Member postings for John Bramwell

Jasons diagram has it exactly. Except for some f!exibility in the joints to allow for the arc (11 units at the p shaft). I was thinking slots or !inear beatings. You see how simlple it is for a novice, one piece. As for the timing, if the stroke is 99units and the port is 33 units and the piston just goes from one side of the port to over the port then to the other side of the port the opening stats at 1/3 of 180 =60 degrees. A wobbler engine has !ess i think.

Sorry guys the CAD dimensions are x10 what i want to build. But you advice is very helpful. In order of posts': yes I have the valve piston moving in sync with the power piston I have them both down the same end at the same time both fully open, But that means it would start to open a lot earlier wouldnt it?...I realise now that you can have two cranks off the same side of the flywheel by extending the pin of the bigger one then having an arm on it. The angle of this arm would determine the timing. I like the Caladonian, will work out how to limh to my screen shot but its a bit obsolite now. Thanks again. PS how does a10mm stroke sound for an O gauge?

Hello. Just joined and looking for some comments on a valve actuating mechanism idea. I want to make an O gauge live steam loco that does not have to resemble any actual loco but can pull a train. I want the piston valve directly over the top of the drive cylinder. But that requires an elaborate linkage system. The idea is to have a pendulum lever which drives the valve shaft from the drive shaft. I graphed it out and with a drive pistion stroke of 190mm and a piston stroke of 100mm and an axis difference of 95mm there is a pendulum length of some 280mm . The pendulum arm would have pin holes elonged 12mm to allow it to rock. Maybe this has been tried before but i cannot find any examples. So please advise. I could send CAD if that would explain it better. cheers Jack