Hi all,
I've managed to finish Elmer's Grasshopper engine. I'm always surprised by how much work goes into these models.
I used rubber O rings to seal the valve and piston shafts. The seem to seal without creating much drag as long as they are well lubricated. They are OK with compressed air but I'm not sure how they would go with steam. I can run the engine on a bit less than 3psi air pressure so I guess the construction is OK.
I think I'll give Elmer's Mill engine #33 a go next.
I didn't much enjoy making and fitting the steam chest on the grasshopper. It's a really fiddly mechanism to make and get adjusted correctly. I think I may try modifying the design of the mill engine so as to use a spool type of valve rather than the steam chest design favoured by Elmer. I think this will mean a much greater valve movement. Does anyone have any thoughts on the relative merits of spool valves as opposed to steam chest type valves?
Regards,
Alan C.
I've managed to finish Elmer's Grasshopper engine. I'm always surprised by how much work goes into these models.
I used rubber O rings to seal the valve and piston shafts. The seem to seal without creating much drag as long as they are well lubricated. They are OK with compressed air but I'm not sure how they would go with steam. I can run the engine on a bit less than 3psi air pressure so I guess the construction is OK.
I think I'll give Elmer's Mill engine #33 a go next.
I didn't much enjoy making and fitting the steam chest on the grasshopper. It's a really fiddly mechanism to make and get adjusted correctly. I think I may try modifying the design of the mill engine so as to use a spool type of valve rather than the steam chest design favoured by Elmer. I think this will mean a much greater valve movement. Does anyone have any thoughts on the relative merits of spool valves as opposed to steam chest type valves?
Regards,
Alan C.