The video model is taken from beyerpeacocks order 890. In the main window seen below are controls which immediately affect the computations and influence the valve gear simulation. At the time, i was writing programs to solve the kinematics for a sheep shearing robot, so i. Gears can be animated with various speed to demonstrate working mechanism.
American railroads summit river and pine valley is a first person railroad simulation set in the steam era, at the turn of the 19th century the core game focuses expanding your transportation business. I think my best bet is to figure out the simulator and configure it to the petrolea. Valve gear design simulator software charles dockstader has written a program for ms windows which will take the geometry of your valve gear design pretty much every gear type imaginable and show the physical arrangement of the motion, animate the events, draw an indicator card, etc. This tutorial covers just the wheels, coupling rods, connecting rods, and crossheadpiston. Most locos built since the 1920s use piston valves as per the diagram. Zoom right into the valve gear to see the detail and timing methods used by the gear. Since then i have made continuous additions and improvements to add other types of valve gear and improve functionality and ease of use. Don ashtons steam locomotive valve gear treatise on full and scale valve gears, including simulation and setting of model valve gears, is quite useful. It is an early example of misusing a launchtype link and although centrally suspended appears not to incorporate correction. Allans software is a little trickier to use, especially the stephensons where it asks for certain. The hall simulator automatically sets the valve for equal leads, but with some choice in the case of stephenson s, even if the gear design does not support equal leads.
Valves and valve gear mechanisms william ernst dalby full view 1906. Procedure for setting front dead center and adjusting the valve. Contains 82% of the steam locomotives remaining worldwide. Is there any rules of thumbs as to which angle to use. Steam simulator operating manual disneyland railroad. The stephenson valve gear or stephenson link or shifting link is a simple design of valve gear that was widely used throughout the world for all kinds of steam engines. Not the simplest solution, but the gear had the distinctive feature of the drive rod having a large mass at the valve gear end, and thus a taper in the reverse direction. In the interests of keeping these available to everyone, i have installed the programs and his documentation on my website. It is not necessary to guess the angle of advance as per lbsc to set the valves correctly. By removal of the valve gear from between the wheels, a better opportinity is afforded to introduce frame bracing, thus reducing the possibility of frame. There are other valve gear analysis tools available. Please note that this software is neither supported by charles or myself. If you mean would it allow a small amount of control over steam cut off.
Jul 25, 2005 the valve gear was adjusted electrically, and the vaves could be set in in open posion for coasting with minimum resistance. Joy valve gear is a type of steam locomotive valve gear, designed by david joy 3 march 1825. Allan wallace also has a steam locomotive valve gear simulator and notes on full and scale valve gears. Charles dockstader has created an excellent program that simulates the operation of stephenson valve. Charlie dockstader has produced a comprehensive set of valve gear simulation programs for windows. My usual practice in the simulator is to set the valves for lead equality, which was the valve setters primary operation. Bill hall papers and locomotive simulation software by chris newman jul 18, 2017 the ast trust is grateful to mrs mary hall, the widow of the late bill hall for granting permission to make available for download copies of her husbands steam locomotive simulation software suites perform and perwal. The easiest one to use for stephenson s is bill halls. Locomotive valve gears 2 railway wonders of the world. This video runs in windows media, the more recent versions of which allow the option of. The simulator always start with a cold engine, without a. Here you can see, graphically, the resultant changes in steam flow and therefore engine performance caused by variations in valve gear geometry, angle of advance, and. For those that would like to study how valve the valves of a stanley engine function this program is highly recommended. This is a simulation of the walschaerts valve gear, one of the most widely used designs towards the end of the steam era.
Layout of stephenson gear on a churchward standard 2 cylinder. Charlie has put this program in the public domain but is not to be sold. Steam engine valve gear on the computer downloadable freeware simulations of every kind of valve gear youve ever heard of by charles dockstader ca. The first simulator software i came across was the famous one by charlie dockstader who originally came up with the idea for proving the valve gear on one of his friends locos. Apparatus for drawing valve displacement curves mechanically. The mechanism of the walschaert valve gear is entirely different than the general run of valve gears in that the resultant motion of the valve is due to two independent component motions. It takes time to bring the engine from cold to operating pressure, but the simulator offers several quick options to get the engine ready. To view his description and download the programs, click here. Bill hall papers and locomotive simulation software. The decision to closely follow the pattern set by cock o the north means that the locomotive will have the original semistreamlining. Wallace of adelaide, author of another valve gear simulator, has kindly removed the anchor link constraint, very cleverly maintaining first design principles by using an optional tick box that also includes the eccentric rod and return crank.
Valve gears such as stephenson s for example are variable lead valve gears. Simscale is a 100% cloudbased cae software for valve simulation that lets you test, validate, and optimize your designs through cfd, heat transfer and thermal analysis. Stephenson valve gear on a 280 would look something like this. Deerfield and roundabout railway an educational demonstration steam powered 7 and 12 inch gauge railway operated by the. The red area represents steam admission and the blue, steam exhaust. In 1986 i wrote the first of the msdos versions of the software to simulate baker valve gear. Gear generator is a tool for creating involute spur gears and download them in svg format. Jun 20, 2006 hi, i have just received an ho bachmann spectrum 280 with stephenson valve gear.
This page uses frames, but your browser doesnt support them. Valve gear design simulator software southwest cyberport. Theres a link on don ashtons website to where you can download it from. The poppet valve gear doesnt count because it wasnt used nation wide like the baker, walschaerts, stephenson valve gear. Valve gears such as walschaerts are said to be constant lead valve gears. Perwal incorporates an algorithm that more accurately predicts valve events based on the use of walschaerts valve gear. As far as the eccentrics go, i need to fix their angle onto the crank shaft. You could model the linkage in dockstaders valve gear simulator software to be sure you had it correct before cutting any metal. Charlie has put this program in the public domain but is. Ive been simulating the baker valve gear on a 3d cad software and i believe i got a reasonably grasp of how it works. The amount of lead remains constant over the whole range of cut offs that the gear is designed to provide. The angle of advance determines the amount of lead given to the valve and the simulator allows you to play with the angle until you get the amount of lead required.
This is where certain data computations are displayed in counters or registers. Note that the slotted link is operated by an eccentric adjacent to the central crank. Bill halls programs serve both walschaerts and stephensons gears in. Detailed simulation of throttle, reverser, valve gear, firebox, boiler and steam chest, including the effect of opening and closing the admission and exhaust valves as well as the cylinder drains. Stephenson valve gear model railroader magazine model. Allan wallace which covers walschaerts, stephensons, and baker. Setting eccentrics model engineering clearing house. A software simulation of joy and other common valve gear configurations is available for download from.
The throw of eccentric formula, below, applies only to locomotives using stephenson valve gear. To this end i have the valve etch from bill bedford but as usual their are no instructions. Dockstaders program that demonstrates an outside admission type stephenson valve gear. Stephenson valve gear was an early type of valve gear that allowed the cut off of steam admission to be finely adjusted from the footplate.
Walschaerts valve gear applied to inside admission piston valve. The valve gear was adjusted electrically, and the vaves could be set in in open posion for coasting with minimum resistance. As his simulator permits manual adjustment of the valve on its spindle it. It is named after robert stephenson but was actually invented by his employees.
Fully steerable, kinematically simulated locomotives with working stephenson valve gear, rods, pistons. The valve gear is responsible for timing the cylinders inlet and exhaust. An approximate, but logical, method of designing walschaerts. Okay, which of the 3 or so types of valve gear that were popular in north america were actually the best and most efficient. Lead is a function of the valve gear geometry and not a physical quantity that can be machined, so the valve can only respond to the ability of the gear to produce the necessary lead at each dead centre crank position. The stephenson valve gear or stephenson link or shifting link is a simple design of valve gear that was widely used throughout the world for all kinds of steam. These days if someone asked me to reset their stephenson valve gear for me i would probably first check the valve gear on a computer simulator, play around with it a bit, and the computer will then work out for me the correct angle or amount of advance. As his simulator permits manual adjustment of the valve. The stanley steam engine stephenson valve gear computer simulation program charles dockstader has created an excellent program that simulates the operation of stephenson valve gear action. Through these sine curves one can easily see the amount a valve port is open at any crank position. Mar 18, 20 internal stephenson valve gear on a 7mm scale 0 gauge gwr 460 saint class locomotive, saint david. Probably this was the last large scale application of stephenson gear in american railroading. Animating walschaerts valve gear at the steam4me site. A tutorial on how i animate the driving wheels bogie for steam locomotives in trainz.
Animated mechanical control linkages from the cab controls to stephenson s valve gear, ash pan, injector, crosshead. Stephenson valve gear applied to outside admission unbalanced slide valve. Instructions for download and installation the bcwrr is delighted to host charlies valve gear program on its web site. Valves and valve gear mechanisms william ernest dalby. Boiler and steam engine with stephenson gear duration. In much the same way that tornado was constructed as the 50 th a1 rather than a replica of the original members of the class, if given the goahead no. Box 3111 california valley, ca 934533111 tel 805 475 2519 the programs have been placed in public domain and are freeware. It is unfortunate that the page in my build notes that has lbsc explaining how to set the valve timing is missing or partially removed. Some older american locos used bolton walschaerts or baker gear to update them.
They are not large scale drawings but the layout is all there. Steam to the inside cylinders is controlled by the walschaerts valve gear arranged on the stephenson molyneux system. Linking up the gear allows for more cut off but it also creates more lead, also not a bad thing for a quiet engine but i not sure if youll gain any efficiency by using a stevensons gear over a cam and poppet valve arrangement in a uniflow. Charlies has by far the most numerous of valve gear designs there are 67. Stephenson valve gear computer simulation program charles dockstader has created an excellent program that simulates the operation of stephenson valve gear action. Because stephensons gear can achieve near perfection in enabling a onepiece valve to supply both ends of a doubleacting cylinder equally its design in any one particular case ought to follow a complete and correct procedure, in the knowledge that straying from its basic simplicity will impair its excellence. The stephenson valve gear was developed by william howe and william williams at the stephenson locomotive works in 1841. This is, as it were, the control station of the engine. I think this finding is interesting because i believe that both the stephenson and the walschaerts produce even event at each side. This software is a must for any steam or live steam enthusiast fantastic stuff. It is named after robert stephenson but was invented by his employees. The hall simulator automatically sets the valve for equal leads, but with some choice in the case of stephensons, even if the gear design does not support equal leads. I am afraid that i wll need to become an expert with the software to figure this out.
The walschaert gear also transmits the moving force of the valve in practically a straight line. Apart from the usual couple of hours worth of tweeking to get it to run to my satisfaction, i am sure the valve gear has something missing. Staying competitive requires engineers to constantly innovate and find new ways to improve their designs while reducing the development costs and time to market. Animating steam loco driving wheels bogie trainz content. Steam locomotive valve gear trains magazine trains news. Locomotive valve gears 2 the principles of the joy and walschaerts motions.
Tho drawing of the valve displacement curves of a stephenson link motion. Dec 08, 2010 valve gear design simulator software charles dockstader has written a program for ms windows which will take the geometry of your valve gear design pretty much every gear type imaginable and show the physical arrangement of the motion, animate the events, draw an indicator card, etc. Shorttravel slide valve engines like the ones i believe you are building with properly maintained and calibrated stephenson s valve gear would not be driven any cutoff much lower than 35% because it ends being more inefficient than to drive at a higher cutoff, as the steam doesnt have the time or port area to fill the cylinder up to the. I am in the process of building a brassmaster class 5, what i would like to do is 4767 which has stephenson valve gear. Both diagrams and figures then provide immediate verification of any detailed alterations and confirm expected performance, once the user becomes conversant with the program. Sep 12, 2009 this is another video my brother made. Steam locomotive valve gear trains magazine trains. These are actually of the nominally collett 9300 class, but the layout is fundamentally similar on all the classes with two outside cylinders. In early 1999 i started converting one of the valve gears to the windows format. Layout of stephenson gear on a churchward standard 2 cylinder locomotive click on the sketches to enlarge them. Although stephenson s valve gear consists of two simple eccentrics connected by a curved link its main application between the locomotive s frames precludes visual study in motion. They were unique in that they combined stephenson gear with spool type valves.
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