The idea that mismatched engines will burn one motor up or cause problems has been around since the forties when cheap three pole motors were the norm. I got into HO in the early sixties and have never had a problem with mismatched engines doing anything other than running. I asked this question several years ago on the AOL boards and got zero response that anyone ever had a problem so I am asking it here now. Has anyone ever experienced any problems of any kind with mismatched locos? I think it is time we put this non-problem to bed. Better to run matched engines? Sure. Mandatory? I don’t think so. It would appear to me that the improvement in drive trains over the last 60 years has solved this one.
Well, DCC has certainly helped – with proper decoder tuning, you can bring mismatched engines to almost identical performance characteristics.
All locomotives will not run alike.You can buy two locomotives of the same type from the same manufacturer, on the same day, from the same dealer and WHAM! One will be faster then the other.[}:)] So,I match my locomotives to those that runs close to each other.Not perfect but,it works…I have not burnt a motor out to date by doing this…Yes,DCC will cure that problem…But,I been matching locomotives for years in DC by using the aforementioned technique.
I often wondered about this, Is it better to have the stronger engine pull or pu***he weaker one ?
I always put the faster locomotive in front so it can pull the other along. Pushing the slower engine can cause derailments on curves because the couplers are exerting sideways pressure on the lead engine, and if this is severe enough it can pu***he locomotive off the track. I have never had any problem with burning out a motor. I did, however, drag a Proto 2000 that wasn’t running so far without realizing it that I flattened the wheels.
I’ve run double headers and triple headers and the only problems I’ve had when the rear engine speeds up on the front one causing the couplers to disconnect.
I think with wheel slip, over-straining motors is minimized. However, I do get concerned when two engines have traction tires. I’m quite sure this is where you will see engines burning out.
Speed matching with DCC solves most of this. To speed match two locos, I put them together, one on the main, another on a siding.
Then I run them at first movement, 1/4, 1/2, 3/4 and full throttle settings and adjust the loco speed curves to match. Most of the time I simply use the trim CVs, CV66 (Forward trim) and CV95 (reverse trim). As long as the speed curves are similar, you can use the trim CVs to get the speed pretty close on both locos.
One “gotcha” can happen when using back EMF decoders. With back EMF, the decoder tries to keep the loco running at a constant speed based on sensing current generated by the rotation of the motor. It works slick until you put two locos with high back EMF settings together, then if one slips or lugs, the other locomotive over-compensates and the two locos “fight” each other, lunging back and forth in a very unsightly manner.
The best thing to do is turn back EMF off, or at least set it very low for consisted locomotives.
I have never had a problem with miss matched engines except that one goes faster than the other…simple solution…put the faster loco as the lead engine …my problem is that I wear the locos out within 10 years of purchase…but 10 years out of a blue box Athearn is ok…i got my money’s worth out of them…Chuck[:D]
MUing dissimilar engines:
Puts push-pulling strain on the couplers, cause derailments; if severe, will ‘polish’ rails and wear the plating on the wheels - not to mention ‘amatuerish’.
On brass engines, will pull off the (soldered) pilots.
signed: former amateur.
my problem has been with broken couplers and uncouplings. Running a dramitcly slower engine with a faster engine over time will break a coupler. I’ve broken kd’s this way. With uncoupling; If the slack is create sometimes the lead unit will uncouple and 'run off" not problemswiwth engine burning yet
andrew
I’ve found a slight speed difference can be handy in yards. I was recently operating my Proto 1k C-Liner with my E R Models FP7 - FP7 is slightly slower, no problems with Kadee fixed uncoupling magnets. When I recently bought an E R Models Sharknose (specifically to pair up with the C-Liner) I found that they had almost identical running speed, result being that I frequently end up with one loco wandering off alone followed by the other at a short distance! I’ve found that this isn’t a problem if I have a few cars coupled behind them. I would agree that running massively mismatched locos is not a good idea for the reasons listed above however!
I found out a couple of years ago at my club that you can’t really run a Proto 2000 and a Kato together. The Proto does all the work while its keeping the faster Kato on a leash. That causes the two engines to damage each other’s couplers because it is like a tug-of-war contest and the Proto usually always wins while the couplers loose.
cacole,
Flattened wheels? 1:87 railroading seems to be getting into all aspects of emulating 1:1 railroading! [:D]
Jon [8D]
I had an F unit that I powered with two PFM spud units. I bought them at the same time but when I got them out I found they had slightly different mouting bolsters. One had a pointed top the other was rounded. I just figured it was a newer run, or 2nd production as all the other specs appeared to be identical. Well the locomotive could hardly move itself let alone pull a train. I finally figured out (by putting a timing mark on each of the wheels) that the units had slightly different gear ratios. The two trucks were working against each other skidding one or the other down the track. No damage just pathetic performance. This would not have been an issue had they been on separate frames, where they could have pulled against a load.
I don’t often run mismatched locos, but if I do, I usually put the faster one on the train and the slower one at the front.
I find that the load of the train slows down the faster one so that it now matches the slower one at the front.
Does that make sense to anyone else?
I also find that there are other 2 other variables other than speed that can cause problems.
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mismacthed starting voltage. (one starts moving before the other)
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large differences in flywheel coasting (one stops before the other)
Both of these will cause jeky starts and stops.
But the thing I hate the most is the dreaded downhill back and forth jerking or hunting caused by excessive driveline play.
That’s exactly what I’ll do with a “slightly faster engine”. The rear faster one will will be slowed pulling the train. The slower engine/s usually just go along for the ride up front until they are needed for a grade.
The only drawback to this is when decending a long grade. Any worm gear play can cause bucking.
I will run a 30 hopper loaded coal drag during shows and open houses. I run 2 P2K Chessie SD50s in the lead and use one of my Atlas GP40 or 38 behind pulling the train. I have done this for 3 years now with many, many hours of run time without any ill effects to any of the drives.
I always run the faster one behind so the weight of the train slows it. The slower one goes in front. There is a limit to everything and if the difference is too great I do not bother.
Jim