1941 City of Los Angeles

[R.K. Maroon]

Of course the key is to support the worm shaft in between axles.

I suspect the worm and a wormgear want to push apart from each other and in the middle gear they succeed

I think Bob and Allan are on to something here. I was thinking maybe the middle worm was wobbling or vibrating or something but I never thought about the fact that the worm and wormgear push apart from each other -- I should have though, as it is on page one of the Gear 101 textbook. Once the lightbulb came on it made me think of yet another Adams drive I have for a C-truck locomotive:


https://dl.dropbox.com/scl/fi/qy9myplrrexlrjf9rocz0/A-S-Drive-02.JPG?rlkey=ryl28hmwn4oto1b4pwm56gja5

This is one truck from a two-truck set I found on the sales tables at O Scale West. They are brand new, which makes me want to believe they are a newer rather than older, though that of course is not guaranteed. I have seen a lot of Adams drives and this is the only one I have seen like this. Note, per Bob's idea, that a support has been added between the worms on the worm shaft. Note also that the case has been designed for this -- it wasn't an add-on by a modeler. I will ponder what it would take to add a similar support to my E6 cases. Could be fun.

Note in passing the larger worm gear on the new gearcase -- twenty teeth instead of the fourteen on the E6 units. Twenty teeth is the minimum size found in the Boston gear catalog for this pitch.
Jim

Edited to repair photo link

[ScaleCraft]

I guess the two or three I have seen have been the shaft supported units. Been a while.
But, if the contention is the worm shaft is wobbling or vibrating..enough to throw the shaft out of alignment and cause gears to unmesh..well, I'd want to know about what is happening to the metallurgy in the shaft. The working of the shaft in that case should be weakening it.

Having some experience with setscrew and balance, the new one you show has either no setscrews, allen head setscrews, or maybe roll pins. The balance issues on a 14T axle gear final for speed on the wormshaft, with those huge screwheads mostly on one side, might also be an issue.
I still think a small amount of play in the axle holes with the weight of these things is okay. I also think you'd be far better off making new axles of a diameter to size to a clean hole, coring out axle wormgears to match, but, hey, I've only been helping design and build drives for 20 years.
http://www.nwsl.com/Gear_Request_FORM.html

[webenda]

And the theory of dissimilar metal bearings is that things imbed in the softer material and wear at the harder material - I have no reference for that, so opinion

Unless an oil film can be maintaned to separate the two materials.

Babbitt linings provide an excellent wetting surface that promotes smooth oil flow throughout the bearing minimizing vibration. Smooth laminar flow of the oil film and reduced wear are insured by the unique ability of babbitt metals to embed debris particles in their surface, thereby protecting the shaft and providing longer life.
Reference: http://www.wheelerfluidfilmbearings.com ... t-bearings

[ScaleCraft]

All I know is the geartrain designers always told me worm harder than worm gear. Not necessarily dissimilar, but usually that's what it entails.
I know one place they used brass worm and brass worm gear...but hardened the worm, worked good.
The old doorstop phenolic or fibre worm gears held lubricant like nothing else. Probably why they are still going 70 years later (turner....errr...opinion).
Most long lasting and quiet transmission gears on old cars I have ever had were a pair of overdrive three speeds I picked up stored in a bus in a junk yard.
No oil, no side covers.....knew what they were....junk yard did not...twenty bucks for the pair.
Every gear was rusted. Took the boxes apart, glass beaded gears (did not mix between boxes), cleaned out any residue.
The light pitting seemed to actually hold 90w on the faces. The first one lasted about 8-10 times longer than non-pitted gears did.

Anhydrous Graphite. Had model railroad units with noticeable gear wear and noise. Applied that stuff, no more wear (and it's been 35-40 years) and far quieter.
Raoul (NWSL) used to argue with me about that. Claimed it couldn't work. Yet it did. And does.

[R.K. Maroon]

I appreciate everybody's input on those gears. I am getting ready to start a round of business travel so not much will get done on the COLA E6s for a while. In the meantime, I thought I would revisit the other two E6s that I posted. Here are the side views of the first:


https://dl.dropbox.com/scl/fi/nr59r5i4q9ry1guefew60/Adams-and-Son-E6A-1_03.JPG?rlkey=vlf2wtcvqngwu3c9146zp0355


https://dl.dropbox.com/scl/fi/ldfn5oajk8cbnuqkagh0s/Adams-and-Son-E6A-1_04.JPG?rlkey=xg77pgncxu7kaxcm6iuohxge1

It took me a while for the recognition to set in, but there are two things about these sides that are not correct. First, the pattern for the window and vent openings is for an E7. Second, the sides are on backwards. That is, the right side is on the left and left side is on the right. The sides are screwed on so I could reverse them, but that won't correct the pattern.

Here is the E6:


https://dl.dropbox.com/scl/fi/h0uipr5mupxw6bjmxxcho/SRR-E6A.jpg?rlkey=blpmgq8fpbnjp92dxngp8sfzp

And the E7:


https://dl.dropbox.com/scl/fi/cypzna5ppgv15sjqlxoy9/SRR-E7A.jpg?rlkey=pqpexyl0ja05vtswapjjabjxg

If you look at these long enough, you will see that the E7 side is longer than the E6 side by about the width of the cab door. So even though the window and vent pattern is cut for an E7, the sides are too short to be used for one. *sigh* -- you always get more (er...less) than you bargained for with these things.

More later. Off to the airport.
Jim

Edited to repair photo links

[Rufus T. Firefly]

Fascinating...........

*sigh* -- you always get more (er...less) than you bargained for with this things.

Just remember, even if it's free, you can always buy it cheaper somewhere else.

More later. Off to the airport.
Jim

Safe travels!

[aww]

Jim

Concerning the sides on these E6's, the A & B you got from me, I made new sides from thicker brass sheet. I hand cut the windows to match the E6 drawing in the Kalmbach Diesel book. The window pattern on those was completely wrong as I got them.

Allan

[sarge]

Jim:

If you are keeping that E6 for use rather than a donor (I forgot what your intent with the silver one was), I'd go ahead and flip them around and change the grabs for the rear of the unit back up after you do so.

Then, I'd suggest some serious digging around before I'd sweat that vertical vent. The real ones aren't as consistent as you might assume (For example, when I did research on E7s for Sunset I came up with three distinct side variations just for NYC units IIRC). I wouldn't be surprised if a late E6 might have had that vent and carried over to the E7. I also wouldn't be surprised if it appeared during the life of some E6 or another, cut in by the owner railroad (especially if it was Rock Island-Grin!)

I don't know about that particular vent on E6's, but early carbody EMDs were notorious non-conformists to drawings. There might be salvation yet!

Part of the fun!

[aww]

These sides are not easy to replace, the B has an aluminum roof so it can't even be soldered, and the A is bear because the bronze roof takes massive amounts of heat and the sheet sides take very little. It's easy to over heat the sides. also I suggest building a wooden jig to clamp everthing in place, straight and true before soldering starting.

Allan

[bob turner]

I am with Allan - a nice piece of 032 brass, cut the way you want it, will save hours of work and anguish. I have done it both ways, and never quite get it right when plugging and adjusting windows.

I am not an E-6 guy, but I can tell you those sides are also incorrect for the E-7, which is where my interest starts. With care, one can screw and solder new sides on with a simple pencil torch, playing heat on the casting near where solder is to flow. Never aim heat at sheet metal when soldering heavy castings.

[bob turner]

This is Jim's E-6 with windows and vents in reasonably proper size and position.

[bob turner]

This is my first attempt at sides - new sheet metal, and .010 rivet strips soldered on:

[bob turner]

This is morerecent - I tried to salvage the original Adams sides, plating and cutting windows, etc. it was a lot of work, and did not turn out as well as I had hoped:

[bob turner]

We ( Jim and I) are going to try heavy paper, done in an old fashioned typewriter, for rivet strips next time. Te obvious first attempt is an aluminum "B". So far, we have not taken the time to locate such an antique typewriter.

You have no idea how long it takes to make and solder brass rivet strips.

[R.K. Maroon]

Several posts up Sarge suggested that perhaps there might be a prototype E6 with the offending E7 vent, and I should not give up on those sides just yet. As Bob's photo of the same loco with new sides shows, it's too late -- I already gave up on them. The problem wasn't just the one E7-style vertical vent at the front, it's that all the windows and vents are in the wrong location. You can see this by looking at the side near the back end. It's like they took an E7 side, which is longer than an E6, and cut off the last couple of scale feet. As a result, if you put these sides on an E6 all the windows and vents are shoved to the rear of the locomotive a few feet. More to the point, Sarge, I don't think it would have been easy for a road the add the vertical vent to an E6. The vent fits on an E7 because without the shovel-nose the E7 cab is further forward and provides more space on the sides.

I knew Bob had cut sides previously so I called him to get pointers. Bob graciously offered to cut new sides if I would provide him a true 1:48 line drawing of an E6 side (for me) and an E7 side (for him). I scanned the Kalmbach drawings that Allan referred into my computer and scaled them up, printed them. I took several tries until the scaling was correct and I had to print to two pages and then tape together, but it worked. I still want to try cutting sides myself someday, but I have to say that Bob's turned out great. Here is the other side:


https://dl.dropbox.com/scl/fi/34b9zgn0wlrzyoln1gfb3/Adams-E6A-Turner-Sides-02.JPG?rlkey=2kxgujziy5kb6f7to88jiocnm


https://dl.dropbox.com/scl/fi/h9062ixq1794w5vnf20in/Adams-E6A-Turner-Sides-03.JPG?rlkey=85i9q47au3bszqqd6lh0vsjh2

The baton strips are an experiment that Bob did (on just this side only). I believe they are paper soaked in cyanoacrylate glue. They look better than I would have thought. From that came the idea of using a typewriter-on-paper to add rivet strips.

Muggy in Melbourne tonight. I'm told there a launch at the cape tomorrow.
Jim

Edited to repair photo links