FIRST TIME ON FORMS. PLEASE BE PATIENT. here we go. i have a digitrax system.dt 400 series trrottle.i have 4 overland diesels trying to speed match. i program 29 to50 &51 for forward&reverse.when programing on the main i can program 67 through70 or 71 . then when i try to program 72 i don't get any response in speed. then i go out of programe mode and run that loco with throttle it goes fine until i guess i reach the speed of the cv i could't program and it takes off. don't know what i am doing wrong.PLEASE HELP ME FROM START TO FINISH THE CV"S I SHOULD USE OR WHAT I AM DOING WRONG. DESPERATE. THANK YOU. RICH.
Richard,
Why are you programming individual CV's? Also, most folks use 128 speed steps. If you are not building custom speed tables, do this:
1) Run the engines for at least 5-10 minutes so they 'warm up'. You may need to 'reset' the decoders to get them back to factory defaults).
2) Program CV5 for the Max Speed you want your engine to run at
3) Program CV2 so that the engine starts moving at the first 'click' of your DT400 throttle.
4) Program CV6 for your 'mid point' setting.
The internal speed table will adjust all of the intermediate speed steps automatically. Start with the engine that is 'slowest'. If you have a computer available, get a USB to Loconet interface(Digitrax PR3 or a LocoBuffer USB)and download a free copy of Decoder Pro - It makes programming you engines so much easier!
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
JIM thanks for your reply.i wishi understood dcc better. i probability didn"t explane myself correctly.yes i would like to build the custom speed table cv's 67 through 94.i will try cv's 2-5-6 like you said.but i would like to do the custom speed tables and compare. maybe i,am going over my head hope i did this right. happy railroading . rich.
Rich,
Custom speed tables can be tricky(even using Decoder Pro software). Using Decoder Pro, you can graphically 'adjust' your speed table. I 'played' with a custom speed table once(and that was using Decoder Pro). I have found that the '3 point' method really does everything needed to speed match engines. The hard part is timing them(I use a 5' 'trap' and a stop watch). Once I got that 1st engine running at my standard 70 mph, I match all other engines to it. I set my Mid Speed to about 35 mph. This works fine for running most HO engines in MU. You will find that some of the P2K engines have a rather slow top speed(like the passenger engines and the U-Boats with compound gearing).
There are several good web pages on speed matching and speed tables...
Speed matching
If you want to run your DCC locomotives together in a consist, you need to be sure they will go the same speed at the same Digital Command Control speed step. Speed matching involves programming your locomotives so they can run together smoothly. But before you adjust your decoder CV numbers, you need to be able to accurately measure the locomotives’ Mph speed and also know the CV Decimal numbers that will produced these results at Start, Mid. and Max.
Speed Traps
60 Mph is 88Ft per second. In 6 seconds you would travel 528 Ft. A Speed Trap could be set with start and stop sensors at 528 Ft. If the measured time from the sensors is less than 6 seconds, then you are speeding. The measured time in seconds becomes the record of your actual speed in Mph. Then in N scale this is 528/160 = 3.3 Ft in 6 Seconds, and in HO scale 528/87 = 6 Ft in 6 seconds.
Fixed distances and a stopwatch
Speed Traps N Scale HO Scale smph = (6.0 sec. / Time, sec.) x Speed Trap Mph
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120 Mph 6.6 Ft. in 6 Sec. 12 Ft. in 6 Sec. smph = (6.0 sec. / 4.8 Sec.) x 120 Mph = 150 Mph
60 Mph 3.3 Ft. in 6 Sec. 6 Ft. in 6 Sec. smph = (6.0 sec. / 5.3 Sec.) x 60 Mph = 68 Mph
30 Mph 19.8” in 6 Sec. 36.4” in 6 Sec. smph = (6.0 sec . / 6.4 Sec.) x 30 Mph = 28 Mph
6 Mph 2.0” in 6 Sec. 3-5/8” in 6 Sec. smph = (6.0 sec. / 7.2 Sec.) x 6 Mph = 5 Mph
3 Mph 1.0” in 6 Sec. 1-7/8” in 6 Sec. smph = (6.0 sec. / 4.5 Sec.) x 3 Mph = 4 Mph
electronic speedometer
“Train Speed” by TDP & Associates, Inc. can measure smph accurately to 150 Mph. It has two photo cells with can make a speed trap for any scale. It is designed for control panel or façade mounting.
http://www.trainspeed.com/TrainSpeed1.htm
“Bachrus speedometer” MTS-DCC50 for Decoder Pro, allows measurement of scale speed of locomotives while running under DCC control. The locomotive's wheels rest on a set of ball-bearing-equipped running stands. One set of rollers, called the reader, is connected by a wire to a portable console that reads out the locomotive's scale speed, and other information.
http://www.bachrus.com/speedometer.php
http://www.youtube.com/watch?v=kPLiJyZ21fk/url]
Speedometers are so accurate that you never get the same Mph display at full speed forward and full speed in reverse. (Motor friction.) This is why I plot my Mph speed data as “Ave. Mph”.
You have a DT400 with a 0 to 99 display. Turn the throttle to start running slow, say about 6 Mph and you display is say 20. (0.20 time 255 = 51 then CV2= 57 is 6 Mph ?) Mid. 0.50 time 255 = 127 then CV6 = 127 at 50 Mph? and Max. 0.99 time 255 = 254 then CV5 = 90 Mph? Plot your three point of CV dec. numbers Vs Mph.? Now deside what you would like. Lets say: Start = 4 Mph, Mid. = 36 Mph and Max = 68 Mph. (This is a straight line.) Read your CV2-6-5 Dec. at 4-36-68 Mph on your plot. Program in the new CV2-6-5 Dec numbers Then do this procedure with your other DCC Locomotive. They will be very close to being Speed Matched. You can add more DCC locomotive to your selected freight Mph targets.
Robert Frey
Website: http://bobfrey.auclair.com
This is my way of doing it, as I Digitrax SEB. I reset all my engines I want to speed match, this way everything is starting at base line. Then I warm up all my engines and assign them address.. Once I am ready I choose my base loco, I start with the CV2 for the other loco and program that in using the Operations Mode (which will only change the CV's in the loco you choose) Once I am happy with the starting speed I will work on my max speed I want. Send the base loco out on the layout and start playing chase with the second loco, adjusting CV 5 up and down until they maintain the same distance from each other. Repeat for the CV6, again playing chase until the second loco is dialed in. If you are using all the same brand locos, that is a big plus as there should be very little difference to start with. Of course having one of those train radar gun things would be great and you would not need to play chase.
sorrey fellows i forget to mention i am using tsunami decoders. they don"t recognize cv"s 5&6 on decoders that i mention.i have other decoders i will be using that use cv 's 5&6 so thanks for the great info. thanks JIM i got some great info on web pages you mention RICH.
The real issue here is Why can't values be programmed into CV71 and above?
You wouldn't happen to have gotten your DT400 into Hex mode? Is there a little x appearing in the display next to the numbers when programming? If there is press the right button one time while in programming mode. The display will toggle between decimal and hexidecimal each time the knob is pressed.
Martin Myers
I find that in the long run it's often better to take the time to make a speed table for each loco and document it. Reset all of your decoders and run the loco's. Find the slowest loco and use it as your baseline to match the rest to.
Springfield PA
RICH,
Tsunami Decoders. CV29= 2 (128 Mode), CV29= 18 (128 Mode & CV25 Speed Table), CV25=16 (Use Table CV67 to 94). Now you are ready to use Decimal Numbers: CV67=1 to CV94=255.
Say your start display was 20 then 0.20 *255= 51 then CV67=51, CV68 to CV80= 127 and CV81 to CV94= 255 Did you notice the speed jumps from start to mid? and also from mid. to Max? When your display was 50 was the speed jump from Mid. to Max. near the dispaly of 50? It may be that CV82 is your Mid.
RICK, now you are ready to find your Start, Mid, and Max. Decimal Numbers at say: 4-36-68 Mph. (straight line) This is known as "Matched Ends" in the JMRI User Speed Table. (Straight line from Start to Max.) NOW, you have many way to measure Mph! You can also use different Max. and Start speeds for: Passanger, Freight and Swithcher DCC Locomotives.