Recently my original 2025 steam engine--the one that got me started in this hobby when my Dad bought it for me new in 1947--stopped running. I dug out an old CTT article that described how to tune it up and fixed the motor (broken wire) rather quickly. While I had it apart, I also replaced the brushes and cleaned the armature face, being very careful not to remove the armature for fear I'd throw the drivers out of quarter. The motor now works fine, but when I replace the main rod crossheads and eccentric cranks, the wheels jam up. A quick inspection reveals that, somehow, the drivers DO seem out of quarter. So my two questions are: 1)How can this happen when you have not removed the armature to allow the drivers to spin freely, and 2)Since indeed it seems it HAS happened, is there anyway I can repair the problem without a wheel puller (which I do not own)? Any tips will be appreciated.
John
The wheels are probably still quartered, but the axles are not indexed to each other due to a spur gear tooth-skip from slightly excessive end play.
This can all be checked visually - one tooth skip is quite obvious.
It is possible that the wheels have come loose on the axles, you can check this by checking each axle set to be sure the left side wheel is 90 degrees ahead of each right wheel.
Let us know.
Rob
It may not be exactly that a driver is no longer quatered per se. It sounds more like one of the drivers has maybe slipped it's gear slightly so it's no longer exactly lined up with the other two.
Good question John. I am in need of that info also. Guess I'll have to buy my LHS tech or another local for a hands on demo.
Papadiesel
Since you had the linkage apart, I would check that your are not 180 degrees out on the eccentric crank. That would cause it to bind also.
Bill
Since the axles are splined, I agree with those who think it unlikely that your quartering has been disturbed. Somehow something has been loose enough that one wheelset or another has slipped by one gear tooth; or Bill is right about the eccentric crank's being set wrong.
Don't look too closely at the accuracy of the quartering. All that is needed for the model to run smoothly is that any quartering error be the same on all three wheelsets. So you may observe or measure a few degrees of quartering error, which will get you into more trouble if you try to "fix" it.
It would be interesting to know whether the locomotive indeed has left-hand lead, as Rob says. That would be correct for a PRR locomotive. Lionel also used left-hand lead for the 773, which, being a model of a NYC Hudson, is very wrong.
Bob Nelson
Thanks for the info, guys. Sorry to take so long to get back on, but I had to go to work.
I had thought about the eccentric crank being 180 degrees off and tried moving it that much, to no avail, so I don't think that is it. I am wondering about wheels coming loose on an axle--perhaps esp. the center drivers in this case. When the weights on the 2 outer wheels are centered on 6 o'clock (on the left, or fireman's, side), that on the center wheel is at 8 o'clock. On the right (engineer's) side, when it's 6 o'clock on the outers, it's at 4 o'clock on the center.
I did check to see if the loco has left-hand lead, and it does. I have another 2025--a junker I bought for parts, though its wheel alignment seems right--and the set up is the same there.
Assuming it is a matter of wheels loose on the center axle, how do I fix that?
A quick visual inspection of the gears suggests there may be some gear damage on that center axle--several teeth in a row seem shorter than the others, though I may need to clean off some grease to see it better. Also, as originally mentioned, the engine runs really well without all the side hardware. If it were a gear problem, would that be possible?
Again, thanks in advance for any tips.
Yes, with the side rods off, it would run just fine with the wheels at any angles. You can easily verify whether the wheels are loose on the center axle by trying to turn the center wheels in opposite directions. But I doubt that that is the problem.
I think the problem is that the gears have slipped a tooth or two. There must be enough end play in the wheelsets, or wobble room for the other gears. Since the middle wheelset is the one that is off from the others, I would suspect it. You might pull gently on the wheels to see whether they could have slipped apart enough at one time to create the clearance for the gears to disengage. The bottom line is that you will have to fiddle with those wheels and gears to try to discover how they did disengage, as they almost certainly must have. But if they can get out of whack, there must be a way for you to get them back into whack again.
Boxcar Bill Papadiesel Since you had the linkage apart, I would check that your are not 180 degrees out on the eccentric crank. That would cause it to bind also. Bill
Carl
He tried the eccentric-crank fix without success: "I had thought about the eccentric crank being 180 degrees off and tried moving it that much, to no avail, so I don't think that is it."
And he can see that the wheels are not at the same angles: "When the weights on the 2 outer wheels are centered on 6 o'clock (on the left, or fireman's, side), that on the center wheel is at 8 o'clock. On the right (engineer's) side, when it's 6 o'clock on the outers, it's at 4 o'clock on the center.
servoguyI am wondering how he got the side rods on the loco if the wheels are not where they belong. That would be a real trick. If a wheel is off as far as he describes, the side rods could not be installed...
One tooth off, the rods will go on, two teeth off and they probably won't.
ADCX Rob The wheels are probably still quartered, but the axles are not indexed to each other due to a spur gear tooth-skip from slightly excessive end play.
OK, time out here.
The wheels are not quartered, the axles are not indexed, and the eccentric crank.........
What does it mean to quarter the wheels?
How are the axles indexed to one another?
What is an eccentric crank?
Remember, no question is a dumb question.
Rich
Alton Junction
"What does it mean to quarter the wheels?" On a 2-cylinder double-acting steam engine, which is what most prototype locomotives have, the cranks on the left and right sides of each axle need to be 90 degrees apart, so that one cylinder or the other can always turn them. Since the cranks are integral with the wheels (after the nineteenth century), this means that the wheels on each end of the axle are 90 degrees apart. This is called "quartering". There are two ways to do it, with the left side leading the right side by 90 degrees (when running forward), the arrangement used by the Pennsylvania railroad, the "standard railroad of the world", and with the right side leading, the arrangement used by pretty much everyone else. On a model, quartering is not very important, except for looks, and not important at all when all the axles are actually driven by gears, as is the case here.
"How are the axles indexed to one another?" Whether or not the wheels are quartered accurately or at all, they need to be connected to the gears that are actually driving them so that the cranks make their revolutions at the same time. Otherwise the cranks try to stretch and bend the rods, causing the engine to bind. This is what was meant by "indexing" the axles.
"What is an eccentric crank?" The eccentric crank is a second crank on one of the drive wheels that the main rod is connected to. It is 90 degrees from the main crank. Its purpose is to operate the valve gear. It is often omitted on cheaper model locomotives. It is connected to the wheel through the crank pin of the main crank and is of much lighter construction than the main crank, since it transmits very little power to the valve gear. There is a valve gear, the Young valve gear, that dispenses with the eccentric crank entirely. It uses the motion of the main crank on the opposite side of the locomotive instead, transmitted by a shaft that runs under the boiler.
lionelsoni "What does it mean to quarter the wheels?" On a 2-cylinder double-acting steam engine, which is what most prototype locomotives have, the cranks on the left and right sides of each axle need to be 90 degrees apart, so that one cylinder or the other can always turn them. Since the cranks are integral with the wheels (after the nineteenth century), this means that the wheels on each end of the axle are 90 degrees apart. This is called "quartering". There are two ways to do it, with the left side leading the right side by 90 degrees (when running forward), the arrangement used by the Pennsylvania railroad, the "standard railroad of the world", and with the right side leading, the arrangement used by pretty much everyone else. On a model, quartering is not very important, except for looks, and not important at all when all the axles are actually driven by gears, as is the case here.
Thanks, Bob. I knew you would set me straight.
You didn't mention what an eccentric crank is. Is it just like a Timboy?
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