Jim, thanks for the info. I have them programmed with the same number now so I can test the response.
Is there a way to gain control of the left throttle on a DT-400 after you have MU'ed engines?
MC
All of the above is good info. One additional item - Run your engines for 15-20 minutes before attempting to 'speed match' them. They really need to warm up and get the lube flowing. Also if you run a lot of MU - You might want to turn BEMF off in the decoder, or at least set it back to the factory default. Many times it is set too high and will cause 'bucking' in MU'ed engines running in a consist.
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
Thanks to everyone for the ideas. I have adjusted the CV 's 2,5,6 on the Digitrax decoder's and now the GP-9 & 7 are pretty close. The GP-9 with Tsunami decoder is another animal all by itself. When I set CV's 2 & 5 it took off like a jack rabbit. I put everything back to the original setting and it starts with the other two engines but won't keep up with them at mid range. I may try adjusting CV-25 on the Tsunami to see what happens. Has anyone played with the CV-25 on the Tsunami decoders?
I run my layout in DC i speed match my locos with a stopwatch on different throttle settings. IE i clock them going at 45,65,85. My consists are pretty close i try to mu the engines with almost the same time together.
Mark: Good explanation of a potentially complicated enterprise. I particularly liked the suggestion to set CV3 and 4 to 0 as the first step. I think that's why I've had trouble. Thanks. Joel
What do i do? I make them CLOSE. They do not have to be perfect. I do tend to avoid Tsunamis as they unfortunately decided not to include CV6 mid speed support which sometimes forces you to go to a speed table for matching, unless all changes can be done on the other loco.
Either give them the same address temporarily, or consist the two you want to match. At speed Step 2 or so, adjust CV2 on the slower one to match the faster one - if one of the locos is a jackrabbit and takes off fast at a low speed step, unless something is programmed incorrectly, you can;t slow it down, you can only make a slower one faster.
At or near full throttle, adjust CV5 to slow down the faster one.
That alone is often good enough, but you cna check middle speed and if using decoders that supprot it (most current ones except Tsunami) adjust CV6 to either speed up the slower one, or slow down the faster one. With speed matched at 3 points across the power band, it will be pretty close at all speeds. Certainly close enough so that one doesn;t start spinning its wheels trying to drag the other one before it starts. Most small irregularities smooth out when the weight of a train is added.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
kgill This sounds so overly complicated when DCC is supposed to be awesome... What did people do with plain ol DC, but thats for a different topic i guess.
This sounds so overly complicated when DCC is supposed to be awesome...
What did people do with plain ol DC, but thats for a different topic i guess.
Mark R. Interesting, but has absolutely nothing to do with DCC ! Mark.
Interesting, but has absolutely nothing to do with DCC !
Mark.
Correct. But not everybody uses DCC, and some people may even want to MU with DC.
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
BroadwayLion Run the engine at a known voltage and measure its speed. (The time it takes to run a measured length of track) (Test the engines running in both directions.) Run the second engine at the same known voltage, and measure the speed. Is it faster or slower? Take the faster engine and drop the voltage by 1.2 volts and repeat the test. Is it withing suitable specs, or is it still too fast? If too fast, take another 1.2 volts off the tracks and try it again. When you have that dialed in, add rectifiers inside of the engine, each rectifier drops the voltage 1.2 volts. You need to put them in in pairs one pointed in each direction so that the engine will continue to operate in both directions. Now you have their speed roughly matched. ROAR
Run the engine at a known voltage and measure its speed. (The time it takes to run a measured length of track) (Test the engines running in both directions.)
Run the second engine at the same known voltage, and measure the speed.
Is it faster or slower?
Take the faster engine and drop the voltage by 1.2 volts and repeat the test.
Is it withing suitable specs, or is it still too fast? If too fast, take another 1.2 volts off the tracks and try it again.
When you have that dialed in, add rectifiers inside of the engine, each rectifier drops the voltage 1.2 volts. You need to put them in in pairs one pointed in each direction so that the engine will continue to operate in both directions.
Now you have their speed roughly matched.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
Speed matching engines really isn't that difficult. MU your two engines together (or give them both the same address if you have a separate programming track) and place them side by side on two parallel straight tracks.
Set CV3 and CV4 to 0 as momentum will interfere with your initial matching process. You first want to work with CV2 - starting voltage. Adjust CV2 in each engine so it just begins to move in speed step 1. Adjust this value so both engines crawl along right with each other. Now adjust CV5 which is the mid point throttle setting. At mid throttle, if one engine is running faster, adjust CV5 down until it runs the same (or vice versa depending on which unit you are matching). Finally, set CV6 in the same manner which is the top speed setting.
Once you have them matched using CV2, CV5 and CV6, you can then introduce your momentum settings using CV3 (acceleration) and CV4 (decelleration). Set one engine with the momentum settings you like, and then set the second unit to match - the values may not necessarily be the same for both engines in order for them to run the same.
What most folks do is to create a "Golden Engine". This is the engine that all the rest are matched to. If you have an engine that performs the best, use it all the time when speed matching a new engine. This way, your entire fleet will be perfectly matched to each other enabling you to MU anything together knowing they will all work just fine.
delray1967My thought is to (eventually) get a 'speedometer' of some kind and make every loco match a certain speed to a certain speed step (I think I can do this?). Or, I think it'd be convenient for every loco to increase 1 scale mph (smph) for every speed step (maybe finer speed control from step 1-10?); this way, the throttle speed step will match smph and will help engineers control the speed of their locos.
If you are thinking of getting a speedometer, or even if you are going to use some sort of measured distance method, what you need to look into is getting a free decoder programming program called DecoderPro. You can look into that information and download the program from: http://jmri.sourceforge.net/download/index.shtml
I don't think you want to go with the 1 speed step equals 1 mph increase method, as that will just cause you unnecessary complication. First off, that would imply that all your engines would hypothetically go 100 scale miles per hour. When you get your speedometer you'll find that some don't actually go that fast wide open (Atlas), while others go faster than that (Athearn). Plus not all controllers display speedsteps. Plus some DCC systems can display a speed range of 128 speed steps.
Better off to determine what you think your highest speed will be, and then adjust all you locos to run together within that speed band.
BroadwayLionWhen you have that dialed in, add rectifiers inside of the engine, each rectifier drops the voltage 1.2 volts. You need to put them in in pairs one pointed in each direction so that the engine will continue to operate in both directions.
Yes, you can speed match them.
No, no rectifiers or changing of track voltage is required.
C&O Steam, how do you speed match your locos now? One 'golden' loco that all others are calibrated to, or the time/distance method, or do you do it like me and only run one engine at a time? lol I just got 4 of the C&O GP9's and will be needing to speed match them to other locos (I like how the C&O seemed to use any locos in a consist, very interesting to look at, but it's gonna be a pain to get every loco to match).
My thought is to (eventually) get a 'speedometer' of some kind and make every loco match a certain speed to a certain speed step (I think I can do this?). Or, I think it'd be convenient for every loco to increase 1 scale mph (smph) for every speed step (maybe finer speed control from step 1-10?); this way, the throttle speed step will match smph and will help engineers control the speed of their locos. Function 10 on BLI locos will give you an audible readout of the smph; you could use this to help calibrate.
Good luck, I will be addressing similar issues with all my locos (only 7 or so) soon and have been thinking the best way to do this for a while now.
http://delray1967.shutterfly.com/pictures/5
SEMI Free-Mo@groups.io
Do easy with DCC! Or so you might think.
Yes you can speed match them. It doesn't matter what engine you buy, even two of the same make and model aren't going to run at exactly the same speed. In this case, you'll need to use CV 5 and 6 to slow down the faster engine so it matches the slower one.
I just purchased a new Genesis GP-9 with Tsunami sound and was hoping I could run it with an Atlas GP -7 with a DH 165AO decoder Installed. The problem is the Atlas is a faster engine. Can someone tell me if I can speed match the pair to run together. If it isn't possible I can purchase another GP-9 and install a decoder but what type should I use. (DZ 125PS, DZ123PS, DN135DS or DH165AO) I don't have to have sound in the new engine I just want to run them together.
Thanks