mXion DRIVE-L assistance

[Andrew_au]

Installed an mXion DRIVE-L in my 28002 (replaces a Massoth-L). All good, except that the loco doesn't move.

I know it's receiving the direction commands, as the lighting changes front / rear as I change direction, but I can't get the motors to turn. I think it's a decoder issue, because the sound box is hooked up to the motors and that's not going either.

Is there some setting on the DRIVE-L that could cause the motors to not respond to speed commands? I'm wondering if I've accidentally enabled the "handbrake" or some such.

 

[PhilP]

Have you perhaps touched a DIP switch, turning off one motor feed?

A wire to the motor connections come adrift?

As you will have had the block off, is the quartering and motion correct? - This could jam the motion.

Other than that, I can't help, as I do not know the specific make of decoder.

One final thought :
Are the lights driven differently? - Could your new decoder be on a different address?

PhilP

 

[The Shed]

I'm wondering if I've accidentally enabled the "handbrake" or some such.

 

[idlemarvel]

Have you accidentally set the LGB 4 way switch to lights only? Switch is in the cab I seem to remember.

 

[Andrew_au]

Update: I got this working. Here are some of my findings:

• I needed to set a quite high value for CV 2, in my case around 80. Much less and the motors would not start turning.
  • Measured by just looking at the wheels on the programming track. I didn't get a multimeter out.
  • I also turned load control off.
• Behaviour of CV 3 and 4 seemed to be a little unpredictable. With values around 100, it would still start rapidly but take a very long time to stop if I set the throttle to "stop". In the end I turned both off and am controlling accel / decel manually.
• CV 6 does not seem to be applied correctly when using 128 speed steps. When using 28 SS, moving CV 6 (and CV 2) changes the observed throttle behaviour. When using 128 SS, CV 2 changes the throttle behaviour, but it seems to be linear across all speed steps despite changing CV 6.

Unrelated tip: the LGB baseboard already includes dimming for the 5V lights, so CV 51 & 56 are set to 100 (= 100% of track voltage).

 

[Greg Elmassian]

interesting results.

• So the higher CV2 is explained by turning load control (BEMF) off. (wonder why you turned it off)
• That high of a CV2 would cause me to go through the drivetrain for excessive friction or binding
• So, you can set CV3 and CV4 separately. Strange it almost sounds like CV3 never "took"
• CV6 can be weird on some decoders, some decoders ignore it on with certain settings, should not be, but that's what I have seen also.

Congrats on completing the task!

Greg

 

[Andrew_au]

Interesting result.

• So the higher CV2 is explained by turning load control (BEMF) off. (wonder why you turned it off)
• That high of a CV2 would cause me to go through the drivetrain for excessive friction or binding

While trying to diagnose things, BEMF was an additional modifier to loco behaviour (and has its own CVs to configure).
When I was using the 55021 and Massoth eMotion-L I had BEMF turned off also. Both of these started with much lower values of CV2 (about 5). The train seems to run fine with CV 2 = 80, but it does go from stationary to slow-medium very quickly - it's very hard to get clean slow-speed performance. I have seen no evidence that this is the fault of anything other than the decoder.

I could pull it apart again and try putting the eMotion-L back for comparison, but the LGB-28002 is a real pain to access the decoder. I basically have to deconstruct the entire engine (other than the motor block), compared to the two starter set locos where I just undo a couple of screws and pop the cabin off.

Congrats on completing the task!

Thanks. For a little while I was despairing - having all the auxiliary functions work isn't a good tradeoff for the motor not running.

Part of what took me so long to figure things out is that the factory settings required I set the throttle to almost 60% before the loco started moving, which is obviously not something I wanted to do with a loco that filled most of a 300mm programming track. Once I set up a rolling road and tried pushing the throttle way up things became a bit clearer.

 

[Greg Elmassian]

So, if the speed is not very linear, you might contemplate a custom speed table... that will fix it right away.

I actually set mine up so (I run class 1 railroads) that the speed step matches actual scale speed... and tapers off above the prototype top speed, no matter what the speed step.

are you positive you are running 128 speed steps?

Greg