I have two 2-6-0 HO scale locomotives that when pulling 2 cars (plus tender) on a 1% incline is fine but when pulling three or more cars they just sit and spin their wheels, any ideas on how to solve the problem, thought about adding weight to the locomotive itself for better traction....
Adding weight is certainly one option. Another is a product called "Bullfrog Snot" which is an rubbery adhesive type material that is added to one set of the drivers to improve traction. Also, have you checked the rolling characteristics of your cars? You might want to investigate using a "Truck Tuner" marketed by MicroMark to free up your wheels and improve the rolling characteristics of your cars.
Joe
Not being able to pull 3 cars on a 1% grade in HO more than likely means something is wrong.
I don't want to sound insulting but..... are you sure the grade is 1%? A 1% grade is a rise of 1" over 100" of track. Or a 1/8" rise in 12" of track (slightly more than 1%). Very few of us have the space to hold grades at 1% unless the grades are for cosmetic purposes only. And builidng a smooth 1% grade means some pretty accurate cutting of risers (track supports). A 1 degree grade is actually a 1.7% grade. Even with a 2% grade, your 2-6-0s should pull more than 2 cars upgrade.
I would start trouble-shooting with the cars (easiest). I put a piece of flex track on a 25" length of 2x4 (can be any scrap wood that will be rigid over a 25" length).. Starting from a level surface, I elevate one end of the 2x4 by 1/2" - equivalent to a 2% grade. All cars - including passenger cars - must roll down the 2% grade on their own (my personal standard). If they don't, the trucks need work. You have to have reasonably free-rolling cars to know whether your engines are performing acceptably.
On steam locomotives, the most common culprits that reduce pulling power are (in order of frequency) 1) a too-strong spring on the pilot truck, 2) tenders that are not free rolling, and 3) too little weight or weight not being balanced over the drivers. In my experience, if any of these causes are present to the extent that the engine only pulls 2 cars up a 1% grade, I'm also going to see derailments of the engine and/or tender. Since you didn't mention these engines derailing, your track cannot be oily or greasy and expect to have normal pulling performance. Just rub your fingers along the rail head, and you'll know.
For the spring on the pilot truck - the downward force, which turns into a lifting force on the front of the engine, should be as little as practical. Many modelers remove the spring completely, and add weight to the pilot truck (wrapping solder around the axle is a workable way to add weight). I prefer to have light spring action to help guide the engine with the pilot truck. If the pilot truck is free to flop around, small engines have a tendency to wallow - angle from side to side - on straight track that is not at minimum track gauge.
Ideally, the tender should be as free-rolling as your cars. Reality is that many tender trucks are not very free-rolling, especially when electrical pickup wipers are present. This will often manifest itself in derailments when backing up. Anything you can do to make a tender roll freely is helpful.
On a 2-6-0 the weight should be balanced over the center driver, or at worst, in the gaps either side of the center driver. Use a round pencil centered under a piece of snap track with the engine only also centered on the track to check. Move the pencil to establish where the balance point is.
Thinking more on the issue as I write, the drawbar and stiff wiring between engine and tender can also shift engine weight from the drivers to the tender, or lever the rear drivers slightly high. This is more true on modern models that have a too-stiff cable of wires running from engine to tender.
just my thoughts and experiences
Fred W
....modeling foggy coastal Oregon, where it's always 1900....
Are you sure there's nothing slippery on your track, loco wheels or both like graphite, some kind of oil (smoke oil was the culprit for me) or some kind of track cleaning agent that leaves a film? All of these will knock your traction down to near zilch.
On the recommendation of Bullfrog Snot, it's great stuff but be aware that you will lose the power pickup from the wheels that it's applied to. Also if the loco runs over any dust that's on the track for whatever reason the Bullfrog Snot will lose it's sticky quality and you'll have to remove it and make a new application. It will also gradually lose it's stickiness over time even on clean track and let's face it, there's no such thing as clean track unless you polished it to a brilliant shine and locked it in an airtight case and removed all the air.
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Wolf,
Just saw your post today, and the subject line reminded me of an ongoing problem I had with a Bachmann Spectrum Decapod with a factory-installed Tsunami decoder. This locomotive was unable to climb a grade even travelling light (no rail cars attached), right out of the box. I laid the blame at the feet of the loco because it is mostly plastic and weighs next to nothing. A call to Soundtraxx solved the mystery. CV 212 (BEMF feedback Intensity) was at the default setting (128) which it turns out was too low a value to get this thing to climb (3 to 4% grades). On Soundtraxx's advice, I increased the value to 255, the maximum, and it now climbs very well even pulling a good load. You didn't mention, are your locos DCC equipped?
Wilton.
Lots of good suggestions, esp on making sure everything else is freewheeling. It could likely need some weight too. If so there are a lot of ways to do it like filling in molding voids in the boiler with lead that you size to fit.
Richard
oregon shayJust saw your post today, and the subject line reminded me of an ongoing problem I had with a Bachmann Spectrum Decapod with a factory-installed Tsunami decoder. This locomotive was unable to climb a grade even travelling light (no rail cars attached), right out of the box. I laid the blame at the feet of the loco because it is mostly plastic and weighs next to nothing. A call to Soundtraxx solved the mystery. CV 212 (BEMF feedback Intensity) was at the default setting (128) which it turns out was too low a value to get this thing to climb (3 to 4% grades). On Soundtraxx's advice, I increased the value to 255, the maximum, and it now climbs very well even pulling a good load. You didn't mention, are your locos DCC equipped?
He said the locos just sit with their wheels spinning. That's loss of traction pure and simple and changing all the CV's in the world isn't going to fix that. I've had some 2-6-0's and 0-6-0's that couldn't win a tug-o-war with a house mouse that had grease on it's feet. The only fix was to add more weight anywhere it could be added. One of my relatives had a 70's era Bachmann 0-6-0 (now mine through inheritance) that had the same problem. He found somewhere a metal body that he put on it and now it'll probably pull wallpaper off the walls. I've had it pulling as many as twenty-five NMRA weighted cars at once with no help, a dozen at least up a 2% grade.
Make sure all the drivers are touching the rails equally. If not, your 2-6-0 will act like a 2-4-0. Use a piece of paper under each driver wheel and check the drag. Repeat with the rest and compare. One set of drivers may need to be shimmed down.
Jim
ANOTHER likely culprit is the transition into the grade. If the transition is too abrupt the locomotive will bridge the start of the vertical curve, and the wheels may not touch the track at all. Or enough weight is taken off of the wheels that they start spinning.
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Jeffrey,
After reading your reply to my post, I went back and re-read the original poster's remarks. Wolf stated that the locos could pull 2 cars up a 1% grade, but would break traction with a heavier load. I saw a lot of similarity with the situation I encountered. I'd really like to see a response from the OP, to see if any of our suggestions were helpful. I'd like a little more information, as well - are these locos new, have they always behaved like this, is it just on one incline on the trackwork, are the locos DC or DCC?? But all this guessing is educational.
Respectfully, Wilton.
oregon shay Jeffrey, After reading your reply to my post, I went back and re-read the original poster's remarks. Wolf stated that the locos could pull 2 cars up a 1% grade, but would break traction with a heavier load. I saw a lot of similarity with the situation I encountered. I'd really like to see a response from the OP, to see if any of our suggestions were helpful. I'd like a little more information, as well - are these locos new, have they always behaved like this, is it just on one incline on the trackwork, are the locos DC or DCC?? But all this guessing is educational.
Thanks to all who put in some great ideas. I have added weight to the loco and that seems to have worked. As for the cars, they all roll extremely well. Also borrowed an older 2-6-0 loco the was heavier and found no problems with it pulling the grade. my loco's are brand new and the weight compared to the borrowed loco's are greatly reduced. Problem solved. Thanks again everybody!