3 truck shay

[vinny37]

I recently purchased a new in the box 3 truck shay.
I noticed that the water bunker power truck would not
rotate. I contacted Bachmann service and was told it was not
supposed to rotate. Watching the video on how to lube the loco
it shows the truck rotating.  Can someone please help me
get it to rotate. Thanks

[JerryB]

The prototype Shay's 3rd truck does not rotate independent of the tender water bunker. It is firmly attached to the water tank. The water tank, including the  truck assembly is free to 'rotate,' as well as moving up and down and from side to side with respect to the mainframe assembly due to the drawbar and the driveline slip joint and universal joints.

Same is true of the model. It properly duplicates the prototype.

I really don't understand why you want the truck to rotate, but I guess you could take the truck off the fuel bunker and devise some kind of pin arrangement. I am pretty certain that doing that would make the model unable to properly track, thus rendering the model (at least the third truck) non operational.

[Kevin Strong]

Are you sure you weren't seeing the 1st or 2nd truck on the Shay in the video? The 3rd truck is designed to be rigid to the bunker.

Later,

K

[Chuck N]

I agree with  Jerry and Kevin.  The water bunker is at the end and is not rigidly attached to anything but it's self. 

The length of the water bunker and its wheel base is very short.  There is no need for it to rotate.  It is about the same length of the 2-axle mine cars.  These are the wheels on those are fixed to the body.  Those cars are designed to go around very tight curves 4' or even less.

Chuck

[vinny37]

I went back and looked at the video again.  When he is putting the water bunker on
it's side, the power truck is rotated.  Maybe it is that way on the newer Shays.l

[Chuck N]

Are you sure that your video isn't for the two truck Shay?  The instructions are very similar.  The fuel/water bunker on the two axle Shay, looks a lot like a water bunker.  Especially if the coal bunker hasn't been put in.

Chuck

[vinny37]

No.  This is the video for the 3 truck shay. It show the water bunker
detached from the loco.

[JerryB]

I would really like to see that. I am pretty experienced on Shays, both two and three truck, and both prototype and model, and can not imagine how the water bunker could have a swiveling truck under it.

Even more perplexing is why you think it needs to swivel. If the third truck can swivel independent of the truck, it would mean the tender could and will turn sideways as compared to the rails and direction of travel. This would mean the water pipe and coupling would probably be torn off.

Why would you think this is necessary? And more importantly, how do you think that it could possibly work?

How about a link to the video you are referencing? I would sincerely like to see what you are posting about!

Happy RRing,

Jerry

[vinny37]

The video is  the DVD that came with the unit, showing
how to lubricate the loco. Also showing some of the history
of the Shay loco.

[Chuck N]

Looking at the parts diagram of the water bunker,  it looks as if there might be a screw that holds the truck to the frame.  There seems be be a bracket between the power block and the bottom of the bunker.  If you can get into that assembly you might be able to loosen the screw.  Although, for the life of me (and Jerry) I can't figure out why you would want too.  My only guess is that might be needed for 4' diameter curves.

Look at page 8.

http://www.bachmanntrains.com/home-usa/dwg/dwgs/82494.pdf

It looks like it is part #00101.  There appear to be 4 screws that hold it to the bottom of the bunker.  You would need to remove the 4 screws and add a single one in the center.  I accept no responsibility regarding the above suggestion.  

Chuck

It would be  best if someone from Bachmann would clear up this confusion or post a link to the 3-truck shay video.

[vinny37]

When I first tried the Shay on 4' curves it did not seem to work.  Tried it again today
and had no trouble with the 4' curves.  Guess it will be OK Locked.  Sure do wonder
why it showed rotated in the video. 

[Chuck N]

I have heard that you should always have slip joints on the inside of the curve if you are using 4' diameter curves.  If you have them on the outside, they may come apart.  My curves are all 10' d and on them it doesn't matter, but I only have a 2-truck Shay.

It sure would have helped if you had mentioned earlier that you have 4' d curves.

Chuck

PS The Bachmann website (online store) says that this model works best on 8' diameter or greater curves.

[JerryB]

I don't see the information on the website at this time, but I believe Bachmann recommended 7' diameter (3.5' radius) as the minimum to operate the three truck Shay. As Chuck N suggested, the limit is in the slip joints and other 3rd truck driveline components.

While you might force it around a 2' radius, you have a significant possibility of damaging the drive line on such sharp curves. When the driveline binds, the truck will be forced off the track. This can cause serious damage to the truck and driveline components.

Once again, there is no way that having the bunker 'swivel' on the third truck will affect this problem. The bunker is not the limiting factor: The driveline is where the binding occurs.

The OP has reported that his Shay initially would not go around his 2' radius curves, but now does. I would suggest a careful examination of the driveline, as it is possibly damaged by operating on the too small radius curves.

Happy RRing,

Jerry

[Chuck N]

Jerry

Open the 3-truck Shay page.

Click on one of the 3-truck shays and it is at the bottom of the description.  I clicked on the bottom one.

I tried to paste a link to the bage, but it didn't work.

Chuck

[JerryB]

Thanks Chuck N!

I was wrong about the 7' minimum diameter. Bachmann says:

"This model performs best on 8' diameter curves or greater."

I would be very surprised if it would operate on a much smaller radius, otherwise Bachmann would advertise it as such.

I guess my 7' diameter statement was based on my memory of some user reports. Still a long way from 4' diameter, and the factory statement reinforces my belief that you can easily damage the driveline on those tight curves.

And, as I wrote above, having the tank swivel would not affect the minimum operating radius at all.

Happy RRing,

Jerry