Doug,
Aah! The good ole’ days. (young) [swg]
Frank
Take a good look at the truck. I have seen times whre the worm wheel gear will come with its axle pooped out. Hard to notice. This is the gear that the worm gear drives. It will make the truck wheels turn without any weight on them. When you put it on the track will cause the gear the slip and makes the truck jump and make noise too.
Does your unit make a lot ot noise?
Something else that may have happened is that both trucks are front or both are rear, and they are pulling against each other. Check the locomotive very carefully to see if all the wheels are turning in the same direction. If not, then one of the trucks is the wrong type.
Thanks for more info. Both truck sets did this, (old set and new set) and I thought new trucks would fix it. Not so and yes everything is seated inside the truck and ok. The trucks are installed in the right direction according to Atlas tech who I talked with yesterday. So I’m going to wait for the new second order of parts and see what happens. Could be the frame itself has a twist or something but I don’t see that either.
We have had five power outages in a week here and three of them were yesterday and night so it is a good thing I have battery back-up but I have been turning off the computer itself because of these electrical storms. Doug
It’s basic, but have you tried swapping parts between the 2 engines till you find which part makes it stop?
Of course, you could end up with two non-runners this way.
That is one thing I haven’t done and really, in all honesty, don’t mess with whats working really well with the other engine. This is quite a puzzle and I am going to wait for the next new parts order and install. I will let everyone know then what happens if anything. I love real Lemons but not this kind of Lemon. But they were used and I like to fix things to run again into the Sunset.
I also know Atlas is coming out with SD9’s in first quarter of 2015 in Rio Grande. More bad Electrical storms predicted for today so will have to turn off the computer if it builds up. Doug
Received the parts from Atlas in Friday’s mail and installed Saturday evening. New body castings and new drive lines. The engine is running well now in forward and very minimal slip once in a while in reverse. I noticed that when starting the engine forward or backward the trucks don’t have a slight lurch in each direction as before. I also noticed that the truck pockets in the replacement frame halfs did not have much slop in the milling as the old frames. I could slide the trucks back and forth in the old frames just a little but in N Scale that can be serious.
So now with new trucks, new frame and new drive line I give it a huge improvement. Even the new trucks had serious slop in the old frame truck pockets and I now think that the milling of the old frame, first production which started in 2003 had much to do with this issue. The frames that Atlas sent me now had to be a later production run because you could see the slight difference in the milling of the truck pockets.
I have to say that Atlas is really helpfull to work with and very prompt in there shipments. I am going to further test and hopefully install the body shell in the next few days. I live in the foothills and summer keeps me real busy outside. Thanks to everyone for their input. Doug
I have read this entire thread, including all of the replies. Then, I re-read the OP’s original post.
It sure sounds to me like the frame is warped.
Rich
You know Rich I think that could be part of it. I did check the old frame during my problem and could not find twist in it but for me, a metal straight edge is all I could use. When I got these two new frame halves on Friday I also checked their straightness and found one to be slightly bent. Using a metal straight edge again I spent some time to bring it back to normal.
As above mentioned it really runs well going forward and mostly in reverse after the repair but it will slip some at times. And where it will slip randomly, it is never in the same place on the track. I’m going to keep testing it for a few days as I get time and see what happens. Doug
Doug, that is good news.
I cannot recall if this has already been suggested elsewhere in this thread, but you might try adjusting the trucks so that they hold the rails better as the frame is “flexing”.
Rich
Doug,
There is not enough weight involved for the frame to actually flex. If the frame is indeed warped, more movement of the trucks is needed. It still sounds like they are too rigid, along with driveline, like I tried to explain before, fore and aft, up/down, port/starboard up/down.
Take Care!
Frank
Of course not, Frank, that is why I put “flexing” in quotes to describe a warped metal frame that cannot hold the trucks on the rails. Everybody else hopefully understood what I was describing. A warped metal frame will do what Doug describes. I know because it has happened to me.
Rich
I have been, from the beginning of this issue, slightly adjusting the tightness of the frame screws and it does make a difference for sure. One of the things I am looking at now is if the frame has a small arc, (up down) of each frame half. Even though all the truck wheels look like they are touching the track using special lighting and magnafacation it does make sence to me, that if the body or a body half is slightly arched, it could effect the way the truck and wheels are touching.
I do have good movement of each truck in the new frame truck pockets and no slop as before in the old frame and good preformance in the forward direction. Just sometimes some spinning in the reverse direction now and not in the same place in the track. I have many engines, as most of you do and this one is the only problem I have on the Layout. I have been working on this when caught up on chores outside. Doug
Doug,
Did you try putting it on a flat piece of glass or mirror and try to slide a piece of writing paper under the wheels, you will surely know that there is an arc or warped frame if you can slide the paper under one and not the other.
Take Care! [:D]
Frank
Good idea, Frank. [Y]
Rich
Thanks for that Idea Frank. I’ll try it tomarrow. Doug
Ok Frank, you are dead on right. Using the mirror glass and writing paper on each wheel it proved that there is track contact problems on some of the wheels. This is a six axel loco so two on the right front and two on the left rear are not making contact to the mirror.
The frame will only screw together in a quided fashion so would I carve out some of each truck pocket on each side that is not touching the mirror, or take a little plastic off the top of the plastic tab that would ride on the top of the truck pocket? Or do I botch everything up and use two pairs of pliers and twist the frame and hope it works? Ha!?
Never a dull moment in model railroading, thats for sure. The trucks do flex from side to side and fore and aft but the paper test proves not enough even though electric contact is still good because all wheels provide current. Adjusting the frame screws out more than they are could be a problem getting the body back on. Just thinking. Doug
Is there any verticle play in the axles?If the axles can not float ton a certain degree they may just not be able to make all 6 wheels touch.I am asuming you did the paper test with the bloco in one piece.Isuggest you pull the trucks and check them one at a time with the paper if you’ve already done this don’t bother doing it a second time.
Yes Catt, I did the test with the trucks in the loco and the frame screws adjusted to the best operating condition of this loco. I’ll check these new trucks out of the engine when I get a chance. Thanks for input. I am determined to get this engine running well but summer chores are keeping me busy. Doug
Ideally, you would remove the motor, drive train, and trucks, and then do what it takes to straighten the frame.
Rich