The Application Of Sumter Magnetos

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Rex Box P, Bedford, MA 01730

Sumter magnetos were used on many early engines, Fairbanks Morse being one of the most popular. These early all brass magnetos are extremely well made and marked SUMTER TELEPHONE MFG. CO. SUMTER SO. CA. Sometime before 1919, Sumter was purchased and incorporated as the Sumter Division of Splitdorf Electrical Company at 1466 Michigan Ave, Chicago IL. The Sumter name was retained for magnetos made by Splitdorf at their Sumter Division. In many references I have seen, the name Sumter is commonly misspelled as Sumpter.

I was fortunate in being able to locate an early Sumter manual dated 3/19/19. With less than 20 Splitdorf branch houses and service centers in the United States, a couple dozen manuals were sufficient to supply all the centers. Because so few copies were needed, many pages of the manual were hand typed carbon copies. Below is an exact copy as it appears from certain hand typed manual pages dated 3/19/19. It should prove useful to readers who are trying to identify Sumter magnetos and determine their recommended application.

SUMTER MAGNETOS

The following is a list of practically all the models of Sumter magnetos which have ever been manufactured, with a brief description of what each one is and how it can be identified:

IMP #10 The original IMP magneto had low magnets, about an inch shorter than the present IMP. There was no magnet band over the top. Current was taken off the collector ring, brush being located in the top plate. Timing marks on the end of the shaft or bearing, long since discontinued.

IMP #11 This magneto was successor to No. 10. Has magnets about an inch higher. Has magnet band over the top, on which is No. 11. Current taken off the collector ring, brush being located on top plate. Timing marks on end of shaft and bearing. Supplied with armature with #22 and #23 wire. Our latest production and repairs have #26 wire. Discontinued about 1916.

IMP #12 This is the same magneto as #11, except it has outstanding lugs or ears on each side of the base. Manufactured exclusively for Fairbanks-Morse. But furnished also with reversed base in small quantities to some other concerns, then known as #12-R. Discontinued about 1916.

IMP #14 This magneto was made special for plugoscillator work. Has tapered shaft, no timing arrangement; current is taken off the hardened end of the armature shaft by a button carried in a Bakelite terminal cap. Has magnet band with #14 on it. Magnets, frame, etc. about the same in dimensions as the IMP #11. This is a current model. Armature wound with #26 wire. All except our earliest production has oil well bearings.

IMP #15 This magneto is the successor to the IMP #12, and has the same type of base. Has terminal cap, taking current off end of armature shaft. Magnet band shows #15. Straight shaft with timing disc. Has oil well bearings; No. 26 wire armature. Current model.

IMP #16 This magneto is exactly like #15, except that it has a square base, with lugs. This is the successor of the IMP #11. Current model.

SATAN #20 The original Satan model, no magnet band. Current taken from end of armature shaft by a brush inside of a fibre brushing. Has timing disc. Long since discontinued.

SATAN #21 This model corresponds in all respects to the IMP #11, except that it is larger.

SATAN #22 This model corresponds in all respects to the IMP # 12 except that it is larger.

SATAN #23 There was one small shipment of SATAN magnetos which left the Sumter factory marked SATAN #23. This designation was later changed, however, to #25.

SATAN #25 This magneto is the successor of #22. It has the same lugs on the base, has magnet band marked #25. Has current collector on the end of armature shaft, carried in Bakelite cap; has timing disc, #26 wire armature. In fact, corresponds in all respects to IMP #15 but is larger.

SATAN #26 This magneto is just the same as #25 except that it has a square base.

J-R This is one of the original standard Sumter magnetos and is marked JR on the older models; JRS on some models; JRCS on some models, all of those designating some slight changes. The original models had the magnets held on with screws running through them. These magnets are single, no lamination, except on the JRL, very few of which were made for Lauson with laminated magnets. The present model JR-30 is marked JR-30 on the magnet band; has porcelain terminal taking current from end of magnet shaft.

B-N This magneto is larger than the JR but made in the same way. Has single magnets, porcelain terminal, timing disc. One of the original Sumter models. A limited quantity manufactured.

BN-R This model is the same as model B Standard, except that it has a tapered shaft corresponding to the taper used on the Bosch NR magneto.

B-40 This magneto was one of Sumter's standard magnetos, having laminated magnets, bronze end plates, porcelain terminal and is marked #B.

BD This is the same as the model B except that the armature is wound with larger wire, giving lower voltage for special work.

BS This magneto is the model B modified and mounted in a tilting cradle for advance and retard.

BSD This model is the same as the BS, except that the armature is wound with larger wire, giving lower voltage.

AP-40 This is the original standard Sumter magneto with three laminated magnets, brass end plates, porcelain terminal, Marked AP.

AP-AR-3 This is the same as the model AP except that it has a tapered shaft, to agree with the Bosch model AR-3 magneto.

APD This is the same as the model AP except that it has a lower voltage armature for special work. Marked APD.

AS This is the model AP magneto somewhat modified and mounted in a swinging cradle so as to get advance and retard.

ASC A few special magnetos made up for Foos Gas Engine Company some years ago.

ASD This is the same as the Model AS, except with a lower voltage armature.

AG This a larger Sumter magneto, has the same construction as the Model AP, except wick oilers on the bearings and magnets considerably higher, giving greater output.

AGD This the same as Model AG, except with low voltage armature. Some of these were made up without special designation, but with tapered shaft instead of straight shaft.

300 This is the JR magneto with tapered shaft, arranged with two horizontal springs to make it an oscillator.

301 This is the JR magneto with tapered shaft, arranged with one vertical spring to make it an oscillator.

400 This is the B magneto equipped with two horizontal springs and a tapered shaft to make it an oscillator.

401 This is the B magneto, equipped with tapered shaft and one vertical spring to make it an oscillator.

500 Model AP magneto, equipped with tapered shaft and two horizontal springs to make it an oscillator.

502 This is the AP magneto, equipped with tapered shaft and one vertical spring to make it an oscillator.

503 This is the model AP magneto with tapered shaft and two vertical springs to make it an oscillator.

MAGNETOS RECOMMENDED FOR H. P. AS FOLLOWS

IMP1 h.p. or in some cases 1 ? h.p.
SATAN2 to 2? h.p.
JRUp to 4 and sometimes 6 h.p.
B6 to 10 h.p.
BH5 and 6 h.p.
AP10 h.p. and up
AGVery large motors 29 h.p. and up
BSOnly when range is excessive.
ASOnly when range is excessive.
RTDixie 1 to 4, not over 3 ? h.p.
DIXIE10 and 20, not over 3 ? h.p.
DIXIEM-1 up to 4 ? h.p.
DIXIEM-2 up to 4 ? h.p.