richhotrain Is there any downside to doing this?
"There are always consequences, Captain". OK, I guess that's not exactly the quote.
I'd say to be sure the drill bit is not too big of a step up from the size of the present hole. I'd use a pin vice and carefully "shave" the metal out being careful that it does not grab. Using a power drill might cause the bit to pass right through the plastic journal cover
You'll notice the stamping is made with a radius so there is a little more bearing surface. I suppose it would be nice to be able to polish the surface a little after you open the hole.
Again, a reamer would be the best route if you can find a 1.55 mm reamer?
I don't think you'll affect the gear "mesh" or backlash at all since most mass produced locos have pretty sloppy gearing anyway.
I suppose you could cut down a tapered, round toothpick so it would fit into the enlarged center hole then use a "grinding compound" of some kind, metal polish or scouring powder. This might help smooth over any possible rough spots?
Should be an interesting project
Good Luck, Ed
Lastspikemike Before you modify the truck "journals" is it possible the rear truck is running out of vertical travel somehow and just lifting the front truck by enough to derail it?
Before you modify the truck "journals" is it possible the rear truck is running out of vertical travel somehow and just lifting the front truck by enough to derail it?
Lastspikemike Does the locomotive derail when reversing but traveling in the same direction over the particular track section?
Does the locomotive derail when reversing but traveling in the same direction over the particular track section?
Lastspikemike If you consist your two PA does this truck still derail when running in either direction of the consist?
If you consist your two PA does this truck still derail when running in either direction of the consist?
Rich
Alton Junction
I have a real question about the design of these Proto PA power trucks.
It looks like the design of these trucks is a combination of older (metal sideframe) and newer (plastic sideframe) Athearn trucks.
There appear to be two support points on each end of each axle, the new style bronze bearing (red circle) and the sideframe (blue circle).
What is the point of having the axles extend into the sideframes? Athearn did away with this when they updated to the bronze axle bushings and plastic sideframes.
Having the truck sideframes put downward pressure on the axles seems like it would also weaken the electrical contact between the bronze bushing and the electrical strip (green circles).
What would happen if all the axle extensions were removed from the wheel sides to make it like a newer Athearn design? Would the replacement Athearn 42 inch wheel/axle/bearing assemblies fit in this model?
-Kevin
Living the dream.
LATEST UPDATE:
Lots going on this morning.
I finally got up the nerve to open up the gear box. Ed, thanks to your excellent tutorial, which I followed to the letter, everthing went along just fine. No broken tabs.
I took a pretty good look at the middle wheelset. I could not see any problems. I decided not to ream the axle point holes, figuring that I can always do that later if necessary. When I re-assembled the gear box, the parchment paper no longer slipped under the middle wheelset. Hmmm.
Before disassembling the gear box, I ran the loco very very slowly over the exit point of the curve. Although it did not derail in several tries, I did notice a slight vertical hiccup.
So, I marked the exact spot where the hiccup occurred. I then moved the loco manually over that spot and noticed that the middle wheelset moved ever so slightly vertically upward at the point where two rails join together. Hmmm.
Then I moved the other PA manually over that spot. Nothing, no hiccup. I got a small metal file and ran it a few times over the edge of the rail joint. Took the problem PA and moved it manually over that spot. Nothing, no hiccup.
Dunno, have I solved the problem? I will run some full passenger trains around the layout several times later today to see what happens.
While I was at it, I glued the brake cylinder back on the truck and glue the two vertical handrails back in place. Looking good.
Yep, those are E8 photos. That front wheelset pivots. There are two gear box covers, one for the front wheelset and the other for the middle and rear wheelsets.
SeeYou190There appear to be two support points on each end of each axle, the new style bronze bearing (red circle) and the sideframe (blue circle). What is the point of having the axles extend into the sideframes?
It would be overconstraint to have two sets of bearings -- to say nothing of preventing the 'knee action' from doing anything -- if the sideframes were rigid like those illustrated for the PA truck in question and the axle ends located by them.
I need to look at all of my 6-axle diesels to see if any pivot. I find this interesting and something that I never noticed or thought about.
SeeYou190 I have a real question about the design of these Proto PA power trucks. It looks like the design of these trucks is a combination of older (metal sideframe) and newer (plastic sideframe) Athearn trucks. There appear to be two support points on each end of each axle, the new style bronze bearing (red circle) and the sideframe (blue circle). What is the point of having the axles extend into the sideframes? Athearn did away with this when they updated to the bronze axle bushings and plastic sideframes. Having the truck sideframes put downward pressure on the axles seems like it would also weaken the electrical contact between the bronze bushing and the electrical strip (green circles). What would happen if all the axle extensions were removed from the wheel sides to make it like a newer Athearn design? Would the replacement Athearn 42 inch wheel/axle/bearing assemblies fit in this model? -Kevin
Kevin, This is the E8 truck, Ed was showing how it is different.
The weight is on the inner bearing like the 4 wheel Athearn design. The one axle pivots. All axles are powered.
The axle extension extends into the journal just for the looks of the moving/floating journal boxes.
The PA truck is completely different and bears the weight of the loco on the axle ends, there is no inner bearing at all.
Ed also posted photos of the PA truck.
Sheldon
ATLANTIC CENTRAL The PA truck is completely different and bears the weight of the loco on the axle ends, there is no inner bearing at all. Ed also posted photos of the PA truck.
So, did the problem disappear by re-assembling the truck?
Simon
snjroy So, did the problem disappear by re-assembling the truck? Simon
I released the sideframes from the gearbox, popped the gear box cover, opened up the sideframes, and took the middle wheelset out to examine it. I could not detect any problems, so I reassembled the truck.
Once reassembled, I could no longer slip parchment paper under the middle wheelset. I put the PA back on the layout and ran it without any derailments.
I canonly guess that by taking the truck apart and putting it back together, I must have repositioned the middle wheelset and solved the problem.
richhotrain ATLANTIC CENTRAL The PA truck is completely different and bears the weight of the loco on the axle ends, there is no inner bearing at all. Ed also posted photos of the PA truck. If you look at that last photo that I posted, that is the disassembled front truck on my problem PA. You can see that the assembly is rigid, no pivot point. Rich
If you look at that last photo that I posted, that is the disassembled front truck on my problem PA. You can see that the assembly is rigid, no pivot point.
Yes, the PA truck is rigid, the EMD E8 truck pivots. Do you have any Proto2000 E units?
ATLANTIC CENTRAL Do you have any Proto2000 E units?
richhotrain ATLANTIC CENTRAL Do you have any Proto2000 E units? No, not Proto 2000. I have three E-units, but they are all Broadway Limited Paragon passenger diesels. Rich
No, not Proto 2000. I have three E-units, but they are all Broadway Limited Paragon passenger diesels.
All of my E units are Proto2000, a B&O set, C&O set, and one ATLANTIC CENTRAL set.
They are very nice, but in my case they are also very quiet.........and they don't have any brains.......
No pictures handy......
richhotrainIt appears that it did.
I'd be happier knowing what might make that center axle hang upward slightly, but still turn, in that odd design of rigid sideframe with some kind of bearings presumably taking the geartrain thrust. In that little detail, I suspect, hinges both the derailment propensity of the truck and perhaps some of the assumptions in what made for 'bulletproof' track alignment that could apparently be fixed with a few gentle file strokes...
Overmod richhotrain It appears that it did. I have always been profoundly nervous about mysterious problems with no apparent cause that spontaneously resolve themselves with removal and reassembly. What happened once might happen again in a case like that. I'd be happier knowing what might make that center axle hang upward slightly, but still turn, in that odd design of rigid sideframe with some kind of bearings presumably taking the geartrain thrust. In that little detail, I suspect, hinges both the derailment propensity of the truck and perhaps some of the assumptions in what made for 'bulletproof' track alignment that could apparently be fixed with a few gentle file strokes...
richhotrain It appears that it did.
I have always been profoundly nervous about mysterious problems with no apparent cause that spontaneously resolve themselves with removal and reassembly. What happened once might happen again in a case like that.
I agree with you, Overmod, that just because the problem went away after disassembly and reassembly of the truck does not instill a great sense of confidence that the problem will not reoccur.
What I feel more comfortable with is the fact that the "few gentle file strokes" really seemed to result in much smoother passage of that front truck over the trouble spot.
The thing that keeps twinging like a tooth pain is that slight elevation. Which went away with R&R and didn't require any reaming to fix.
Tell me again if the locomotive had trouble from day one it was taken out of its box. That would indicate some issue with assembly alignment (as I don't see a manufacturing defect like slight warp in a sideframe or error in registering the metal 'bearing' insert to the plastic face being resolved just by taking the truck apart) and I'd like to figure out what that might have been in case it's a common-mode issue in other examples.
I wonder if reaming the center bearings might actually tend to make the axle kick up and bind a bit under certain conditions if it is driven by a train of gears with relatively sloppy engagement fit and bearing precision. My gut hunch, of sorts, is to ream or relieve just the bottom edge of the bearing, so that the center axle can drop a bit but not rise relative to the 'square' of the outer four wheels.
ATLANTIC CENTRAL richhotrain ATLANTIC CENTRAL I have to say I have never liked cork and can't even think about the idea of putting track on foam. It just does not feel firm enough to me. I sold it for years in the hobby shop, I built display layouts for the store with it. But I have actually never built any part of any of my personal layouts using cork roadbed. As I plan the new layout I am actually considering between Homasote (since a new Homasote roadbed product may appear on the market soon) and possibly making my own wood roadbed. I know cork works well for many people, I just like a more solid feel to benchwork and trackwork. Interesting comments about cork, Sheldon. On my prior layouts, I used Woodland Scenics Foam Track Bed. I always found it to soft. I nail down my track, and the softness of foam winds up deforming the foam when nailed down. On my current layout, I went with cork. Midwest products makes 3' strips and it is firm and supportive for nailed down track. However, for curves, I bought sheets from a commercial source and cut the cork to form the 32" curved roadbed. It seems fine to me, but once ballasted I have noticed that if you remove the ballast to re-lay track as I have done on these two curves, the cork is no longer flat but a bit wavy. Not good. What other alternatives are there for roadbed? Homasote? Wood? Rich Back in the dark ages of this hobby, in the 1950's and 60's, soft woods like basswood or pine were milled into roadbed. Some modelers made their own. The Tru-Scale brand being the biggest commercial line. They made three primary products. Ready Track - it was wood roadbed and ties milled from a single piece of wood. The ties had milled in tieplates (oversized) which helped position the rail, rail was spiked in place with very small spikes. Track was ready go, with the tie area stained brown and the ballast slopes painted gray with some "grit" in the gray paint. Self Gauging Roadbed - simply the product described above in kit form - raw wood milled roadbed with ties, you do the staining, spiking and ballasting. Plain Roadbed - smooth wood roadbed with no ties for use with any brand of flex track, sectional track, or as a base to install your own hand layed ties and rail. A simple Google search for "Tru-Scale Roadbed" will provide some images. Some can always be found on Ebay. They also made a complete line of turnouts, crossovers, crossings, also available "Ready" or in kit form. And the roadbed came in a wide selection of curved radii sizes. In the 70's modelers started making their own roadbed from Homasote - a messy and time consuming job. Then the Homabed product hit the market, similar to cork, two strips already beveled, layed back to back. For curves the sections are kerfed to allow bending. That product changed hands several times as so many products do in this hobby until it got to the last guy, Cascade - then he closed up. Over the years and last two owners the product line expanded to include ramps, different side slope angles, different thicknesses, all in an effort to acheave better realism and improve ease of use. As best we know Cascade closed do to personal family issues, not a lack of business or profit. There is curently an effort underway to get a replacement product on the market. One way or the other I will use wood or Homasote, or some of both. And my track will be glued down to avoid the possiblilty of movement. Yes, I am completely old school on this, the proof is in the pudding. Layouts like the Severna Park Model Railroad Club are still running on track layed on homsote in the 1960's and 70's with minimal repair or maintenance. That layout has only undergone minior changes to the track plan since it was mostly completed in the early 70's. Solid is better, and in my experiance no more noisy than all these "soft" materials. Sheldon
richhotrain ATLANTIC CENTRAL I have to say I have never liked cork and can't even think about the idea of putting track on foam. It just does not feel firm enough to me. I sold it for years in the hobby shop, I built display layouts for the store with it. But I have actually never built any part of any of my personal layouts using cork roadbed. As I plan the new layout I am actually considering between Homasote (since a new Homasote roadbed product may appear on the market soon) and possibly making my own wood roadbed. I know cork works well for many people, I just like a more solid feel to benchwork and trackwork. Interesting comments about cork, Sheldon. On my prior layouts, I used Woodland Scenics Foam Track Bed. I always found it to soft. I nail down my track, and the softness of foam winds up deforming the foam when nailed down. On my current layout, I went with cork. Midwest products makes 3' strips and it is firm and supportive for nailed down track. However, for curves, I bought sheets from a commercial source and cut the cork to form the 32" curved roadbed. It seems fine to me, but once ballasted I have noticed that if you remove the ballast to re-lay track as I have done on these two curves, the cork is no longer flat but a bit wavy. Not good. What other alternatives are there for roadbed? Homasote? Wood? Rich
ATLANTIC CENTRAL I have to say I have never liked cork and can't even think about the idea of putting track on foam. It just does not feel firm enough to me. I sold it for years in the hobby shop, I built display layouts for the store with it. But I have actually never built any part of any of my personal layouts using cork roadbed. As I plan the new layout I am actually considering between Homasote (since a new Homasote roadbed product may appear on the market soon) and possibly making my own wood roadbed. I know cork works well for many people, I just like a more solid feel to benchwork and trackwork.
I have to say I have never liked cork and can't even think about the idea of putting track on foam. It just does not feel firm enough to me.
I sold it for years in the hobby shop, I built display layouts for the store with it. But I have actually never built any part of any of my personal layouts using cork roadbed.
As I plan the new layout I am actually considering between Homasote (since a new Homasote roadbed product may appear on the market soon) and possibly making my own wood roadbed.
I know cork works well for many people, I just like a more solid feel to benchwork and trackwork.
Interesting comments about cork, Sheldon.
On my prior layouts, I used Woodland Scenics Foam Track Bed. I always found it to soft. I nail down my track, and the softness of foam winds up deforming the foam when nailed down.
On my current layout, I went with cork. Midwest products makes 3' strips and it is firm and supportive for nailed down track. However, for curves, I bought sheets from a commercial source and cut the cork to form the 32" curved roadbed. It seems fine to me, but once ballasted I have noticed that if you remove the ballast to re-lay track as I have done on these two curves, the cork is no longer flat but a bit wavy. Not good. What other alternatives are there for roadbed? Homasote? Wood?
Back in the dark ages of this hobby, in the 1950's and 60's, soft woods like basswood or pine were milled into roadbed. Some modelers made their own. The Tru-Scale brand being the biggest commercial line.
They made three primary products.
Ready Track - it was wood roadbed and ties milled from a single piece of wood. The ties had milled in tieplates (oversized) which helped position the rail, rail was spiked in place with very small spikes. Track was ready go, with the tie area stained brown and the ballast slopes painted gray with some "grit" in the gray paint.
Self Gauging Roadbed - simply the product described above in kit form - raw wood milled roadbed with ties, you do the staining, spiking and ballasting.
Plain Roadbed - smooth wood roadbed with no ties for use with any brand of flex track, sectional track, or as a base to install your own hand layed ties and rail.
A simple Google search for "Tru-Scale Roadbed" will provide some images. Some can always be found on Ebay.
They also made a complete line of turnouts, crossovers, crossings, also available "Ready" or in kit form. And the roadbed came in a wide selection of curved radii sizes.
In the 70's modelers started making their own roadbed from Homasote - a messy and time consuming job.
Then the Homabed product hit the market, similar to cork, two strips already beveled, layed back to back. For curves the sections are kerfed to allow bending.
That product changed hands several times as so many products do in this hobby until it got to the last guy, Cascade - then he closed up.
Over the years and last two owners the product line expanded to include ramps, different side slope angles, different thicknesses, all in an effort to acheave better realism and improve ease of use.
As best we know Cascade closed do to personal family issues, not a lack of business or profit.
There is curently an effort underway to get a replacement product on the market.
One way or the other I will use wood or Homasote, or some of both. And my track will be glued down to avoid the possiblilty of movement.
Yes, I am completely old school on this, the proof is in the pudding. Layouts like the Severna Park Model Railroad Club are still running on track layed on homsote in the 1960's and 70's with minimal repair or maintenance. That layout has only undergone minior changes to the track plan since it was mostly completed in the early 70's.
Solid is better, and in my experiance no more noisy than all these "soft" materials.
Overmod Tell me again if the locomotive had trouble from day one it was taken out of its box. That would indicate some issue with assembly alignment (as I don't see a manufacturing defect like slight warp in a sideframe or error in registering the metal 'bearing' insert to the plastic face being resolved just by taking the truck apart) and I'd like to figure out what that might have been in case it's a common-mode issue in other examples.
Overmod I wonder if reaming the center bearings might actually tend to make the axle kick up and bind a bit under certain conditions if it is driven by a train of gears with relatively sloppy engagement fit and bearing precision. My gut hunch, of sorts, is to ream or relieve just the bottom edge of the bearing, so that the center axle can drop a bit but not rise relative to the 'square' of the outer four wheels.
I get what you are saying about just reaming the bottom edge of the bearing. I have to say, the very thought of reaming it bothers me. Why? Just because. It seems like a radical thing to do.
Hmmmm... this indicates an emergent, and perhaps transient, issue with the PA axle, perhaps combined with a slight emergent 'warp' right at that particular joint between rail ends. Could there be something in how the locomotive was oriented or handled when put away, stored, and taken out again that might have cocked or 'mislocked' the axle in question?
Whatever else this analysis establishes -- it sure proves that very small causes can produce substantial derailments when allowed to act.
Overmod Could there be something in how the locomotive was oriented or handled when put away, stored, and taken out again that might have cocked or 'mislocked' the axle in question?
Could there be something in how the locomotive was oriented or handled when put away, stored, and taken out again that might have cocked or 'mislocked' the axle in question?
Overmod Whatever else this analysis establishes -- it sure proves that very small causes can produce substantial derailments when allowed to act.
But, I learned from my mistakes. That's why I titled this thread, in part, as "bullet proof" track work. When I completed the double mainline, I was pleased but not surprised that my locos performed flawlessly without any derailments. So, I was pretty surprised to run into this problem with one of my PAs.
As I write this, I wonder if that 12 foot section of track slightly warped as a result of ballasting or humidity changes or whatever. Perhaps just enough to cause derailments with a flawed truck.
OvermodMy gut hunch, of sorts, is to ream or relieve just the bottom edge of the bearing, so that the center axle can drop a bit but not rise relative to the 'square' of the outer four wheels.
My theory would be that the center axle should be allowed to rise, rather than drop. So, ideally, you could elongate the bearing vertically by removing material above the journal rather than from below.
When observing some of my L-L PAs I could see the lead or trailing flange rise above the rail when encountering a small rise in the rail profile (frogs especially).
Small dips or depressions did not pose a problem as you point out the four "corner" wheels would remain in good contact with the rail.
Imagine a six-leg table where the floor humps and you now have a seesaw (teeter-totter in some parts).
If the floor sags the table will lack support in the center but at least will remain stable.
Regards, Ed
So, then, what would be the objection to slightly reaming the entire bearing?
richhotrain One issue that I perhaps need to consider is weight. What effect does weight have on derailments? Rich
One issue that I perhaps need to consider is weight. What effect does weight have on derailments?
Weight (or should I say lack of) will directly affect tracking
All of my rolling stock are weighted as close to possible to the NMRA recommended practice RP-20.1 I can pretty much back a train of around 25-30 cars around a modular layout built almost 40 years ago with out derailments
richhotrain So, then, what would be the objection to slightly reaming the entire bearing? Rich
Well, that's why I mentioned that earlier. It is much easier to make a small round hole into a larger round hole.
Being that it is a "blind" hole you really couldn't get a file in there. Ideally you would have an HO scale Bridgeport and a 1.5 mm end mill in order to elongate the existing bearing hole.
Enlarging the bearing all-around is simply an easier operation. If Removing the metal strip would be an option then you could certainly file the material off but you would have to epoxy the side frame back in place since it is "heat-welded" to the metal strip.
Cheers, Ed
gmpullmanMy theory would be that the center axle should be allowed to rise, rather than drop.
All that ought to be needed to relieve 'one side' of those bearings is to use a variant of time-honored glass-drilling methods. Instead of putting the grinding material or abrasive in a pool on the end of the rod or tube (here, that would just loosely fit in the bearing hole, although it could be smaller), put it in oil on the side, and while spinning it exert gentle pressure in the direction(s) you want to relieve.
Only a hair is likely required (I am saddened that I can no longer use color to denote just how little) as only a hair was associated with the original issue.
Overmod gmpullman My theory would be that the center axle should be allowed to rise, rather than drop. My concern with that theory is that what I recall Rich reporting was that the center wheelset is what was a hair high.
gmpullman My theory would be that the center axle should be allowed to rise, rather than drop.
My concern with that theory is that what I recall Rich reporting was that the center wheelset is what was a hair high.
I am curious about something here. Is it possible that the center wheelset bearings are in line with the leading and trailing bearings but that the flange(s) on the middle wheelset are slightly smaller in circumference? At times like this, I wish that I owned a caliper.