Hi,
On my HO layout there is a 30 inch radius helix which makes the locomotives work quite hard. So, to pull up a 38 car freight four six axle Katos are used. They seem to do quite fine, but was wondering what difference traction tires would make. One of my engines is a Roco bought last year new with four traction tires. So put it in front of the freight and it pulled the train nicely. After 4 times up and down the layout I noticed the motor getting quite hot.
With this result I took my multi meter that has a thermocouple attachment and reduced the length of the train to 26 cars. Again, put the Roco engine in front of the train and pulled it up the helix, three times. The temperature from the motor went from 72 at rest and room temperature to 78 to 82 to 88 degrees Fahrenheit.
Next, took a Kato SD70mac and again, at rest the engine was at 70 which is room temperature (previous measurements were taken the day before), then the motor went to 73, 79, 82 and this is the temperature it remained at after 10 minutes of continues operation. This was with 12 cars in tow going up the helix spinning all the way up so by no means light load for the locomotive.
So my question is that since the big steam engines that pull 60 or more cars do not have a much bigger can motor then the diesels, how long do they last? Can you feel them getting hot inside the locomotive when you touch the shell?
If my Kato does not heat up any more then this then it is safe to say that spinning the axles under load will not hurt the engine, since the motor does not increase in temperature, which puts to rest my fears of burning the motor out.
What are your experiences?
Frank
"If you need a helping hand, you'll find one at the end of your arm."
I have 3% grades. The only two engines I routinely subject to heavy trailing loads are the BLI Pennsy J1 2-10-4 and the PCM N&W Y6b. I have 16-18 BLI 'loaded' H2a hoopers plus a caboose on the J1, and can't say I have every felt it more than just slightly warm...hardly noticeable. As for the Y, I think I could tow a brick behind it with the brick dragging right on the rails. It never gets warm, even with 20+ cars on those grades (mind you, I run it at drag freight speeds up that grade, so maybe 15 scale mph).
Also, I don't run my trains for 20 minute or an hour. I run them maybe four minutes, park them suitably, and move on to another consist.
-Crandell
I have no experience with traction tires (although I'd expect the motor to burn out if it can't turn under load), but know that spinning of drivers increases wear. My advice is to shorten trains, or add more locomotives if your system has sufficient amperage, and stop the spinning.
Mark
I don't have a helix, but I have long stretches of 2-2/14% grades on the Yuba River Sub. The heaviest trains I run are about 25-30 cars behind my heaviest locomotives (2-8-8-2, 2-8-8-4), but like Crandell, it's usually for just one trip around the layout. I don't have traction tires on any of my locos, so sheer weight and careful balancing is what keeps them pulling. I've never noticed any warming up of my motors, either can or open-frame, even at scale speeds (15-20smph).
When I do assign a non-articulated loco to a heavy train, I either double-head or include rear train helpers. The last thing I want to see is spinning drivers, LOL!
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!
that's why the real thing have that big ammeter sitting in front of the engineer marked with the allowable time in each zone.
i don't have any mainline grades over 1 1/2% and a pair of atlas HO geeps will handle anything i ever want to run. more than 2 and i am just showing off. never burned out a motor in 50 years of running 35/50 car trains.
grizlump
Things electrical (motors, transistors, IC's etc) heat up when they are working. Long as they don't get too hot they will last a long time. Rule of thumb. If you can lay the back of a finger on the part for the count of ten, it's not too hot.
Electric motors are quite rugged. They will run happily and hot for years. The common failures are bearings and wiring faults, neither of which are very temperature sensitive. So, long as you can lay the back of a finger on the motor, it's fine.
You do want to make sure the motor doesn't stall. Motor current varies with speed. As a motor is loaded down it draws more current in an effort to keep turning. If the motor cannot turn at all, it will get quite hot. On model locomotives, as long as the motor can spin the wheels should the train get stuck, it will be OK. In HO is is difficult-to-impossible to pack enough lead into the model to prevent the wheels from slipping.
David Starr www.newsnorthwoods.blogspot.com
Traction tires allow the motor to be overloaded.
Without traction tires, the wheels will almost always spin before the motor is overloaded - assuming the mechanism internal load is reasonable. Spinning wheels do not protect the motor from mechanism and gear binds.
Spinning the drive wheels does put some additional wear on the locomotive mechanism (not the motor), but so does running maximum loads (without spinning drivers) for prolonged periods. How much wear is too much is an interesting question in light of modern Chinese plastic production with no spare parts.
The best way to monitor load at the motor is with an ammeter. And if you can find out the maximum continuous current rating of the motor, and keep the load to less than 80% of that value, you will likely never have a motor problem.
Large die cast steam engine models typically have a motor rated for a little more current than a plastic diesel model. They also have significantly better airflow for cooling the motor. But reality is that those large steam engines don't pull 60 car trains very often. If they did, wear could be a real concern. Cudaken is probably the poster child for frequently pulling long trains with his large steamers, and he has experienced wear issues.
The older US made die cast locos, and many (but certainly not all) brass locos, have more rugged drive trains than today's plastic production. Steel worms and brass worm gears have longer lives than their plastic counterparts - but are often noisier and certainly more expensive. Bearing inserts are replaceable when worn; axles riding directly in soft metal frame slots are not. On steam engines, the hardness of the material used for the side and main rods impact their longevity. I have seen O scale steamers with inserts added into the holes to prolong the life of the rods.
my thoughts, your choices
Fred W
da_krautOn my HO layout there is a 30 inch radius helix which makes the locomotives work quite hard. So, to pull up a 38 car freight four six axle Katos are used. They seem to do quite fine, but was wondering what difference traction tires would make. One of my engines is a Roco bought last year new with four traction tires. So put it in front of the freight and it pulled the train nicely. After 4 times up and down the layout I noticed the motor getting quite hot.
Have you considered placing a cooling fan either on top or bottom of the helix to move air through the helix area?
Spinning wheels is a good indication that you either have too long a train or not enough power to pull it. Continuous wheel spinning will cause excessive wheel and rail wear.. You didn't mention whay grade % you have in the helix. A curve on a grade can easily increase your net grade % by 50%, so a 2% grgrade can actually act more like 3 to 3.5%.
Kato locos, as great as they are, are not very heavy, any weight you can add to them will help. I try to get my locos to around 18 to 20 ounces.
A rule of thumb I use: 10 weighted cars per 4-axel engine, 15 cars per six-axel engine. With today's high efficiency motors the max current draw at full load shouldn't be more thsn .75 amps per engine.
Jay
C-415 Build: https://imageshack.com/a/tShC/1
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modelmaker51Spinning wheels is a good indication that you either have too long a train or not enough power to pull it...
Sort of....but not really Spinning wheels means insufficient traction for the trailing resistence, assuming the engine can actually move itself on the grade. So, if the wheels spin, there is lots of power, just insufficient weight over the tractive wheels. If you add another 60 gm of weight to the engine, and that enables it to grab and continue to tow the trailing resistence, then power is not an issue.
If one can't reasonably add to the engine's weight, and thereby improve traction, or if one can't swap out traction tires and get the same needed traction, then yes, trailing resistence must be reduced...drop cars. Or, reduce the grade.
Hello,
Thank you everybody for all of the replies. They certainly all are great points to keep in mind.
My helix has a grade of 2.2%. I was aware of the increase in drag friction going around a curve, but not by as much as 50 percent. That is a lot. Also good to hear that the motors in the locomotives are powerful enough so that there need not be any worries about burning them out. Being an electrician I wish the manufacturers would post the rated full load current of the motors they put into the locomotives. Then one could weigh the engines to such a degree that they would loose traction at 80 percent of full load current.
Again, thank you for your advice.
I have run 80 loaded hoppers with 2 steamers up front and 2 pushing on the clubs long grade of more than 2% leading into a 7 turn helix. My advice is use distributed power after you speed match your locos. This cuts down the load on each loco for the ruling grades. With all the locos up front they tend to pull each other and the train. I have also noticed that my 0-6-0 can push many more cars than it can pull for some reason. On flat level track it pulls 20 cars but it can push 26 cars before the drivers slip for some reason. Perhaps its the way the draw bar is attached and where the pilot coupler being slightly lower.
Pete
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
locoi1sa I have also noticed that my 0-6-0 can push many more cars than it can pull for some reason. On flat level track it pulls 20 cars but it can push 26 cars before the drivers slip for some reason. Perhaps its the way the draw bar is attached and where the pilot coupler being slightly lower.
I have also noticed that my 0-6-0 can push many more cars than it can pull for some reason. On flat level track it pulls 20 cars but it can push 26 cars before the drivers slip for some reason. Perhaps its the way the draw bar is attached and where the pilot coupler being slightly lower.
My theory is the engine becomes slight skewed when pushing, thus creating more friction/traction on some of the drivers.
For most good quality HO scale locomotives, the motors can handle more weight than it's possible to add. The problem with adding weight and using traction tires is that a point can be reached where a train is too heavy to be moved by the loco and its wheels are unable, because of the traction tires, to spin. Continuing to apply current can damage the motor under these conditions.
Even the notoriously poor-pulling Athearn Mikado was able to move a sizeable train (I don't recall the car count) when I draped a 24oz. "saddle" of sheet lead over its boiler. I continued to add cars until it spun its drivers, and the motor was barely warm to the touch. Since there was no chance of concealing that much weight within the loco, the actual car count didn't really matter.
The loco shown below is at its maximum weight (32 oz. balanced) and can just barely slip its drivers under a heavy load:
This loco, also 32 oz., could easily handle more weight and still slip its wheels - problem is, there's no place to hide more of it:
Wayne
fwrightCudaken is probably the poster child for frequently pulling long trains with his large steamers, and he has experienced wear issues.
Some how I knew my name would come up! My ware issues is because I run my trains a lot. I did ware out my Y6-b PCM, but it was the engines mounting points (no lube) and I have fixed the problem. My two PCM models Y6-b and Big Boy do have bigger motors than my BLI steamers or any of my diesels.
One of the reason the engine may feel warm to the touch is because the shell dissipates heat better. To me that is a good thing. Holding the heat in is a bad thing.
If you are looking for steam power, the PCM Y6-b is a monster and I love the Loksound decoder it came with.! Hauled 70 coal cars up a 1.5 % grade at K-10 Model Train Christmass party and was not working hard. String lined at 100 cars, but the engine was not the problem.
The Y6-b.
Braking stuff again, Cuda Ken
I hate Rust
da_kraut...good to hear that the motors in the locomotives are powerful enough so that there need not be any worries about burning them out. Being an electrician I wish the manufacturers would post the rated full load current...
Frank, the decoders are actually the limiting devices because they will allow their magic smoke to issue from their plastic covers if they draw much over 2 amps for much more than two seconds. The decoder costs as much as the motor replacement (if a low function, non-sound decoder), or seven or eight times as much as a replacement can motor if it is a sound decoder with various functions.
In fact, the way to test the stall current, as I understand it from descriptions, is to get a RAmp Meter that tests under DCC current connected to the rails, start the engine quickly at full throttle and clamp it firmly (very carefully!) against the rails, and let the amperage build until you get a max reading, then instantly let go to allow it to slip and/or reduce the throttle speed to zero.
cudaken If you are looking for steam power, the PCM Y6-b is a monster and I love the Loksound decoder it came with.! Hauled 70 coal cars up a 1.5 % grade at K-10 Model Train Christmass party and was not working hard. String lined at 100 cars, but the engine was not the problem.
No doubleheading?
A buddy of mine does that with them doubleheaded. And he usually has between 70-90 cars behind.
BTW--Ken--Love the picture of that Y6-b.
Any argument carried far enough will end up in Semantics--Hartz's law of rhetoric Emerald. Leemer and Southern The route of the Sceptre Express Barry
I just started my blog site...more stuff to come...
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I ran my new Paragon 2 Y6b with diecast bolier and traction tires 2 times around our 20X60 club layout max grades were 1 1/2 -2% with 100 nicely weighted cars with easy rolling metal wheels and though it was very empressive have no plans on repeating it in the future. 60 to 70 cars is plenty empressive for me.
http://www.youtube.com/watch?v=d43t-ms3yJI
Another thing that adds to heat buildup is lack of airflow within the engine. You don't say if you are running DC Analog or DCC Digital but keep in mind that without airflow the decoders can also put out a lot of heat. John