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mu-ing with lenz.

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  • Member since
    September 2003
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Posted by mlehman on Saturday, June 29, 2013 3:14 PM

Yeah, sounds like a plan. There was definitely no Digitrax involved in my own manipulation of electrons documented above.

Mike Lehman

Urbana, IL

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Posted by moosecreek on Saturday, June 29, 2013 2:56 PM

Thanks re decoders.The fault does seem to lie with digitrax-will press on with myCVs.

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Posted by betamax on Friday, June 28, 2013 4:15 AM

Speed matching and tuning is needed when you want to MU two engines.  They are supposed to operate as a unit.

Since you never indicated what brand decoders were in use, the answers will be general in nature.

Consisting with Lenz

Back EMF

These links might help.

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Posted by mlehman on Thursday, June 27, 2013 11:39 PM

Consistedmy only Lenz Silver-equipped loco, a Liliput Gemeinder Diesel converted to HOn3, with my kit-built PSC DL-535E, equipped with a NCE D-something. I did nothing to prep the locos, not even bothering with speed matching. They did just fine on my NCE Power Pro-powered layout.

Here's the test train, my ultra-modern San Juan Zephyr luxury narrowgauge cruise train. Unfortunately, we can't do close-ups of the observation/tavern/hot tub car in this family-oriented forumWink but it is unique.



My ruling grade is 4% with 24" min radius uncompensated curves. After the photo here, starting the train on the grade resulted in some very realistic sounding wheelspin out of the big Alco, while the Lenz never stumbled. That was the only time I noticed anything different and it was a sorta good thing.Yes



They pretty much ran fine together.





Mike Lehman

Urbana, IL

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Posted by moosecreek on Thursday, June 27, 2013 1:29 PM

Thank you all-I will keep trying.

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  • From: Reading, PA
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Posted by rrinker on Thursday, June 27, 2013 11:47 AM

 Needing to disable BEMF when consisting seems to be one fo those enduring myths. Or maybe it only applies to certain decoders.

 My primary motive power for trains shows is a pair of Proto 2000 GP7's. Both have TCS T-1 decoders with the TCS automatic BEMF. Definitely NOT disabled. The do not buck and fight one another, running light tor when pulling a train. I also sometimes run doubleheaded PCM T-1 steam locos, both have Loksound sound decoders, which have BEMF. No issues.

 Sometimes people think they BEMF is off when using Digitrax decoders - well, if you are using CV19 consiting it might be, but even thought he default CV settings for the DIgitrax decoders with BEMF is such that BEMF is disabled when in consist - this only applies to CV19 consisting. Default Digitrax consisting does not use CV19, so the BEMF is still on. NCE uses CV19, so consisting Digitrax decoders with NCE results in BEMF being turned off, unless the decoder has been set to not do this.

                  --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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  • From: Christiana, TN
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Posted by CSX Robert on Thursday, June 27, 2013 11:39 AM

 

jrbernier

  Leaving BEMF while in any type of consisting can produce 'bucking' - You want if off with a consist...

 I have heard this before, in fact my understanding is that is the reason for the default settings in Digigtrax decdoders.  I have never had a problem using bemf compensation in consists as long as the locos are somewhat closely speed matched and I have talked to several other people with the same results.  If he does desire to have bemf off when in a consist, he needs to make sure he speed matches them with bemf off.  Programming CV57 to a value of 0 will turn off bemf both in a consist and when running alone.

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Posted by jrbernier on Thursday, June 27, 2013 11:11 AM

CSX Robert
What do you mean by "loose power"?  Do they run, but just run a lot slower than normal?  If so, my bet is you are using Digitrax decoders and advanced consisting.  Digitrax decoders default to using bemf compensation when not in a consist, but turn it off when in a consist.  The easy answer is to program CV57 to a value of 102 so that bemf compensation remains enabled when in an advanced consist.  For more information read up on Scaleable Speed Stabilization in the Digitrax decoder manual.

  Leaving BEMF while in any type of consisting can produce 'bucking' - You want if off with a consist.  I think the OP needs to 'speed match' his engines first.  I usually let my engines 'warm up' by running them for about 20 minutes before doing any speed matching.  Since he has Digitrax decoders, he can do the following:

Set CV2 - Vstart - Get each engine to start at speed step 1 on your throttle.

CV5 - Vmax - Set The top speed of your engines to the same top speed.  Find your 'slowest' engine and match the other fast ones to it).

CV6 - Vmid - Set your normal 'cruising' speed,

  This should get your engines to run in a consistent manner.  Make sure that your acceleration/deceleration  or BEMF have not been adjusted..  If you have been 'playing' with CV's, do a 'decoder reset'(CV8 = 8 for Digitrax decoders) so you have a level playing field.  Also, make sure your track is 'clean'!

Jim

Modeling BNSF  and Milwaukee Road in SW Wisconsin

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Posted by CSX Robert on Thursday, June 27, 2013 10:34 AM

moosecreek

Any suggestions please as to why two good running locos loose power when in a consist. This happens to any two MU locos and they struggle to go at all. Any help appreciated.

What do you mean by "loose power"?  Do they run, but just run a lot slower than normal?  If so, my bet is you are using Digitrax decoders and advanced consisting.  Digitrax decoders default to using bemf compensation when not in a consist, but turn it off when in a consist.  The easy answer is to program CV57 to a value of 102 so that bemf compensation remains enabled when in an advanced consist.  For more information read up on Scaleable Speed Stabilization in the Digitrax decoder manual.

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  • From: Bedford, MA, USA
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Posted by MisterBeasley on Wednesday, June 26, 2013 4:53 PM

Mark R.
Mr. Obvious has to ask the question .... have you MU'd them so they are both running in the same direction together ?

Yes, the "obvious" is what came to me, too.  Look closely at the wheels.  If they're spinning in opposite directions, that's the problem.

But, it may not be your problem, it may be the decoder.  Some decoders simply don't like going into consists in reverse, even though you do everything right.  If you think you've accounted for the direction issue, try powering off and powering back on.  This will usually correct the direction issue, and it will stay corrected until you take it out of the consist.

It takes an iron man to play with a toy iron horse. 

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Posted by Mark R. on Wednesday, June 26, 2013 4:32 PM

Mr. Obvious has to ask the question .... have you MU'd them so they are both running in the same direction together ?

If the second unit is facing backwards, you have to reverse the direction of the second unit so it will match the first. Otherwise the stronger engine will just push or pull the other (you might not hear it) which would appear as though they have little or no power.

Had to ask to get the obvious out of the way ....

Mark. 

¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ

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Posted by locoi1sa on Wednesday, June 26, 2013 4:16 PM

How do they run if you double head instead of MU?  MUing locos with BEMF can be touchy and one or the other will either drag or run like mad spinning its wheels wildly.

        Pete

 I pray every day I break even, Cause I can really use the money!

 I started with nothing and still have most of it left!

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Posted by rrinker on Wednesday, June 26, 2013 3:44 PM

Which decoders are in the locos? It's the decoders that matter, not what system is used to run them.

        --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    September 2003
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mu-ing with lenz.
Posted by moosecreek on Wednesday, June 26, 2013 3:11 PM

Any suggestions please as to why two good running locos loose power when in a consist. This happens to any two MU locos and they struggle to go at all. Any help appreciated.

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