The Craftmans Shop > Model Engineering

Pickering governor in 2 inch scale

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Brass_Machine:
 :jaw:


 :bow:

Eric

steamman:
Hi I have made a similar scale  governor to yours ,I had the same problem of the springs not flexing orstaying in one position after turning the governor at speed in the lathe, if you look closely at your full size governor you find that the balls have a slight  taper and clearance on the upper half of the ball this is to allow a slight movement of the springs before actual main movement of the valve takes place,it also serves to stop the ghost like appearance of balls when they are spinning.I used a very fine slitting saw to cut the slots in mine ,as you can imagine the slitting saw of only .032 thick does deflect and cause a slightly wider slot at the top of the ball I used a allen grubscrew to secure the balls to the springs making sure that the wider part of slot was uppermost on assembly. With regard to the springs I have tried using Spring Steel from old alarm clocks however it is difficult drill or punch holes without breaking and eventually used shim steel instead clamped at each end by pins and circular wedges held in place by a circular collar on both top and bottom ,the pins allow certain flexation radially to the springs this also helps I used a milling cutter 16 thou wider than the width of the spring but mounted the pins centrally, You say you soft soldered your assembly perhaps the heat has affected the feeler gauge causing local loss of flexibility?Also several people in the minature engine world have used double layer springs ie 2No .003" would give .006 total thickness may be worth a try.Finally I agree some things you just cannot scale  and Physics is one of them I myself have tried over several years to get valve that would work in steam without success,so best of luck and keep trying.Steamman

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