Looking for some help with live steam

[Trainman3450]

Not sure where else to post this, so here goes

I've recently been having a quite troubling issue with an aging Accucraft open cab live steam shay of mine. It works just fine in forward gear, but throw it into reverse and it jams up right away. It'll rotate freely without steam, but when I open the throttle, the cylinders appear to start fighting each other, pushing each other in the opposite direction.

I've checked the valve timing, and that wasn't the problem. The placement of the reversing bar wasn't the problem either, and neither was the piston valve reverser. However the eccentric rods are rather worn and may be one cause of the problem. In any case, I'm not sure what the problem is and if I can fix it at all. Any words of advice would be appreciated greatly.

Regards, Alex

To the mods: If this is in the wrong place, put it wherever you see fit will you? I'm still fuzzy on where to post things here.

 

[Philjoe5]

It'll rotate freely without steam, but when I open the throttle, the cylinders appear to start fighting each other

You say that the timing is OK in reverse, but the eccentric rods are worn. Can you be more specific, or show a photo?

Cheers,
Phil

 

[Trainman3450]

You say that the timing is OK in reverse, but the eccentric rods are worn. Can you be more specific, or show a photo?

Cheers,
Phil

Phil, unfortunately I'm not sure how to elaborate on the issue further. The engine runs perfectly in forwards, and the timing is as good as I can get it (Re-timed it a week before this issue arose). Yet like I said, the engine seems to freeze when in reverse for some strange reason! Well, "freeze" as in the engine stalls and the pistons seem to want to go in opposite directions, one in forwards and the other going backwards. I can post a video of the issue tomorrow or later tonight if you'd like.

 

[robcas631]

Train, It might be that you have to tinker with the steam chest?

 

[Trainman3450]

That may be so, but I fail to see how the piston valves may be the cause of this. They're working fine as far as I can tell.

 

[Philjoe5]

Can you elaborate on the wear on the eccentric rods? I assume you're referring to wear in the bearings on either end.

Cheers,
Phil

 

[Trainman3450]

The eccentric rods are fairly worn down where they come in contact with the eccentrics. There's quite a bit of room between the rids and eccentrics, enough to move it around more than I'd like.

 

[Gedeon Spilett]

May be I'm wrong, but on this loco the backward run is obtained through a exchange of the steam distribution between admission and exhaust in the piston valve.
Either the reversing valve or the reversing lever is not fully working, and stay blocked midway while reversing, not too hard to fix I would bet.
a picture of this nice loco is anyway welcome...

 

[Trainman3450]

Hmm... I think you may have solved my problem. How would one fix this issue though? I can't seem to find spares for reversing valves on the Accucraft website, or anywhere for that matter!

 

[Gedeon Spilett]

Hi,
Without knowing how the reverse command links are arranged, it is difficult to fix it!
I'm pretty sure that the reversing valve is not guilty, most probably some sliping in the links or a bent link hinders the valve to be fully moved.
post a picture showing this part of the machine
Cheers