Locomotive Is Too Heavy When?

[Anonymous]

I'm adding some weight to a Athearn SW1500 to increase it's performance. So far I have added about 1 1/2 ounces and it seems to be improving, but how much is too much? I have seen mentioned in one of the MR locomotive reviews(Athearn GP60M) that adding weight can be done, as long as the wheels spin before stalling the motor. Can you do this by holding the loco stationary(not applying downward preasure) and see if the loco spins it's wheels while advancing the throttle?

Also, I'm assuming the reasoning behind letting the wheels spin is to keep from burning up the motor. If I advance the throttle and it won't move because it has too many cars coupled to it, would it still hurt it for just that short time the motor is stalled?

[Budliner]

we need a scientist for this one

[Anonymous]

I would find the manufacturers recommendation for pulling weight and additions to your locomotive.

[mcouvillion]

Ron,

I don't believe you could add enough weight inside an Athearn SW1500 to cause any damage - there just isn't that much room. Hold the engine by the coupler and turn up the throttle. It should spin the wheels as the engine loses traction - before it reaches full throttle. If the wheels never break free, it is too heavy. I had a used engine I purchased that had about two pounds of strip lead weight in it. Way too much. After removing about half the weight, it ran really well. I think you'll know if it's too heavy, but I don't think you can put too much weight in that particular engine.

Mark C.

[Texas Zepher]

QUOTE: Originally posted by R.W. King
how much is too much? ...as long as the wheels spin before stalling the motor. Can you do this by holding the loco stationary(not applying downward preasure) and see if the loco spins it's wheels while advancing the throttle?

I'm assuming the reasoning behind letting the wheels spin is to keep from burning up the motor. If I advance the throttle and it won't move because it has too many cars coupled to it, would it still hurt it for just that short time the motor is stalled?

Your assumtion is correct if you are using straight DC and You have actually answered both your own questions if you think about it.
1. Instead of holding it, hook the locomotive to something stationary or near virtually stationary (too many cars) to perform the wheel slip test.
2. If the wheels are spinning because it is hooked to too many cars then the motor won't be stalled. If the wheels don't spin when coupled to too many cars you have too much weight in it.

There might be some point at which the wheel bearings could not support the weight or turn freely with that much weight on them. But, as Mark says, that would probably be in the pounds not ounces category.

With DCC it is not just motor slip but current draw. As you add weight the motor will consume more electricity. You would add weight until the wheels don't slip OR the current draw of the motor approaches the rating of the decoder. Leave some leeway because it will consume more "starting" than running.

[Anonymous]

Thank you.

Mark: True. It was hard enough finding room for just the 1 1/2 ounces!

TZ: Thanks. DC. I coupled it to a car and held the car and the wheels started spinning. I need to do some searching for info on current draw, amps and all that good stuff.

[canazar]

QUOTE: Originally posted by R.W. King

I'm adding some weight to a Athearn SW1500 to increase it's performance. So far I have added about 1 1/2 ounces and it seems to be improving, but how much is too much? I have seen mentioned in one of the MR locomotive reviews(Athearn GP60M) that adding weight can be done

For giggles and grins, would you happen to know the copy of the MR issue? I happen to have 3 of those RTR GP60s. I love them, but they are kinda light compard to others.

Thanks.

John [8D]

[Anonymous]

QUOTE: Originally posted by canazar

QUOTE: Originally posted by R.W. King

I'm adding some weight to a Athearn SW1500 to increase it's performance. So far I have added about 1 1/2 ounces and it seems to be improving, but how much is too much? I have seen mentioned in one of the MR locomotive reviews(Athearn GP60M) that adding weight can be done

For giggles and grins, would you happen to know the copy of the MR issue? I happen to have 3 of those RTR GP60s. I love them, but they are kinda light compard to others.

Thanks.

John [8D]

It's on the MR section of online reviews:

http://www.trains.com/Content/Dynamic/Articles/000/000/005/020imjnf.asp

[joeyegarner]

My personal oppinion...Load as much as you can get in it !! I don't think you can add too much to a Locomotive. There is only so much room on the inside of one anyway.

[twcenterprises]

Using your trusty amp meter, add weight until the motor draws just under an amp (about .8 amps or so) with the wheels spinning. Any current draw above that will drastically shorten the motor's life. Of course, you may not have enough room to add that much weight, in which case, add enough to make it "scale weight". A real SW1500 weighs about 250,000-260,000 pounds, which calculates to about 6.3 ounces, give or take.

Brad

[Budliner]

Walt Disney sat on his trains
now thats added weight
http://www.amazon.com/gp/product/1563420090/002-1981193-3634411?v=glance&n=283155

[doctorwayne]

When the wheels begin to slip, the current draw should drop from whatever it was when pulling a heavy train. If your locomotive draws 1/2 amp while pulling your train on level track, the current draw should rise if you run the train up a grade. The current draw will increase, depending on the weight of the loco, until the wheels slip, at which time it should drop. If you increase the weight of the loco and run the same train up the same grade, the current draw will increase to a greater degree than in the first scenario. If the wheels slip, the current draw will drop, depending on how much weight you've added, to a point not much more than that in the first example. If the train stops moving forward, but the wheels do not slip, the current draw will continue to rise until something fries: motor, decoder, power pack, or wiring.
I had an old Tyco C-630 that was powered by a "pancake" style motor mounted on one truck. Since the rest of the body shell was pretty much empty, there was lots of room for added weight. Unfortunately, the motor didn't have enough power to move the added weight if more than two cars were in the train. It also didn't have enough power to slip its wheels. The weight was removed.
As for most present day locomotives with all wheels powered, there's probably not enough room in them to over-ballast them, with the possible exception of those with full width carbodies, like E units or PAs. I have 3 Athearn U33Cs that have been ballasted to about 33 ounces, each with 2 Mashima can motors. One of them at full slip draws about .7 amps, the key word being "slip", even at a weight of 33 oz. Measured drawbar pull is 8.3 oz. each, which seems to be more or less a constant ratio: maximum drawbar pull (without traction tires) is about 25% of locomotive weight. I hope this information is of some assistance.

Wayne

[Leon Silverman]

You may not be able to weigh down a locomotive with a can motor to the point where the wheels will not slip. I have a Stewart Alco 630 with a jammed truck. The wheels on one truck would not turn, but the motor was still able to turn the driveshaft going to the tower. Now, that is torque.

[ndbprr]

BAck in the dark ages MR had a test rig for pulling power that consisted of a track and a mounted pulley at that end of it. A string was tied to the coupler and a coffee can that was filled with shot until the engine would spin its drivers. Ah the good old days. If you ever saw a Penn Line (now Bowser) engine the weight of an Athearn engine is inconsequential. Those old Penn Line steam engines weigh in at 3-5 pounds each and I have actually seen them cause roadbed to sag if left in one place too long or in an unsupported section of a layout. As others have said add away.

[Anonymous]

A locomotive is too heavy when it breaks through the benchwork, lands on your foot and it has to be amputated because it is crushed beyond repair. Until locomotives reach that limit, they are ok.

[Anonymous]

hold the loco on the track so it can't move (but don't press down on it) then turn the power all the way up and it should spin the wheels-there is too much weight if it doesn't spin the wheels or if they spin very slowly--they should spin but not too fast- yet quick enough so the motor isn't straining----you will be able to judge for yourself.

[Budliner]

see what the proto type weighs in at
and devide by 1/87th



lol

[SteelMonsters]

Actually, only length reduces by a factor of 87. Area reduces by a factor of 7569. Volume reduces by a factor of 658503.

A dash 9 for instance should weigh in at .588 lbs at 1/87th scale.

[espeefoamer]

Run the loco over a wooden trestle on your layout. If it falls through, the loco is too heavy.

MERRYCHRISTMAS!

[SteelMonsters]

No, that only means you should have put in a steel trestle.

[johncolley]

...you crank up the throttle, the locomotive groans and the whole neighborhood blacks out!

[Anonymous]

QUOTE: Originally posted by johncolley

...you crank up the throttle, the locomotive groans and the whole neighborhood blacks out!

Now that's funny right there! I don't care how you are!

While we are on this subject, what do you guys use to add weight to your locos?

[Anonymous]

QUOTE: Originally posted by twcenterprises

Using your trusty amp meter, add weight until the motor draws just under an amp (about .8 amps or so) with the wheels spinning. Any current draw above that will drastically shorten the motor's life. Of course, you may not have enough room to add that much weight, in which case, add enough to make it "scale weight". A real SW1500 weighs about 250,000-260,000 pounds, which calculates to about 6.3 ounces, give or take.

Brad

That's more of what I am worried about, and that is, the motors life. I have a P2K SD60 that must have some serious weight in it. The thing is probably the best running locomotive I own, but how long could it last lugging that much weight around? I read in a thread a while back about how a person was having trouble with this same locomotive(SD60) while running it for long periods of time (overloading the power pack). The SW1500 needed extra weight. I just don't want to sacrifice motor life for the ability to pull X amount of cars.

[Budliner]

I use car tire balance led

K-