I have an Athearn Genesis F7ABBA consist on a DCC layout.
All four locos run at different speeds.
Is speed matching recommended, or does it really matter.
All four locos are equipped with NCE DA-SR decoders. If I speed match, what is the best way to do it?
Rich
Speed matching is recommended. Before I start to speed match loco’s I set CV’s 3 and 4 to 0, these are acceleration and deceleration CV’s. Next set CV2 (start speed)so the loco’s just begin to move on speed step 1. Try the loco in both directions as they may run differently in reverse. Adjust CV2 so the loco runs the same in both directions. Then adjust CV5 (top speed) to 255 and CV6 (mid speed) to 125. Place the locos on the track several inches apart, run on speed step 1 and readjust CV2 on the locos that don’t maintain the same distance while running. Some decoders do not support CV’s 5 and 6 and are not adjustable so you should know that before you try to adjust them.
Read the documentation that comes with the DA-SR decoder pertaining to adjustment of CVs 116 and 117, in addition to CVs 2, 5 and 6. NCE recommends that you adjust CVs 116 and 117 before CV2.
Hi, Rich
I have been dipping my toe into the waters of speed matching. I found this writeup from Tony’s to be helpful.
http://tonystrains.com/technews/loconews/loco_speed_matching_easy.htm
I have a situation where I want to MU some early run Life-Like E-8s that have speedier gearing with some of the slower Walther’s versions which seem to use a different gear ratio.
Hope this helps, Ed
Rich.
Like horse shoes and hand grenades close counts. Individually I set CV2 to start on SS1 as slow as can be. Then top speed in CV5 since most models run faster than the prototype. The split the difference of CV2 and 5 in CV6. Add a little momentum in CV3 and some deceleration in CV4. Place them all on a loop of track about a foot apart and see what happens and adjust from there. Try this in forward and reverse. Some locos run better one way than the other and you will have to trim that as best you can.
Pete
Definitely follow the instructions that cacole posted above with those NCE decoders. They have some of the best slow speed capabilities of any non-BEMF decoder, but you need to tweak the drive paremeters before setting CV2
Once you’ve got them all starting as best they can individually, now you speed match the start speed with CV2. The fastest one will be your benchmark here, assuming you’ve adjusted the drive paremeters, it’;s running as slow as it can, so your only recourse is to slightly speed up the ones that start even slower.
Once you have them all starting close (and really, all this just needs to be close, not absolutely dead on, coupling them together and adding a train will compensate for a LOT - remember in DC there was no such thing as speed matching, we just coupled a few locos together and hooked up the train), work on the top speed. In this case, the slowest one at full throttle will be your benchmark, you can;t make it go any faster,. Use CV5 on the others to slow them down to match.
Mid speed might be fine then all by itself, but you can then repeat the process at half throttle, in this case you can adjust CV6 on any of them to set a standard, and then match the others to it.
–Randy
Hey, I got it, and I appreciate everybody’s comments and suggestions.
I messed with CV5 and CV6 until I got all four units running at pretty much the same speeds.
I left CV2 unchanged at zero, and I have a hard time understanding that CV.
When you place a value in CV2, what exactly is that doing?
Can someone explain to me the relationship of different CV2 values for each of the four locos in the consist?
Rich
Rich.
CV2 is the starting voltage in speed step 1. This CV will dictate how much voltage goes to the motor to start it spinning but not the current to the motor. The current to drive the motor and keep it spinning comes from what NCE calls the torque compensation. This is all in the decoder information pages you can download from the NCE site.
Did you finally get to the bottom of the issues you were having with your DASR decoders?
Pete
Pete, let me ask you this about CV2.
Let’s say that I have two locos in a consist, an F7A and an F7B. Say that the F7A starts to move at SS3 and the F7B starts to move at SS5. Do I want both locos to start moving at SS1 or am I trying to get both locos moving at SS3.
Is that what the value in CV2 is supposed to do?
Rich
P.S. I have all four locos running fine with DA-SR decoders installed. I sent the faulty one to NCE after talking to Larry. I asked him to let me know what was wrong with it since power was being picked up at the front tabs but not transferring power to the motor.
Rich.
I try to get my locos to move at SS1. If it just barely moves (I watch the motor shaft ) then adjust non BEMF decoders torque compensation to keep it moving as slowly as possible. TCS calls it Dither, NCE calls it torque compensation. CV2 will get it moving. CV116 and 117 will keep it moving. I do this so all my locos can be interchanged and consisted. Here is a link to the DASR sheet. Page 3 has an explanation on what each CV does. http://www.ncedcc.com/pdf/dasr.pdf Please note that the non BEMF powered decoders should stop spinning the motor on SS1 when the loco is blocked or held. If the motor spins too fast you will have little slow speed response.
All my switchers are set to the same top speed, all my road freight units steam and diesel are set to the same top speed too. My steam passenger engines are set faster than the freight engines and the passenger diesels are set faster still. This way I can consist like units and still double head consists too. My previous club had some big hills to climb. I would advanced consist 2 steamers at the head end and then double head (old style or command station consist) one or a consist of 2 engines to push on the hill. I also run a six pack of Atlas and Athearn RS1 and RS3 engines using the same address style of consisting.
When I set up a new loco or one that has been repaired or upgraded I will speed match it with one of my older ones set up already. All my locos have a straight line (no speed curve) acceleration. They all have some momentum but not lots of it. The only two locomotives that never see a consist are the Tsunami powered steamers. Since I cannot set the top speed. They also tend to jump start and then crawl. Motor control is very important to me.
Pete
The part in black makes sense to me, and I did that, and I am pleased with the results.
But the part in red confuses me. Why would you readjust CV2 at that point? Once you speed match with the proper values in CV5 and CV6, would any further adjustments to CV2 be necessary? What would it accomplish?
Rich
Let’s try phrasing this differently. CV2 is telling the decoders to “begin moving”. Now, if you’re using 128 speed steps, having locos begin anywhere between steps 2 and 5 may not be a big deal. But let’s say you’re using 14 speed steps. By the time you get to step 5, one loco may already be going 10-15 scale miles per hour (SMPH), and another may just begin moving. Adjusting CV2 will correct this so all begin to barely move on speed step 1.
Now, by saying you have already matched your locos, and that you are pleased with the results, that indicates to me that you have them reasonably well matched, in which case further adjustment of CV2 may not be absolutely necessary. Only you can be the judge of that.
Personally, my eventual goal is to have all my locos set up to move “as slow as possible” on speed step one, maybe 2-3 SMPH.
Brad
Brad, after I read your reply, I went back and re-read retsignalmtr’s post. Now, I see what you and he were saying.
In retsignalmtr’s post, he set CV5 and CV6 to fixed values, then re-adjusted CV2.
What I did, after first finding the appropriate value for CV2 in each loco, was to adjust CV5 and CV6 on each loco to match speeds, so I was done. No need to re-adjust CV2 at that point.
One thing that I will point out about my own situation. Although I have been operating in DCC for almost ten years now, I have spent way too little time learning about CV’s. I either have bought a loco with decoder (and sound) already installed, or I simply installed a non-sound decoder myself and set up the basics, ignoring everything else. I have done little consisting and when I have, it has only been with two matching diesels. In the case of this 4-loco Athearn Genesis F7ABBA consist, I never attempted to speed match.
Everyone probably knows, from my other related posts, that I have had a lot of issues with these four locos, their decoders, and their lights. I am at the point now where everything is running smoothly, so I have turn my attention to the speed matching issue. I am somewhat embarrassed that it took me this long to tackle an issue like speed matching and the larger issue of fine tuning the various other CVs such as 116 and 117 and 95. But, I am getting there, and I appreciate all the good help and advice that I am receiving here.
Rich
Rich,
First let me say that I’m glad you got everything worked out with these locos.
I have two 3 unit sets of Genesis F units, DC powered of course, which are amoug my best running locos.
Your original problem is the one thing I just can’t get over about DCC.
My 6 Genesis F units all run great together - right out of the box.
As do all 15 Proto FA 's, the 8 Proto GP7’s, the 4 Proto BL2’s I have - I can mix and match those 27 locos at will.
Not to mentiion 4 Proto PA’s that all run fine with each other, as do my 6 Proto E8’s.
So I don’t get why four Athearn Genesis F units with the same decoders did not run fine together?
But again, glad you got it worked out - and glad I don’t have to “speed match”.
Sheldon
Sheldon,
We all know you dislike DCC, and of course every single DC loco you own runs perfect.
WE GET IT. Every single post from you, saying the same thing, over and over and over.
Enough already.
No, you don’t get it. I don’t dislike DCC, I don’t need DCC. There is a big difference. And yes, when I am done with them, all my locos run perfect, as they would if they had DCC as well. It just takes way less work to get hem to run perectly on DC.
Sheldon
Sheldon, I have to agree with Michael. This is not a DC versus DCC issue at all.
It depends what you mean by running “fine”.
Remember, I have had these locos for 10 years and they have always been coupled to one another.
Early on, I discovered that the wheels on the front truck of one F7A had flattened because the gears had locked in the truck assembly. Athearn sent me a new front truck assembly. From then on, my only problem with the Genesis F7A units was the premature burn out of the incandescent bulbs. So I replaced the bulbs with Miniatronics bulbs and more recently with LEDs. But that bulb problem was typical of Genesis locos and I am surprised that you have never experienced the issue. It occurs in both DC and DCC. It is a bulb problem, not a DCC problem.
Now, regarding how “fine” they run, they have always run fine. When I recently had a decoder problem on one of the units, I decided that it was time for me to fine tune all four units. I soldered the power pick up t
Yes you are indeed a DCC hater. Its the tone you speak about it, how “difficult everything in DCC is.” How in DC you could do this, that and the other. You never change your tone. Its always the SAME thing.
Can’t you think of something else to say?
I speak for others as well, as we are sick of the DC verses DCC talk from you.
I don;t see it taking more work to get locos to run together on DCC - it only does so because there are features that let you fine tune them - OPTIONAL fine tuning - that you don;t have in DC. I read all these people setting up loops, with one of the various speedometer products, or using the Bachrus test stands with speedometer, and writing these scripts in JMRI to tune locos to run together - at first I think,. hmm, I ought to get that too. Then I think, but I haven’t done diddly to any of my locos to make them run together, they just DO, just like people using DC.
There just should never be so much variation between a group of same brand locos witht he same motors and drive trains, using the exact same decoders, assuming someone hasn’t mucked around with the decoder settings.
What you CAN’T easily to in DC is make various different brands run together easily - unless you consider swapping drive trains and/or motors to be ‘easy’ compared to setting 3 numbers on a decoder. Even then - I’ve said it before, I have a 3 unit consist I run at shows all the time, with a pair of Proto GP7’s sandwiching an Atlas Trainmaster. The Geeps ahev TCS T-1 decoders, the Trainmaster is a Gold series with QSI sound. I didn;t set anything other than address - they run together fine when pullinng a train. If I operate unprototypically and try jackrabbit starts, the Geeps will spin for a while until the TM catches up, but if I operate in a more reasonable fashion, there’s no problem. I didn;t run them through mearures test loops and tweak CVs for hours to do this, I just put them on the track and ran them. Same as DC.
Again, it’s a matter of doing soething because you HAVE to, or just because you can? Just because you CAN build 28 step speed ables into most DCC decoders and make things absolutely dead on at all speeds - should you waste all that time? Even with JMRI to help, it takes a while - if you simply put the exact same table values in eve
You would think so, and in a perfect world, I suppose that would be true. But it may be a matter of quality control that four Athearn Genesis F7 units don’t run at the exact same speed. Slight differences in the gears, or motor, or drive trains, or wheel sets.
The other issue in speed matching is the layout itself. I have a double mainline with more outer curves than inner curves so the loco on the outer track has more distance to travel than the loco on the inner track.
But, overall, the speed differences are not that great.
Remind me, though, is it better to have the faster or slower loco in the lead?
Rich