Keith's video showing how a slide valve floats by the relative movement of the valve in relation to the nut retaining the valve rod sitting in an open channel made perfect sense to me - that is until I got to the valving on the Stuart No 9 that I'm rebuilding! I cannot currently get this engine to run because the valve has no fore and aft movement and is being held an estimated .015" off the port face. Hence any air applied simply blows straight out of the exhaust. Stuart plans show that the valve is cross drilled 5/32" for the 5/32" valve rod with the nut sitting in the middle channel being retained by 4BA threading. The nut and rod therefore has no fore and aft movement that is independent of the valve. I can only assume that builders are expected to mill the valve face thickness very precisely so that when everything is bolted up it fits pretty much exactly against the port face. Unfortunately my original builder was not up to this standard. To overcome the misfit I'm thinking of cutting down from the valve outside faces into the 5/32" holes to produce a couple of channels to take the rod and give some float so that applied air or steam will hopefully allow the .015" to be closed to make a seal. Any comments?
Fiddling around with valve timing is a good way to spend hours & hours,if the adjustment screw is on the outside ,if it’s under the eccentric strap it’s a pain ,my beam engine is like this the timing slipped and it’s set approximately but I can’t be arsed to fiddle with it.
The plans I have for a Stuart engine just shows the slide valve with 1/8 gap for the bar and the bar material is called as 1/8. Never mentioning to be any loose fit so I can see why newer people like me could go wrong. I did make that adjustment but probably should have trimmed the slide valve to uncover the cylinder ports better. But it runs.
@@keithappleton You would think after so many years Stuart Models would update the plan sheets to reflect correct machining. My plans were even missing dimensions altogether. No discount in pricing though!🤣
Hi, sorry, I was not able to see which way you turned the valve around. I tried on my 10V to turn the valve 90 degree and for a short time during the stroke both the top and the bottom were open at the same time. Did I turn it wrong?
That's the only way you can do it (90 degrees) if the engine runs better with the slide valve fitted that way then leave it like that. Sometimes the steam ports can be slightly inaccurate to the drawings.
It is already on the channel as part of my How To Build A Model Steam Launch Series. Please look on my www.mainsteam.co.uk website on the "Video Playlists Page".
Thanks for showing the before and after slow motion clips, the change in sound is noticeable at slow speeds.
Thanks, this makes valve timing very clear to even the meanest understanding.
The slow- mo sound is very telling. I think it’s very easy for an amateur to hear the timing
Thanks for sharing! Very interesting process to set the timing!
Thanks and happy birthday
Keith's video showing how a slide valve floats by the relative movement of the valve in relation to the nut retaining the valve rod sitting in an open channel made perfect sense to me - that is until I got to the valving on the Stuart No 9 that I'm rebuilding! I cannot currently get this engine to run because the valve has no fore and aft movement and is being held an estimated .015" off the port face. Hence any air applied simply blows straight out of the exhaust. Stuart plans show that the valve is cross drilled 5/32" for the 5/32" valve rod with the nut sitting in the middle channel being retained by 4BA threading. The nut and rod therefore has no fore and aft movement that is independent of the valve. I can only assume that builders are expected to mill the valve face thickness very precisely so that when everything is bolted up it fits pretty much exactly against the port face. Unfortunately my original builder was not up to this standard. To overcome the misfit I'm thinking of cutting down from the valve outside faces into the 5/32" holes to produce a couple of channels to take the rod and give some float so that applied air or steam will hopefully allow the .015" to be closed to make a seal. Any comments?
Thanks for sharing 👍
Fiddling around with valve timing is a good way to spend hours & hours,if the adjustment screw is on the outside ,if it’s under the eccentric strap it’s a pain ,my beam engine is like this the timing slipped and it’s set approximately but I can’t be arsed to fiddle with it.
The plans I have for a Stuart engine just shows the slide valve with 1/8 gap for the bar and the bar material is called as 1/8. Never mentioning to be any loose fit so I can see why newer people like me could go wrong. I did make that adjustment but probably should have trimmed the slide valve to uncover the cylinder ports better. But it runs.
It is down to tolerances. A 1/8" shaft in a 1/8" hole will be tight because of what is called an "interference" fit.
@@keithappleton You would think after so many years Stuart Models would update the plan sheets to reflect correct machining. My plans were even missing dimensions altogether.
No discount in pricing though!🤣
Hi, sorry, I was not able to see which way you turned the valve around. I tried on my 10V to turn the valve 90 degree and for a short time during the stroke both the top and the bottom were open at the same time. Did I turn it wrong?
That's the only way you can do it (90 degrees) if the engine runs better with the slide valve fitted that way then leave it like that. Sometimes the steam ports can be slightly inaccurate to the drawings.
@@keithappleton Many thanks
Hello Keith , it is possible to reupload video about how to make sail ship model stand? or give link where its possible to watch it? Regards Karol
It is already on the channel as part of my How To Build A Model Steam Launch Series. Please look on my www.mainsteam.co.uk website on the "Video Playlists Page".
⭐🙂👍
don't you like the sound of syncopation? . . . you took it out of the sound of that little red engine.
Syncopation is not sinusoidal .......
@@keithappleton so it's tangential?