Crank settings for 3 cylinder locomotives

[Pete Harvey]

I would not of posted it if there was a chance of a virus Bill.

 

Pete

[ozzyo]

Yep you are right, but your drawing shows an uncorrected 124deg between the wheel cranks.

Bill, 

 

if the drawing shows an incorrect angle of 124 deg. between cranks how could it work? 124 X 3 = 372 deg. Now that will never work. Please have another look at the drawing.

 

R/H crank at the horizontal back position. then it shows the middle crank at 112 deg. after that it shows the LH crank at 123 deg. then back to the RH crank at 124 deg.  OK that adds up to 359 deg. Not 360 deg. But if your going to read a drawing please read it all not just one dimension, as I had put all of the angles on the drawing.

 

At the end of the day all most of us were trying to find out was do three cylinder engines have RH lead the same as most two cylinder engines.

 

OzzyO. 

 

Edit,  my approx angles are out, The 124 deg, should read 120 deg, The 112 deg. should read 112 deg. 52' and the 123 deg should read 127 deg. 8'.

Sorry for any confusion.

[billbedford]

The correct angles from the A1 motion drawing are RH crank to middle crank: 113 deg, middle crank to LH crank: 127 deg, LH crank to RH crank 120 deg. The 123 and 124 degree values on your drawing are in error.

[ozzyo]

Bill,

 

I did say that all my angles were "APPROX". Due to me drawing the centre lines on the drawings. If I have get them within a degree or two that should be good enough.

 

OzzyO.

[billbedford]

This is how modeller's myths start. If the basic principles of the layout were understood, i.e. that all the cranks were set at 120 deg to each other but the centre crank was shifted to compensate for the higher centre cylinder, then it would be obvious that the angle between the LH and RH cranks was always going to be 120 deg.

[PhilH]

Thanks ozz for your positive contributions to this thread.

 

There is a hell of a lot which could be added but would bore the pants of most sane people or those not involved with 12in/ft locomotives, and which is certainly not needed within the context of the OP.. 

[Horsetan]

There now follows learned argument between Bill and Ozzy as to who's got the better drawings.....

Quod erat demonstrandum.

[ozzyo]

Quod erat demonstrandum.

 Er what's that in English, please.

[ozzyo]

Hello all,

 

I have edited most of my post to show the correct angles, not MY approx angles. Which were out by a few degrees.

 

OzzyO.   

[Poor Old Bruce]

Quod erat demonstrandum.

 

 

Er what's that in English, please.

Something like "Thus it is demonstrated/shown." We had to put "QED" at the end of lab reports etc at technical college.

 

Nil illegitimi carborundum Ozzy (that's don't let the bas****s grind you down).

[unclebobkt]

-- I was at RUGBY during the 1948 Locomotive Exchange Trials and made a point of seeing as many of the locos. that passed through as possible; no need for Platform-passes or any such nonsense in those days - one could stand in the four foot to take a photo. of a starting loco., if one wished

with nothing more than a toot from the whistle; I remember thinking how melodious the LNER's sounded!

- I can well remember the LNER's representative - 'Seagull.', I believe - trying to depart with an UP train. Eventually the driver backed-down a certain distance and after an amount of wheel-spin got under way very cautiously. I enquired as to why backing-down was needed and was assured that with some 3cyl. engines it was necessary to get the motion into its optimum position. True or false?

- Of course that was in the good olde days before the Eisenbahnpolizeibeamteren, 'elf. 'n' safety and suchlike.

 

-- A pity that the SR's 'Belgian Marine.' did not have its Stanier tender painted in malachite green with the three sunshine stripes: :-(

 

 

-- :-)

[PhilH]

Most definitely true - for instance it can be a right royal pain in the a*se trying to get 34007 Wadebridge away on the MHR. 

 

Thank goodness for steam operated reversers.....

[MikeOxon]

What is an '.exe' file? Why should I not expect it to be a virus?

An 'exe' file is a program file and, in principle could be anything.  If you are sure of the source then ok but you are right not to trust anything on the web without some such assurance.

 

i have only just come to this thread and the 'home' of these valve gear animations seems to have moved. I found all the necessary files at http://www.billp.org/Dockstader/ValveGear.html

 

downloaded some of the files from there and they work fine and give good animations of a huge range of types of gear.

 

Bill Bedford's caution is justified, however, since I also found the files on another 'filesharing' site, where my anti-virus software warned me that they contained malicious 'adware'.  The ones at the link given above were 'clean' when I downloaded them.

[unclebobkt]

  ... .

  ... .

  ... i have only just come to this thread and the 'home' of these valve gear animations seems to have moved.

  ... .

 

  -- Mike.,

 - Thanks for the interesting & useful info. from Mr. Dockstader's web-site.

 - Search engine Google! - 'Steam locomotives' Valve-gears.' has some helpful data and animations, too.

 - Also these two web-sites -

>1.- > http://www.steamlocomotive.com/appliances/valvegear.php <

>2.- > http://www.animatedengines.com/locomotive.html <

  --  :-)

[unclebobkt]

Most definitely true - for instance it can be a right royal pain in the a*se trying to get 34007 Wadebridge away on the MHR. 

 

 -- Not surprised!

 - But are Wadebridge's problems caused by it's being a 3cyl. loco. or being a Pacific type?

[PhilH]

The wheel arrangement has nothing to do with it in this instance - the only problem with a 4-6-2 is their inherent tendency to slip, especially when starting away.

 

The things 'sit back', in the same way as the front end of an accelerating car lifts, thus transferring some weight from the driving wheels to the trailing truck which results in a loss of adhesion