Author Topic: Jowitt MkII Popett Valve Steam Engine  (Read 27104 times)

Online Jasonb

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Re: Jowitt MkII Popett Valve Steam Engine
« Reply #90 on: May 15, 2018, 05:11:36 PM »
The "wedge shape" is simply the mitre effect of the vertical hole meeting the horizontal one, shown in green.

The CSK area shown in red is what the valve seats against and when that is open it lets the air out from the cylinder via the cross drilling then passed the valve seat and finally down the exhaust hole as shown in blue.

Quote
Also are the steam inlets holes bored into both cylinders as you mentioned in the thread or is it just in the intake side.?

Not sure which hole you are refering to and there is only one cylinder, can you give a bit more detail.




Offline Jo

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Re: Jowitt MkII Popett Valve Steam Engine
« Reply #91 on: May 20, 2018, 04:51:04 PM »
For reference: The original Jowitt casting set  ::)

Jo
Enjoyment is more important than achievement.

Offline warrenmaker

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Re: Jowitt MkII Popett Valve Steam Engine
« Reply #92 on: May 24, 2018, 11:19:18 AM »
The "wedge shape" is simply the mitre effect of the vertical hole meeting the horizontal one, shown in green.

The CSK area shown in red is what the valve seats against and when that is open it lets the air out from the cylinder via the cross drilling then passed the valve seat and finally down the exhaust hole as shown in blue.

Quote
Also are the steam inlets holes bored into both cylinders as you mentioned in the thread or is it just in the intake side.?

Not sure which hole you are refering to and there is only one cylinder, can you give a bit more detail.

Sorry, I didn't notice your reply. That drawing makes much more sense now. Thanks heaps. I am besotted by this simple yet elegant little engine.:praise2:

MB if I ever finish off my 7A, I will make a start on this one.   

Offline Brian Rupnow

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Re: Jowitt MkII Popett Valve Steam Engine
« Reply #93 on: May 24, 2018, 11:29:44 PM »
Thank you for the very informative thread Jason. I don't know much about poppet valves, but would like to know more.---Brian

Offline Brian Rupnow

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Re: Jowitt MkII Popett Valve Steam Engine
« Reply #94 on: May 25, 2018, 01:53:25 PM »
Jason--I have to pay to get downloads from your hosting site. If I open all the drawings you have posted here on the forum, are they correct enough to model the engine from?---OR would it be overly bold of me to ask you to email me a .step file of the entire engine assembly?---Brian
brupnow@rogers.com

Online Jasonb

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Re: Jowitt MkII Popett Valve Steam Engine
« Reply #95 on: May 25, 2018, 02:22:46 PM »
Thats odd Brian, Several people have built this engine and the Chuky and not had any issues getting the drawings from Dropbox. You can also get the pdf files by clicking the drawings on David Carpenters site.

http://modelengineeringwebsite.com/Jowitt_engine_build.html

Please note the "for personal use only" caption. I was given the original drawings freely and have offered my version for free and would like to see that continued on any other versions.

I'll need to go through the assembly drawing as it has lost some constraints since I updated my version of Alibre but should be able to get a step file from it.

Offline Jo

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Re: Jowitt MkII Popett Valve Steam Engine
« Reply #96 on: May 25, 2018, 02:25:07 PM »
Jason--I have to pay to get downloads from your hosting site.

:disappointed:

Don't you hate it when some people take other people's engine designs redraw them in CAD making a few tweeks so that an engine sold as a casting set can be made using bar stock or changing the scale then they have the cheek to charge for the drawings  :ShakeHead:

Jo
« Last Edit: May 25, 2018, 04:43:50 PM by Jo »
Enjoyment is more important than achievement.

 

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