ModelRailroadForums.com is a free
Model Railroad Discussion Forum and
photo gallery. We cover all scales and sizes of model railroads. Online since 2002, it's one of the oldest and largest model railroad forums on the web. Whether you're a master model railroader or just getting started, you'll find something of interest here.
I am having a hard time figuring how to slow my Bachman 4-8-2 mountain.
I cant seam to get the top speed down to a scale speed? I have a Tsunami tsu-1000 decoder. I can match start and decell with other locos but the top speed is the issue. I want to double head with my other locos that maintain about a scale 50-60mph
I looked online at the manual but cant seam to get it right.
Trent
I haven't checked my Tsunami manual (it isn't handy), but my QSI Quantum manual was nearby. CV5 is the V-Max output setting for the decoder. In your case, it may also be CV5, but your manual (available online at Soundtraxx's site) will give you the actual CV if it is different. Find out what it is, what the maximum range is for that CV, and then adjust it accordingly. Half the range would be a good start, and do your timings when your speed is dialled up to the max to calculate your speed. Adjust as necessary.
-Crandell
What Crandell said.
Typically decoders default to 0 on CV5 which is actually the same as 255. 0 or 255 in that CV means max possible voltage to the motor. To drop the max speed you'll decrease the value from 255, for example 220 or 210. You can set it on the fly using OTM programming and see what happens.
Keep in mind you may also need to change the mid speed value at CV6 - on my NCE decoders (which should be the same as your decoder under NMRA compatibility rules) the default is 0 which is the same as 128.
Here's why you may need to change it: when using the default speed table setting (not custom programmed), the decoder automatically maps two linear sets of speed values (0 to 50% from the start voltage value to the mid speed value, then 51% to 100% from the mid value to the max value). If you dropped the max speed value significantly (say to 170 or 150), then the mid value won't really be 50% speed anymore. For a true linear speed, you want to set mid value to the median between the start voltage (CV2) and the max speed (CV5).
Mark
What DCC system are you using?
With NCE it's a simple menu option for min, max and mid speed. It does the work for you.
Im running a MRC Advanced squared
thanks for the tips. I will try those CVs. Now I have an issue with the decoder not reading on the program track! This has been the biggest PITA decoder I have had so far.
I like the options but Its a little out of my world with all the options. LOL
Trent
has anyone had issues with the soundtraxx sound decoders.? I hear most praising them? the first one I had was faulty right out of the package (no sounds) but the engine would run. Now the 2nd one I bought last sat afternoon was working great for half the day and then it just quit. I get the idle sounds but no movement from the engine. no headlight and it wont reset etc... So far im not really impressed with the issues. I spoke with the costomer support and they were very helpfull but had no luck getting it to run.All my other decoders have been flawless for the last year.
It could be defective, but so could a couple of other things. Have you verified output current atht the decoder terminals, and have you verified output voltages at their destinations? Could be a bad wire, a bad solder, bad light...
not yet. But I was thinking to check some readings If could find a pin out online. Oh and please excuse my ignorance to some of this, Most of this technical DCC stuff is still very new to me
Thanks
Trent
Well I got the decoder back. I had soundtraxx reset it for me wile at the hobby Expo today. Very frendly people there to help a newbe. I was worried that it was messed up like my first one was. I still cant control top speed. i dont see CV5 listed inthe manual
http://www.soundtraxx.com/documents/manuals/tsunamisteam_users_guide.pdf
I think I can actavate speed control with CV29 but I heard not to mess with CV29 unless you know what you are doing.
any advice?
Man, that's a long manual!
It seems weird that CV5 isn't detailed as IIRC it is a standard value in the NMRA spec. Both my NCE and MERG decoders support this.
CV29 will (among other things) turn on the speed table. This would allow you to set custom values to the speed steps. CV5 would be a far easier and quicker way to accomplish this, but if the decoder doesn't support it you may be stuck on setting a speed table instead.
Mark
Thanks Mark
yea 70 some pages of bla bla bla that I dont fully understand yet!. I have been pulling my hair out looking for that max voltage CV thats not there!!!
It looks like most of the CV options will be usefull if I set up a 0-28 speed table. I assume I can set up a table with the last speed step(28) set to a value of 100 or so. Right now I think its set to the highest value of 255? the loco will start very slow and accel perfect but that top speed is way to fast!
I will say that this decoder is a little difficult to learn for a newbe but I think It will be great once I figure it out. After triming out the diffrent sounds last night and properly installing the speaker into a box it really does set the bar high.
Trent
Affiliate Disclosure: We may receive a commision from some of the links and ads shown on this website
(Learn More Here)
