Hetzel. This is very interesting, as Barbara gives rare insights into the Bulova watch company, the development of the Accutron, and her father's involvement.
Click here to listen...   (1044K, 106 secs)
- Question 1: The plastic cell coil and component coil mouldings in the 214 are works of art in their own right. Do you recall:
a) What material was used? Was it glass-filled diallyl phthalate, a very stable plastic compound often used in electrical connector moldings? b) Who made the injection molding dies for these? Can you remember were any advanced die-sinking techniques used (for example spark erosion), or were they are completely hand made in a jig boring machine. c) Regarding the injection moulding dies, how many formers were made on a die set? d) What kind of varnish was used to seal the coils after they were wound. It seems like some kind of polyurethane?
Answer for 1a...   (105K, 10 secs)
Answer for 1b...   (274K, 28 secs)
Answer for 1c...   (154K, 15 secs)
Answer for 1b...   (85K, 8 secs)
- Question 2: The gear train in the 214 Accutron is a masterpiece of elegant simplicity. Did you do all the design and ratio calculations yourself? How did you figure it out without a calculator or computer?
Answer...   (88K, 8 secs)
- Question 3: Do you recall what the index and pawl fingers were made of? Perhaps Nivarox or Elinvar, as used on balance springs?
Answer...   (96K, 9secs)
- Question 4: Do you recall who made the index and pawl jewels? Have you any idea how they were able to cut such small accurate square stones?
Answer...   (214K, 21 secs)
- Question 5: I believe the tuning fork tines were made of NiSpan C. What were the cups made from?
Answer...   (117K, 11 secs)
- Question 6: What were the magnets made from? Were they Alnico or some other rare-earth magnets?
Answer...   (88K, 8 secs)
- Question 7: The mass production of tuning forks made to vibrate with the correct amplitude for a given driving force must have been quite a challenge. Do you recall any details of this?
Answer...   (724K, 74 secs)
- Question 8: Why was the frequency of 360Hz chosen for the fork frequency? (in the 214 and 218)
Answer...   (655K, 67 secs)
- Question 9: I understand from a recent NAWCC article that the index wheels were made on a gear-hobbing machine. I presume that several or many pre-punched blanks were mounted on a spindle and hobbed at the same time. Do you remember any details about this? What precautions were taken to prevent vibration or temperature changes causing dimensional differences in the the finished index wheels?
Answer...   (273K, 27 secs)
- Question 10: The 218 movements are also superb watches. Were you involved in the design of these? Also, were you involved in the design of the 2210 movements? What was your role?
Answer...   (318K, 32 secs)
The Hetzel Family in 1975
To learn more about Max Hetzel, the inventor of the Bulova Accutron, and a more detailed history on the early development of the Accutron, I recommend you visit Barbara Young-Hetzel's site ACCUTRON - Max Hetzel, the Man behind the Invention.
Also, you may wish to visit the Accutron History page on this site. (Click Here)
On behalf of Accutron enthusiasts all around the world, I would like to thank Barbara and Max Hetzel for their efforts in bringing to you this very interesting interview and insight into the Bulova Watch Company, and the Accutron watch.
Pics courtesy of Barbara Young-Hetzel.