You could try to measure how fast the engine goes at full throttle (easy with the QSI "talking" ones where it reads off the speed to you) and then if it's too fast lower CV 5 - top speed until it's where you want it. A Mike generally wouldn't be going much more than 50-60 MPH so if it goes say 90 MPH now you'd want to knock the CV down to about 170-180 and see how that works. I usually then just make CV 6 - midrange 1/2 of the top one. To get a very gradual start and stop I use fairly high momentum settings in CV 3 and 4.
Thanks, Randy. I get it. I was thinking that starting with settings someone else had used and was satisfied with would give me a beanchmark to tweek from, but I see what you're saying about individual locomotives, so I'll just use the 5/50/250 to begin with and work from there.
All my other programming has been on the programming track so we'll see how this goes,
The CV values are a function of top speed. Allowable values depend on the decoder manufacturer, if you look in the DZ125 instructions that come with it there are 3 examples given. Digitrax CV2/5/6 values are 0-255, 255 in CV5 would be the same as 0, meaning, full throttle is full power. The settings are highly dependent on the individual loco, and how you want it to run. A different BLI model might take different values than yours, so other people's settings would be of limited value. Use the programming on the main option to set it like I mentioned and set it up to run the way YOU want. As a guess, 5/50/250 would give a slow ramp up to mid speed, then rapidly increase to almost the same top speed as you have now with no value set. 5 may be enough to get it moving at speed step 1 or 2 (I like using 2 so there is that 1 step dead band for stopping), or it might jump into action. There's really no "just use these values", the best way to set them is still trial and error, which is why programming on the main is so useful - as you change the values, the loco speed with change.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
System is an MRC Prodigy Wireless and is set up to allow a user to program start/mid/max as a function of top voltage, e.g. start= 5, mid=50, max=250 if top voltage=255. This is done without addressing the specific CV independently. Resetting the individual CVs is also possible, but I was hoping to tap into someone's experience with steam locos, and BLI in particular, for a benchmark.
If no one has specific suggestions, I'll try the default configuration above (5/50/250) and see how it works.
Thanks.
DZ125 is a BEMF decoder. If you have a DT400 throttle, or a computer interface so you can use JMRI throttles, so you can tell what speed step you are at (you can't with jus tthe Zephyr or a UT4 throttle) - or if you have another system that shows what speed step you are at, set to speed step 2 and then program CV2 on the main with gradually increasing values until the loco just begins to creep. If you have a layout that allows continuous running, next set the throttle to the mid point and program CV6 with a number higher than what you put in CV2, until the loco is running at your desired 'medium' speed. Finally increase to full throttle and then program CV5 with something higher than CV6 until your loco is running at what you want for a maximum speed. You now should have nice smooth control from a dead stop all the way up to full throttle.
Does the DZ125 decoder have BEMF? If not than raise CV2 to a level that gets the loco to just barely move. If the decoder features BEMF than you will need to enable it.
Pete
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
They can be reprogrammed, even the DC starting voltage can be. I talked to a factory guy at a train show. I don't know how to do it.
I have a BLI 2-8-2 Heavy Mike with the Blueline sound system and a DZ125 motion decoder. Runs nice and smooth once it gets going, but it seems to need several throttle notches to get moving and then does not ramp up smoothly but pretty much takes off. I know the issue can (should) be resolved by tweeking the speed curve, so I'd appreciate any suggestions on settings before I start playing with it. I'm sure the decoder is presently set at factory defaults.
I guess implicit in the question is also a desire to know if the starting and stopping profile is different for a steamer than a diesel.