Odhner Mechanical Calculator

Today, once again I am feeling very under the weather, I can hardly feel the left-hand, both upper arms and shoulders are hurting and I have a headache. However, one can only spend so much time asleep, after which even in this state one needs to potter. I ought to be completing my Open University tutor marked assignment on which I currently have an extension, but this requires a degree of concentration which I cannot at present manage. I therefore decided to do something mindless, so despite the numb left-hand, I decided to fix the Odhner calculator as this is a purely mindless repetitive task which only requires care.

When I posted my blip of Saturday 5 January 2013, I said I would post a picture of the Odhner in parts, during repair. Here are the major sub-assemblies, ready for reassembly, having completed the repair of the reset mechanism on the left-hand register. The fault was a cam follower, which had failed on the reset mechanism of the left-hand register and simply needed to be moved back into the correct position for normal operation. The machine has been fully reassembled and tested since this picture was taken and works perfectly. It is interesting to note that this particular model gives a higher resolution of its calculations, than does my normal electronic calculator!