HI Guys
A little help please.
I don't want to return this loco if there is'nt a real problem. I hooked it to 9 cars and even at almost full power it gets down to a crawl with wheels spinning wildly on a 3.3 percent grade.
My SD7 (6 axle) hooked to the same train sails over the grade with hardly any slow down.
My 8-4-2 spectrum does the same, no sweat no strain.
I have been putting run time on the 2-6-6-2, I cleaned the wheels and track very good. If I put extra weight on the loco it will pull the grade.Anyone think there is a problem with it?
Thanks
Lee
Ask Cuda Ken, but this Thread might help. (EDIT: I know that his is a BLI, but he still might help.)
Lee:
I hate to tell you, but with a 3.3% grade, you're hoping against hope that the 2-6-6-2 will pull much MORE than 9 cars. The reason your diesel will sail up the grade is that it has smaller wheels and more direct weight on the wheels themselves.
Question: What is the radius of the curves on your grades? Remember, that 2-6-6-2 is a LIGHT mallet, one of the smallest ever built. Model or prototype. You could probably put more weight in the boiler--making sure that you balance it toward the front--but that might put additional stress on the Spectrum motor and drive mechanism. But if you have tight curves--anything less than about 24" radius--ANY steamer is going to have trouble with the grade.
My Spectrum 2-6-6-2 will comfortably pull about 18 cars up my 2% grades, but I also have 34" minimum radius, and my grades are not constant. But 3.3% is really a very stiff grade for either a model or a prototype. Especially if you have tight radii on the curves. Possibly, as you run it in (with lighter loads) and wear off some of the factory finish on the treads, you might increase the tractive effort, but frankly, with that grade and that size articulated, you may just be at the limit. And it has nothing to do with the quality of the locomotive, it simply has to do with the fact that you've got one really STIFF grade for a steamer.
Frankly, a 3.3% would almost halve the cars that I could pull with one of my old, heavy brass Yellowstones. And those puppies can pull almost anything I want to put behind them.
It's the grade, not the locomotive, at least IMO.
Tom
Tom View my layout photos! http://s299.photobucket.com/albums/mm310/TWhite-014/Rio%20Grande%20Yuba%20River%20Sub One can NEVER have too many Articulateds!
twhiteIt's the grade, not the locomotive, at least IMO.
Thanks Tom That is what I was looking for, an educated opinion. I'm new at this. I just thought it should pull as much as my 4-8-2 mountain. The grade is almost straight, and levels out for a 39" reverse 185 degree turn back downhill. I just had a thought. Maybe the mountain has almost as much weight on fewer wheels and that creates more friction. I'm not sure how the friction thing works. Just a thought.
Opinions are good.Thanks
Well Lee break out the scales see how much they weigh.
Tom is right on every account. Give the wheels some time to break in. I have a Proto SD 7 when new could only pull 12 cars or so. Now that the wheels are broken in it will drag 30 coal cars with no problem.
Adding weight will all so help. I had 2 Bachmann GS-4 steamers that would only pull around 15 cars new. I added around 3 oz of lead to there chassis and got them up to 25 cars. More weight over the drive wheels sure helped. If later you do add weigh, make sure the motor will still have sufficient power to spin the drive wheels if there is a stall.
Did your engine come with traction tires?
3.2 % grade is stiff, most of the time that steep of a grade is used for logging layouts.
Good luck Lee, Ken
I hate Rust
cudaken Did your engine come with traction tires? 3.2 % grade is stiff, most of the time that steep of a grade is used for logging layou
3.2 % grade is stiff, most of the time that steep of a grade is used for logging layou
Hey Ken
I never thought about traction tires, but I'm not sure how you put them on. Bachmann did say that if I open it up that I would void my warranty.My layout was smaller when I set up the grades and I needed height for crossover.I really like the engine but I'm totally surprised at how little it will pull. I ran the SD7 up the hill this morning with 14 cars, no visible slowing down. Going to look into traction tires.
Thanks for jogging the old brain.
Ed Appreciate the compliment. When I started the layout I remembered the trips we have taken to the Rocky Mountains etc, Vancouver an Banff to Dorango Co. I visualized a small railroad town on the west slope free lancing the Great Northern. The mountain section still needs work and the rail yard / industrial park needs detail for my vision. I need a small grass air strip with a little yellow Piper for a fishing camp.
Have fun Lee
yankee flyer cudaken Did your engine come with traction tires? 3.2 % grade is stiff, most of the time that steep of a grade is used for logging layou Hey Ken I never thought about traction tires, but I'm not sure how you put them on. Bachmann did say that if I open it up that I would void my warranty.My layout was smaller when I set up the grades and I needed height for crossover.I really like the engine but I'm totally surprised at how little it will pull. I ran the SD7 up the hill this morning with 14 cars, no visible slowing down. Going to look into traction tires. Thanks for jogging the old brain. Lee
By all accounts, that Bullfrog Snot stuff works well. No need to disassemble the loco to add traction tires. However, do not make it so that the loco cannot slip if truly overloaded. Having a model completely stall out rather than slip with a heavy drawbar load is just asking for the motor to burn up. I'd start with 1 on each side and see how that does. Have to have one on each side or the single traction tire will grab and skew the whole engine to one side and more likely than not completely derail it.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Unless the model came with a separate pair of traction tire equipped drivers you can install, traction tires aren't going to fit. There is a product called Bullfrog Snot for adding traction to standard drivers being discussed here.
Nelson
Ex-Southern 385 Being Hoisted
The suggestion for Bullfrog Snot is a good one, IMO. I've heard good things about it from a couple of other posters who have tried it on some lighter locos and improved the tractive effort considerably. I'd coat only one pair of drivers--possibly the last drivers on the second set near the firebox.
I think Crandell said it takes about 24 hours to set up, but it doesn't leave any residue on the rails.
BTW: That's one very nice-looking layout you've got.
Good luck with that little lokie. I think as you break it in you'll find it to be a good one. I sure like mine.
twhite I hate to tell you, but with a 3.3% grade, you're hoping against hope that the 2-6-6-2 will pull much MORE than 9 cars. The reason your diesel will sail up the grade is that it has smaller wheels and more direct weight on the wheels themselves.
Diesels don't usually have to pull a tender either.
OK, OK. A Heisler is not a diesel, but in the model railroading world, a Heisler pulls like a diesel locomotive.
Mark
On level track, my Spectrum 2-6-6-2 can pull 32 ore cars and a caboose, could possibly do more. The heavy Mountain can do pretty close to that maybe 28, the light one is limited to about 24 cars. (I run ore cars in "mini-quad" groups of four.)
One thing to watch for on the Spectrum HO 2-6-6-2 is that sometimes while being jostled around in the box on it's way to the hobby shop, one set of drivers can get pushed up into the body a little and stick there, so the wheels aren't making good contact with the rails. I would try feeling and tugging on the drivers a little to be sure they're all settling down properly on the rails.
BTW, actually the "light" USRA Mallet isn't a small engine at all, there were 2-6-6-2's built for std gauge logging railroads that were much smaller. It's small for a Mallet, compared to a 2-8-8-2 or 2-8-8-4 etc. but it's still a very big engine. Don't confuse it with say the Mantua logging 2-6-6-2 etc.
http://orion.math.iastate.edu/jdhsmith/term/slususra2662.jpg
Lee,
I have done a fair amount of research/documentation on pulling power. Without detailing all of it here, the following may be of some help.
I have three Spectrum 2-6-6-2's and six Spectrum 4-8-2 Heavies.
All my tests are done with a large fleet of Athearn 50' flats w/vans. Each car weighs 4.3 oz and is equiped with Kadee sprung metal trucks and Intermountain wheel sets. They are VERY free rolling.
In the prototype, these two locos are very similar in adhesive weight. The 2-6-6-2 is 162 tons, the 4-8-2 is 160 tons.
But the smaller driver size of the 2-6-6-2 would make it a slightly stronger puller and a little slower. Unfortunately the physics does not scale down so well. I will not go into all the research by myself and others about model tractive effort, but suffice it to say you cannot compare diesels to steam, diesels will win every time in model form compared to the best model steam.
Grades - on the prototype a 3% grade would reduce a locos pulling ability to only 9% of what it could pull on level ground. Thats why railroads avoided such grades. One other big difference on the prototype, often the whole train is not on the grade at the same time reducing its effective grade. Often on our model layouts it is just the opposite.
In my tests both the 2-6-6-2 and the 4-8-2H pulled 30 of my 4.3 oz cars on level track. I have no grades that steep to test, but based on my 1.8% grades and John Armstrong's work in this area, we can use his chart from his "The Model Railroad Track Plan Book" and assume that the pulling power of the locos would be reduced to 22% on a 3.3% grade.
30 x .22 = 6.6 cars
The explaination for the difference between the 4-8-2 and the 2-6-6-2 has a lot to do with weight distribution and locomotive suspension design. Actually the same reason the diesels pull better, their adhesive weight is better applied in model form than we have ever been able to do with model steam locos.
Often the steam loco with fewer wheels and simpler suspension pulls better in model form. The spreading out of the same weight on more drivers with the 2-6-6-2 is a big issue in compairing the two. We cannot scale down the metal molicules of the rail and wheels so there is a minimum threshold of weight needed to create tractive friction.
You can add more weight, but there is little room. I have filled the domes with moldable lead on two of my three 2-6-6-2's but could not really measure any improvement.
The Bullfrog Snot traction tire idea is a good one but as of yet I have not tried that product.
Regular traction tires require a grooved driver which Bachmann has no provision for - not a good idea.
Well, even without getting into too much math is this has gotten quite long. Hope this info is of some help.
Sheldon
Is thiis an N-scale or HO-scale loco?
Boiler-man Is thiis an N-scale or HO-scale loco?
HO
twhiteThe suggestion for Bullfrog Snot is a good one,
TomI'm going to look into the bullfrog stuff, just make sure I don't call it bullfrog something else with an "S" Thanks on the compliments. I've made a lot of mistakes but over all I'm satisfied with the way it's going. Here's part of the other end. Horse and cattle farms.
At the risk of boring everyone with my little layout, here's another picture.
I've been working on learning about decoders and the internal workings of the locos lately and letting the scenery slide.
Keep those trains rolling.
ATLANTIC CENTRAL Is thiis an N-scale or HO-scale loco?
Boiler Man
It's HO, just kind of small. I started out to make a small layout so I could play with my grandkids (8' X 12') It's now kind of 5' x 19'. O course the kids have an attention span of about 10 minutes but I'm hooked.
Lee, could you post better Pictures of the 2-6-6-2? I like a better idea of what it looks like. Does it have sound? Good looking layout as well.
By the way have you seen this post I started?
http://cs.trains.com/trccs/forums/p/156024/1722594.aspx#1722594
You got me thinking about it. How far away do you live from Maryville IL? Also like to visit and bring over a few engines to try on your 3% grade.
Ken, a friend you have not meet yet.
I thought that it may have been an N - Scale loco.
I model in N - Scale and have 3 of the Bachmann 2-6-6-2's and they did not pull good at all, the Bullfrog Snot is the way to go from the reports that I have see on the product, it works wonders on slippery locos no mater what scale.
I ended up machining recesses in the rear most drivers and installing traction tires before Bullfrog Snot came on the market.
Now I am going to remove the Traction Tires and fill the recess with Bullfrog Snot.
cudaken Lee, could you post better Pictures of the 2-6-6-2? I like a better idea of what it looks like. Does it have sound? Good looking layout as well.
Here are two pictures that you ask for, and yes it does have sound. Another skill I'm working on is taking and posting pictures. Black can be difficult to photograph, so I think I need some light reflectors to bring up detail.
Shovel that coal.
Good looking engine Lee, hope to hear it some day.
Ken