I have two Athearn blue box F-45s, built about the same time, with NCE decoders I installed on an NCE system with JMRI. With CV 29, the directional CV, set at 50 on both, using JMRI, one runs forward and the other backward. Both have the gray - wire on the top motor contact and the orange + wire insulated on the bottom contact. Both the headlight white wired, and the rearlight yellow wired LEDs work in the correct direction. Both motors are sitting in their cradels in the correct direction, one turns clockwise the other counter clockwise. Both engines can be turned on the track and will still operate the same. The only answer I can seem to figure is that one of the motors is wound opposite to the other motor. Is that possible, or what other answer could there be? I can fix the problem motor by reversing the wires, but the "why" is bothering me something bad. Any opinions are greatly welcomed.Capt. Brigg CEOPacific Cascade Railway in HO gauge
The rotors absolutely face the same way? Brushes on the same end of the loco?
Either the magnets are reversed, or one set of windings was placed on the shaft backwards, which seems unlikely as the solder points for the commutator segments are only on one end. My bet is on the magnets being reversed.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Randy;Yes the motors are facing the same way. They only fit between the trucks one way because they are offset with the brushes on one end.Capt. Brigg
Cap'n,
Why not just add a "1" to the value of CV29 (i.e. make it "51" rather than "50") of the locomotive running in reverse? It would be quicker and easier than switching motor wires.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
tstage Cap'n, Why not just add a "1" to the value of CV29 (i.e. make it "51" rather than "50") of the locomotive running in reverse? It would be quicker and easier than switching wires. Tom
Why not just add a "1" to the value of CV29 (i.e. make it "51" rather than "50") of the locomotive running in reverse? It would be quicker and easier than switching wires.
Wont that make the lights opposite direction?
The lights will switch the proper way when you change CV29.
I will be running the "reversed" engine in reverse at the end of a three engine consist. If I set the consist up with that engine assigned to the consist in reverse it seems like I will be setting up a double reversal. You can also add several throttle notches in NCE for kick starting the engine in reverse as they often start harder in reverse. It seems like I could be getting into some very complex codeing, while it will be much simpler to just switch the motor wires and leave the CVs where I expect to find them. I can fix the problem; I'm just curious why it exists.Capt. Brigg, CEOPacific Cascade Railway in HO scale
Hmm, this is a bit of a mystery.
Let me ask you this. Did you buy both of these locos new or were they purchased used? I am wondering if a prior owner messed with the motor. Just trying to do some detective work here.
What if you removed the decoder on the problem loco and ran it on a DC track? Could the decoder be at fault? Kind of a long shot but if your curiosity is getting the better of you....
Rich
Alton Junction
I still say it's the magnets. There are two things that control the direction of a permag DC motor - the direction of current flow in the armature windos, and the polarity of the permanent magnets. The first is almost surely the same with both motors, so only the magnets are left. However, it is not recommended to disassemble the motor to fix this, as it can weaken the magnets and reduce motor performance.
rrinker I still say it's the magnets.
I still say it's the magnets.
True. There is a very slight possibility that it's the decoder, but since the orange and grey wires aren't right next to each other it's ard to get them swapped on the deocder itself.
If the issue is the magents, then the problem loco should run the opposite way even on DC. It's a little hard to flip the rail pikcup wiring when one side of it is the loco frame. This could be tested by disconnecting the decoder and using a 9V battery and see which way each motor turns, no need to completely revert it back to DC.
Good point, Randy.
IIRC, Athearn BB locos could run backwards if the front and rear trucks were switched. So if the wiring looks the same from the top, maybe the leads of one loco is getting current opposite of the other because the trucks have been installed on the wrong ends.
- Douglas
DoughlessIIRC, Athearn BB locos could run backwards if the front and rear trucks were switched. So if the wiring looks the same from the top, maybe the leads of one loco is getting current opposite of the other because the trucks have been installed on the wrong ends.
So if I took my DCC loco that is running forwards picked it up and spun it 180 degrees and put it back on the track, it would run backwards?
Henry
COB Potomac & Northern
Shenandoah Valley
No, it would still run forwards. Front is front.
Capt.Brigg I will be running the "reversed" engine in reverse at the end of a three engine consist.
I will be running the "reversed" engine in reverse at the end of a three engine consist.
Exactly, tho' I confess I did almost propose the same solution until I thought about it. I did test out my theory before I went into print
Allright so here is where I am at. I pulled both of the engine's motors and hooked up a good DC throttle with the + and - wires on the same side of the motors and the newer motor turned clockwise and older motor turned counter-clockwise eliminating all other causes. Then to satisfy my curosity, I pulled the shell off two other "newer" Blue Box Athearn engines with the same motors and they both turned clockwise like the "newer" NP engine. Some how my older PCRy engine which I aquired about 40 years ago is the odd motor. Now I have to decide which motor to change. Since I use brass clips on all the decoder wires changing wires is much easier than soldering. You can see the clips in the attached picture.
The reason I don't leave one of the engines running in reverse of what it should, is that the headlight and rear light don't match the running direction. Also, when using DCC the engine can be pointing in either direction and will still move in the same direction as both trucks are exactly the same. With NCE decoders when you consist engines they will respond to both the consist number and either of the lead or last engine numbers. The NCE controller remembers what engines are associated with the consist number. Time for me to move on. Attached is a picture of the motors out of the engines. Click the picture and it will take you to a larger image on my PCRy web site.Capt. Brigg, CEO Pacific Cascade Railway in HO gauge
Capt.BriggThe reason I don't leave one of the engines running in reverse of what it should, is that the headlight and rear light don't match the running direction.
Someone posted earlier that shouldn't be the case. Does anyone have an explanation on why it does happen, just the backwards magnets?
BigDaddy Capt.Brigg The reason I don't leave one of the engines running in reverse of what it should, is that the headlight and rear light don't match the running direction. Someone posted earlier that shouldn't be the case. Does anyone have an explanation on why it does happen, just the backwards magnets?
Capt.Brigg The reason I don't leave one of the engines running in reverse of what it should, is that the headlight and rear light don't match the running direction.
I know that that someone is incorrect, or at least partially. CV 29 does automatically swap the lights. But if direction of travel is wrong for the lights, it will swap the lights when you change NDOT. Lights will still be wrong.
I know because Ive been there, done that, and have the "I installed the drop in decoder upsided down T-shirt".
You would have to reprogram the appropriate lighting CVs to correct the lighting.
Swapping motor leads is easier, and less confusing later.
Read please some history from May/June 2015.
http://cs.trains.com/mrr/f/744/t/247652.aspx
My error was that I installed the drop in decoder upside down. This had the effect of swapping the motor leads. Flipping it over fixed it.
Edited, and I still cant seem to link internal posts properly.
Edit again, thank you to tstage and cuyama for explaining the fix.
Well now it COULD have been simply that the motor in the backwards unit was installed upside down. Sans the clips, the 'top' and 'bottom' of the Athearn motors is exactly the same - so if in a previous life the motor had been fully removed, the mounts pulled off, etc - and then put back together upside down, the commutator would still be on the right end, but the motor would be flipped in polarity.
That's even more likely than the magnets having been put in backwards.
rrinker Well now it COULD have been simply that the motor in the backwards unit was installed upside down. Sans the clips, the 'top' and 'bottom' of the Athearn motors is exactly the same - so if in a previous life the motor had been fully removed, the mounts pulled off, etc - and then put back together upside down, the commutator would still be on the right end, but the motor would be flipped in polarity. That's even more likely than the magnets having been put in backwards. --Randy
Now that makes the most sense out of all the replys. What I am wondering about. Is why the OP is using the frame for the positive + side of the motor pick-up. All the Athearns I have and all the others prior, had the positive pick-up from the band on the top of the trucks, which is the right side of the truck, going forward. Unless I read His post wrong.
Take Care!
Frank
Doughless IIRC, Athearn BB locos could run backwards if the front and rear trucks were switched. ...
IIRC, Athearn BB locos could run backwards if the front and rear trucks were switched. ...
That's true only for DC......the OP is running DCC....
BMMECNYCI know that that someone is incorrect, or at least partially. CV 29 does automatically swap the lights. But if direction of travel is wrong for the lights, it will swap the lights when you change NDOT. Lights will still be wrong.
You can say it was me, BMMECNYC. My statement was made with the front headlights being on in the forward position. When the locomotive is flipped 180 degrees, it would still be the same. Sorry if that wasn't clear.
BMMECNYCSwapping motor leads is easier, and less confusing later.
I agree with you wholeheartedly about that. While I do think it would be quicker changing CVs to change the direction of the lighting, I like to swap motor wires to make CVs consistent between all my decoders.
Though it's now an academic issue, I think turning the motor over would be VERY difficult. The black end plates are very different top to bottom with the housing for the plastic mounting pins only on the bottom. The electrical brush assembly is also part of the plastic end plates. Also if you just rotate the metal center housing I don't see how that would reverse the spin of the armature. I admit I have never taken an Athearn motor completely apart, but why would you? If someone out there has actually taken a motor apart and had it reverse, please speak up and tell us how you did it, with pictures.Capt. Brigg; CEO Pacific Cascade Railway in HO gauge
The reason I don't leave one of the engines running in reverse of what it should, is that the headlight and rear light don't match the running direction.
Well...I have to admit I haven't used NCE decoders, but unless this is a very old (like 1990's - early 2000's) decoder, you should be able to set the lights however you want by changing the CVs that control the lights. Not sure why one would want to do this, but as an example, if you wanted the rear headlight of an engine to be on when the engine was going forward, and the front headlight on when the engine is backing up, you can do that. Remember, some railroads ran diesels short hood forward, and some ran them long hood forward, so decoders are designed to let you pick which is the 'front'.
Or you could just set the CVs so both headlights turn on when you press F0....
doctorwayne Wayne, If You look at the OP's pic's of the two engines......the top metal plates that are on the right side of the truck and cannot be removed and pick-up positive.....if the front/rear trucks were reversed.....the metal plates would be on the opposite side of the truck. That means that the left side of the truck which gets its pick-up from the frame would now be getting negative from the right rail moving forward. That is assuming that the BUS is wired with the top rail positive looking at the track in a horizontal plane......which btw, is the way I was taught how to wire the track in 1950. Looking at the track in a horizontal plane...top rail was N for positive and S for negative. Like a compass, which never changes. I still wire all My track the same way. I had a couple Athearn engines..two SDP 40's/45 that had the same motor as the OP's that I got in 1966......and they ran right rail pick-up positive front plated side of truck and negative from truck bolster on frame. I sent them to My friend in the UK 4 months ago. The instructions had a 1966 date on them. I would just reverse the motor leads and be done with it.........and throw the decoder away....LOL DC die-hard..... Take Care! Frank Doughless IIRC, Athearn BB locos could run backwards if the front and rear trucks were switched. ... As far as I'm concerned, Douglas has answered your question. When I bought Athearn's newer style Flexicoil switcher trucks with the plastic sideframes to replace the old older ones that had cast metal sideframes (I'd already replaced those with cast metal Flexicoil sideframes from Juneco, but the detail on the new plastic ones was too good to ignore), I was initially surprised to learn that there were different part numbers for the front and rear trucks. If you think about, though, one truck is always running forward or backward, while the other is running backward or forward, respectively. Switching the trucks from end-to-end in the frame will solve the problem. Wayne
Wayne,
If You look at the OP's pic's of the two engines......the top metal plates that are on the right side of the truck and cannot be removed and pick-up positive.....if the front/rear trucks were reversed.....the metal plates would be on the opposite side of the truck. That means that the left side of the truck which gets its pick-up from the frame would now be getting negative from the right rail moving forward. That is assuming that the BUS is wired with the top rail positive looking at the track in a horizontal plane......which btw, is the way I was taught how to wire the track in 1950. Looking at the track in a horizontal plane...top rail was N for positive and S for negative. Like a compass, which never changes. I still wire all My track the same way.
I had a couple Athearn engines..two SDP 40's/45 that had the same motor as the OP's that I got in 1966......and they ran right rail pick-up positive front plated side of truck and negative from truck bolster on frame. I sent them to My friend in the UK 4 months ago. The instructions had a 1966 date on them.
I would just reverse the motor leads and be done with it.........and throw the decoder away....LOL DC die-hard.....
Don't have a clue as to what happened to My post above..it also timed out.
A couple of pic's of the two I had. Did not come with fly-wheels in 1966:
BigDaddy Doughless IIRC, Athearn BB locos could run backwards if the front and rear trucks were switched. So if the wiring looks the same from the top, maybe the leads of one loco is getting current opposite of the other because the trucks have been installed on the wrong ends. So if I took my DCC loco that is running forwards picked it up and spun it 180 degrees and put it back on the track, it would run backwards?
Doughless IIRC, Athearn BB locos could run backwards if the front and rear trucks were switched. So if the wiring looks the same from the top, maybe the leads of one loco is getting current opposite of the other because the trucks have been installed on the wrong ends.
What I'm saying is that the tall metal truck tower conducts current from one side of the truck, either + or - depending upon how its installed in the loco. The other side of the truck conducts the opposite current to the frame. If you switch the front truck to the back and the back truck to the front, the loco will run in the opposite direction then it did before you switched them. It happens sometimes when you remove the trucks to hard wire them, or take them apart to clean them, tune them up, etc. They can get reinstalled opposite if you dont pay attention.
So if the wiring looks the same on both locos (especially the color wires going to the motor leads), then maybe the trucks are switched on one loco relative to the other.
But if the motors themselves spin in opposite directions when powered only by wires, then its not obvioulsy the trucks. Either the magnets are reversed or the motor is upside down.
I suppose you could set the CV to reverse polarity to the motor, but that's sort of solving the problem without knowing what the problem really is.