N scale with DCC

[Blacksheep]

So I've been dinking around with my new Walthers Mallet this past few days, N scale has come a long ways since I was involved in it and I'm loving it.
I fired it up with a basic MRC DCC system and the factory Walthers Decoder and sound and all that. It worked pretty awesome...at first. Last night I noticed a fair amount of jerkiness to it and I figured it was track. So I laid a nice flat piece of test track, soldered my leads and I have the same thing.
Not being very familiar with DCC could this be a Start Voltage Adjustment in the CV programming or am I barking up the wrong tree? Wheels look clean, it has enough pickups that i cant see that being a problem to begin with. It happens at all speeds, not horrible but its not good either and like I mentioned, it wasn't there at first unless I flat out missed it.

PS, Didn't know if this post should go in the DCC / Wiring or n scale.

 

[LotoQuestions]

Jerkiness - locos

I noticed a fair amount of jerkiness to it ...... It happens at all speeds, not horrible but its not good either and like I mentioned, it wasn't there at first unless I flat out missed it.

Sounds similar to my HO Intermountain F7 although in that case the problem was with the mid range (Look in DCC forum). The solution was that one of the midrange BACK EMF settings was over 50%. Setting it down close to 0 was magical.

This occurred after resetting the decoder. I hope yours is also DCC related and not mechanical.

,,, ken

 

[UP2CSX]

The first thing I would try is resetting the decoder. I don't know what kind of decoder Walthers uses but setting CV8=8 should reset most decoders back to factory specs. The instructions that came with the engine should give you information about resetting. If it doesn't behave better after the reset, I'd call Walthers and describe the problem to one of their techs. He may be able to give you some CV settings to try. If nothing works, it sounds like a mechanical problem and you'll have to exchange it for a new engine.

 

[Blacksheep]

You guys both mentioned something I overlooked. I did re set the decoder, I think a while after that is when I noticed the jerky-ness. I'll try those CV settings right after I return from standing in line at my favorite State run agency. Woot.

Thanks guys!!

 

[Blacksheep]

Arrhhhggggg.

It figures, I think it needs to go back to the factory. I remembered that this unit will also run on DC so I hooked it up on a different test track with a decent MRC unit. Same jerky stuttering outcome. I double checked and reset the Decoder to "factory", tried a new piece of test track. Checked for crud and nothing, no improvement.
Bummer.........

The good thing is that the gentleman that I purchased this unit from is working with me above and beyond the call of duty and that's all that counts.

 

[Blacksheep]

Hold The Phone.........

After reading several links suggested in this thread and researching until my eyes bugged out, using my electrical skills, track gauges, testing continuity on all drivers/pickups/wires/plugs etc...... I think I found the issue.
Let me describe in a little better detail of what is happening and maybe you all can help walk me through some of these CV settings. Remember I do not have the software or any thing like that, just my basic MRC system, the loco, and three feet of brand new test track with soldered wiring.

Start up now seems fine. No, it seems perfect. Not jumping, no glitches, nothing just nice and smooth. The first few clicks (128) up to about 8 or 10 so seem fine as well. I get it to surge moving from there to around 15 to 20, after that its fine until I bump it up again. Deceleration seems fine.
I started randomly (After a master reset of the decoder, which btw I did right before this thing starting freaking out) selecting some low numbers in the SV, ACC, dec, and TV settings. But I'm not sure what I should be entering. I did some how get rid of some jerking, I dont know exactly how but I think it was CV 6, I had to bump it up a little.
So sorry for being so ignorant with DCC, it makes sense to me but actually entering the correct data is difficult, I've never done this before so therefore I dont have a clue about correct CV settings in that realm of things. I keep reading how these settings should be closer to "Zero". I have it react poorly when some of these settings are near zero (Atleast I think so)
Any help is appreciated,
Andy

 

[LotoQuestions]

After limited success ......

Andy it sounds to me more and more like what I was faced with on my HO intermountain F7B after a reset. The reset was necessary because nothing funtioned. After the reset I was left with jerky movement in the midrange only - impossible to consist. The Intermountain uses a Quantum - I think yours does as well.

What I would do ..

1) read the thread "Intermountain F7B DCC won't move" http://www.modelrailroadforums.com/forum/showthread.php?t=14373&page=2 especially mssgs 19 & 20

2) load decoder pro - even without a computer interface - it helps understanding a lot (I have DP with a LocoBuffer)

3) with DP load a definition for your decoder ( I would use the beta for the latest definitions)

4) Play with the variables in the user panels for BEMF

5) list the CVs and that way you can go from an easy panel to knowing what CVs are likely to need modification

6) ensure all the BEMF variables are close to ZERO

7) hope your result is as magical as mine

,,,,,Ken

PS. I was close to tears this was sooo frustratiing - I was going to buy a replacement......

And prove that I am all wet with my direction......

The CVs in question are indexed and are 56.5, and 56.18.0 to 56.21.2

Moving to the DCC might get more response ......

 

[Blacksheep]

^ Thanks again! I'm doing just as you suggested right now. I'll let you guys know as soon as I can get my peanut to understand some of this.

 

[GP30]

Someday, I would love to get into DCC, but reading stories like this terrifies me because I am a Electrically and Computer dummy!

Johnny B

 

[Blacksheep]

Someday, I would love to get into DCC, but reading stories like this terrifies me because I am a Electrically and Computer dummy!

Johnny B

Please, don't let my challenges and problems discourage you from enjoying one of the greatest attributes to the hobby. I usually let the "simple stuff" beat me. I understand and usually pick up on the more difficult things while I let the easy things kick my butt.
These guys here on the forum are awesome, very knowlagable and can help you out of problems like these.
I'm very happy I went with DCC and someday it will make operations on my future layout that much more enjoyable. To have the sound and the amount of control that we do, especially in these smaller scales, is just mind blowing and very exciting. It revived my love for the hobby to be honest. I couldn't go back to DC now, no way.
Just FYI, the biggest issue I had was getting "Decoder Pro" to be accepted by my new laptops operating system, I think that was more laptop than anything (or operator). After that all of this makes a lot more sense than the engineers description drawn out over 100 pages in a manual.

 

[GP30]

Please, don't let my challenges and problems discourage you from enjoying one of the greatest attributes to the hobby. I usually let the "simple stuff" beat me. I understand and usually pick up on the more difficult things while I let the easy things kick my butt.
These guys here on the forum are awesome, very knowlagable and can help you out of problems like these.
I'm very happy I went with DCC and someday it will make operations on my future layout that much more enjoyable. To have the sound and the amount of control that we do, especially in these smaller scales, is just mind blowing and very exciting. It revived my love for the hobby to be honest. I couldn't go back to DC now, no way.
Just FYI, the biggest issue I had was getting "Decoder Pro" to be accepted by my new laptops operating system, I think that was more laptop than anything (or operator). After that all of this makes a lot more sense than the engineers description drawn out over 100 pages in a manual.

Oh I havent let it detere me. In fact last friday night I attended a open house at a fellow model railroader's house and he had a DCC operating system. BOY OH BOY am I in love with DCC now!! LMAO!! I'm definetly investing in DCC now. I have enough fellow railroaders that can help me set this thing up.