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Zephyr and motor control

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  • Member since
    September 2014
  • 311 posts
Zephyr and motor control
Posted by PRR_in_AZ on Tuesday, October 19, 2010 7:10 PM

All,

Need some advice.  I have a Zephyr system and I'm not quite happy with it.  I'm installing decoders in some brass locomotives and installing new can motors.  One is an NWSL and the other is an older sagami.  With the decoder hooked to the sagami the motor makes a sort of sing-songy type of sound as I increase the throttle.  I can actually hear a distinct and separate pitch change as I advance the throttle.  Same when I decrease the throttle.  I've been through the digitrax manual and checked that the Zephyr is operating in 128 speed step mode and also that the decoder is in 128 speed step mode.  The NWSL motor doesn't sing like the sagami but still seems to have noticeable pulse and pitch change.  These motors operate completely smoothly hooked up to a regular DC power pack.  It seems to me I should have better (smoother?) motor performance from 128 speed steps.  Are my expectations too high and this is  just the way DCC is?

Chris

  • Member since
    July 2006
  • From: Vail, AZ
  • 1,943 posts
Posted by Vail and Southwestern RR on Tuesday, October 19, 2010 7:21 PM

The decoder is more likely the issue than the Zephyr.  What are you using?

Jeff But it's a dry heat!

  • Member since
    September 2014
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Posted by PRR_in_AZ on Tuesday, October 19, 2010 7:22 PM

Digitrax DH163

  • Member since
    February 2002
  • From: Reading, PA
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Posted by rrinker on Tuesday, October 19, 2010 8:23 PM

 That sounds like a decoder that does not have high frequency drive, but the DH163 does. And it can't be turned off in DIgitrax decoders, so you didn't accidently program the wrong CV. But for the heck of it, program CV8=8 to reset the decoder just to be sure. It will reset to address 3.

 Perhaps you just have better than average hearing and can hear the high frequency. Most people can't.  You might have to use a better decoder with more control over the motor drives - Lenz and Zimo have plenty of options for the motor type whic adjusts the frequency for different motor types, top quality can motors may need different settings for optimum performace relative to a cheaper motor like Athearn. Problem is, neither one documents those settings very well.

 Also make sure the Zephyr does not have a loco selected on address 00 with some speed other than stop - this unbalances the DCC signal and it might be getting through to the motor. Select address o and move the throttle to stop. Then hit Loco and Exit. Now try the two decodered locos again.

                                    --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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    September 2014
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Posted by PRR_in_AZ on Wednesday, October 20, 2010 12:01 AM

One thing that  I don't like about the Zephyr is that you don't know what speed step you are on.  It just has a throttle dial.  I have never used one of Digi's handheld throttles so I don't know if they tell you the speed steps or not.  When tuning an engine, I'd like to know if the engine is moving at speed step 1 but  can't with the Zephyr.  Also,  it seems my motors are running at max RPMs at the 4 indicator on the dial and turning it up does not increase the speed, so over 1/5 of the dial does nothing.  Anyone else experience this?

Chris

  • Member since
    July 2003
  • From: Metro East St. Louis
  • 5,743 posts
Posted by simon1966 on Wednesday, October 20, 2010 7:29 AM

Again this is a decoder/ decoder programming issue.  I have  a Z and it is quite possible to adjust the start voltage so that the loco creeps at the slightest movement of the throttle and tops out at the end of the throttle.  How well this works has a lot to do with the decoder you use, some have much better motor control at slow speeds than others.  My preference for programming these type of things is to use the JMRI Decoder Pro on a PC connected to my Zephyr via a Locobuffer 2 PC interface. 

Simon Modelling CB&Q and Wabash See my slowly evolving layout on my picturetrail site http://www.picturetrail.com/simontrains and our videos at http://www.youtube.com/user/MrCrispybake?feature=mhum

  • Member since
    September 2014
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Posted by PRR_in_AZ on Wednesday, October 20, 2010 11:21 AM

That's great Simon,  so what CV's are you adjusting to get this wonderful performance?  At any rate, I think this is too odd of an issue to solve on a forum.  I truly think something is broken in my Zephyr and am sending it off to Digitrax tomorrow.

Chris

  • Member since
    February 2007
  • From: Christiana, TN
  • 2,134 posts
Posted by CSX Robert on Wednesday, October 20, 2010 12:50 PM

rrinker

 That sounds like a decoder that does not have high frequency drive, but the DH163 does. And it can't be turned off in DIgitrax decoders, so you didn't accidently program the wrong CV

...

Actually, the high frequency drive can be turned off on Digitrax decoders.  For some reason, Digitrax no longer documents it, but the PWM frequency can be adjusted using CV9.

  • Member since
    September 2014
  • 311 posts
Posted by PRR_in_AZ on Thursday, October 21, 2010 12:20 PM

So, I discovered a few things last night, that surprised me so I thought I'd share.  I've just been keeping the loco ID set to 03.  I would hook uo different decoders and motors all set to 03 to test them.  Last night I decided to change the ID of one loco to a four digit number.  Somehow this got rid of the pulsing I had been experiencing.  Don't know if the Zephyr somehow got confused.  I've been playing with the start voltage, mid voltage, and max voltage to get a better range on my Zephyr throttle (actually use the whole throttle).  Seems like there is a lot of dead space on this throttle towards the upper end, meaning I seem to reach speed step 28 at around throttle marking 5 and moving the throttle through 6 to full doesn't increase the speed.  When I set V-mid to a lower value (less than 50% voltage at seped step 14), then I can push the dead space back to around 5 1/2 on the throttle.  So, I was wondering if using a custon 28 speed step table will give me better control to match my throttle?  Any thoughts?

Chris

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    May 2008
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Posted by Hamltnblue on Thursday, October 21, 2010 2:24 PM

A late entry on the install but is the motor isolated from the track?  Some older loco's have to be isolated before installing a decoder. 

Aside from that I would reset the decoder to factory default to see if the other issues clear.

Springfield PA

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