I'm also having the same issues with a 2-6-6-2 DCC Bachmann sound loco.
1) How do I change to 128 step speed control?
2) What CV's control Vmin & Vmax ?
Thanks,
Mark
I have rulled out that the issue is the decoder. I swapped the tenders between my 4-8-2 and 2-6-6-2 and the performance of the loco did not change.
Mark565 I have rulled out that the issue is the decoder. I swapped the tenders between my 4-8-2 and 2-6-6-2 and the performance of the loco did not change.
Even after a lot of work I improved the loco some but not very much. If you read back through the post you will see the things I tried. Also note the post was last active a year ago.
Good luck.
Lee
Lee,
By chance do you guys have back-emf turned on. When I did this with my 2-8-4 P2K Berk it cut it's max speed in half. Turning it off solved the problem. I then did a reset and performed very conservative adjustments on the BEMF CV's and restored most of my speed. Turns out I had too much active correction.
Don - Specializing in layout DC->DCC conversions
Modeling C&O transition era and steel industries There's Nothing Like Big Steam!
At one time or another I feel I've changed every CV there is. I have stored the CV,s on Decoder Pro So that I don't have to go back and redo the whole thing.
Have a good one.
Mark,
As I advised Lee originally in this thread, my 4 DC versions, all decoders removed, jumpers installed, do not have these performance problems. They do not surge, buck, and have normal top speeds.
And, to the issue of top speed, be reminded I only use 13.8 volt power supplies with my Aristo Train Engineer throttles which then actually only put about 13.5 volts on the track.
So, I still think this is an issue with the Bachmann decoder and the use of another brand of decoder could easily be the cure.
All of the bachmann factory decoders are the same, so using the 4-8-2 tender did not change anything. I still suspect the basic design values of the decoder are not correct for this loco.
Again, I have three H5's and an H4, no sound, no decoders, no probelms.
Sheldon
Mark565 I'm also having the same issues with a 2-6-6-2 DCC Bachmann sound loco. 1) How do I change to 128 step speed control? 2) What CV's control Vmin & Vmax ? Thanks, Mark
Typically CV 29 bit 1 (value 2) will determine if you are using 128/28 speed step or 14. But Tsunami manual doesn't document it that well.
CV2 = start voltage
There is no max voltage. You will have to use a custom speed table and recalculate all the CV's for that speed table...That means programming all 28 of them.
By default is comes from 128 speed step from the factory. Changing it to 28 on your cab or on the decoder will make no difference. It will just make your speed adjustments more coarse. In matter of fact you can have your decoder set to 128 and your cab set to 28, and it will still max out in speed. 28/28 on your cab will equal 127/127 on your decoder. (It's complex to explain why.)
yankee flyer At one time or another I feel I've changed every CV there is. I have stored the CV,s on Decoder Pro So that I don't have to go back and redo the whole thing. Have a good one. Lee
Sorry you are having so many problems. I'll just throw one more out there. When you do a general reset (CV8 = 8) You next have to remove power from the tsunami for the reset to work. I get 50 smph out of mine no problem. (And I had 4)
Asking Bachmann for a replacement after 1 failed fix shouldn't be an issue for them. They are usually very good about that.
Sorry, I should have clarified it better, my Spectrum 4-8-2 run great and has a very good top speed. That is why when I switched tenders and each locomotives performance did not change I think it is a drive train issue and not a decoder issue.
Mark565 Mark565: I have rulled out that the issue is the decoder. I swapped the tenders between my 4-8-2 and 2-6-6-2 and the performance of the loco did not change. Sorry, I should have clarified it better, my Spectrum 4-8-2 run great and has a very good top speed. That is why when I switched tenders and each locomotives performance did not change I think it is a drive train issue and not a decoder issue. Mark
Mark565: I have rulled out that the issue is the decoder. I swapped the tenders between my 4-8-2 and 2-6-6-2 and the performance of the loco did not change.
Mark, it may be a drive train issue from the stand point that the 2-6-6-2 is articulated with a gear drive and the 4-8-2 is a belt drive. BUT, that does not mean that the 2-6-6-2 drive is defective or flawed - it may only mean that the ablities of the decoder and the nature of the drive are not compatible, which is what I have been saying about this for a year now.
I would politely suggest someone who is having this problem use their jumper plugs to completely disable the decoder, run the loco on DC and evaluate the performance of the drive under the same load conditions but on DC. Lee was unable or unwilling to do this.
There must be some explaination as to why the locos do not have this problem on DC.
I know that the idea that the "DCC" element here could be at fault is hard for some of you to accept, but like any new technolgy, it is not always perfect.
I went to great lengths to help Lee with this, review my earlier posts. Again, all four of mine run fine on DC, using Aristo Train Engineer throttles, which provide pluse width modulated motor control just like a DCC decoder, BUT with no BEMF or other automatic or ajustable features.
My top speeds are much higher than Lee reported and I only put 13.5 volts on the track. My locos pull and push 20 or so cars up/down a 2% grade with no surging? WHY?
Sheldon thanks for the feedback , I've read all the old post. I'm of next week and will work on bypassing the decoder and post back.
One thing we've seemed to have forgotten is the H4 with its 56" drivers was in fact a drag freight engine with a top speed of about 35mph.
Even in MRs review of this engine this was addressed, their saying when running on DC top speed was about 50mph and with DCC 35mph.Here is my H4 working up a 11/2% grade with 27 hopper cars at what i feel is a prototypical speed.
http://www.youtube.com/watch?v=IeGCwPrlt2I
CB&Q Modeler One thing we've seemed to have forgotten is the H4 with its 56" drivers was in fact a drag freight engine with a top speed of about 35mph. Even in MRs review of this engine this was addressed, their saying when running on DC top speed was about 50mph and with DCC 35mph.Here is my H4 working up a 11/2% grade with 27 hopper cars at what i feel is a prototypical speed. http://www.youtube.com/watch?v=IeGCwPrlt2I
Nobody is disagreeing about the fact that 35 smph is a reasonable realistic speed. However, there is nothing about installing a decoder in a loco that should effect its top speed in this way - AND - Lee orginally reported that his loco would not even go 35 smph.
The other, more important issue is the surging on grades, a problem only experianced by those running H5 sound equiped versions of the loco on DCC with factory decoders. The new H4's have a completely different lighting board and possibly a different sound board/decoder.
I still content there is a compatiblity issue in the H5 sound versions where the motor control aspects of the decoder are simply not compatible with the motor and driveline of this loco.
I repeat, I have both H4 and H5 versions without sound, and have removed the decoders as I run DC. On my 13.5 volts all 4 locos run about 48 smph and have no surging issues.
Your You Tube video lists it as a 2-6-6-6-2. I think you have an extra 6 in there
Springfield PA
So it did! .........edited out that extra set of drivers.
Hey Guys
Having beat that horse to death I'll go one step farther and give it a few more whacks.For what its worth, I know the drive train has a lot more slop in it than my other locos, 4-8-2 mountain, 2-8-0 con. and others. I like to hear the engine lug when climbing grades so my BEMF is now turned on low and it will surge at very low speeds going down grade. If It had a constant voltage applied to it, as in DC I don't believe it would surge. The speed is close to 35-smph I will live with that. If those interested noticed I did remove the light board an cut the capacitor, but the Bachmann, version decoder does have it's limitation IMHO.
Now let's haul that freight.
Well I took my H5 and ran it on DC, it runs better, faster and the sound is more in sync with the speed. Look like I'll be changing the decoder and see what happens.
I have the Vandy tender version lettered for my RR
It has DCC-Sound and has only been run about 30 minutes
I run it DC ( am going to upgrade to a DCC entry level Digitraxx eventually )
With full throttle DC and 12-- 55 ton coal hoppers and caboose all weighted to standard it will hit 40-42 MPH on level track
51% share holder in the ME&O ( Wife owns the other 49% )
ME&O