I am reviving this 5 year old thread because I am having the same sort of stalling problems described in the OP with my two SW7s when passing over the insulated frogs of Atlas turnouts. In reading the replies, it seems Frank (zstripe) had a good handle on the problem. It's a combination of insufficient weight over the trucks and poor conductivity in the trucks.
My way of testing pick up issues is to do it with the loco stationary. I turn on the bell and lift various wheel combinations and see which cause the bell to stop ringing. If I lift a truck or one side of the truck and the bell stops ringing, I know I'm not getting good pick up from the other wheels. Initially, I thought one of the SW7s was not getting pickup from the truck under the cab but I discovered if I pressed that truck down on the track while the other truck is raised up, the bell will continue ringing so it appears that is probably a weight issue.
Frank has suggested a two pronged approach to the problem. Adding weight and improving the pick up by cleaning and maybe resoldering the connection to the truck. There is a limited amount of weight that can be added inside the shell although I will do what I can there. With the shell off, there appears to be no easy way to get at the trucks. It looks like I would have to remove the decoder and then the motor assembly and all the moving parts to get access to the trucks from above. That always makes me nervous, especially when it involves an expensive decoder. I'm always afraid I won't reassemble it correctly and end up frying the decoder. Does anyone know if it is possible to pop the trucks out of the frame and pull them down enough to examine and repair the connection? I don't see any screws holding the truck in place when looking at it from below.
southernalco I tried the extra wt. It didn't help. I also have an LL/P2K S1 and it's a sweet runner. It'll go thru my switching module at 0.27 SMPH (SS1) 99% of the time and it's a lot lighter than the BLI. BLI said they would fix it for $50.00 (since I didn't send it back when it was under warranty--wouldn't run from day one-my mistake!!). But I got the impression from talking to them that they knew there was a problem from the get go. So I'm going to try fixing it myself. I'll to keep you all updated.......
I tried the extra wt. It didn't help. I also have an LL/P2K S1 and it's a sweet runner. It'll go thru my switching module at 0.27 SMPH (SS1) 99% of the time and it's a lot lighter than the BLI.
BLI said they would fix it for $50.00 (since I didn't send it back when it was under warranty--wouldn't run from day one-my mistake!!). But I got the impression from talking to them that they knew there was a problem from the get go. So I'm going to try fixing it myself. I'll to keep you all updated.......
Try to concentrate on the truck pick-ups......with the pick-up problem's solved and added weight, it will work like it should, going through any turnout...I know that for a fact... You still don't mention if You have the non-traction tire one or the one with the traction tires. People complained about the one without traction tires not pulling very well...BLI then made them with one axle with traction tires....but Did Not fix the poor pick-up problem's so the result was, they ran worse than the one's without traction tires...this goes back quite a few yr.s 07 I believe. This was all over all kinds of Model Railroad sites back then. Do a Google search for BLI NW2/SW7 pick-up tips. Some are no longer there for some reason, but there are other forums from other sites that are.
You are probably only picking up power from one truck.....that's what it sounds like from Your description, on Your turnouts.
Good Luck!
Frank
I have a BLI Paragon2 NW2 which is the same thing, except some details, as the SW7. It will stop dead on Atlas turnout, not always and not always on the same turnouts, but it is annoying. I once decided to inspect the trucks and found a lot of grease that I removed, as Frank suggested. The loco ran better but the problem is not completely solved.
I also have a P2K S-3 which has the same pick-up problem. Some could say that the problem is with the short base between the trucks. There is certainly more than that as I have an Atlas S-2 which is certainly one of the best runner of the roster. The guys at Atlas certainly know how to make outstanding engines that worth the few more bucks they ask.
Frank,
Thank you for the detailed information about all things that should be checked. I will give them a try on those two favorite, but impotent, locos.
Guy
Modeling CNR in the 50's
Southernalco,
Almost positively it is Not Your turnouts. Your engine is more than likely experiencing the problem they all had. When they first came out, without traction tires, they were very light and when going over turnouts the slightest lift of any wheel would cause it to stall, lose power reset almost all the time. You may have the other issue it also had of poor power pick-up from the trucks, which was a wire soldered to the pick-up bar that rode on the inside face of a blackened wheel. The wire in some instances, including continuity tests show that it was ok, but it was hanging on by a thread, even looked ok. Some had too much grease in the gears of the trucks, causing it to insulate the pick-ups. BLI's fix was to put traction tires on some wheels, which made the pick-up worse. People who had them removed the traction tire wheels and got solid replacements for them, took off all the wheel blackening/grease, resoldered all the pick-ups and crammed every bit of weight they could into every nook and cranny in the engine compartment, which is not a lot, with the decoder and speaker in there. I know all this for a Fact, because I have 2 of the ones without traction tires. They were a pain in the butt to get working half way decent, to even break them in. Now with all the weight I put in, redoing the trucks, blah, blah, they will finally run decent. I used round lead fishing sinkers that are shapeable from Bass pro-shops and put it in every place I could. To test if You have a pick-up problem, lift one truck at a time when running and see if they both pick-up and keep running. The weight problem I found by adding two bean bags laying over the engine and with that weight just laying on top, I was able to go anywhere, turnouts included on the layout. They used to have how to's out on what people did to correct the problem's but they are gone, I even had one...but it shows on sites no longer.....
I believe that is what is happening to You.......Your track can be squeaky clean and it will still happen.
Edit: Also I forgot to add....put Your engine on a sheet of glass/mirror and see if You can slide a sheet of paper on any of the wheels....could be one of the trucks is not seated on the bolster or in My case...one of the pick-up wires to one truck was caught by the chassis and was preventing the wheels/truck from sitting firmly on the track.......very noticeable when going over turnouts and frog area, instant lose of power pick-up.
Check to be sure both trucks are picking up power. Maybe one of the wires from one truck to the decoder got broken or otherwise interrupted.
On straight track carefully lift one truck, then the other off the rails while running at slow speed. If the engine stops you know the truck still on the rails is electrically dead.
Just an idea...
Good Luck, Ed
I reckon it shorts as it stops dead and NO light. Direction doesn't matter as it does it both ways.
We need more information here. Is it stalling? Shorting? Derailing? Only in a certain direction through? Only when turning? When turning a certain direction? Goes through one route of the turnout and not the other? Where exactly in the turnout does it stop/stall/derail? Give us a little more information so we can help.
Mike
I have a BLI/Paragon SW7 that absolutely refuses to go thru Atlas or Peco turnouts. The track and loco wheels have been thoroughly cleaned. It runs great on tangent track.
Has anyone else had one of these with the same problem. My little light LL/P2K S1 will go thru my Peco turnouts at 0.27 SMPH, so I know it's not the turnouts........
HELP