DCC Reccomendation for 3 Truck Shay?

[wizard]

I am looking for a reccomendation for a DCC system that will work with the factory installed DCC and sound of the new 3 truck Shay.

It may be the only engine I will have with DCC or I might add DCC to other engines.  I'm not looking for something that is wireless, just something that can sit where my other controllers are.
Any help would be most apprciated as I am totally lost.

Thanks!!!

Karl

[Jim Banner]

You cannot run DCC and dc on the same track at the same time.  If you are already wired for dc, why not run your Shay on dc?  Locomotives fitted with DCC decoders can be run on dc with no modification required.

[bobgrosh]

Hi Karl.
I hate to disagree with Jim, but, you CAN run DCC and DC at the same time.

If you are wired for DC, even if you have switches to kill some sidings, just insert a DCC command station\booster between your DC power controller, and all the track.

Turn the DC all the way up, select locos 0 to run any DC loco, and then select loco 3 to run your new DCC shay.

You can still control any one DC loco, park the others on isolated sidings just like before.

Advantages:
All the passenger cars and the selected DC loco lights will be on full brightness no matter what speed you run the DC loco.
You will have full control over all the special sounds and lighting in the new shay.

As to my recommendation, Buy an 8 amp Digitrax DCS200 combination command station/booster, (about 249$)

Also, you will need a throttle, either the Digitrax UT4 (about 65$) or a DT400 (about 145$) You really don't need anything else.

The reasons I recommend these:
1 - the command station puts out 160 watts.
2 - the command station supports DC locos as loco 0
3 - the throttle is a good match for the features in the Tsunami sound card. IE You can "play" the whistle simply by pressing lighter or harder on the whistle button. The Digitrax and Tsunami cards both support the same advanced functions (like feedback) that you may want to take advantage of in the future.
4 -  both of the above throttles will work great when tethered and placed next to your existing control panel.

Bob

[Jim Banner]

Bob is correct.  You can run a dc locomotive on DCC.  What I should have said was that you cannot connect a DCC command station and a conventional dc power pack to the same track at the same time.

Some large scale dc locomotives should never be run on the DCC version of dc.  These include certain LGB locomotives which have coreless motors.  Some physically small motors do not do well on DCC type dc.  I personally smoked a Bachmann hand car in less than 5 minutes on a DCC track.  And if you use any Big Haulers or other locomotives with poorly ventilated motors, you should consider installing fans to prevent motor burnout. 

The "dc" from DCC command stations is really ac with a dc component.  The ac heats motors, even when the locomotive is stopped.  This effect is worst with coreless motors which have no iron mass to help conduct the heat away from the windings.  It is also bad with motors that have little or no air flow to cool them.  Bottom line, you can use DCC to control a dc locomotive but do so with caution.  Monitor motor temperatures until you know how your locomotives react, and be aware that the worst heating generally occurs when the locomotive is standing still.

[bobgrosh]

Some large scale dc locomotives should never be run on the DCC version of dc.  These include certain LGB locomotives which have coreless motors.  Some physically small motors do not do well on DCC type dc.  I personally smoked a Bachmann hand car in less than 5 minutes on a DCC track.  And if you use any Big Haulers or other locomotives with poorly ventilated motors, you should consider installing fans to prevent motor burnout. 

Jim, could you please tell me what LGB locos have coreless motors?

I have run all my non-factory installed LGB locos on DCC as loco 0 for at least some period of time prior to installing a decoder. None have heated up or even become slightly warm while just sitting on the rails. Some were run on DCC for months prior to me getting around to chipping them. I leave my outside track powered 24-7 and there is usually one DC loco on it all the time. I don't take the locos in at night and often don't chip a loco until I'm satisfied that it pulls well and runs smooth.

I also have an older DCC command station powering my display shelves where I store some locos that are just not suitable for my outdoor railroad. These include several without decoders. The locos include Bachmann, Aristo-craft and USAT. Analog (unconverted locos) from Bachmann include a Big hauler, an Annie, a 2-truck Shay and a open trolley. Some of these locos have been there for over 5 years. I keep them powered by DCC so the lights are on. It makes them look nicer on display, especially at night when they also serve as a night-light for my office. I just checked all of them and the only heat being generated is from a couple of the headlights. (I also noticed I burned out two bulbs.) I went out to the garden shed and fetched a throttle, and plugged it into the spare command station.Selecting loco 0 and nudging up the throttle a little, all of the locos moved or slipped their wheels, (I have wheel stops on all of them to prevent accidents). So, none of them ave burned out, even after 5 years on DCC.

There was a recent discussion on a DCC forum about this subject. It seems to be a common Urban myth that running a DC loco on DCC will burn it out. In theory, a SMALL coreless dc motor, like those used in "N" scale should over heat and melt the glue used to hold the motor windings in shape. In reality, Nobody could say that it was DCC that made this happen. Most locos that had failed on DCC without decoders also had a reputation for failing with decoders and on plain old DC. After a rather heated discussion, it became apparent that some testing needed to be done. Some reported that a typical HO locos , running at 12 volts in free air with no load got fairly  warm, the same motor with DCC applied but not running generated heat that was barely measurable, less than one degree. Running on stretched DCC at the same speed as 12 volts DC raised the motor to the same temperature as running it on DC at 12 volts. Many were surprised that there was almost no discernible difference.

By the way, I USED to have a Bachmann hand car. I should have known better than running it on a LGB Jumbo 5 amp DC supply, Having more amperage available than that provided by the Bachmann starter set was not a good idea. One little bind or one sudden stop and 5 amps will fry most small motors. So, my question to you is, was it the DCC signal that burned out your hand car, or was it because you did not have a 1 amp fuse in line with your 10 amp system?

[Jim Banner]

Bob, I am glad to hear that none of your locomotives over heats on DCC.  Obviously you have taken the time to check, which is what I advised Karl to do.  I have to agree that over heating is more common in the smaller scales, both because they have physically smaller motors with less thermal mass and because those smaller motors have less inductance, thus lower impedance ("ac resistance"),  making it easier for the ac component of DCC to pass through.

As far as LGB locomotives with coreless motors goes, the Chloe leaps to mind.  Closer to home, I have rebuilt/replaced the motors in several Bachmann pre-Annie 4-6-0's that were run on DCC type dc.  But to be fair, I have also rebuilt/replaced motors in ones that were fitted with decoders too.  I cannot say for sure how they were run - they were not my locomotives.  I suspect their relatively small motors with no air cooling are particularly susceptible to pulse drive, be it in the form of DCC type of dc, motor controller output, or even pulse power pack.  Then again, these locomotives can overheat on dc too.  I would be interested to hear whether you have any of these older ten-wheelers on your display and whether they over heat just sitting.  I long ago got rid of all over heating problems in my own ten-wheelers by installing microprocessor fans in them.  With the fans, they can run all day with 15-16 cars and not over heat.

The hand car in question burned up its motor when run by a Digitrax Zephyr  (2.5 amp output.)  This is about the same current a conventional 1 amp power pack puts into a dead short, at least until the circuit breaker trips out.  This is actually an advantage of using a command station as a dc source - if overloaded, it instantly shuts off its output without any circuit breaker delay.  As far as adding a 1 amp fuse, putting one in series with the power supply would stop you from running more than the one unit at a time, which defeats the whole purpose of DCC.  If a fuse were necessary at all, it would be better to install it inside the mobile unit.  That would then limit the current in that unit only.  To make the motor draw excessive current would require a faulty unit, either a mechancial fault in the mechanism or an electrical fault in the motor.  Were we both dealing with faulty units?  Could be.  But try explaining that to the proud owner.  In the meantime, I have quit test running anything on DCC type dc because urban myth or not, a customer is more easily convinced that his unit was faulty if it was tested on a plain old fashioned dc power pack.

Which DCC forum was the discussion about over heating on?  I would like to read it and see how they did their testing.

[Curmudgeon]

Ah, Jim.
Coreless motors in lgb?
I've had to work on quite a few.
Mabuchi cans, maybe, but I have yet to see a coreless motor in one.
Yanked some apart to see what made them fail.
Standard armature and magnets.
That includes the little plantation engines.
Now, granted, they may have for a while, in some, but even the local lgb repair and sales place scratched their heads.

The little Porters now for sure have Mabuchi's (irregardless of hyped-up marketing releases).


On Anniversaries....... there are no part numbers on the motors from Mabuchi, I have inspected all types.
Identical.
Same 5-poles, all 4-6-0's except Version 1.

As far as eating motors up, low frequency PW will do motors and gears, especially with the mass of LS.
The cheap Mabuchi motors will do it for no real reason, especially if locked up drive or too much weight in the loco.

That said, I don't think I've lost a Bachmann motor in all these years.
Buehler cans, yes, but the Mabuchis just run until I re-chassis them.

[bobgrosh]

Hi again Jim.

As always , you make some very good observations and comments.

I have one Annie, and one Big-hauler. The Big Hauler is 10 to 12 years old and was part of a set that I think included two circus cars. It was my very first "G" loco. It ran on DC for a year, was converted to batter/RC, then converted to DCC for about 2 years. When I took it out of service due to UV
deterioration, I removed the decoder and converted it back to it's original DC. It has been on the DCC powered display .track for at least the last 5 years. And Yes, it still runs and does not heat up while on the DCC track. I should have mentioned that I run the Display track at the 12 volt setting on the Digitrax 5 amp command station to reduce the brightness of the lights. However, Locos outside run at 22 volts and do not seem any warmer when just sitting.

Yes, The fuse should be in the loco. .

I have the LGB Chloe, and it's sister, the Olmana, and 12 of it's cousins, both steam and diesel Field railway locos. All of them have the same motor. I have had one of those motors apart. It is not the Famous LGB Bueler 7 pole ball bearing motor found in other LGB locos, but instead, a smaller 5 pole  iron core motor with bronze bushings. Many of mine are no longer in service but still have the decoders, the field locos are not displayed on powered track because they have no lights. The only ones that have lights are the Chloe, Olmana and two of the field locos that I added lights too. They are still in service and are outside. So, as you can see, I don't have any long term use of non DCC Chloe locos, as compared to the Hauler or Annie.
I DO have two brand new Field loco diesels that have not yet been converted to DCC. They have been outside on the 22 volt layout and are powered by DCC.  These have the exact same motors as the Chloe.  While it is rather chilly here today, (about 50 last night) I just checked them, and, they seem stone cold. I didn't open them up to feel the motor, so it is possible that the motors are a little warmer than the outside of the motor block. They have been out there for a couple months sitting on DCC powered track.

So, we seem to agree that older Big Haulers sometimes have motors burn out, on DC or DCC. Each of us has had a motor fail in a hand car, one on DC one on DCC but both of them on power supplies larger than 2.5 amps.

Neither of these two facts seem to point to DCC used to run DC locos as the culprit. All of my research shows that this is still just an urban legend, It's history seems to be from the days of pulsed DC packs using SCR's where the pulse rate was much slower than today's DCC. I just don't see any way that a "G" scale loco could have a motor that has such low impedance that at DCC frequencies it would draw enough current to heat up. But then, maybe I'm wrong.

Right now I still have nearly a dozen un-chiped locos waiting for enough run time to convince me they will fill the role I intend for them. This is somewhat normal for me. I usually run a loco a month or two prior to doing a conversion. Usually, that means new locos wait while till the current test subject has proved it's worth. Nearly every loco that did not come with a built in decoder has run at least 10 hours and spent a minimum of a couple weeks sitting sitting on DCC prior to conversion. I have never had a single problem related to motor burnout or over heating when trying out new locos using DCC and pulse stretching. I consider the ability to run a single unconverted loco on DCC to be one of the most valuable features of DCC. Since I eliminated all the old block wiring, switching back to DC to test a loco is not practical for me because all the decoder equiped locos would convert to DC ans start running at the same time. Using loco 0 pulse stretching lets me test a new loco while the rest of the locos are still running normally.

It may be archived but the last good discussion on DCC pulse stretching was  was on the Digitrax Yahoo forum.

[Jim Banner]

Thanks, Bob, for your tests and in depth analysis.  You have convinced me that it is most likely an urban legend. 

Thinking back, the only locomotives that I can say for sure died from pulse width control were some Tycos in HO scale that I burned up testing a form of carrier control back in the sixties.  In large scale, it is hard to say for sure what caused the damage, except in cases of flagrant under lubrication. 

I like your program of thoroughly pretesting locomotives before installing decoders as it weeds out problems that otherwise might well be blamed on DCC.  Unfortunately, when I install decoders for others, they want the locomotive back yesterday, so other than applying power to the wheels to see that they turn, not much testing gets done.

I am not sure where I originally heard about coreless motors in LGB - it is something I had filed away in my head with a red flag attached.  I just Googled LGB coreless motors and George Schreyer's site came up.  I believe he was talking about older (maybe very old?) Chloes, so I am left wondering if they switched to another line of motors when DCC came out.

I am afraid that any outdoor testing up here in the frozen north will have to wait until spring.  Our present temperature is -16 C (about 3 F).

All the best for Thanksgiving.