Best Of The Overland/Wiseman brass Western Maryland Shay thread

[u18b]

When replacing that damaged pyramid gear, I discovered they are brass and can be damaged.

Resistance soldering with fine tweezers can get it off.  I remove the u-joint and now I can slide the damaged pyramid gear off.





But I discovered that – even though I did not have the level cranked up high-  the heat was too high anyway and it damaged the gear.  It spread the teeth out and crushed the gear a bit.



Good thing I learned this on a damaged gear instead of a good gear.   When I installed the good gear, I heated the shaft instead- using very low heat.  Notice that you need to install the gear while the shaft is in the truck on order to get it at the right position.



Once installed, the journal cover can be replaced as well as the U-joint.

[u18b]

With all of the handling of the mechanism- especially without the shell-  the cylinder assembly broke off AGAIN.   

I was determined to make this stronger so it would not happen again.  Through trial and error, I have determined the only best way to install this assembly is by installing the mounting plate onto the cylinders FIRST.   Make it good and strong.   Then install the whole assembly onto the Shay mechanism.

First, since the cylinder assembly was broken loose again, I soaked it in lacquer thinner even more with periodic scrubbing.  I then used an optivisor and a pointed #11 Xacto knife and got every possible paint particle out of it.  This made it MUCH more free turning.

I then cleaned up the whole mounting plate.  No corrosion.    I did the same with the loco frame.





Next, I used an Xacto to thoroughly scrape all solder down to bare brass on the 8 mounting posts on the cylinder assembly frame.   Those are the square pads on either side of the crank shaft.  We are looking at the back side.  I also scraped any corrosion on the back side of those posts.



I also scraped all of the paint and corrosion out of the hook in the front posts (yellow).   The blue points to a cleanly scraped back post.  I then fluxed and tinned all of the posts as shown in pink and yellow.  Blue still to go.  Of course, I want to be careful.  I don’t want any flux or solder to flow onto the crankshaft.



Since the cylinder solder joints can break, I went ahead and added extra solder to the back of the cylinder mounts- blue.     THIS is why you should mount the plate onto the cylinders first.  You could never got to those two middle joints if this was mounted to the loco frame already.

I then soldered on the bottom mounting plate- but did it differently than before (I really don’t want this coming loose again).    I inserted the plate into the grooves in the front.   Then tack soldered it.   I then used resistance soldering to weld the plate onto all 8 posts.    Then, I went back and added MORE solder on two areas.

First, I carefully added a solder bridge from the tips with the grooves to the mounting plate.  As shown here:



This is a fuzzy pic, but you can see here.  I was careful to not get solder on the crankshaft parts.




I also added solder to the back side at the joints to the post so that the solder pooled a tent slightly- pink.  Resistance soldering again to heat each joint up to really melt the solder.    I used high heat for a shorter time- and then blow to cool it off.  We don’t want other parts falling off from the whole assembly getting too hot.



Here is a good view of the extra solder.    I’m hoping this will do the trick and prevent this plate from breaking free in the future.   

By the way, one of the delicate parts we do not want to overheat is very close- it’s the eccentric bearing on which the lifting rods ride.   That actually three soldered pieces- two washers soldered onto a small central barrel.



This joint needs to be re-heated.  You can see a line of shadow – blue.   That means I have a cold joint on the bottom side.  When heated properly, the solder curves as in the photo above.

[u18b]

I then add a good deal of tinning solder to the mounting plate.  This is the part that will mount to the frame.  All solder- no corrosion!  I want a better joint this time.



Time to solder the assembly onto the loco frame.  I found you need three (or four) hands.  Since I only have two, I used two aids.  First, you need to install the shell onto the frame.  This helps get the whole cylinder assembly placed properly.  Without the slot created by the shell, you are guessing and will have to re-do it (ask me how I know).  Second, I use gravity.  I tack the solder joint, then go back with the resistance soldering tweezers and melt all along the mounting frame (a little bit at a time).



Before I installed the power truck, I tested the freedom of movement in the front truck and the crankshaft.  As you can see in the video, this is now VERY free rolling.  (remember, this drive train was locked up when I got it).

All back together.  I got the cylinder assembly too close to the cab by about one half a millimeter- but since the whole process was so difficult (and I had already done it multiple times), I thought it was close enough.  Getting it placed perfectly is very hard.

[peteski]

As usual, the quality of your work, and documentation (inicluding photography) is outstanding!

I seem to recall that I have heard that when brass models are assembled, they use solders with different melting temperatures.  That way when some already soldered items have to have additional items soldered later, those get soldered using solder with lower melting temperature (so the soldering process does not affect the earlier joints).  I have used that technique on some of my brass projects.

I have sliver bearing solder which has the highest melting temperature, then I use the 63/37 electronic solder for medium temperature, then Tix solder for low temperature soldering.

[garethashenden]

This thread makes me both want to buy one of these to work on and run as far away as possible. Great work as usual!

[u18b]

Thanks guys.   I really love these locos.

And I knew  this current version 1 would be a challenge.   Since all my other craftsman experience is with version 2, I'm having to do a lot of exploration and experimentation.

But I love the challenge.

[u18b]

Truck Primer

I covered some truck info a long time ago:
Here:  https://www.therailwire.net/forum/index.php?topic=48999.msg652007#msg652007
and here: https://www.therailwire.net/forum/index.php?topic=48999.msg652242#msg652242

But recent questions reminded me that my info could be a bit more complete.

So I’m going to disassemble and then tune this truck.  What you are about to read took a couple of hours (counting photographs).  So yes, this is tedious and requires persistence.  Now, this is not a waste of time since when I eventually paint this loco, I’ll have to disassemble all of the trucks to get the wheels out.  Thus they will all need to be tuned again.



This is a spare tender truck.  The bottom side has a cross brace.  The version 1 power truck has no cross brace, but most other trucks (version 1 and 2) have it.  Remove the tiny screws and the cross brace.



On the top side, if I’ve never disassembled the truck before, then I remove the single screw.   It might take some work to chip the solder away if solder has been applied. 
Removing the single screw lets the non-geared sideframe be removed.  Watch out for the tiny washer.



Missing from this photo is the tiny washer and the wheels.



That tiny washer is so little and so hard to work with, that I just soldered it in place.  It sandwiches UNDER the bolster and on top of the sideframe piece.



It’s good to check the supports.   The lower support is bent.    I will straighten it.

If the truck is functional, then be cautious about changing the upper support because this will change everything.   (When I did this once, the functional truck was no longer functional because it changed the geometry of everything.  I had to bend it back.)



Here is a wheelset The crown gear is on one side and is all solid with the axle.  The insulated wheel is the non-geared side.






To get more at the question that Max asked, here is the wheel partially disassembled.  The tip (red) inserts into the bearing on the sideframe.

Therefore, the first lip (green) is the part that rides up against the bearing surface when everything is pretty snug.
The next portion is where the insulated wheel slides on (yellow).

So if we had a gap that needed a shim, then the washer must slide over the tip (red) and ride at the green spot- which means the hole must not pass to the yellow.

By the way, as this loco is over 30 yrs old, the plastic insulator in the wheel can degrade a bit and become loose.  This is not unusual as I have seen it in other old locos.  I may need to fabricate a new insert one day which is tighter.  For now, a little superglue on the back side (if needed) can help.



I have encountered quality control issues with the wheels.   They are not all identical (disappointing).  In particular, the crown gear wheel is not pressed onto the axle exactly the same way  (As if they were done by a different workers or in different runs).

You can see this in two ways.  Here the tip protrudes past the crown gear on one, but is slightly recessed in another.  That’s a HUGE difference.  This difference effects the mesh with the pyramid gear.  The mesh may be loose if the wheel is press on too far.  If not far enough, then the whole wheelset itself may ride too hard on the pyramid gear (instead of equally on the bearing and the gear).



You can also see it on the axle in the photo below.  You can tell that the wheel on the right is has been slid further onto the axle than on the left.

I need to state a great warning here.  Many pages ago in this thread, I used a puller to move the crown gear wheel- and succeeded.  However, that was a fluke and the wheel was not excessively tight.

The next time I tried this I ruined the wheelset.  The solid wheel was so tight on the axle that it took a LOT of force to move it.  The chrome plated brass axle tip compressed under pressure and became fatter so that it would no longer fit into the bearing on the truck.  Therefore, I would suggest you NOT use a puller on the crown gear wheel.  (some day, I may explore better ways of moving that wheel)

A better solution would be to possibly disassemble ALL trucks and pair up the wheelsets  that match the best.
In other words, the axles with short tips paired in one truck and the axles with long tips in another truck.



Well, that tip fits into pads on the back of the sideframes.  This is obviously the geared sideframe.  That pad is the bearing itself.

I want you to notice that these bearings are right behind the lineshaft- which you can see through the hole.  Well…. since the lineshaft requires oil, then oil will possibly get onto the axle tips- which is the main conduit of electricity.  Conductivity may thus be reduced- especially over time.   That’s why a wiper on the back of the solid crown geared wheels improves the electrical flow in this loco.  It gives the electricity an alternate path.




Here is the bearing surface for the insulated side.



Notice in this photo that the gap can be very small.  The sideframe and the wheel on this side are electrically charged opposite.  The insulated wheel must not touch or a short will happen.



So if you do need to fill a gap... can you use a plastic washer?  I have tried- but do not have a good size.   This is a thrust washer from an Atlas loco.  You can see the hole is too large for the .88 mm tip.    The hole is probably 1.5 mm.

So yes, this could fill a gap, but also might not work well.  If anyone knows of a source of thin plastic washers that have about a 1 mm hole, please post.



A 00-90 washer worked better (though still slightly large).  Are there 00-90 plastic washers?  A brass washer could work but ONLY if it is of smaller diameter than the insulator.  A metal washer cannot touch the wheel itself.



While the size of the hole is OK, the problem is... this brass washer is probably too fat for most trucks.  If this will work anywhere, it will be in the power truck where the gap is largest.



If the gap is ve5y small, I can reduce that gap by bending the non-geared sideframe inward.  It has two thinner areas in the casting- as shown.



The top side



And the bottom side. 

You cannot bend much or you can place a bind on the tip inserting into the bearing because the bearing hole will be pointing slightly in the wrong direction.

On THIS truck, the sideframe was too tight.  I experimented with bending the sideframe outward to create a small gap and take away a bind.

[u18b]

OK.  I reassemble the truck.  The first thing to check is:  does it ride evenly on the rails?   This one did not.  The far right wheel in this photo did not touch the rail.  The truck would thus rock back and forth.



If that is the case, then the truck will need to be twisted to get the orientation correct.  If I need to twist, I test it on the rails again until I get it right.



The truck should be functional at this point.  I then put some pressure of the bolster and run the truck back and forth to seat the gears.



If the truck is functional, I then try the push test.  Where I am in this whole process is determined by if the truck rolls freely.

   

If the truck is functional and there are no problems (like chipped gears!!!), then much of the rest of the tuning is getting the gap just right (and thus also the mesh of the crown gear). 

The first place to look is the sideframe pivot.  The insulated side had only one screw and it can pivot a fair amount.

In these photos, I’m squeezing one side and then the other to show how the gap changes.






But the crown geared side can pivot also, even though it is less since it is held by two screws.   The bolster on the geared side should be as perpendicular to the sideframe as possible.  When it looks good, tighten down the two screws.

From here it is experiment and test, repeat.   



The best test is when the truck can rolls freely and wonderfully on a inclined track by gravity only.  Rolling by gravity at a sharp angle is good….



But rolling at a lower angle is great- and the desired goal!




The experimenting might include bending the sideframe slightly in or out.  It might be shimming the gap.  Always checking the pivot on the insulated side.

Here is a short video of the testing I do so you can visually see the truck getting tuned better and better.

When I feel I’ve reached success, then I solder the sideframe on the  insulated side adding a little solder to the joint and to the screw.

If I ever need to disassemble this truck again (like for painting) then I remove the two screws and remove the geared side.   It obviously will also be better if I place the same wheels in the same holes.

When all trucks are tuned well, the Shay will run more smoothly and quietly.

[nkalanaga]

For very small plastic washers, how about 0.005 inch styrene, and drill the hole? 

[mmagliaro]

Very thin tiny washers with 1mm bore, you say?

https://www.ebay.com/itm/284849375621

Bores from M0.8 to M1.0
The M1.0 smallest are 3mm OD with .15mm thickness (.006")
If a .96mm bore (instead of exactly 1mm) will work, you can get an OD of 2.2mm

They are black nylon with graphite.  I have some.  Very nicely made, and very slippery.

Here's another seller who has them in M1.1, with a small OD of 2.2mm (also thickness=0.15mm)
https://www.ebay.com/itm/284853977450

[u18b]

Max, sorry so much time has passed.
Thank you for the suggestions.

I've placed an order and will report back if this ends up being a good solution.

[u18b]

Back to the Shay.

My washers came in from overseas (which Max suggested I buy).  However, I’ll get to them later.  First, I was thinking I REALLY need to be able to move the wheel with the crown gear so that the position of the tip in the bearing can be adjusted.

On this version 1 Shay, the two wheelsets in the main drive truck are different.  The wheels with the crown gear is pressed onto its axle differently.  This makes the truck unsymmetrical and causes an uneven mesh with the tiny pyramid gear.  As shown in these photos where you can see the axle tip sticking up past the crown gear differently.



You can also see this as a gap or no gap on the back of the wheel.



In this early photo as I received this Shay, you can see one wheel is very tight to the sideframe (red).  That crown gear is riding tight and hard on the pyramid gear.  But the other wheel has a huge gap (black).  This unequal spacing allowed the crown gear on the main drive axle to not mesh properly with the pyamid gear (causing wratcheting past each other, cogging and locking up the driveline, and the eventual failure in the pyramid gear where a chunk fell out of one of the teeth).



You will remember that a long time ago in this thread, I said I used a puller to adjust a wheel with a crown gear.   A long time later (and thus more recently) I reported that I encountered a wheel that was REALLY stuck and I damaged the wheelset with the puller.  Well, I actually damaged the tip of the axle so that it would no longer slide into the bearing hole in the sideframe.  Because the axle is simply chrome plated brass, and since so much force was being applied by the puller… that little tip compressed and spread out.    My conclusion was that I did not want to risk doing this again.

But this week, I decided to try again- but smarter.

I decided to try to spread the force around so that less of it was applied to the tip of the axle.
I’ve got three points where I can push (next photo).  In the past, all I was pushing against was the tip (red).  Now I want to add yellow and black points.



So here is what I came up with- why not create a new tool with telescoping (nesting) K&S brass tubing.  I did some quick tests and it looked possible.

Here is what I used.  A brass rod, a small brass tube for the tip.  The next size larger brass tube to slide over the first.  You also see here a tiny diamond burr for reaming out the small brass tube a bit.



I first took a piece of small tubing and reamed out the hole until it would slide over the axle tip.  This would push on the yellow point above.



I then fit the next size large tubing.  This would push on the black point.



I lastly inserted the solid rod into the small tubing.  This will press onto the tip (red).



I fluxed and then soldered all of this on the outside edge while pushing everything tight on the axle.  It would be counter productive if something slipped out of place.  I did not go overboard with too much flux and/or too much solder and/or too much heat for too long.  I did not want to solder this tool to the axle!



I then cut off the excess wire and filed it all smooth.
This now slides onto the end of the axle and I can use it to press or hammer.



To be extra safe, I took one of my spare wheels which also had a gap too wide on the back side of the wheel... meaning, the wheel was not properly pressed onto the axle.  I’ll see if this works before trying on the wheels of this Shay.



With the insulated wheel removed, I then set the crown gear onto some wood and slid the new tool onto the axle.   Next, a few taps with the hobby hammer on my tool and it drives the axle into the wheel nice and tight- as you can see here.  No more gap.  The force is spread between those three points shown above so the axle tip was not damaged.



I now consider this tool a must-have item if you own a Shay.   This worked.

[u18b]

I want to thank Max for his washer suggestion.  I bought several different ones and the third one was the best.

Here is the label. 



They are a Delryn-like material.  They have a 1mm hole, 3mm diameter and 0.2mm thick.  I bought these from Asia off ebay as Max suggested.

Pack of 100.



These are very even and smooth. 



 I bought some others that are smaller, but they are not flat.  They are cupped from the process of punching out the center hole.    They will have a use in my modeling, but more as spacers for non-moving parts.
But as you can see, these are wonderfully smooth.


And they are the absolute perfect size for an OMI Shay.
I used the method described above to move the crown gear on both axles on the main drive truck so that they were identical (and not uneven as before).  This still left gaps on the back insulated side.  So I added one washer to one wheel and two on the other.

Here is a stock wheel.  This is the insulated side that needs shimming.

 

And here is the shimmed wheel.



After re-assembly, they worked great.

[u18b]

I then turned my attention back to the motor.  I needed an end bearing to help reduce any slight wobble in the shaft (pink arrow).

I first had to fill part of the hole (blue arrow) at the back of the frame so a bearing could sit there.



I found some brass sheet that was the same size as the sheet under the gearing.  I made sure there was a gap at the back edge so that the shell could lay on the chassis frame.  I soldered it in place (red).



As for a bearing, the old Atlas RS-3 bearing came to the rescue again.  That’s the bearing with the rectangular housing and a phosphor bronze ball in the middle.  My worm shaft was 1.5 mm and that’s the same size of the Atlas bearing.  The ball allows the bearing to pivot to find the perfect spot- making 100% precise placement less important.



I set the bearing in place and saw that I needed to raise the motor a bit to get good alignment.  So I soldered some brass washers onto the frame.   



With the motor at the correct height, I experimented with temporarily  supergluing the bearing.  Once convinced this would work, I mounted it.

I used a pick-up strip from an old Kato or Atlas loco.  I think this came from an old SD40.  There is a groove in the plastic housing and I needed to trim the strip so that it would lay inside the groove.

I then made bends and lastly drilled holes in the strip for M1.4 mm screws.  With the motor in place and the bearing in it’s spot, I marked a hole with a marked.   Took everything off and drilled and tapped a hole for a M1.4 screw.   I put everything back, mounted that screw, and marked the second hole.  Removed everything and drilled and tapped the next hole.  After cleaning everything up and reassembling I now had everything in place.





I wiggled the worm as a check.   The shaft of a motor has a small amount of lateral play (it will go in and out).  I always wiggle the worm to see how free that wiggle is.  If there is no wiggle, then there is a bind (maybe the bearing is too close, or maybe the motor is not at the correct height).  The goal is to have that wiggle as free as possible.

[peteski]

Excellent, as usual modification.  One thing that worries me is that it's a brass shaft turning in a brass bearing.  We know that it's a no-no for two brass gears meshing, but does the same apply to shafts and bearings?