RS3 DCC just arrived - question on speed w/NCE BACHMANN

Started by timhar47, March 22, 2013, 05:48:15 PM

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timhar47

Hello - my PRR RS3 just came. Its my first N Engine in my switching back to N. I hooked up 4 pieces of unitrack, and the NCE and while it does run, it wont move (just hums) until the throttle is up to like 14. Is this normal or do I have a bad engine? Or is there a setting thats wrong? (I havent programmed anything yet on it)

Thanks - Tim

skipgear

NCE DCC system?
28 or 128 speed steps?
What is the track voltage?
Have you give it any break in time?

Usually, the Bachmann loco's have just the opposite problem, Vmin has always been set too high, making for unneeded jack rabit starts. Usually I set V min to o or 1 and it will crawl at speed step 1 or 2 on a Digitrax system on 128 speed steps set to 12V track voltage.
Tony Hines

Modeling the B&O in Loveland, OH 1947-1950

timhar47

Hi,

Yes - NCE meant NCE DCC simple system. Used with previous HO layout.

Didnt measure track voltage as the HO worked fine. I took everything off the HO layout (small layout) and 'jumper-wired' from that track to the N gauge  4  pieces of unitrack (new). All I wanted to do was to be sure the engine ran.

The engine doesnt start moving until the throttle is at 12-14. I also cant break it in, I just had 4 pieces of 9" unitrack set up - no layout yet

Have not looked at any settings, as I assumed it would run normal out of the box, and I am not real familiar with messing with the settings.
The Bachmann notes say its preset to 28 speed step

skipgear

The speed step setting is relative to your throttle, not the loco.  If you turn the throttle all the way up, how high does it go, what number?

If it is on 128 speed step, then 14 is fine. If it is on 28 step then 14 is a bit much. You can change CV2 in these decoders to set start voltage.

Before passing judgment on the loco, you really need to give it an hour or so break in to loosen things up. Tolerances are pretty tight in N scale so breaking in helps wear in out of spec parts and smooth up the drive line.

That said, the only new generation Bachmann DCC diesels I have are a doodlebug, 44T and a GP7 but they, after lowering CV2 to 0 or 1 depending on the loco, will start at speed step 1 and crawl a tie at a time. The doodlebug did have some screws overtightened in the power truck that made it a little stiff to start. An 1/8 of a turn with a screwdriver solved that and it has been quiet and smooth since then. I haven't played with an RS3 yet but they should act the same.
Tony Hines

Modeling the B&O in Loveland, OH 1947-1950

timhar47

Hi Tony,

The window on the Cab says 28 at the max. The engine moves at what you would call a 'safe' top speed, but not a ridiculous one like some do. I did change CV2 to 0, it was at 10, but it didnt really make a difference.

I cant do a break in w/o taking everything out to the workshop. No room in here for the size kato loop i bought yet. Trouble with that is I would have to take all the NCE stuff out also, or just run it on a DC power pack out there.

Unfortunately, this is the only N engine I have right now, so its not like I can compare it, or even remember how different they ran, compared to the HO engines. I feel like they always started moving at the lower numbers on the throttle but that was over a year ago.

I took the track out to the shop and ran it on DC both directions for a while. Seemed to run normal, well, as normal as could be tested with this crappy Model Power DC pack I have.

I will try it again later this week.



skipgear

Beaking it in on DC would be fine. Running is running. It does sound like it is a little off though. Even at Vmin at 0, my locos will make an attempt to move at the first speed step on my Digitrax at 128 speed steps.

On DC it should start at around 3-4V and accelerate from there to max speed at max voltage. The new locos are geared alot lower than the old days and should run much closer to a scale max speed on 12V.
Tony Hines

Modeling the B&O in Loveland, OH 1947-1950

timhar47

OK - this thing HAS to have something wrong with it. No matter what I set CV2 or 3 to, it still will not move until the throttle is at 11 or 12 - that means one has to turn the thumbwheel several times to make the thing go - thats just plain dumb.