I have an Atlas GP-40 (no decoder) running on a MRC command 2000. While it runs smoothly at moderate speeds, it starts and stops at around 10-20 smph. I figured it may do this cause of the light weight of the loco. Since I'm new to N scale, is this common to all N scale locos? Does the newer locos perform any better?
My advice - get it a decoder. This loco is not an "old" loco per se, and is not light either (at least for N scale). When running a non-decoder equipped loco on a DCC layout, some strange things can happen, what you have mentioned included. The reason for your problem is this. With DC control, you vary the voltage in the rail, so the loco only picks up the amount in the rail. With DCC, there is a constant voltage in the rail (around 12v), and the decoder tells the loco how much voltage to pick up based on your signal. So, a non-decoder equipped loco will have more voltage at it's starting point, and therefore a higher speed. Any more questions on DCC you can put in the DCC forum. ------------------ Corey Lynch Pres - Rensselaer Model RR Society NEB&W RR http://www.rpi.edu/~lynchc/Railfanning/railfanning.htm - My Site http://www.union.rpi.edu/railroad/ - NEB&W
I slightly disagree with that. I have many DC Atlas Locos that never skip a beat at any speed. However, this has been a problem with some of the GP40's. This is a contact problem that can be corrected by bending the contact strips down a little so they meet with greater force. I've never had this problem and I've had four or five GP40's at one time. I sold them off so I could get some SD60M's, no problems with them either. DCC is the way of things to come, but I'm in no hurry to jump into it. ------------------ Brent Tidaback, Member #234 BNSF Railfan-to-the Max and a N-Scaler to boot! "Ship it on the Route of The Roadrunners!" The Aransas Odessa & Western, a division of the BNSF
Hmm, could work, but he has no problems at other speeds. A contact issue would most likely give him problems all the time. If he put his GP40 on a DC layout, it, too, shouldn't "miss a beat" at low speed. However, since he is running it on a DCC layout, what I mentioned could be the problem. It sure wouldn't hurt to try. BTW Brent, did you run those locos on a DCC layout and not have any problems? ------------------ Corey Lynch Pres - Rensselaer Model RR Society NEB&W RR http://www.rpi.edu/~lynchc/Railfanning/railfanning.htm - My Site http://www.union.rpi.edu/railroad/ - NEB&W
How do you run DC locos on a DCC layout? I didn't think that was possible. I think it is the contact problem here. Remember, it's happening at slow speeds. The flywheels don't help as much at this speed, so yes, it will stall if contact is broken. This really isn't a problem at regular or high speed because the flywheels take over until power is reestablished. Dirty track could also be causing this. Cory, I've been using DC FOREVER and have seen it all as far as what causes stalls. With this loco, it has to be a contact problem. I don't discount that going to DCC wouldn't help with this, but if it's a contact problem, it's still there if you go DCC. Try bending the contacts BEFORE spending all that money on DCC. It's a lot less expensive to possibly solve this problem to try that first. Buy the way, although DCC has constant voltage in the rail, you don't have constant voltage to the motor, If you did, your GP40 would be going like a bat out of hell all the time. Think about it. ------------------ Brent Tidaback, Member #234 BNSF Railfan-to-the Max and a N-Scaler to boot! "Ship it on the Route of The Roadrunners!" The Aransas Odessa & Western, a division of the BNSF [This message has been edited by Maxwell Plant (edited 07 November 2000).]
Yes, Brent, it would be zipping around if it were picking up all 12 volts (same as opening the throttle on a DC layout). Posted by davef: <BLOCKQUOTE>quote:</font><HR> I have an Atlas GP-40 (no decoder) running on a MRC command 2000. While it runs smoothly at moderate speeds, it starts and stops at around 10-20 smph. I figured it may do this cause of the light weight of the loco. Since I'm new to N scale, is this common to all N scale locos? Does the newer locos perform any better? <HR></BLOCKQUOTE> Notice Dave says he is running a non-decoder loco on an MRC Command 2000 (which is a very low-level DCC system - so he already has DCC) hence my first suggestion - get it a decoder!! Now with DCC I know you can adjust start voltage of locos, but I'm not familiar with the Command 2000 system - or running a DC loco on a DCC layout (which can be done). So the starting voltage that the GP40 is getting is too high. There might be a way to change it. I would check the manual. If all else fails, spend the $30-40 to get the decoder. ------------------ Corey Lynch Pres - Rensselaer Model RR Society NEB&W RR http://www.rpi.edu/~lynchc/Railfanning/railfanning.htm - My Site http://www.union.rpi.edu/railroad/ - NEB&W
<BLOCKQUOTE>quote:</font><HR>Originally posted by Maxwell Plant: How do you run DC locos on a DCC layout? I didn't think that was possible. <HR></BLOCKQUOTE>This is my first time here doing a reply with a quote so hopefully it it works. Anyway, you can run DC locos on a DCC layout,at least on mine anyway(MRC command 2000), but just on one of the throttles. The one thing I noticed though is the "humming" noise the DC loco makes when idleing. They say it does no harm to the loco as long as the loco does'nt sit there all day idleing. I tried the DC loco on one of my old DC power packs and it does indeed start out smoother. But I still had problem at low speeds sometimes where it would stall unless I gave it more throttle or gave it a shove. I think my problem is that I'm used to HO scale locos with the heavier weights and better contact with the rails and since N scale locos weigh so much less, they require wheel cleaning more often.I just bought the loco so I figured the loco would already be good to run for a while but I noticed the lights flickering. Also, anybody know if theres a decoder for the GP-40(Atlas). I hear theres one by Digitrax for the GP-40-2(Atlas) but was wondering if it will fit my loco.
Dave,the GP-40-2 frame is decoder ready(plug-n-play).The 40 frame can be milled for a decoder but it will not be a plug-n-play type of install.You could possibly buy the 40-2 parts from ATLAS (frame,motor contact etc) then you could use the plug-n-play decoder.You could also just buy a GP40-2 and swap the chassis for the GP40 unit.Hope this rather long winded speil helps a bit. ------------------ Catt!#118
