Hey brianel027…installed the spring this afternoon and it completely resolved the problem…much thanks. I was so pleased I lashed it up to one of my road’s longer freight
drags in run 8 just to see if I could put it on the ground…not a problem even with intentionally starting up on a long curve-great suggestion.
<<Also bear in mind gang with kooljock Jon’s list that the William’s Alco is really in a whole different league from the Lionel and K-Line versions we’re discussing. The Williams units are closer to scale in size and very very nicely detailed. They could win the competition against other even better quality Lionel engines. >>
Actually, Williams makes two different Alcos–the scale version and a smaller version (very similar to the small Lionel Alcos) for the Golden Memories series.
<<You guys will notice that where these engines tend to “growl” the most is going around curves.>>
The growl you hear at low speeds and going through curves arises because the AC track power is full-wave rectified but not filtered before being fed to the DC can motors. The motors are thus getting unfiltered DC. This evidently causes the motors to vibrate, and these vibrations are what we hear as a growling sound.
To quiet these engines and other engines of similar design, I have built an auxiliary box that converts the AC to filtered DC (using a full-wave rectifier and a lot of capacitance) before feeding it to the track. With filtered DC, these engines run VERY quietly.
However, DC track power does not work with engines that have horns, since DC may activate the horn constantly. Also, with filtered DC, these engines do not handle as well–they tend to start suddenly and can be hard to control at slow speeds. Unfiltered DC actually spikes the motors 120 times per second, which causes the growl but also overcomes stiction in the drive train, thus allowing the engines to start smoother and run better at slow speeds. Finally, DC track power can magnetize the solenoids in track-powered switch machines, resulting in rather bizarre behavior; fortunately, the solenoids seem to become demagnetized when operated by AC again.
Richard Bjorkman
“To quiet these engines and other engines of similar design, I have built an auxiliary box that converts the AC to filtered DC (using a full-wave rectifier and a lot of capacitance) before feeding it to the track. With filtered DC, these engines run VERY quietly.”
Richard, what do you mean or do for the capacitance?
I didn’t mention here, but I have pulled circuit boards from a number of my locos and run them on straight DC current. I find the engines do run more quietly and much smoother with consistant speed. Although there still is a little growl noise on the curves over the straight. I have also removed one traction tire from each truck if the two are on opposite sides of the same truck. I adhere the remaining traction tire with 3M carpet tape.
Now, it’s been said that no 2 motors of this type run at the exact same speed. So I’ve also tried experimenting with just motorized truck. Again there is still some noise on the curves. The only units I’ve left as single motor units are my Budd Cars, since I tend to run on their own or with a couple of extra passenger cars. Part of this was motivated by some of the single DC motor locos I have - like the Lionel steamers, Docksides, and Industrial Switchers - which all run quietly.
I have noticed some noticable inconsistancy with the tightness of the gears in some K-Line engines. On one MP-15 from the Overland Set period, the gears are very tight, and although they do turn, it takes more effort to do so. I have also found (for whatever reason) that some of the earlier made locos (manufacture date, not model type) run smoother and more quietly than newer ones.
Just some of my observations. Curious to know more what you did Richard. Thanks.
Just a clarification: As Richard states above, I was talking about the Williams “Golden Memories Series” ALCo FA, not the earlier scale offering.
The scale version is actually one of the few out there with a fixed pilot, and is indeed in a totally different class than the units we all know and love.
Jon [8D]
<<Richard, what do you mean or do for the capacitance? >>
The crux of the matter is that not all DC is the same.
If you run AC through a full-wave bridge rectifier, you get what is known as full-wave rectified AC or pulsating DC. This is what Lionel and K-Line do on their inexpensive engines. The resulting wave form is a pretty rough 120 Hz wave. It will run a DC can motor but, because of the roughness, is rather noisy.
The next step is to apply capacitance to filter the pulsating DC. This smoothes out the electrical wave form so that it approximates a horizontal line. This is what I did, and the result is very quiet operation of previously noisy engines. By the way, the more capacitance, the smoother the horizontal line; the smoother line, the quieter the engine.
(There is a third step you could go through–voltage regulation using a solid state voltage regulator. I did not bother with this, and I wouldn’t recommend that anyone else do it either.)
So let me try to describe what I did:
The box I built has four terminals. Two are AC input from the transformer, the other two are filtered DC output to the tracks. The output terminals are marked + and -.
I bought a heavy duty full-wave rectifier at Radio Shack and three of the largest-capacitance electrolytic capacitors Radio Shack has (don’t have the part numbers at the moment). The rectifier has four terminals, two marked with a squiggle, one marked with a +, one marked with a -. The electrolytic capacitors have two terminals, one with a + and one with a -.
Wire one of the input terminals of the box to one of the squiggle terminals of the rectifier (doesn’t matter which one).
Wire the other input terminal of the box to the other squiggle terminal of the rectifier.
Wire the + terminal of the rectifier, the + terminals of all three capacitors, and the + output terminal of the box together.
Wire the - terminal of
Just please remember not to try this with any engines equipped with TMCC, RailSounds, or DCS. Using DC track power will permanently kill the electronics.
If you DO use this method(and it really does work!), and you have a stable of both kinds of engines, you MAY want to have a way of clearly labeling what kind of power is being fed to the tracks at any given time, so you don’t accidentally “fry” something!
Jon [8D]
For folks considering my “madness” yes, I have labeled throw switches between AC and DC current to the track. I don’t run any command, use off-board sound and have also marked engines that are DC only with a small sticker underneath the frame.
If I were to do this all over again, I might to it differently. But when I got back into the hobby, truck mounted DC can motors were the norm. Many engines didn’t have horns - and the horns in those that did left much to be desired. So many of my locos are of this type. I’ve repainted a lot (probably 90-95% of all locos) so I have things in the exact roads and paint schemes I like - most of which still have yet to be offered in equipment that runs and looks good on 027 curves… hard to believe, but true. Sure, I like the NYC, Chessie, ATSF and PRR. I just would like more options than those. So I’ve done it myself.
So I went the way I did based on what I had and how to make it run better. And I’m anxious to try the capacitors to see the improvement they make.
Here are the Radio Shack components I used in my AC-to-filtered-DC box:
276-1185 full-wave rectifier, 25 amps, 50 volts
272-1022 4700 microfarad electrolytic capacitor, 35 working volts DC
I used three of the capacitors in parallel.
Hope this helps.
Richard Bjorkman
I put rectifiers inside my (mostly postwar) locomotives. That way I can run them on AC, but with the benefits of DC to the motors. Because any short circuits due to derailment occur upstream of the locomotive, I can use a much more modest rectifier, no more than 5 amperes; and, because the only DC load is the motor and e-unit, I usually get enough filtering with 4700 microfarads. You have to avoid connections to the locomotive frame downstream of the rectifier. This usually means ungrounding the motor field winding and insulating the e-unit frame (or wiring the e-unit coil around the built-in switch and, optionally, through another SPST switch).
Some folks warn than running an e-unit on DC will magnetize it. I have never observed this problem. I also run my (mostly Lionel O27) switches on DC and have never seen the magnetization that Richard describes.
I’ve been using DC power for over a year now. Although I also have the option of using AC current too. I do notice that the electomagnetic e-units can hesitate a little with DC current, that’s the only drawback there. I do notice the track and loco wheels need cleaning a little more frequently - but that’s the nature of DC current.
I am anxious to try the capacitors as Richard mentions. I will say my locos run smoother and more quietly on the DC current. I call it a poor-man’s speed control - because speed is much more consistant and smoother on DC current. It is a noticable difference. But I will note I also remove the circuit boards from the engines. Using the DC current with the board intact doesn’t make the difference that it does once I remove the board.
I do know part of the “growl” noise is just inheritant with the truck mounted DC motor. Part of it too is due to having 2 traction tires on opposite sides of the same motor truck. The growl is more noticable on curves over straight track. I remove one traction tire and adhere the other one - and this has helped.
Your idea is neat too Bob. I may have to try it.