Anyone have any good CV settings to make a Tsunami equipped diesel start/stop slower/smoother without getting into all the speed table stuff?
Step 1 on the throttle makes an abrupt start/stop. Step 1 needs to be slower.
I tried changing the Throttle Speed Limit (%) on the JMRI Roster Tab to 75% (from 100%) & it didn’t seem to make any difference.
The locos in question are Athearn Genesis GE U50. Throttle is Digitrax DT402D
If CV2 is already 0, you can’t make it any slow with any sort of speed table, you need to work with the Back EMF CVs and adjust the motor control.
–Randy
The throttle speed limit on the roster entry pane of JMRI is only in effect for JMRI throttles.
Thanks Randy. That’s what I was afraid of. I have some ATHG F45 with the same that I made a lot of BEMF changes to. I guess I’ll copy those to the U50 and see what happens. The F45 aren’t where I want them yet but better than default.
And thanks CNR - that’s good to know. So that Roster Throttle setting would work with an Android running through JMRI? Or just from JMRI?
Setting CV 2 to 1 or 0 is about the best I can do provided the loco doesn’t vibrate or shutter at that low of setting. On step 1 of 128, take off and overall speed is acceptable, but stopping is still way too abrupt.
I dont have JMRI and figuring out BEMF adjustments to yield better results is above my pay grade.
Sorry Arto, don’t know the answer to that part. If I remember I’ll try it next week at the club.
Peter
Mark Gurries has this page for tuning soundtraxx decoders
https://sites.google.com/site/markgurries/home/decoders/decoder-motor-tuning/soundtraxx
Are these the decoders where the momentum CVs don’t do anything? I have a couple of those.
To prevent jackrabbit starts, I adjusted Vhigh. I don’t think it’s the CV it’s supposed to be, but the Soundtraxx documentation does tell you what it is. You may need to play with Vmid, too. This does limit the top speed of the locomotive, but I never run my engines at warp speed anyway.
Which Tsunami are you working with? The TSU-1000’s or the newer Tsunami 2 ?
The TSU-1000 do not support CV’s 2, 5 and 6.
Not quite right, they only support Vmin (CV2)
Peter
Randy, can you be more specific in terms of CV adjustments? CV 2 at 1 provides acceptable speed for me, but the stops are really abrupt.
Do you have any magic combination of CV values to do your BEMF suggestion?
For abrupt stops or starting you should be looking at momentum CV3 for acceleration and CV4 for deceleration. Start increasing CV4 until the stopping is what you want or expect.
Peter
Arto,
One of my biggest beefs about the Tsunami decoders and why I prefer Loksound or TCS Wow!. The motor-control for the Tsunamis is so-so and definitely inferior to the latter two brands. While I do enjoy sound (in reasonable doses), motor-control is WAAAAY more important to me than sound - especially in switchers, which make up the majority of my roster.
I’ve never been able to get a Soundtraxx decoder under 2 or 3sMPH - even with tweaking CVs. With either ESU or TCS decoders, I can consistently get <1sMPH - right out of the box. [Y]
I believe the newer Tsunami 2 decoders have made improvements in the area of motor-control. However, I haven’t been able to confirm that yet. Until I do Loksound and TCS will remain my go-to sound decoders.
Tom
I suggest to go to the “Advanced” page of the decoder in Decoder Pro. The values of Motor Kp Coefficient and Motor Ki Coefficient should be set to values 75 and 5 as a first try. Stay for Kp values above 25 and Ki between 3 and 10. The unusal low valus of Ki is key for slow speed.
The speed table shall be “User defined speed tabel” start at 1 slow increasing up 10 in increments of 2 and than straight to the max. Forward and Reverse Trim set to 40 is fast enough for most engies.
Give it a try and the older Tsunami 1 will behave quite nice.
The new Tsumani 2 behaves out of the box similar to Loksound without the nasty humming sound.
I think Peter is on the right track, I’d suggest setting CV 3 and 4 to say 10 and see how it reacts. Increase by 5 or 10 if it’s not enough difference and try again. The momentum CVs will smooth out the transitions between speed steps.
That’s encouraging news to hear, Reinhard.
Tom
I’ve tried the deceleration momentum, which is CV4. Cranked up the value to near its maximum. It works and looks good when taking the throttle from, say, speed step 5 of 128 down to 0. The deceleration over a longer period masks the abrupt stop when going at low speed.
But going from step 1 of 128 to 0 looks abrupt. CV4 doesn’t seem to matter. Loksound and even old QSI both tend to have a softer landing at that speed even with no momentum.
Thanks Reinhard. It seems that each decoder has its imperfections in one way or another and compromises have to be lived with. I was hoping that replacing my buzzy Loksounds with Tsunami 2s will not impair ultra slow speed performance.
I’ll try one and see what happens.
I must be the only one who doesn;t hear the buzzing from Loksound. And my favorite to operate is my Baldwin switcher, at very slow speed and very close to it while switching cars. Maybe the Canon motors in them are not as affected by the motor drive pulses? But my old Loksound 3.5 PCM steamer doesn’t buzz either. Though I think they used Canon motors in those, too.
–Randy
I hate to mention brand because the net can be a source of misinformation or confusion, and I don’t want to impugn a company. Lets just say that the newer stuff, even nonsound decoders, buzz a lot on my layout. 21 pin stuff from several manufacturers.
Only my QSIs and NCE DA-SRs are truely silent. Tsunamis are silent also. And they are the old tech guys by today’s standards.
I use an NCE Power Cab factory out of the box and my locomotives are all Atlas, Intermountain, and Walthers Proto from about 2004 vintage to the newest vintages. As a general observation, the older vintages are quieter than the newer vintages. None have been run very long.