By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Allendale Jan 24th

Stuart No. 9 slide valve

Am unclear about steam valve dimensions and setting up

All Topics | Latest Posts

Search for:  in Thread Title in  


ME Centennial Collection Issue 7 -  Parts 1 and 2

ME Centennial Collection Issue 7 - Parts 1 and 2

Model Engineer Centennial Collection Issue 7 - Stationary Engines

mike robinson 229/11/2009 13:54:55
18 forum posts
7 photos
The Stuart drawing item 31 shows a milled pocket in the gun metal valve that is 1/2 wide and 5/8 tall * 1/8 deep. The dimension fixing a start position for the 1/2 inch wide pocket is not shown so it could be milled out anywhere - clearly not correct.
I have read Tubal Cains book on building a No.9 and he refers to the valve having a line and line exhaust lap and a 3/32 steam lap. According to TC the start of the steam transfer pocket is 7/32 from the "toe" of the slide valve The eccentric has a 5/16 throw.
Having modelled in CAD the cylinder ports at the as cast dimensions and the  valve and I am still uncertain of dimensions for the pocket such that the ports are "fully" open at each end or have the correct "lap". If one end is set up to be fully open then a the other end of the 5/16 stroke the port is only half open,
I would like to understand steam lap can anybody describe what it is and or how to calculate this so I can be certain of the dimensions to cut the pocket.
Appreciate any help - I have illustrations from CAD but cant upload - to this site.
Thanks , Mike

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Support Our Partners
Allendale Electronics
Eccentric July 5 2018
Eccentric Engineering
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest