Changing gear ratio of the 28T Shay

[Screwy Nick]

  While I do like my new Shay, I got to thinking:  can I take the trucks off a 2 cylinder Open Cab Shay with a much higher gearing and slide them onto this one??  That should give a longer distance and time run on equal amount of water and fuel.  First look told me they are basically the same trucks.

   I first needed a base to to compare.   I ran the 28T Shay 'as built' (accept for a NiCr screen over the burner) to see the time and distance traveled.   Measured time was 16 minutes at a steady boiler pressure of 50lbs and at a slow walk before the pressure started to drop, indicating the water was below the flue pipe.  Shut off the gas, and the distance was 3.25 laps around the track oval.  With a little coaxing it made it another 1/4 to come to 3.5 laps.  That is the base I am going to work from.

   While swapping the trucks I checked engine revolutions to wheel revolution.   3 cylinder engine 3.5 rev's to 1 wheel rev.    2 cylinder engine 2.5 revs to 1 wheel rev.

    The swap was easy as the trucks are basically the same.  I had to swap the rear truck shaft as it was shorter on the 3 cylinder to make allow room for the additional slug. 

    Fired it up and off it went.  Controlling the speed with the throttle to a slow walk equal to yesterday's run took almost 1/2 turn of the oval.  I found it took much less fuel to maintain 50 lbs pressure and the burner was more silent..  It went a full 4.5 laps around the oval before the pressure started to drop,  off fuel, and it made it the rest of the way with more throttle on it's own to 5.  

     What I liked most was the engine movement was still very visible without the  blurred action with the low gearing.  That is probably desirable to many and that is why it was made that way, but to each his own.  

    I will now install the very low geared trucks on the Open Cab Shay were the trucks came from. I will most likely keep the arrangement as it is now, but the swap is so easy that in the future there's no sweat putting both back to 'stock'.   Thank You.  

[Sean]

Nick

I can't see the pics!

[Screwy Nick]

Sean, if you insist, here they are:  took me a bit as the new Apple Captian down load changed how I access my photo's.  Had to contact Apple and Nikon to get it squared away, so I'm glad you asked.     See the difference in the gearing??    

[Sean]

Nice idea Nick!

The pics really help to see the difference!

Thanks for posting this!

[Screwy Nick]

Sean, you are very welcome.  This one came to me at 0215 one morning and I couldn't go back to sleep till I took some measurements.  It's been rolling around in the grey matter till yesterday.  Glad I did it, but I don't think it will be very popular with the purest's .   Thank you.  

[Jerry B44]

When I made my Shay I got the gears from Chicago Gear, don't recall the ration 3:1 I think.

[Screwy Nick]

If I may add: today I installed the lower geared trucks on the Open Cab 2 cylinder Shay that the higher geared trucks came from. It seemed to like them. It ran for 22 minutes at the same slow walk as the 3 cylinder did yesterday, maintained 45+ lbs pressure and made 4 full laps around the track before showing signs of losing steam pressure, and it holds about 50 mls less water. As soon as it did I shut off the gas as this one has a Radiant Burner and I didn't want to take any chances. In conclusion IMHO the swap benefitted both locomotives and I will most likely leave it as is. BTW. I have a much older 2 cylinder Shay, my very first LS loco, will leave that gearing alone, also made my first radiant burner for that one. I realize I like tinkering as much as running.  

    Jerry, before Sean Asks, PIC's please,  (grin)  

LIFE IS GOOD