The Smiths Magmo Speedometer.
This small speedometer was fitted to cars in the very early 1930's onwards. It shares a very broadly similar design but not inter changeability of parts with the Smiths Nemag. It operates with the same 'Eddy Current' principle as does the Smiths AT and the Nemag. The dial is printed with the Smiths MA logo MA referring to the Motor Accessories division.
Physically it is similar in size to the early 60mm diameter Nemag speedometers, it only has a single threaded lug on the back of the case for fixing to the car's dashboard. The speedo cable is fitted with an external threaded section which fits into a internally threaded element in the mazac casting.
I think that originally the speedo was designed to be read from above and at a slight angle the speedometer indication is painted directly on the drag cup, there is no needle or pointer on the Magmo. The distance travelled or 'Total' as printed above the odometer, there is no trip. The odometer numbers are slightly different in colour to those of the Nemag, the 1/10 mile are orange and the other numbers have a slight yellow tint, this of course could be sunlight damage.
The dial is a fairly complicated pressing usually fitted with a chromed bezel, with three lugs to hold the bezel to the speedo case, the bezels are slightly unusual as they may be rolled with an obvious soldered joint, below the chroming.
The stator plate is oval in shape to accommodate the off centre design of the mazac housing.
The photographs shows the oval stator plate assembly including, the hair return spring, the stop mechanism and the odometer advancing pawl. The speedometer numbers are painted directly on to the drag cup.
This photograph shows the Odometer cradle sitting on the top of the stator plate
This photograph shows the major components of the Magmo. The Drag cup sub assembly and the odometer sub assembly have not been disassembled in the photographs. One of the major differences between the Magmo and the Nemag is that the magnetic spinner assembly has a steel worm wheel, on the Nemag it is brass. The odometer drive gear is Brass and of a much smaller diameter than is found on the Nemag. The Smiths Magmo is a far different, yet confusingly similar type of speedometer, it is very well designed and while sharing some similarities with the Nemag, as can be seen, is quite different.
A Smiths MA ( Motor Accessories) Magnetic Magmo speedometer which has been recently restored in the workshops .
A new Chromed bezel has been fitted and the odometer has be returned to Zero miles.