Contact Us!
  • White Facebook Icon
  • White YouTube Icon
Subscribe for updates!
Support 

Subscribe to receive email updates from time to time. Never miss a thing and unsubscribe whenever you like.

This website and forum is free to use. The vast majority of video content produced is available on youtube.

However, should you find Charlotte's Steam Clinic useful and if you fancy supporting this platform/content, you can become a Patreon for as little as $1 per month. There's no obligation, it's just a nice way to help out and to show appreciation for the time that goes into this platform. 

 

If you prefer to use PayPal or if you would like to make a stand alone donation (and not a monthly one) here's a link to our PayPal account. Thanks again if you make a donation. It makes a difference to us. 

© 2017 by Charlotte's Steam Clinic Proudly created by Visual Trailer Ltd.

u87project
May 4, 2018

Steam valve timing

5 comments

Edited: May 4, 2018

 

I've been building a Model Maker steam engine from solid billet (no castings). I have deviated from the blueprints by adding reversing gear to the engine. I have set up temporary adjustable valve rods to try to determine the best length. While I have equal travel of the valve...I'm finding that I'm not getting full steam port exposure with the valve moving top to bottom. I'm guessing there's really two ways to make adjustments to this..one: mill off the top and bottom of the actual valve block or two: make new eccentrics with a slightly larger throw. I'm a bit concerned with milling the valve...my thought is if I mill too much..I may not get adequate coverage of the ports during exhaust. It seems remaking eccentrics with about .060 throw might give me the port open g I'm looking for. Any thoughts or recommendations of options or concerns would be appreciated.

 

 

 

 

Hugh Coleman
Jun 15, 2018

Hello,

Looks to me like you need more throw. you want to open the inlet port enough but not close the exhaust port at the same time.

Can you show us the uncovered port face?

cheers,

Hugh

u87project
Jun 15, 2018

 

 

u87project
Jun 15, 2018

 

 

Hugh Coleman
Jun 15, 2018

The lands on the slide valve need to be about 20% wide than the inlet ports. No wider. it also looks like your slide valve is very long by comparison with the ports.

At midstroke, both inlet ports should be covered (rule of thumb, this is adjusted to allow early inlet in practice) with excess of the valve face covering by the approx 20% at each extreme end.

cheers, Hugh

 

 

Jerry McCracken
Aug 9, 2018

Hugh

Are you saying the slide valve should be 20% of the port opening overlap when the slide valve is at midpoint?

New Posts
  • CastingIronEngines
    May 13

    I saw a photo of a green twin oscillating steam engine on the Preston Services website a few years ago, and a Canadian buddy of mine challenged me to make one. Long story short, I built a foundry, used a 3D modeling program to model the engine using 3 photos, made the patterns, and cast the parts for a 60% scale engine. I recently got the engine running, and it can be viewed here: https://www.youtube.com/watch?v=UxIZ4iuhLyM The plan at this point is to finish the painting work on the engine, and publish it in Live Steam and Outdoor Railroading magazine. It was a long journey to learn the foundry work, but I was able to cast some of the parts in gray iron, with the remainder being cast in 356 aluminum.
  • J. Meaney
    May 28

    I recently acquired a Stuart Turner 3MTB stationary engine. Unfortunately the slide valve and ancillary parts are missing. does any have or know where I could get drawing of these parts. I have contacted Stuart Turner who no longer have any of the old drawings or parts. Below is a top view of the valve chest. Any assistance would be appreciated.
  • jatolton
    Sep 6, 2018

    Hello everyone... my name is Jason and I am from Northern Ontario. I recently purchased some steam engines from an estate sale and there is one that is rather interesting. It looks like a Stuart S50 model like right down to the nuts and bolt pattern on the valve cover.... although the crank web on mine is bell shaped where on the early Stuart S50 it is round. The people at Stuart in the UK think it is a 40's ish model based on the photos. I questioned mine because it does not have the Stuart nameplate on the top of the base... where it is located on engine. They sent me a picture of an old model without the Stuart sign on the top of the base but at the bottom instead. The people in the UK say that picture has the Stuart sign on it is photo shopped and there is really not one on it at all. On the pictures of my engine I have put a gold ring on where the Stuart sign is normally. I have never seen a knock-off anywhere online. Opinions are certainly appreciated. Stuart thinks I have the real deal.... and possibly a gem. Any thoughts on the engine? condition, authenticity, value? Thanks so much, Sincerely, Jason.