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Matching Loco speed Rapido w/ESU

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  • Member since
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  • From: Chicago area
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Matching Loco speed Rapido w/ESU
Posted by Arto on Thursday, January 25, 2024 5:48 PM
I got a Rapido ABBA PA/PB loco consist for Christmas. This is of recent manufacture (D&RGW). It has ESU LokSound decoders.
 
I’ve broken-in all units simultaneously, running them all at the same time, uncoupled and separated.
 
While the locos all run wonderfully (great sound too), I’ve noticed some speed variations between the units.
 
I’m not very familiar with LokSound decoders. From what I’ve read, it appears there are three CV that are used for speed matching, CV 2 (start), 6 (mid) and 5 (max).
 
Any recommendations on where to start?
 
I have an ESU LokProgrammer.
 
Also, I should mention that momentum acceleration/deceleration are perfect and momentum performance between the locos appears to be identical.
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Posted by betamax on Friday, January 26, 2024 7:31 AM

You can try the auto-tune feature. The auto-tune will make adjustments to maximize performance.  

These decoders have a speed table. Check CV29 to see if the three point or custom speed table is in use.

You can download the manuals from Rapido's website for both the decoder and the locomotive. There is a lot of information in the ESU manual, so it is important to refer to it.

From there you can adjust the speed table. That is much easier done using JMRI or a LokProgrammer.

 

Tags: ESU
  • Member since
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  • From: Mpls/St.Paul
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Posted by wjstix on Friday, January 26, 2024 9:39 AM

If you're just speed matching the units to each other, CV2-5-6 should be all you need. BTW most decoders have those CVs, they're not unique to ESU.

As they come from the factory, engines are usually set up with all three CVs at 0, which disables them. This means when you turn the throttle all the way up, they will all go as fast as possible. So you can't speed the slow ones up, you have to slow down the fast ones. 

Figure out which one is the slowest, and match the other three to that. CV 5 has a range of 0-255. Try setting CV5 to say 225 and see how it compares to the slow one. Then adjust CV5 up or down a little - say by 10s at first - until they run about the same. Then you can fine tune them until they both run the same at top speed. (If they're really close, that's fine, they don't have to be perfectly identical.)

If the engines now run together at top speed, now try them at lower speed (less than 1/2 top speed). If one is faster then the other at low speed, you can adjust CV6 to slow it down. Start with 1/2 the amount in CV5, and then reduce a little at a time (maybe by 5 to start) until they now run the same at low speed.

CV2 is only needed if one engine starts running before the other when starting up. Adding a bit (5 or 10) to CV2 will make the engine start a bit quicker. 

CV3 and 4 are acceleration momentum and deceleration momentum. ESU decoders I believe come with those already having with a number (28 for CV3 and 21 for CV4, according the Loksound 5 info on their website) so you probably won't need to adjust them. But if an engine hesitates when starting compared to other engines, sometimes adjusting CV3 down a little instead of raising the amount in CV2 up a bit will make it start sooner. 

p.s. if the engines are all pretty close to each other in speed, just tweaking CV5 on the fast ones may be all you need to do.

Stix
  • Member since
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  • From: Chicago area
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Posted by Arto on Wednesday, February 21, 2024 8:44 AM

betamax

You can try the auto-tune feature. The auto-tune will make adjustments to maximize performance.  

These decoders have a speed table. Check CV29 to see if the three point or custom speed table is in use.

You can download the manuals from Rapido's website for both the decoder and the locomotive. There is a lot of information in the ESU manual, so it is important to refer to it.

From there you can adjust the speed table. That is much easier done using JMRI or a LokProgrammer.

 

 

I got a response from Rapido regarding speed matching and fine tuning slow speed operation. The locos I'm refering to have LokSound 5 decoders, so this refers to version 5 decoders only!

"We have received conflicting advice from ESU on the Slow speed thingy - With V4 decoders (pre 2019) it helped quite a bit with slow speed running of individual locos.

With the current V5 decoder, ESU improved the motor control dramatically to the point where they told us that there is really no advantage to using the Slow Thingy.

However, the feature is still there for those folks who want to torture themselves... (I tried it on a couple of locos and had to re-tune them manually.)
If you want to try it, only one loco at a time, the process tests the motor back EMF of a single motor attached to a single decoder, for multiple decoders or a consist it probably will give you an error.
Note: it does nothing for speed matching. The PA's use a speed curve (CV2 - min & CV5 - max), not the Vstart/mid/high adjustment."
  • Member since
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  • From: Mpls/St.Paul
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Posted by wjstix on Thursday, February 22, 2024 9:54 AM

I believe what they're talking about is ESU being one of the decoders that have a "switching speed" option. When you hit a certain function button, it changes the speed settings to 50%, so an engine that normally runs at say 50 scale MPH at full throttle will now only go 25. It's supposed to make slow speed switching easier, giving you better slow speed control when you want it. It doesn't really have anything to do with speed matching the engine to other engines.

Stix
  • Member since
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Posted by betamax on Thursday, February 22, 2024 3:56 PM

Arto

 

 
betamax

You can try the auto-tune feature. The auto-tune will make adjustments to maximize performance.  

These decoders have a speed table. Check CV29 to see if the three point or custom speed table is in use.

You can download the manuals from Rapido's website for both the decoder and the locomotive. There is a lot of information in the ESU manual, so it is important to refer to it.

From there you can adjust the speed table. That is much easier done using JMRI or a LokProgrammer.

 

 

 

 

I got a response from Rapido regarding speed matching and fine tuning slow speed operation. The locos I'm refering to have LokSound 5 decoders, so this refers to version 5 decoders only!

"We have received conflicting advice from ESU on the Slow speed thingy - With V4 decoders (pre 2019) it helped quite a bit with slow speed running of individual locos.

With the current V5 decoder, ESU improved the motor control dramatically to the point where they told us that there is really no advantage to using the Slow Thingy.

However, the feature is still there for those folks who want to torture themselves... (I tried it on a couple of locos and had to re-tune them manually.)
If you want to try it, only one loco at a time, the process tests the motor back EMF of a single motor attached to a single decoder, for multiple decoders or a consist it probably will give you an error.
Note: it does nothing for speed matching. The PA's use a speed curve (CV2 - min & CV5 - max), not the Vstart/mid/high adjustment."
 

The missing critical piece of information is the firmware version.

If the motor control was improved after your decoder was flashed at the factory, you won't have the improved motor control Rapido is referring to. When a new version of the LokProgrammer software is released it often includes firmware updates for their decoders, which may have new features or improvements over previous versions.

  • Member since
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Posted by wrench567 on Thursday, February 22, 2024 9:39 PM

   Arto.

  If their not too far off from each other, don't torture yourself. Running as a single locomotive could very well be different pulling a train. If they are close, they will run together without issue. 

  I've run a consist of three 2-10-0 locomotives all made by different manufacturers up front with two more (sometimes 3) pushing on the back of long strings of hoppers on the old club layout. There was a long grade about 30 foot long and curvy. Never had a problem. I just did a rudimentary speed match that got them close (maybe ten inches in a run of twenty feet) and cranked up acceleration momentum to around 30. Some brass are geared fast so more momentum was added to them.

     Pete.

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Posted by BATMAN on Friday, February 23, 2024 12:19 PM

I agree with Pete. I was obsessive about having them perfectly matched and spent hours trying to do that. I have a 50' loop and can easily get them within a foot or so and that is good enough. I don't worry about it as much anymore. Close is good enough.

I run 50-car trains with mid-train helpers and pushers and have an 80' up-and-down stretch and have never had a derailment with the multiple locomotives.

I have a Rapido A-B-A set and the "B- Unit" ran super fast compared to the "A-Units". I was talking to Rapido one day and asked them about that and they said the motors in the "A-Units" were not the greatest and said I could send them in to have them changed or just send the motors and they would send me two of the newer ones.

Brent

"All of the world's problems are the result of the difference between how we think and how the world works."

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