I have installed a number of Tsunami’s now with good success and have not run across this problem. I have the medium steam decoder setup for 28 steps. I have CV2 set at 0. I used CV210 setup for the loco to move slow at step one. I tried to use CV209 to smooth things out. Well the locomotive jerks until I get to step three and then things are smooth and runs great. Problem is with steps one and two. It is a Pacific type loco with a can motor from the factory. Maybe KTM manufacture. I have moved CV210 around a few numbers within the range I want to no avail. I have been from 0 to 255 with CV209 to no avail. I have even went up and down ten numbers with CV2 to no avail. Any ideas before I get ahold of SoundTraxx?
I had the same thing with a factory Tsunami equipped Spectrum 2-6-6-2 And never did solve the problem even with Decoder Pro. I finally gave up, didn’t want to pay for all the shipping. Bachmann did send a new engine but it does the same thing. I tried all the suggestion from this forum.
Sorry I can’t be of help. [%-)]
Lee
Had you ran the engine before you installed the decoder? Sometimes the jerking can be caused by to much lash in the worm gears or worm gear angle. My BLI steamers had that problem, messed with the motor mount angle and problem went away.
Cuda Ken
It is a brass locomotive and I took most everything apart to paint it. After I reassembled it after lubing I ran the motor chasis with battery power and everything seem OK. When I first tested it with the decoder and found the jerking I took it back apart. I ran wires straight from the motor and reassembled again, used battery power and everything was fine. I did not test it at real slow speed though. I can turn the motor by hand and everything feels ok. I was thinking it had something to do with setting up the decoder that I had not had to use before. Maybe not.
I think Cuda Ken is somewhat on the right track as in being mechanical. I had to shave some weight in order to fit the decoder in the boiler. Maybe to much weight. After some experimentation I think I will have to find places to add in more weight. Those brass Vanderbuilt tenders make things a little tougher when going to DCC and sound.
It could be the motor itself. If it were mechanical, I would think, unless it was a really bad mechanical bind, that the Tsunami’s Bemf compensation would be able to smooth it out. If the motor has one pole that is out of spec from the other poles(it does happen, I have an engine with this problem), the Bemf compensation will not be able to account for it.
No guys, it is the decoder. Just turn of the BEMF. It is dodgy and the factory settings do not work for every instance.
David B
CV10 which I believe is BEMF is set to 0. Again a Tsunami decoder.
CV 10 is BEMF cutout, which sets the speed step at which BEMF compensation is reduce to zero. Setting CV 10 to 0 means no cutout, which means BEMF will be enabled(depending on other CV settings) throughout the speed curve. Setting CV 212 to 0 disables BEMF compensation completely.
Thanks Robert. I gave that a try to no avail. A couple of times now the motor has “locked-up”. Reversing the motor got it going again. So I’m beginning to believe it may very well be a defective motor. I think I will change out the motor as I have another one I can try.
Just and update. It was indeed the motor. I had a spare motor for a Genesis Mikado that I put in. Runs great with a very nice low speed crawl. This is the second time I have used the Genesis Buehler motor for a conversion and both times I have been very satisfied with the results. The motor was very reasonable on Ebay.
Thanks for the update