Best Of The Overland/Wiseman brass Western Maryland Shay thread

[u18b]

Getting Started

I need to disassemble the chassis of the broken Shay.  The frame was a loss, but from this old Shay I still needed:
the trucks,
some of the crankshaft parts,
the motor mount
the motor
the worm and bearings.

The first step was to wash all parts in lacquer thinner to get the clear and/or brass paint coat off.  If you don’t, then when you start heating things up to remove (or add later), the area will turn black as the paint cooks and burns.  Like I discovered here….



I used a resistance soldering station to get the parts off.  You have to be patient and not turn it up too high- or it may melt a part (don’t ask me how I know…. That poor EP-2)

The hard part was getting the motor mount/worm mount base off.  The resistance soldering station was helpful to heat the piece up and get it off.  This is a classic situation where it might have been almost impossible to get that part off otherwise.

I had a spare crankshaft drive gear and worm is replaceable (for now, but the little crankshaft drive gear is not replaceable so far as I know- so the project would have been dead if I had not had one. 

Using the main gear, I was able to determine that I needed a 3/64” brass rod for the crankshaft.

The original crankshaft was a complex assembly of many pieces- in the zig-zaggy shape of a real crankshaft.  The bonus is that it is really cool looking and you can have piston rods that actually move up and down.

Here’s a video from the sound install.  It’s a little hard to see, but you can see the piston rods moving up and down:

My Shay with sound has an original crankshaft.  The down side is that the real crankshaft assembly is VERY fragile.  Consequently, I know that the crankshaft in my Shay with sound will probably one day fail.

Here is an original crankshaft.





When Wiseman rebuilt these, he did away with the zig-zaggy crankshaft look and just used a straight shaft through all the parts.  This was stronger and held everything true in a perfectly straight line.  Gone were the moving piston rods- but they were hard to see anyway without getting really close- so not that great a loss.

I thus decided to go with a straight shaft for the greater longevity of the model.

However, I did encounter a problem.  Through the initial steps of experimentation, I was surprised to discover that the parts took differing shafts.   The main drive gear was 3/64”, but the u joints and counterweights took a smaller shaft.   I therefore drilled everything out in order to use one solid 3/64” shaft.

Here is the new bare frame.

   

 


I cut a 3/64” drive shaft with a lot of extra to work with.  I’ll trim it later.  This is just a plain 3/64” brass rod from K&S brand.

 

I also happened to have a new main drive gear.  I simply could not re-use the one from the broken Shay.
(here’s how bad the rusty steel parts were when I removed the parts)



I happened to have some extra counterweights and I wanted to do all I could to use them as-is.

In almost all other Shays I’ve seen (which is about 5), most had the counterweights trimmed off.   Like in this Shay.

 

I assume this is for better clearance.  But I wanted the look of full counterweights.  You may not be able to tell any difference while the Shay is running, but the effect is noticeable in still shots.

Here is a broken shaft with trimmed counterweight (left) and the full piece I want to use (right).

 

[u18b]

Crankshaft

I laid out my parts for the new crankshaft.  I had to drill out the holes on all the parts except for the main gear.

NOTE: I discovered later that there should be no counterweight on the middle crankshaft part near the gear.



The V-shaped piece is three pieces and requires a bit of explanation.
On the prototype, there are two eccentric bearings down on the crankshaft which raise and lower a lifter (like a valve rod) which go up to the piston head.  Here are the lifters.




But those N scale bearings are rather thick (and they are not eccentric).  We don’t have enough room for squeeze in three sets of two (so six all total).

Consequently, I’m going to use  two shafts riding on one eccentric bearing. 

OMI designed one lifter rod to ride in one bearing (though I have seen a Shay with two rods in one bearing but the bearing must have been modified to make that work because normally two are a tight fit).  I have seen a first gen Shay which had the lifters actually wiggling the valve rockers on the cylinders.  The effect was interesting, but very subtle- so I don’t worry about it.

I gently jammed two lifters into a bearing which made them tight.  I used a rocker to space the rods in the proper V shape.

Now I did have a problem.  I needed three of these eccentric bearings- but only had two in my parts bag.  I had one more from the old damaged Shay, but it was clogged with solder from a poor prior repair attempt by a previous owner.

Should I fabricate one from scratch out of washers?  It would be possible- but a time-consuming challenge.   I could make one out of three washers which would have to be drastically thinned and cut down to size.

For future reference, I would take three 00-90 washers.  The first one would be the center.  I would keep it fat and reduce it’s diameter until a lifter could be placed on it.  I would then take two more washers and treat them the same.   I would drill out the hole until the small washer would fit inside.  I would then thin the washer greatly with sandpaper.  The final (and tricky) step would be to try to solder it together (probably with the lifters in place so that the thin washers don’t solder together).

So this is what I’ve inherited on this broken Shay.




I really hated to throw this one away, but it could not be used without cleaning the solder out of it.
I was wishing I had an X-acto razor saw.   They do make them, but I did not have one.  So I made one.  I got my motor tool out and cut some slots in a old #11 blade.



It worked perfectly to clean the old solder out.  It took a bit of time, but it worked.    I was so glad to be able to save this tiny part.  It was much less effort than trying to fabricate a new one from scratch.




I also used a small round file to open up the hole so that it would easily slide onto the 3/64” shaft with no hindrance.


I installed the main drive gear onto the crankshaft.  It was a good tight fit.  I had to gently drive it on- which is good.  We want it tight.



Because the counterweight will be right up against the gear and because there will be a worm obviously touching the gear, I shaved/rounded the counterweight edges to give more clearance for the worm.  I didn’t want the counterweight rubbing against or being obstructed by the worm.  If it did, the bad result would be excess noise, increased friction and possibly a bind.

NOTE: I discovered later that there should be no counterweight on the middle crankshaft part near the gear.  I corrected this later.

You can see the angles and curves here.  It looks a bit unnatural up close in this macro photo but you can’t notice it with your eyes- especially while the loco is running.

[u18b]

More Crankshaft

I came across a Shay article in Trains Magazine from August of 1967.  It had a helpful diagram of Shay part terminology.  There were a few parts that I’m dealing with that I’m still not certain of the name.  But I’ll adjust where I can.



I needed a spacer between the gear and the eccentric blades (or what I’ve been calling the valve lifter rods) so the worm would not hit and bind with the eccentric bearing for the blades.

A 00-90 washer was close, but I needed to reduce the diameter.  I didn’t want the worm to rub it.

So I jammed the washer onto a small round file and then spun and dragged the washer over another file to cut it down.  Always spinning and dragging at the same time to keep the roundness.



Here is before and after.  The goal was to make the washer smaller than the depth of the gear teeth.




I sanded the washer smooth and installed the spacer/washer and the eccentric bearing with blades.





I installed the other two counterweights onto the crankshaft and test fit the assembly in the frame.  The counterweights were not overly tight so I could move them and position them.

I saw there might be some clearance issues with the driveshaft housing, so I VERY carefully used a motor tool with a disc and opened them up ever so slightly.  For example, in this shot, you can see that the one on the far left curves in toward the counterweight.  I’ll want to trim that back a tiny bit for sure.




Then I saw I might need some kind of bearing on the outside edges of the whole assembly.  So I installed Atlas thrust washers on the end.  Since they are not metal, I’m not sure how long they will last.  These may need to be replaced one day with tiny thin metal washers.

Anyone have a source for tiny thin metal washers like that?

Here is an Atlas thrust washer.



Everything just fit.  I then temporarily inserted the lower worm to check all the clearances.



I then temporarily installed the piston head/cylinder gear so I could turn the worm with my finger. 




I spun the gear by hand to feel any rough or catching spots.  All felt good.  All clearances were good.   I removed the gear and worm when finished.  I also removed the crankshaft assembly.

At this point, I’m feeling more hopeful that this repair might work.
But we have a long way to go.

[Kentuckian]

Ron, this is amazing work. NWSL makes some very thin bronze washers that may be what you are looking for.

[u18b]

Thanks Kentuckian.
I know that I’ve had the privilege of working on a loco that had already be reworked by Max @mmagliaro   
He used very small washers to shim a shell.

[randgust]

Holy...c$%%##.   Ron, this is just extraordinary.

I'm still studying this to see what you've done here.   Frankly, straight-lining the crank is a great idea.  I wish I'd done that looking back.

I sort of did my crank that way.   I built the entire assembly straight line, with the throws, and after it all fit in the bearings and spun freely, carefully cut out the straight portion of the shaft between the throws and then mounted in the piston rods.   It worked.   So did the universals I fabricated.  This predated the Atlas shay by several years, using front-truck drive off of a Kato 11-105 chassis and a Faulhaber motor, so there wasn't much in the way of another approach.   Ultimately the spinning crank idea failed, but at least the crank design worked.  But I'll also admit that was one of the all-time toughest solder jobs I've ever done and I'm not sure I could ever do it again.



Where I got defeated was a crown gear on the face of the wheel with a spur gear.   That's really hard.   Even Atlas struggled with that one, it's a weak spot in the design.   And this one was still a bit of a kludge, and I've repowered it with a gearhead.  It's OK, but the best part was that it led to my complete stubborness on 'working jackshaft or bust' on my Climax B, which actually was successful.

OK, so I'm seeing one thing that concerns me on yours.   That worm/spur gear combination, even after cleaning, still looks really rough -like it will ultimately wear itself out on metal-to-metal contact.   It 'might' polish itself out, or it might wear out....but in this age of some really nice and really tiny brass/nylon worms and spur gears (Rohukan Z comes to mind) I'm wondering if that was a considered alternatives.

[u18b]

Randy.  Thanks.
I can’t take credit for the straight crankshaft idea.  Keith Wiseman is the guy that did it on one of my Shays.
But it does solve a lot of problems.

As for the gears....
I assume you are talking about that little gear on the driveshaft and the worm that sits perpendicular. 
Yes.  They are a little rough, but they are both made of steel. So I’m expecting they will polish each other without the excessive wear you might get with brass.

[u18b]

Strengthening

I’ll return to the crankshaft later, but first I decided to work on a couple of other things.

I thought it best at this time to do some solder reinforcing.  In my experience, the solder in brass models is soft to begin with.  Then, over time,  the lead in the solder often oxidizes and becomes “fuzzy” or powdery.  The joint is now even weaker and can pop loose when handling- as happened in two old Shays I’ve seen.  Remember, these solder joints are over 30 years old at this point.

Adding solder now will make these joints stronger and more reliable- especially with the potential rough handling ahead during this rebuilding process. 

The first step is to always clean old solder and corrosion from the joint I’m working on.  The new solder should be applied to fresh clean brass.  I often  use an X-acto #11 to scrape and expose fresh brass- obviously from hidden surfaces.  If I’m working on a place that is visible, then I work very carefully.

As I described earlier in this thread on another Shay, I added solder to the base of the cylinders.  It is natural to pick up a Shay by these cylinders so they must be strong.  Since this is a visible detail, I had to be very careful in my scraping work in this area.



Also from past experience, the motor well area needs strengthening. 
In particular, the rear frame piece can pop loose (sort of like the rear bumper- the part that holds the tender drawbar.

Also, the thin plate under the cab will almost certainly come loose one day because a screw goes through this plate to hold the shell on.  This plate must be able to take some good pressure since things rarely fit perfectly.  This plate is also actually the floor of the cab.




On the underside of the frame, the little supports for the ash pans were strengthened.  They were already completely broken loose on the non-driven side.



The front pilot takes a lot of wear and tear so I resoldered those joints.  Since most of these joints are completely hidden from view, I did not worry about making them perfectly beautiful for viewing from below.  Remember that the Shay I’m rebuilding already had this very joint pop loose on the old frame.



Also, because I had problems on one of my other Shays, I added solder support to the fireboxes.    The solder is at the joint of the thin firebox wall and the ash pan casting.  Since this joint can’t be seen, I didn’t worry too much about how it would look.  I shot for “nice” but not perfection.



And lastly, the main crankshaft bearings (brass with a square slot) at the bottom of the cylinder assembly needed strengthening.

In this shot, I’ve added solder to the main bearing itself, but also added solder to the joint with the main support posts that stick down from the motor assembly.   In my past experience, this joint will certainly pop loose and needs reinforcement.  When that joint pops loose, the entire cylinder assembly can move a bit back and forth and will effect the worm to gear interface.   This joint MUST hold in order to maintain a good working mesh that is comfortably snug without a bind.

[mmagliaro]

Ron,
Lovely project!  It will be fun no matter what happens, but I do hope you succeed.

About the thin metal shim washers you need, I can see the photo of the Atlas washer you used (and it's probably nylon or PTFE, so it may well just hold up forever).  Can you give me any specs on the washer?  (bore, thickness, outside diameter).
As you might guess, I have a pretty extensive stash of things like that which have been scavanged from all over.  I'll try to help out.
Shoot me an email or PM with the dimensions.

[u18b]

You are probably right.  They feel like they are pretty tough.  Maybe they will do fine.
When I get this running, then comes hours and hours of tinkering and perfecting (based on past experience).
So when the time comes to disassemble, I may have an idea of the wear.

I’ll shoot you a pm.

[u18b]

I was thinking, I should be more specific with my concern.

If you look at this photo of a counterweight, you can see a rim at the shaft hole.  That rim is what will be riding on the washer.


So my concern was that if the washer was not the perfect size, there is not much room for error with that thin rim.
The shaft is 3/64" K&S rod.  So a perfect washer should have a hole that slides right on that shaft.

I'll have to get back with you on measurements of the Atlas thrust washer.

I'm actually further along in construction, but it takes time to process all the information, do the write up, and then the posting.

[u18b]

Motor Area Prep

I now turn my attention to the motor/worm plate.   I was able to get this off the old frame since I didn’t have a spare.  It was soldered onto the old frame.  Here is the underside with the worm and bearings installed.



When I placed it on the new frame, I was rather surprised that everything did not line up properly.  As you can see in this photo, the assembly is rotated clockwise slightly.  Compare the edge of the plate with the frame of the loco on the side facing you.  For example, at the motor mount end, it is close to the edge, but is farther away at the bearing end.



 So I used the motor tool to open up the four holes in the main frame that receive the bearing screws.  This allowed me to rotate the base counterclockwise a bit.

The fifth hole is threaded and is for the upper worm gear.  I’m not messing with that hole.



There are different ways to do the motor mount/worm area.

My first Wiseman Shay does not have this plate at all (the motor is mounted with silicone caulking).  The holes in the frame base are tapped, and the bearings and worm gear are screwed directly onto that main base.

Here is the Wiseman Shay with no motor mount.






And here is the Shay with sound.   The plate is soldered on and all holes tapped all the way through.




I’m doing it differently here.  I’m going to tap all the screw  holes for the motor mount plate.   Then, the holes in the main frame base for the bearings will now be just pass-thru holes.

My main goal is to make the motor mount removable (thus I’m not soldering it onto the new frame).

In the main frame base, only the screw for the worm gear will be threaded.  That’s because the bearings do not need a lot of pressure from their screws.  The thin motor mount is sufficient to hold them  But the worm gear needs to have some pressure so it will not come unscrewed when the gear spins.


Next time I hope to move back to the crankshaft.

[mmagliaro]

I was thinking, I should be more specific with my concern.

If you look at this photo of a counterweight, you can see a rim at the shaft hole.  That rim is what will be riding on the washer.


So my concern was that if the washer was not the perfect size, there is not much room for error with that thin rim.
The shaft is 3/64" K&S rod.  So a perfect washer should have a hole that slides right on that shaft.

I'll have to get back with you on measurements of the Atlas thrust washer.

I'm actually further along in construction, but it takes time to process all the information, do the write up, and then the posting.

There are M1.2 .008" thick "precision" stainless steel washers (on eBay).  I've bought the M1.5 from the same source and they are very very close tolerance - barely fit on a 1.5mm shaft.  They are not your typical M1.2 washer which has bit of slop and an ID of 1.3mm.
OD on the M1.2 is 2.1mm, so it will be    .047" ID, .082" OD.     And with 3/64 = .0468", this washer would be a very close fit.

I'll see if I have any of these, so you don't have to buy 100 of them!

[u18b]

More Crankshaft

I now return to the crankshaft assembly.  Time to install the eccentric blades with their rockers (I call them rockers because that’s what they do, rock back and forth, and because I have not found a diagram with this part clearly labeled).

First, as a reference, I came across some helpful information.
If you want to build a gigantic working live steam WM Shay (for big bucks) there are companies that will help you with parts.

For instance, this guy will sell you highly detailed plans of everything.
http://www.plan-ahead-designs.com/wm6.html

If you click on “set 1” plans, you get a sample of the cylinder area drawings.
http://www.plan-ahead-designs.com/planset1.html

And one of his illustrations is this VERY helpful drawing of the eccentric bearing, blades and rocker. 

http://www.plan-ahead-designs.com/Images/planset1/planset1_clip_image004.jpg

In that drawing, the blades are purple, and the rocker is silver.


Now back to the model….
Here is a rocker casting by Overland. 



I must confess, this is partially a mystery to me exactly what Overland was trying to do (of course, Overland is the importer.   The manufacturer was M. S. Models of Korea). 

When I had a 1st generation Shay to examine, I should have paid closer attention to the area of the eccentric blades, rockers and cylinders.

The rocker casting has three pins (assuming none have broken off!  The brass is a bit brittle).  The two outer pins obviously go to the the eccentric blades which have matching holes for the pins.  No problem there.



It’s the long center pin that is a bit of a mystery.  What is it for? 

The cylinder casting has a HUGE hole.  Does this center rocker pin go into that huge hole?  If so, this is a complete miss-match….. tiny pin and HUGE hole.



I went back and studied a photo I had taken of that 1 gen Shay.  This is as Overland originally designed it.



Here is what I see.   I added pointers on the photo below- so refer to that photo for the color key.

You can see the huge hole in the cylinder frame- green.

The eccentric blades are loosely mounted on the outer pins of the rocker – purple.

Notice the eccentric blade mounting pins are pointed TOWARD the cylinder- so that means the long pin has simply been cut off (once again, I’m not sure what that long pin is for.  Maybe it is like a casting sprue and provides something to hold on to while constructing the model).

Also, note those eccentric blade pins are UNDER the edge of the cylinder frame bracket.

You can also see a small copper wire going through the rocker- blue.
We can assume that this wire goes into the huge hole.


But look closely.  The retaining wire is not going through the center of the rocker.  It is simply going through the big opening on the back side of the rocker casting.  Thus the rocker is not really centered- as it should be.

All of these parts must have been a nightmare to assemble.
In fact, notice that the center rocker assembly to the left looks like it is coming apart (red arrow).



Because this may have been really messy, my Wiseman Shay was assemble a bit differently.

The eccentric blades were soldered onto the pins (not loose like above) and the rocker itself was simply soldered to that big hole- as shown here.

 
 

This is obviously all more secure.
But there is a problem as can be seen in this photo.  Once this is all soldered in place, the crankshaft is LOCKED in and there is no way to get it out for repairs in the future- or even for painting.

So I’m going to try to  redesign this.

[peteski]

While I have not been commenting, I am closely following this thread in awe!

The construction of that engine is simlar to any 4-stroke internal combustion engine used in automobiles.  The rickers and "eccentric blades" are part of the valve gear.

The eccentric on the crankshaft would be equivalent to lobes on a camshaft, the blades would be like pushrods, and the rockers would be similar to rockers in automobile engines.  What is amazing is that all this detail was all modeled, and operational, on an N scale model!