M-209 - Maintenance

Introduction

After WWII, a movie was made which explains how to use the M-209 and to do maintenance operations.

TM 11-380, 1944

Excerpt of the Manual
24. CARE OF CONVERTER

 a. Preventive Checks. Converter M-209-(*) will offer few maintenance problems if it is operated correctly and cared for properly. In many cases a thorough cleaning and lubrication will remedy mechanical difficulties. As the machine is used from day to day, a few simple checks during operation whill help to keep the device in good operating condition. Operators should check the following items:

(1) Spring tension of the vairous visible springs on machine.

(2) Proper lubrication.

(3) Amount of lateral play in the key wheels on the key wheel shaft (par. 26). (Key wheels must be sufficiently tight to avoid slipping to one side, but not so tight that ensy turning is prevented.)

(4) Dried ink on typewheel or dust in operating parts.

(5) Proper positioning of lugs on drum bars.

(6) Tighness of screws on drum base.

 b. Cleaning. From time to time certain parts of the machine require cleaning.

(1) TYPEWHEEL. The typewheel may become cacked with ink and print indistinct or illegible characters. Brushing the typewheel with a small stiff-bristled brush may be sufficient to clean it. If the dried ink has hardened, use a sharp instrument to loosen the ink before applying the brush. Do not damage the letters on the typewheel with the instrument.

(2) GENERAL. When the converter is used in the field, dust may collect in the operating parts and impede their action, especially if the machine has been oiled excessively. If the machine becomes clogged, remove the parts as directed in paragraph 34 and clean with a dry cloth. Lubricate the machine before replacing the parts. Remove the dust from corners and openings occassionally with a smallbrush. Always close the outer cover when the converter is not in use.

 c. Oiling. The oil rod provided with Converter M-209-(*) is attached to the cover of the oil can, and should always be occasionally (for every 256 hours of operation) by placing one to four drops of oil in the lubrications holes provides. The drum bar slots on the left-hand side of the drum should be kept well oiled, but all other moving parts should be lubricated sparingly.

 d. Paper Tape Supply. To insert fresh tape into the paper feed mechanism, release the hinged guard which holds the roll of paper in place and allow the guard which holds the roll of paper in place and allow the guard to tilt forward against the inner lid. Remove the empty spool and place a new roll of tape over the pin. (The tape must unroll in a counter-clockwise direction.) Pass the end of the tape through the slot in the hinged guard, bring the tape forward, and insert it in the tape slot just above the encipher-decipher knob. Push the tape through the tape channel until it appears between the typewheel and the tape- advancing rollers. The tape must pass under the paper guide spring immediately behing the typewheel. Next pass the paper tape between the tape-advancing rollers (fig. 12), while depressing the paper pressure arm.

 e. Ink Pads. Additional ink pads will be found in one of the small metal containers held by spring claps in the outer cover of the machine. To insert a fresh pad, open the inner lid of the converter, use the tweezers to remove the old pad, and insert a new one. The life of the pad, before replacement is necessary, can be prolonged by turning it end for end. The ink pads should re-inked with the special ink developped for the ink pads, or with any standard purple or black stamp pad ink. Hectograph ink should not be used because it dries the ink pad and makes it unfit for further use.

 f. Minor Repair. The operator of Converter M-209-(*) should be able to make certain minor repairs on the machine. Paragraphs 25 through 32 explain the common minor troubles and include information for correcting such troubles. Paragraph 34 explains how to dismantle the machine and limits operator's maintenance to minor repairs.

Oiling

A great picture of the Lubrication order was furnished with the M-209. Sometimes, the code clerk pastes it on the M-209 cover.

References

• San Francisco Maritime National Park Assocation
  TM 11-380, 1942
• War Department, Technical Manual, Converter M-209 Part of David Stroud Collection. Scanned by Nick Spark. Homed by Cryptomuseum - TM 11-380. 27 April 1942.
• iLord.com - M-209 Manual TM 11-380, 1944
• iLord.com - M-209 Encryption Machine Training Video