I have two diesels that are consisted. One runs faster enough then the other that either gears are grinding or wheels slipping that it becomes noisey. Is there anyway to adjust speed or other way to alleviate the problem. Unpowering one of the engines is not an option.
Thank you
I use #22 gauge Nichrome wire to balance my motors. It runs about 1Ω per foot. It’s a bit of experimenting with the length of the wire to reduce the faster locomotive to match the slower one.
If the gearing isn’t the same on the locomotives and one runs much faster than the other you could try diodes to drop the voltage on the faster one. A pair of 1N4000 diodes reverse paralleled in series with the motor will drop the voltage .7 volts.
Mel
Modeling the early to mid 1950s SP in HO scale since 1951
My Model Railroad
http://melvineperry.blogspot.com/
&nb
I’m also a DC operator, and Mel’s suggestions sound good, especially if the operating speeds differ greatly.
Most of my locos run well with one another, despite being from various manufacturers, but I have found that if a train actually requires multiple locomotives to get it around the layout, mildly different running attributes seem to smooth themselves out quite nicely.
My layout has a lot of grades, mostly on curves, so all but very short trains are doubleheaded and often need pushers, too.
If your trains don’t actual need the power of more than one locomotive, but you prefer the look of more than one, take Mel’s advice, even if the speed discrepancy isn’t all that great.
Wayne
Might be worth looking into the gear grinding or whatever the noise is. If not performing properly, best get that sorted out before trying to match it to anything. Certain P2K locos are infamous for cracked gears and no point in matching to one of those sick puppies before making the simple fix required for it to run right.
BTW, what two locos exactly are you talking about? That may help us sort out what your options are.
Hello all,
Many older locomotives are subject to this same problem. I had a rash of cracked gears from older Bachmann diesels and some steamers.
I concur!
Also, knowing the year(s), model(s) and manufacturer(s) of these units helps.
Yes, restricting the voltage throught resistance can work but how are you planning on dissipating the heat generated by the resistors?
This is why dummy units were popular before the advent of DCC and it’s ability to speed match through CV’s.
Hope this helps.
There won’t be much heat dissipation, a ½ watt per volt drop at 500ma.
Mel
Modeling the early to mid 1950s SP in HO scale since 1951
My Model Railroad
http://melvineperry.blogspot.com/
Bakersfield, California
I’m beginning to realize that aging is not f
At full throttle, all of my (ancient, with open-frame amp-hog motors) DC locomotives can reach speeds far in excess of realistic. As a result, track speed in operation (70kph - 40mph) usually takes place at or about 50% on the potentiometer. At that speed most of my locomotives doublehead or push - pull nicely, even different classes or different types. That includes one carbody doubleheaders - juice jacks with two independent drives, one under each end, operating in parallel.
The exception? Two massively heavy (and massively sluggish) DD51 class diesels. The solution? DD51s are given passenger assignments, one locomotive per train. No need to doublehead.
On the other railroad a three car train might need three teakettle tank steamers to climb out of Tomikawa at 25kph - uncompensated 350mm radius helix, 3.51% grade. The three cars; two four wheel freight wagons and an ancient wooden coach. The other passenger train is a four wheel railbus.
Chuck (Modeling Central Japan in September, 1964)
I regularly mu units, but I make sure they are the same manufacturer.
Although I agree if there’s a lot of grinding noise, looking at re-gearing or even re-motoring the faster engine may be a good idea, keep in mind that you could slow down the faster engine by installing a relatively inexpensive dual-mode DCC decoder. You will need to take the engine to a friend’s layout to program it (or, if you buy the decoder at the hobby shop, they may be able to do it there).
When you run a DCC-equipped engine in DC mode, it doesn’t bypass the decoder. The power still goes through the decoder, so the CV settings for momentum and speed control normally still work. Changing just one or two CVs should cut the engine’s top speed under DCC or DC to a more manageable level.
If the locomotives are the same as each other it might just be that one has dirtier wheels than the other and the bucking and gear grinding are because they are not picking up power. I always try to run at least two powered units together. If one doesn’t want to start the other one can give it a nudge instead of me doing it by hand. Try running them separately as a test and clean the wheels as needed. I hope this helps.
I have two new Blue box Proto 2000 locos, an FA1 and FB1 . I replaced all the geared axles LL sent me and they are all identical 12 tooth axles. There is no grinding or binding. But the B unit runs twice as fast as the A unit at the same voltage, same track. I read on a forum that the resistor on the circuit board feeding the headlight in an A unit can slow the motor down. I never opened the B unit which has no headlight, maybe it doesn’t have this resistor, so could this be why it runs faster? Anybody else familiar with this resistor situation?
MM
HI
I found adding a 1/2 watt resistor with about 10 ohm resistance slowed my proto 2k sd45 locomotive’s. The Intermountain ES44AC had to be re wired to feed the motor directly and bypass the electronic board.
Hope it helps
Can Mr. Kraut or anyone else explain the purpose of the circuit board in the Proto 2000 A units? Anything else besides powering the headlight?
The headlights only come on in the forward direction, and the headlights are constant brightness, they are bright even at a slow engine speed. That is what the circuit board does.
Like several others who have responded here, I run DC, and run lots of multiple powered units with little or no speed matching problems.
I have three ABBA sets and one ABA set of Proto2000 FA/FB diesels, they run just fine together with no modifications to the factory wiring.
I have lots of other Proto diesels, GP7’s, PA1’s, BL2’s, E units, SD9’s. They all run together just fine with their duplicate mates, many will run “mixed up” (GP7 and BL2 for example).
None are DCC/sound equiped.
I also run lots of mixed steam double/triple headers. Most recently I pulled about 60 piggyback flat cars with a Proto 2-8-8-2, Spectrum 2-8-0 and a Spectrum 2-10-2.
Sheldon
So it’s still a mystery why my FA runs at half speed. If the B unit has a circuit board, I will wire the A’s motor directly to the trucks. Right now it appears to be connected to an onboard resistor. Is there a certain method to do that? Thanks Sheldon.
It sounds like you have some other problem, better to fix the problem…
Maybe the circuit board in the A unit is bad? Maybe the motor is bad?
Sheldon
Update: I ran the A and B units on parallel tracks again (same power pack) and the A loco is picking up speed. It only lags behind a little bit now, something must be loosening up. There was no gunk in the gears, just fresh LaBelle grease. These were boxed for awhile, but the B unit performed well right away. Guess the A loco caught a bad case of arthritis so I oiled it with an alfalfa powder/Aleve solution.
Anyway it was an education and thanks everyone for your educational help. MM