JasonB | 26/03/2013 10:49:57 |
![]() 25215 forum posts 3105 photos 1 articles | Having received some of the information back from George, these are the revisions and additions to date, click to enlarge.
Where 6.4mm often appears on the drawings this is where 1/4" diameter material was used so either use 1/4" material with matching holes or if you prefer working in metric then use 6mm ensuring shafts and holes are adjusted to suit. J |
HobbyNut | 26/03/2013 16:00:43 |
![]() 113 forum posts 93 photos | That is great Jason, it is starting to make some sense now. |
JasonB | 28/03/2013 17:56:15 |
![]() 25215 forum posts 3105 photos 1 articles | George has now come back to me with the height of the crankshaft, this is best measured from the top of the crankcase so there is no risk of the piston failing the valves. The width of the top face is 33.18 each side from the centre line which will give the correct slope to the sides, the flat section of the cam casing takes it out a further 9.99mm on that side giving the 76.35 overall top as shown in the mag. I've drawn it up below, click for larger view
The overall distance across the feet is 95mm So the overall should look something like this |
Ennech | 29/03/2013 11:56:59 |
![]() 153 forum posts 143 photos | I think there is something wrong. by calculation the height from the base to the crank centre is 77.13. The diameter of the flywheel is 156. This gives an interference of 0.87 with the ground, (not much space for the belt! |
JasonB | 29/03/2013 17:03:49 |
![]() 25215 forum posts 3105 photos 1 articles | George also gave me the 77.13 dimension so total height tallies. I'll wait to see if anything is said in the text about the flywheel but I have done several hit & miss engines where two sizes are given for the flywheel one being scale size and the other larger to get a bit more mass. Its not unusual for flywheels to project beyond the base on engines, many use a sub base or the skid to give clearance and also pullies are common rather than run a belt on the flywheel. J |
Ennech | 29/03/2013 17:57:30 |
![]() 153 forum posts 143 photos | Having looked closely at George's video, there is no apparent sub base attached to the feet of the engine but there does seem to be a very small gap....maybe a washer or two! |
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