Way back in the 50s. There was a guy who created CO2 driven engines. The tender had dry ice generate the CO2 and a motor opened the valve to release the gas. As I remember it suffered from an occasional freeze up but it ran like a real steam engine. Hard to believe that was around 70 years ago
I suppose what I was driving at was realism and to my mind the single decoder would be the way to go (or 2 programmed identically maybe, even in my case straight DC) because I wasn't thinking of inducing slipping but if there were slipping then, given even weight distribution and adhesion, it would more mirror the real world insofar as the steam is not independently controlled. Perhaps for those pulling the heaviest trains the current system helps as it acts a bit like a locked differential because the more I think of it you may end up with one of the engines being quite prone to slipping way before may be practical. So we may be back to dual decoders..........
It's great having these insights though. It's something that's always been bugging me. So thanks everyone for the contributions.
Those are excellent videos Hrvoje
It has already been done before. But only by those who know how to program a DCC decoder to do such thing.
The only thing that prevented me from creating slipping wheels effect in my e.g. Athearn Big Boy is lack of such DCC decoder. In mentioned locomotive there is enough place for two smaller motors, e.g. 16 x 19 mm. The problem is that then these motors has to be controlled independently by two DCC decoders, to achieve one wheels set to slip. One can be without sound, but the other is better, if has sound - and this decoder must have one function that is imitating sudden wheel slip not by sound, but with motor movement. Then sound will follow.
I have seen a video on Internet some years ago, with Australian Garrat locomotive. Two motors (like Mel did), and two ESU decoders. The owner somehow preprogrammed one of the decoder for the above mentioned effect - basically, all what is required is when one function button is pressed, motor receives sudden "voltage burst", e.g. from 4 V, voltage suddenly increases to 12 V. Unfortunately, I could not find it again, to post a link here.
Tsunami 2 has slipping wheels sound effect (when certain function button is pressed), but from reason unknown to me, they did not follow in motor control section this effect. If they did, nothing would prevent modellers doing just what OP asked at the beggining. In fact, then a sound effect would not be needed.
I am surprised that ESU USA has not offered that a years ago (e.g. when Full Throttle feature was offered for diesel), especially having in mind a lot of articulated locomotives that US modellers have, and a fact that in general, US trains (locomotives) a bigger than elsewhere, meaning that there is more space to fit two motors in one locomotive.
In Europe, you can buy locomotives prepared for similar effect, only they are not for articulated, because they are rare here. But, decoders are obviously preprogrammed as I explained above.
Two videos (captions are unfortunately in German). For the first video, the story is that in the first locomotive, a young inexperienced driver is having a lot of trouble to control the locomotive .
Hrvoje
Oh you could, but that defeats the purpose, because IIRC one decoder can only control one motor, so if you want the independent control of each set of wheels(to get the first set of wheels to spin first), two decoders would be reqired.
Charles
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Modeling the PRR & NYC in HO
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Thanks for all those insights fellas.
Mel,
That's particularily good work there. I have to say I have a Rivarossy Big Boy from waaaaay back and I used to use it regularily on a layout I had in the mid 90s. I always felt it was a good runner and decent puller. Dissapointingly I don't have a layout at the moment but that's life when you're on the move as much as I am.
As far as the comment on the dual decoders goes, and I hasten to add I'm a DC dinasaur but what stops both units if they're smaller motors taking the power from one decoder?
Mel, my experience with Rivarossi didn't include articulateds. Always wanted a Challenger, but never pulled the trigger. I sure killed enough smaller ones in my younger days trying to slow them down. I have one remaining, the Heisler, which ran fine, better with additional pick-ups. Dan
I never opened up my Rivarossi Big Boy, and I suspect there is only one motor. But the decoder has sounds that simulates out-of-synch drivers. To me, that's the key...
Simon
Yeah, Bowser made it both ways. The one I played with was a single motor. That thing was so stiff thatit just overloaded the DC power pack we had available. What actually got it going was using address 00 on DCC. The harch pulses broke everything free, and after a few laps in both directions, it then would run on the DC power pack. It really needed a complete teardown - the person who built it didn;t have a layout to run it on, so he tooks ome liberties with painting things for example, mostly assuming it was going to be a shelf queen and not get to run. So after cleaning the paint off all the rolling and contact surfaces.... it still wouldn;t go. You could turn the motor by hand, but it drew more current than the old MRC power pack could handle. My Zephyr with 2 1/2 amps was able to get it to go though. Once it had some break in time, it ran a little better.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
dknelsonDidn't Bowser use two motors for their Pennsylvania RR T1
As I recall (I never owned one) the T1 model could be built in several versions, and at least one of the 'two-motor' versions just duplicated the mechanism to the divided drive -- no conjugating shaft in that version that I recall. (I remember this detail as I was working on deconstructing Riley Deem's 'geared' conjugation for Q2s at the time I first came across those!) There were any number of two-motor GG1s, as I recall, that did much the same thing; it would probably be harder to make a suitable shaft with universal or bending couplings and splined length adjustment than just to duplicate the motor and gears with stock parts.
I'd be surprised to find there weren't other 'two-motor' types that just put a second motor in the chassis and connected it via leads in the pre-DCC age. I think I may just have assumed that 'larger' articulated prototypes would be expected to be the equivalent of two smaller powered models, and be given motors appropriately...
Didn't Bowser use two motors for their Pennsylvania RR T1 (which I know was not an articulated prototype). I think the Penn Line original used one motor and some sort of flexible shaft for the second set of drivers and Bowser changed that. But Bowser might have connected the two motor shafts with a flexible coupling. You could omit the coupling in the never ending goal to make the model as slippery out of the station as the real locomotive!
Dave Nelson
I'm sure it is possible for manufacturers to make artic. locos have independent drives...it would basically be like the Athearn up dda40x model...with two motors and two decoders. Seems like too much extra cost for an additional motor and decoder though, I think consumers would rather pay $100 less, and live without that first set of drivers momentarily starting first.
Then again, that's why if I wanted to buy an MTH GS-4 Id buy an older version, since the smoking whistle adds $100 to the price tag IIRC.
Maybe I underestimated how much consumers are willing to spend on the latest RTR model, but that's my . But hey, if they can manage adding more features in without raising the price, Im all for that!
PS maybe you could just add some thicker grease inside the rear pair of drivers to achieve a "similar" effect
I have to agree about the smoking whistle! Same with all the radio chatter on sound decoders. Not very realistic for the vast majority of steamers. Seems the manufacturers could better spend the money on good quality gears!
Westside Model Co imported some brass articulateds with each engine powered with it's own motors. The Virginian Triplex model for one actually had 3 motors so each engine had it's own power.
oldline1
Southgate Very cool, Mel! Anyone who can make Rivarossis run well has my respect. X 17! Dan
Very cool, Mel! Anyone who can make Rivarossis run well has my respect.
X 17! Dan
Heck yes it's been done in HO brass, and the mechanisms do not last according to Hal Maynard, a noted collector and painter of brass.
During the late 1990's W&R imported delayed motion articulated gearboxes made by Samhongsa, that allow the front engine to slip and begin moving independently of the rear engine. They were about $80 per set of gearboxes purchased from Balls of Brass (Jon Winston). My friends bought many sets of them at the time.
Only thing is they have a pair of small and delicate gears in them (to achieve the independent starting motion) that do not last, so now, those gearboxes are failing in the Samhongsa articulated steamers.
Hal just replaces them with other gearboxes.
John
My Model Railroad
http://melvineperry.blogspot.com/
GP025 Not sure if this would qualify to what you mean- but some of the W&R brass articulateds would allow the front engine to slip a quarter round on starting before the mechanism would lock up both sets. Apparently it was adjustable as well. Still with just the one can motor. Kinda neat, but out of my price range! Kevin
Not sure if this would qualify to what you mean- but some of the W&R brass articulateds would allow the front engine to slip a quarter round on starting before the mechanism would lock up both sets. Apparently it was adjustable as well. Still with just the one can motor.
Kinda neat, but out of my price range!
Kevin
That's interesting. I will do a bit of research on that one. Thanks.
I would love to know whether, in the race to produce the next selling point fo HO steam, whether or not any of the manufacturers have considered powering the driver sets of articulated locomotives independently a la real thing?
Or was this ever tried in the past?
Just seems as though this would be a good selling point in terms of realism. To me at any rate more so than a smoking whistle that looks like a cigarette in an ashtray more than it does steam at boiler pressure.