The obvious can be elusive. My B’mann 3-truck would not handle the 5’ diameter curves. For those frustrated as I was, a close look showed the axles between the trucks were dropping out (pulled better word) of the drive sockets.
Obvious: Run the loco the other direction and the curves will force the drives INTO the sockets. Viola! True.
For those reading and have already used this remedy, what do you find to be the smallest curves possible with the 3-truck?
Wendell
I can run my Shay in either direction on my indoor layout with 6’ dia curves. (R2).
I’ve never tried anything smaller than that.
But I’m thinking there would be a limit as to how far you can push the drive rods into the housings.
OK - I am dimensionally challenged, so I might have this all wrong, but isn’t the drive rod pushed furthest into the coupling when going straight? Seems to me (without looking at the loco) that it extends when turning either direction. One direction may be a bit less than the other - which is probably why Wendell can get it to go around a circle one way, but not the other.
I have this problem occasionally with my live steam Shay. It’s not much fun to try and get the coupling together while the boiler is hot :o It usually only happens if I split a switch with the rear truck, but it happens often enough.
As we have fourteen and thirteen and a half foot radius curves, we don’t seem to be bothered too much by disintegrating Shays of any kind.
Mind you, that’s ALL we have…just curves.
tac
Jon-
I’m adding some data. When the loco was making a turn to the left (the drive system is on the right side of the loco), the harpness of the curve causes the drive rods to pull out of the sleeves. Reversing the locomotive keeps them in. I know, in a way this is nuts.
As far as TAC’s all-curve layout, keep in mind that only the U.S. has the slogan “Circle the Wagons!!”
Wendell
hmmmm… I have absolutetly no problems running my 3 truck Shay on the minimum R1 LGB curves
http://timothydehan.com/redmondcreekrr/videos/3TruckShayFeature_0001.wmv
I - like timmyd have no problem going either direction on a R1 LGB curve.
The track I run the Shay on has 5 ft curves and 1-4 ft curve. I have had not 1 problem with the shaft pulling out of the sleeve.
David
You are right here are 2 pic of 3 truck shay drive line.
Jon Radder said:
OK - I am dimensionally challenged, so I might have this all wrong, but isn’t the drive rod pushed furthest into the coupling when going straight? Seems to me (without looking at the loco) that it extends when turning either direction. One direction may be a bit less than the other - which is probably why Wendell can get it to go around a circle one way, but not the other. I have this problem occasionally with my live steam Shay. It’s not much fun to try and get the coupling together while the boiler is hot :o It usually only happens if I split a switch with the rear truck, but it happens often enough.
(http://freightsheds.largescalecentral.com/users/paps101line/_forumfiles/shay11.jpg)
(http://freightsheds.largescalecentral.com/users/paps101line/_forumfiles/shay12.jpg)
I have no trouble with 5’ and 4’ curves both ways right and left. My 4’ curve is a reverse 90 deg. curve. David
Western Maryland No 6 has a similar problem with the curve in the wye going to Bald Knob…it has to go round the wye and back the rest of the way…
Drive shafts are on right side… not centered… so left turn shoves them in, right turn pulls them out…
Greg
If you have one, take a look, I think you might have that backwards. Mine compresses the shaft length turning right, and streches it out on a turn to the left.
Do I have a strange machine??
John;
That is the way my shay works . In on right out on left ,but That is a Bachmann 3 trucker,
so the center truck does both, the front of the center truck is just the opposite.
Are you as confused as I am?
Remember the center truck is shafted at both ends so it works different than the 2 end trucks.
That’s my Shay in the pic.
I have had no problems on curves even 4 foot curves.
Now if you split a switch that don’t count, anything can happen there.