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Discussion Starter · #1 ·
Hello all!

TL;DR: The valve chest assembly tries to rotate side to side with each cylinder stroke.

I am new to the live steam community, but have been working around steam locomotives for the better part of five years. I just got an Accucraft Ruby as a Christmas gift and am having several problems with it. The locomotive was purchased as a RTR locomotive, so I was shocked at how poorly the QC was.

To preface, I am familiar with the steam up process. I have the Accucraft steam oil, 3-1 lube oil (used where appropriate), had proper amount of water, and correct fuel.

I will say that out of the box, things looks great. the first think I noted was the wheels were extremely hard to turn. I check multiple time to make sure I didn't miss something to keep them locked during shipping. Once I steamed up th locomotive, I was able to get it running and the wheel spun at warp speed just as most videos I have seen of the locomotive. However, after spending about an hour with the locomotive I could hear that something sounded off, which I assumed was the timing. It wasn't something I expected to get to that day, so I didn't worry much about it.

After the engine had been fired and got warm steam oil into the cylinders, I could move the locomotive with a bit of effort on a level surface. Thats when I noticed the running gear wanting to bind just past FDC on the fireman's side. It wasn't very tight, but tight enough that the wheels would stick for a second, then continue. I figured maybe this was something in the eccentrics to I set up my small air compressor to test the engine on air while I was going to time it.

This is where I noticed that while the engine was running, the entire valve assembly was trying to rotate under the smokebox. I am attaching a google drive link for your viewing pleasure. I have never seen anything like this. I knew some of the ruby's could be finicky out of the box with the possibility of timing being an issue, but this not not something I expected. I already send Accucraft an email along with the video in hopes I can exchange it for another one. My big questions are, has anyone ever seen something like this before? Is there something I could do to fix this? Do you have any tips on running a brand new ruby out of the box? (Things to expect, to look out for?)


Thanks for reading!

Matt
 

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Hi Matt, I am not that familiar with Ruby loco's and it's a bit hard to see clearly but I can hear a definite knock so something is hitting somewhere. As I can see the whole cylinder assembly moving on each stroke my best guess to start is to see if a piston has unscrewed from the cross head a little and hitting the front of cylinder forcing the whole assembly to move. You can see if one piston has unscrewed by looking closely at the amount of thread exposed where the piston rod screws into the cross head. If one side has more thread showing than the other then that's the one, all you need to do is clean up the more exposed thread, apply some threadlock and screw the rod back into the cross head. I use needle nose pliers with some thin leather wrapped around the piston rod to stop any marks and scratching to rotate the piston rod.
I have had this occur on a couple of my loco's now and seems to always be the LH side for some reason.
If it's not this then go back to carefully rotating the mechanism to find the tight spot and not position of piston, rods and eccentrics for any hitting of binding. Oh and retighten ant bolts holding on the cylinders to the frame as they will probably be loose by now.
Hope this helps and if not let us know what you find.
Russell
 

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Discussion Starter · #3 ·
Hi Matt, I am not that familiar with Ruby loco's and it's a bit hard to see clearly but I can hear a definite knock so something is hitting somewhere. As I can see the whole cylinder assembly moving on each stroke my best guess to start is to see if a piston has unscrewed from the cross head a little and hitting the front of cylinder forcing the whole assembly to move. You can see if one piston has unscrewed by looking closely at the amount of thread exposed where the piston rod screws into the cross head. If one side has more thread showing than the other then that's the one, all you need to do is clean up the more exposed thread, apply some threadlock and screw the rod back into the cross head. I use needle nose pliers with some thin leather wrapped around the piston rod to stop any marks and scratching to rotate the piston rod.
I have had this occur on a couple of my loco's now and seems to always be the LH side for some reason.
If it's not this then go back to carefully rotating the mechanism to find the tight spot and not position of piston, rods and eccentrics for any hitting of binding. Oh and retighten ant bolts holding on the cylinders to the frame as they will probably be loose by now.
Hope this helps and if not let us know what you find.
Russell
*
Hi Matt, I am not that familiar with Ruby loco's and it's a bit hard to see clearly but I can hear a definite knock so something is hitting somewhere. As I can see the whole cylinder assembly moving on each stroke my best guess to start is to see if a piston has unscrewed from the cross head a little and hitting the front of cylinder forcing the whole assembly to move. You can see if one piston has unscrewed by looking closely at the amount of thread exposed where the piston rod screws into the cross head. If one side has more thread showing than the other then that's the one, all you need to do is clean up the more exposed thread, apply some threadlock and screw the rod back into the cross head. I use needle nose pliers with some thin leather wrapped around the piston rod to stop any marks and scratching to rotate the piston rod.
I have had this occur on a couple of my loco's now and seems to always be the LH side for some reason.
If it's not this then go back to carefully rotating the mechanism to find the tight spot and not position of piston, rods and eccentrics for any hitting of binding. Oh and retighten ant bolts holding on the cylinders to the frame as they will probably be loose by now.
Hope this helps and if not let us know what you find.

Russell
Interesting... I took off the cylinder heads and they are within their range of travel. One thing I noticed is that the "cranks" look bent too me. Maybe im going crazy... I don't think these are supposed to be this way.
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Hi Matt, now you have checked the piston travel the stiffness it could be the eccentric rods, so rotate the wheels slowly and stop every 10 degrees or so checking if the eccentric collars move easily each time. If no binding of the eccentric collars then do the same checking the eccentric rods for any stiffness. Ideally the round running section of the eccentric rods should be parallel to the collars they run on and should run smoothly. Yours are on an angle which normally would cause some initial binding and as wear progress's it will free up and of course more power will overcome the friction. You could put a small dogleg bend in each rod to get the running surfaces parallel but this may alter the timing a bit as well, as you are then effectively shortening the rods a little.
If you find no binding or tight spots then look at re-timing the loco but if still binding investigate where it my occur, another place is the front wheel crank pin can catch the back of the cross head screw.
The video shows it running at a slow pace that seems OK so timing is probably good was this on a low pressure?
Is there someone close by who knows these small engines you can take it to as it's hard to diagnose from half way around the world but I hope I have been of some help and someone else may chime in with ideas for you to try.
Russell
 

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Discussion Starter · #5 ·
I appreciate your “around the world” help Russell. It seems to me that since those “cranks” are flared out like that, that is where I’m getting the binding. Since there are other issues, I will be contacting accucraft tomorrow and exchange it. Like I said, it was a ready-to-run purchase and has no more than two hours just running on blocks since opening it Christmas Day. Now I know what to look for when I replacement comes.

Thank you!

Matt
 

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When I assembled mine, timing is very important. If the piston valve closes the port too soon, a new cylinder set seals so nicely that if feels like it's a mechanical binding, but it is really just a matter of timing in my situation. Tuning it on air one side at a time will make a huge difference.

While contacting Accucraft for material defects is good, if the only issue is tuning the valve gear, I would suggest trying yourself or someone with experience locally. As the timing is something of a maintenance item and will need adjustment as the initial break-in progresses. And again as parts start to wear out.

If you're someone who enjoys "fiddling" and working on things, there are a great many modifications that can be done, use Google search or the search on here.

If your enjoyment comes from being able to steam up and run without worrying about "fiddling" there may be someone in a local club or a dealer nearby that could help, or there may be other members of this site that may be able to work on it if you mail it to them.

Good luck, I know it will bring you lots of enjoyment once it's tuned.
 

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Discussion Starter · #7 ·
When I assembled mine, timing is very important. If the piston valve closes the port too soon, a new cylinder set seals so nicely that if feels like it's a mechanical binding, but it is really just a matter of timing in my situation. Tuning it on air one side at a time will make a huge difference.

While contacting Accucraft for material defects is good, if the only issue is tuning the valve gear, I would suggest trying yourself or someone with experience locally. As the timing is something of a maintenance item and will need adjustment as the initial break-in progresses. And again as parts start to wear out.

If you're someone who enjoys "fiddling" and working on things, there are a great many modifications that can be done, use Google search or the search on here.

If your enjoyment comes from being able to steam up and run without worrying about "fiddling" there may be someone in a local club or a dealer nearby that could help, or there may be other members of this site that may be able to work on it if you mail it to them.

Good luck, I know it will bring you lots of enjoyment once it's tuned.
Thank you for the reply. I did work on the timing for a few hours last night in hopes I could find some sort of correction. As I said in an earlier post, the eccentric cranks are definitely bent. This was based of multiple schematics I found online as well as Dave Hottmann's timing method. What more concerning is that the entire valve chest sways with each stroke (see the video link in the original post). This is not something I want to mess with.

While I love tinkering with things, especially steam locomotives, the quality and condition of this locomotive is not what I expected from a RTR loco. So to be safe, I would rather have Accucraft deal with it while under warranty.

Thanks!
 

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A couple of things
Did you buy this new from Accucraft or a dealer?
The reason I ask is that the fact that it was hard to move at first seems to indicate that it was run and then stored for a long time. The steam oil and water mixture gets gummy after a couple of years
The eccentric rods are bent like you say. Another thing that makes me think it has been handled.
They can be straightened out fairly easily.
I don't remember exactly but I believe the cylinder assembly is screwed on through the stack hole and the screws are probably loose. I think you remove the stack and then the screws can be accessed.
Fooling around with the timing can get you into trouble if you are not used to doing it. If you get stuck, you can get the Ruby kit instructions to get back to square one
 

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Discussion Starter · #9 ·
A couple of things
Did you buy this new from Accucraft or a dealer?
The reason I ask is that the fact that it was hard to move at first seems to indicate that it was run and then stored for a long time. The steam oil and water mixture gets gummy after a couple of years
The eccentric rods are bent like you say. Another thing that makes me think it has been handled.
They can be straightened out fairly easily.
I don't remember exactly but I believe the cylinder assembly is screwed on through the stack hole and the screws are probably loose. I think you remove the stack and then the screws can be accessed.
Fooling around with the timing can get you into trouble if you are not used to doing it. If you get stuck, you can get the Ruby kit instructions to get back to square one
Hi Bill,

Yes, the locomotive was purchased directly from Accucraft at the beginning of this month. I saw on the boiler certification that it was built in 2020. Im not sure if that just refers to the boiler, or the locomotive since Channing at Accucraft made it sound like the locomotives were assembled at the Accucraft store. This was a RTR kit, and from what others have said, they are test fired and ran after they are built, so if it had been sitting for a while, this makes sense as there was still residual steam oil in the lubricator.

I did mention the eccentrics to Channing and he assures me they are correct... I would disagree, but maybe the video is a bit hard to see, so I will wait on this. I did not mess with the timing. I understand the concept of it, but am still learning how to do it. I did send the engine back to Accucraft, and Channing said they will go over it, fix what is needed, and adjust the timing.

Thank you!

Matt
 

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My impression was that it looked like there was some screws missing that secure the cylinders, which allows the cylinders to pivot under load. I mentioned it to the designer of the Ruby and he had the same idea. Check all around the cylinder assembly and see if you find any screws that are loose, or holes that should have screws in them.
 

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Well the eccentric straps are bent. They need to be straight or you will have undue wear on both the eccentrics and the valve gear parts. As to the cylinders moving there are 4 screws that are at the base of the cylinders unfortunately its a total tear down to get to them at the cylinders, the boiler needs to come off. Its not a hard job but for a brand new model it should have not been assembled that way..

Get it replaced or repaired by Accucraft, make sure you scribe or mark the straps so you know they are replaced nit just bent again. As the brass eccentrics with 2 hours run already have uneven wear to them from the canted stainless straps.

Accucraft models are produced and built/packed in China, Kits and RTR.
 

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Discussion Starter · #13 ·
Hey all!

So after a few weeks of waiting, I did receive a new Ruby and runs very well. There are notable differences between the eccentrics on this and the last. First and foremost, I can push the engine freely (I was not able to do that before) and have no binding. The engine ran on rollers for about two hours and performed very well.

I appreciate all of your help in this matter. It’s great to have an operable engine now. Just need to wait for the snow to melt and get it on rails.

Cheers!

Matt
 
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