Too Much "B" Power

[modelmaker51]

You just need to add a constant lighting unit to the B unit. You don't have to hook up a bulb to it, the CL unit will drop the voltage to near equal to the A unit.

[Anonymous]

If all else fails, you could just make one a dummy. Just a thought.

[Texas Zepher]

QUOTE: Originally posted by David Foster
How do you arrange the circuits and how do you arrange the jumpers between locos?

The circuit is simply a wire connecting all the wheels picking up power on the right rail together and a second wire connecting all the left rail wheels together. The coupling between the locomotives is the trick part, and made more tricky by lower quality models that have hot frames.

I have connected the locomotives together in several different ways.
1. Just run two wires from the back of the one locomotive to the front of the next. Make certain the wire has enough slack in it so that it doesn't stretch and break the wire and/or derail the locomotive. This method has the big disadvantage of not looking so good and the locomotives are permanently attached to one another.

2. Make a drawbar with two brass sheets separated by a piece of plastic. Solder one of the power wires from each side to each of the brass sheets. On a hot frame locomotive a spring can be used to transfer power to top draw bar brass. This looks better, but once again the locomotives are permanently attached.

3. I’ve done this with strings of passenger cars but my latest attempt at this is a FT ABBA set. Three powered and one B filled with sound unit and speakers. All wheels pick up power and it is transferred between the units on Minitronics micro-miniature plugs. http://www.caboosehobbies.com/catalog/Description.cfm?sku=04755000102
The “white” wire is always the left rail. On each unit the wire pair comes out of the left side. So in order to plug them together they loop under the coupler. This needs less slack in the wire while allowing more flexibility on curves. The locomotives can be uncoupled. I do some times have to use tweesers to plug them together. There is still one disadvangate in that the front to back direction cannot be changed. Next time I am going to use all female plugs and then connect them using a double male coupler. This will eliminate the directional issue.

[Anonymous]

QUOTE: Originally posted by jimrice4449

I think Robert Knapp hit your problem (I was a little suprised it took somebody that long). The best/easiest solution is to rig the B for lighting as the A is and just paint the bulb black or obscure it in some other way. The way I avoid the problem is to connect all my multi unit consists semi=permanently with a 2 wire power buss between them. One wire draws current from all of the non-grounded wheels and there is a diode bridge at each end of the consist., the one at the west end has the light for the A unit at that end and the one at the east end has the light for that direction and all the motors are connected to the buss. This not only solves the voltage difference between units but it means that each motor in the consist draws current from every wheel in the consist reducing jerking due to dirty track

I don't have a clue about electrics but I was wondering about running the motors in... is it parralel? as in using Bus Bars...

Could you tell us more please?

How do you arrange the circuits and how do you arrange the jumpers between locos?

thanks!

[trainnut57]

Okay-and thanks to all responses. Will try adding the light, as both sets are from the same manufacturer-not outsiders. As to Don Gibson's reply, I double checked the box. It says Rivarossi (red box) E-8 Santa Fe. THis same unit is mentioned in an article about passenger diesels in the latest MR.

THanks again

[jimrice4449]

I think Robert Knapp hit your problem (I was a little suprised it took somebody that long). The best/easiest solution is to rig the B for lighting as the A is and just paint the bulb black or obscure it in some other way. The way I avoid the problem is to connect all my multi unit consists semi=permanently with a 2 wire power buss between them. One wire draws current from all of the non-grounded wheels and there is a diode bridge at each end of the consist., the one at the west end has the light for the A unit at that end and the one at the east end has the light for that direction and all the motors are connected to the buss. This not only solves the voltage difference between units but it means that each motor in the consist draws current from every wheel in the consist reducing jerking due to dirty track

[DrummingTrainfan]

QUOTE: Originally posted by trainnut57


Hey, but what about the Rivarossi problem? That's really worse than the A/B Problem-I only have the one powered E-8 unit and it's hard to convince even my grandson that running in reverse (to be smooth) is natural. He believes "Papa" in most respects, but just won't swallow this one.

Could you just pick up a dummy E-8 that oculd be run back-to-back with the powered one?

[bogp40]

QUOTE: Originally posted by trainnut57

I have two units, a PA/PB and an FA/FB, both by different manufacturers. My problem is the B unit seems to have a little more power than the A in both cases. Is there any way to "power down" the "B" unit slightly to eliminate this problem? These are not cheap units-the PA/PB is a Proto 2000 and the FA/FB is a Walthers Trainline.

Also on a related subject, I have a Rivarossi (no comments, please-I've heard them all) E-8 that runs very jerky when going forward, bot smooth as a newborn baby's uh, butt in reverse. Any suggestions on this dilemma?

Thanks.

trainnut57,
The B unit is most likely running slightly faster because it has no lighting. Having the 2nd unit faster in a consist is not always a bad thing. Many beleive that the faster loco should be out front, this is fine when the consist is running with very light load, howerver, add the load of pulling a string of passenger or freight will have the faster(2nd) unit being slowed pulling the train. The lead engine will be just going along for the ride until it is needed for pulling the grade. The only disadvantage is on a decline, even matched P2Ks can tend to have a slight surging action especially if slowing.
This method of running has proven very satisfacory for me. I have run various units this way for 6-8 hours at a time pulling a 30+ car coal drag at our shows and open houses. My Stewart ABBAs, P2K SD7s,SD50, geeps and Kato and Atlas show no sign of wear from this type of running. Experiment with pulling a train, but have the units uncoupled and set a few inches apart- see what happens. Good Luck
Bob K.

[nedthomas]

Using a resistor to drop the voltage is not the way to go as the voltage dropped will vary with load current. Using diodes will drop the voltage with no or little heat. Wire the diodes (1N4001 is a good pick) in parallel -back to back- i.e. point and tail of one diode to the tail and point of the other. Each unit will drop the voltage 0.7 volts. Install as many of these uints in series as needed. A diode bridge is really two units in one smaller package.

[Don Gibson]

IF the PA AND B are the same manufacturer (and production run) they should run together close enough to not be a problem. Ditto for the FA and B. - but If they don't, something is wrong with the slower units. Just don't expect the two different brand's to match up.

If the differences between engine's of the same brand (as I suspect) are slight, the simplest cure is to substitute a draw bar between the 'A' and 'B' unit's which mechanically link's them. A piece of Styrene with 2 holes in it for R.H.screws (2-56)? would probably do it.

RE Rivarossi 'E'.
Probably play in the worm gear alignment. or U Joint's. Will adding or subtracting small washer's help?. I don't have this engine.

I don't remember R. making an 'E'. Sure it wasn't AHM or IHC? I took mine and substituted a P2K chassis. Both LL and BLI E' s make superior unit's, + You can't get part's for your's.They're Orphan's.

[Anonymous]

I can see your arguement for the money issue, however your arguement that very few could be converted doesn't hold water. Almost ANY locomotive CAN be converted. I take that back,,,ANY locomotive can. It's just a question of how bad you want to do it. It's usually a LOT easier than you think. Having so many though, I totally understand. The only other solution I could think of would be to find some wheelsets with slightly smaller diameter wheels. Perhaps if you know someone with a small lathe, you could experiment around with taking some off the wheel surfaces. I know, that's a whole lotta trouble, but you asked.That would slow it down a tad, though.

QUOTE: Originally posted by trainnut57

Thanks to On30shay, but I just don't have the money to convert to DCC. I have been in the hobby for over 30 years, have many units more than 15 years old, over $5 grand in locomotives, only a very few would be convertable. I thopught about it, but then neither do I want to end a 36 year marriage.

Anything else, suggestion wise?

[trainnut57]

Thanks for the ideas. I am not much of an electrician (truck driver by main occupation for 25 years-paralegal since 1995), so I think the first thing I'll try is areibel's idea of switching motors-or more realistically just swapping body shells. I already checked and the frames look identical for both the A and B unit. Should be an easy switch (famous last words)

Hey, but what about the Rivarossi problem? That's really worse than the A/B Problem-I only have the one powered E-8 unit and it's hard to convince even my grandson that running in reverse (to be smooth) is natural. He believes "Papa" in most respects, but just won't swallow this one.

[Anonymous]

If you load the train down with enough cars then the B unit will never pu***he A unit......

Unless you're going down hill!

A diode would screw up your low-speed operation.

A resistor would heat up, but depending on the value not too much. I'd suggest starting off with maybe a 2 ohm 1 watt resistor. You could adjust it up or down from there.

Adding lead is always a good idea in my book

Mark in Utah

[Leon Silverman]

If the difference is low enough that the B unit will not spin its wheels before the A unit starts to move, I would not worry about it. Otherwise, using a resistor to drop the effective voltage may present a problem because of the heat generated by the resistor. Hooking in a constant lighting kit inside the B unit will reduce the voltage the motor sees by 1.5 volts without generating heat since the zener diode passes the excess voltage through without any resistence.

[areibel]

How about trying to swap motors between the two units? I've had cases where two identical motors will perform very differently, maybe it would help?
Also make sure the rolling resistance is about the same- if you spin the motor by hand, see if one unit is tighter or has a bind in it. Might be a mis-aligned gear in the trucks, plastic flash, etc..
And one other simple thing- try adding some weight to the A unit- maybe it's a traction problem??
Good luck, and let us know if you find anything out!

[joeyegarner]

Here's an idea. I am sure you could put a resistor in the B-unit. I am looking at a simular problem my self. So, tonight I'll spend some time with it later on tonight and let you know what I come up with. (I think Switching to DCC is a very expensive solution.) I may stay with annalog controlI I don't think DCC is necessary, Only a personal choice. Is anyone else out there with an idea please let us know.

[trainnut57]

Thanks to On30shay, but I just don't have the money to convert to DCC. I have been in the hobby for over 30 years, have many units more than 15 years old, over $5 grand in locomotives, only a very few would be convertable. I thopught about it, but then neither do I want to end a 36 year marriage.

Anything else, suggestion wise?

[Anonymous]

Yup. Convert to DCC and consist the two units.

[trainnut57]

I have two units, a PA/PB and an FA/FB, both by different manufacturers. My problem is the B unit seems to have a little more power than the A in both cases. Is there any way to "power down" the "B" unit slightly to eliminate this problem? These are not cheap units-the PA/PB is a Proto 2000 and the FA/FB is a Walthers Trainline.

Also on a related subject, I have a Rivarossi (no comments, please-I've heard them all) E-8 that runs very jerky when going forward, bot smooth as a newborn baby's uh, butt in reverse. Any suggestions on this dilemma?

Thanks.