I have an F3A and F3B engine and would like to run them together. I spent all of my money on trains and tracks and there is nothing left over to upgrade to DCC. I know that with DCC I could speed match the engines so running them together would not be an issue. Do I need to wait until I upgrade or can I run them together now? The engines do run at different speeds, but not by a large amount (< 5MPH scale speed).
Run 'em…You’re good to go…
RideonRoad,
It sounds as though you say that they are both powered. There is no reason that you can’t run them together. They are both DC and will play together without being speed matched. 5smph is not alot.
When you post again or in future, make sure you let others know that you are in N-scale.
Cheers,
Frank
you’ll be fine if you run 'em together, I’m running all sorts of mismatched consists together.
At what speed difference does it become a problem? Seems like one would be partially dragging or holding back the other. Wouldn’t that potentially harm the engines?
I’m not entirely sure, all my units seem pretty closely speed matched except for maybe my GP15-1 and GP9 which are atlas units and move a bit slower than Kato’s.
Well, if there is a problem, the train will let you know about it. Once the motors are moving they will adjust to each other somewhat. Biggest problem is when one motor stalls the other is not strong enough to move it. I get around this by using a draw bar and tying the motors together electrically.
It also brings the equipment closer together, so it looks more prototypical.
ROAR
The old DC test for running 2 engines as a consist (from the 1960s):
- run each separately with cars attached. Begin with equal number of cars for each engine. Compare speeds.
- Add cars to the faster engine, and take away from the slower engine. Test again.
- If you can find any combination of cars for each engine where speeds are close, you are good to go. The two engines will complement each, not fight each other - even though the load will not be split perfectly in half. The motors adjust to the load.
Some like the faster locomotive to be pushing (2nd). Some like it to be pulling. There doesn’t seem to be any difference in the grand scheme of things.
my thoughts, your choices
Fred W
Fred,
Thanks, That makes a lot of sense. I will try it.
[:-^]
I run paired (MU’d) locos all the time, on DC.
The simple answer would be to run locos from the same Mfg. together. ( Athearn<>Athearn)
I have run Atlas and Kato together with out any problems. In fact they work great together.
I would definitely say to keep your Bachmanns together, mine don’t play well with others. But they are good engines.
My favorites would be Atlas & Kato. Really smooth runners.
I also have a couple of Stewarts but I have never tried to hook them to any other Mfg.
For what it is worth, others will surely differ.
Johnboy out…
No it will not harm them, and if you are pulling enough cars to need two locos, they will smooth each other out.
Long before DCC, modelers have been running DC locos in pairs or triples or more with no problem.
Yes they need to run at similar, but not exactly the same speed. Yes it is really helpful if they start at close to the same voltage.
I have never had to diesel models with the same drive that would not run together just fine.
I run many steam locos of different brands and wheel arrangements together with no problem. Currently pulling over 50 piggyback cars on my layout is a Proto 2-8-8-2 and a Bachmann 2-8-0, they work together just fine.
Sure there are some locos that are just too far apart, but many of today’s locos have similar gearing and work fine regardless of brand to model.
Sheldon
I had always tried to keep the faster engine (2nd), the drag of the train will slow that unit. Many times you will see that the 2nd faster one will just pull the train with the front one just going along for the ride. This will be noticeable as you watch the coupler action. The only time this really didn’t work was if there is a substantial speed difference and continuous operation will overrun the very slow engine/s. I used to try to run 2 Proto SD50s with an Atlas GP40 to the rear, the 18:1 gearing of the P2Ks caused quite slow running compared to the 14:1 Atlas. I would do it but not recommend any extended running as a usual consist.
In your case the faster one is most likely the F7B. The lighting of the A unit will cause a slight slower speed/ or at least starting. You shouldn’t have any issue, but if you would like to speed match just add a resistor or add backup light directional circuit.
Hi,
Go ahead and run them. If it is a problem, it would likely be obvious with one spinning its wheels trying to pull the other along. I would likely put the faster one on the front end, which might be best to prevent any possible derailments.
I run analog DC, MZL system, routinely doublehead mis-matched steam locos, and even add a pusher when the need appears. My diesels all play nice when doubleheading, even though their drives are radically different. Since the catenary motors I use on my heaviest trains all have twelve or sixteen drivers they don’t need help, thank you.
For a real prototype speed mis-match, you could look at past New York Central practice. A heavy passenger train climbing West Albany Hill after a station stop would have a high-drivered Hudson on the point - and the 0-8-0 station switcher thundering away at the rear. The mis-match in driver diameters was about the same as the diameter of the wheels under a modern auto rack!
Something equivalent happens every time a locomotive consist of dis-similar units is spliced together. The difference in gearing means that the speed of the whole consist is limited to the fastest safe speed of the slowest locomotive - but they all pull together.
Chuck (Modeling Central Japan in September, 1964)
I run DC and have run many different makes and models of diesels together .If their is a big difference in performance you will know and know that is not a good mix of units. I would bet your A unit and B unit may not have a headlight in the B. I had a set of ABA Hobbytown FA units .The A units have a diode bridge for a constant headlight the B did not .There is a 1 1/2 volt drop across this bridge ,so the b unit was spinning wheels at certain speeds .The cure was to add a diode bridge in series with the B unit motor just like the A units. I just did not install headlights in the B .
If your units will run together without causing train handling problems they should be fine… Units with a great difference just won`t be worth the frustration they will cause. Reading articles about first generation units in the 1950s and 1960s there were enough differences between different builders that even if they could MU they did not always perform well together.
Ron High
I use a stop watch to time my deisels i put the faster in front others put the faster behind. mine run fine with no problems my layout is cab control with a railpower 1400 and a locomotion 2500. they should be fine
In a 1940s issue of Model Railroader, an O scale club used rheostats in their locomotives to speed match them. Perhaps something similar would work with your locomotives to slow the slightly faster one. I’m sure that you can find a miniature variable resistor that could be installed in an HO locomotive.
I gotta agree: there’s not a problem running multiple locos together using DC. It helps if the locos run at a somewhat similar speeds, but it’s not necessary if multiple locos are actually required to move the train.
I’ve posted this before, but it shows multiple locos on a long train, labouring up a twisting 2.5% grade. I have run similar trains using various combinations of the same Bachmann Consolidations, Athearn Mikados, re-motored Athearn switchers and U-boats, and old Model Power FAs.
(The apparent jerkiness is in the video, not the locos - they run extremely smoothly, either alone or in combinations.)
Wayne
I have heard from a large model railroad club that running mis-matched locomotives would damage the motors. Because of mis-matched running, they have had to replace motors in several of their units. They use DCC. Why they didn’t speed-match their locomotives is beyond me. Go figure.
A badly mis-matched pair of locomotives will have one slipping all the time, and the other being pulled along by the first. This slipping and draging will put undue stress on the motors, and after long periods of running, can damage them.
Mis-matched locomotives will also run worse together than the same locomotives if they are speed matched. I have seen this first-hand.
I would suggest installing a resistor of some kind in the faster locomotive to slow it slightly. A rheostat or similar variable-resistance device would work best so that you can fine-tune the locomotive’s speed.
The old DC test for running 2 engines as a consist (from the 1960s):
- run each separately with cars attached. Begin with equal number of cars for each engine. Compare speeds.
- Add cars to the faster engine, and take away from the slower engine. Test again.
- If you can find any combination of cars for each engine where speeds are close, you are good to go. The two engines will complement each, not fight each other - even though the load will not be split perfectly in half. The motors adjust to the load.
Some like the faster locomotive to be pushing (2nd). Some like it to be pulling. There doesn’t seem to be any difference in the grand scheme of things.
my thoughts, your choices
Fred W
S & S,
I thought that also, but not according to Fred W. if you use his method.