Index.htm pp010.htm INTRODUCTION 1999 AND ACKNOWLEDGEMENTS
This report is 68 technical drawings plus 27 photographs of pedal powered equipment (threshers, water pumps, winnowers, grain mills and maize shellers), a tractor PTO thresher, and a wind powered grain mill which I worked on in Uganda 1972 and in Tanzania 1973 through 1978. Regrettably it takes up 6.3 Megabytes in total.
I have recently revamped reports on a 4 MAN PEDAL SORGHUM THRESHER AND GRAIN MILL, a 2 MAN TROLLEY WATER PUMP, and WOODEN BEARINGS - WEAR AND LUBRICATION. This report collects together a bunch of stuff which was not included in those reports, and has 2 purposes: the technical drawings and the photos should give ideas to people working or thinking of working on the same kind of stuff; and the other purpose I guess is nostalgia. There is some stuff here which is effectively obsolete, and other bits which are still to some extent valid. If it gives some people good ideas and/or saves 3 hours work then it has been worthwhile putting on the Web.
Recently while rewriting the THRESHER report, I realised that one can make significant design simplifications and cost savings by putting 2 riders face-to-face on the same pair of pedals, and operating in a reclining position - one of course will pedal 'backwards' while the other pedals conventionally. This opens up new designs for 2 man and 4 man configurations, using either 1 or 2 single pedal bearing units, or utilising crankshaft-based designs. I also recommend that where possible we eliminate 2 stage drives (especially 2 stage chain drives as used for the 4 man pedal thresher), and use if possible single stage belt drive if speeds over 200 rev/minute and less than 1000 rev/minute are required. Such a belt driven machine can use 2 belts per 600mm driver pulley if required. Enough rambling.
Thanks to so many people in Tanzania and outside for work related and non-work- related social interchange. It was a period not without work and personal frustrations, but one which was on balance a very rich and rewarding experience. Thanks particularly to the late Abdon Mwangota and his wife Kathy, to Hosea Kayumbo, to Monta Tshabalala, and to Roland Reichel. All the people of all levels over that long time period in Agricultural Engineering Department, and throughout the Faculty of Agriculture (now Sokoine University).
I did very little to the drawings and there is very little explanation. Anyone who wants such explanation just email email@example.com and we can get you what you need. Anyone who wants a complete package of this I can email the WinZip (TM) file to them and it will run off their hard disc.
Alex Weir, Harare Zimbabwe, 1999 December.