121 Double Header

[Alan564017]

hopefully someone can help with this. I very recently got two 121's, over the moon with them. I first ran them DC for a run in all good, with both on the same track, one was quicker than the other.

I installed the decoders (lok non -sound), got them running DCC, all good. I then set up a double header (or consist, im using a Hornby Elite). One still runs quicker than the other. 

I presume there is an adjustment to a CV required, im not well aquanted with adjusting CV's, any help would be much appriciated. 

[irishthump]

4 hours ago, Alan564017 said:

hopefully someone can help with this. I very recently got two 121's, over the moon with them. I first ran them DC for a run in all good, with both on the same track, one was quicker than the other.

I installed the decoders (lok non -sound), got them running DCC, all good. I then set up a double header (or consist, im using a Hornby Elite). One still runs quicker than the other. 

I presume there is an adjustment to a CV required, im not well aquanted with adjusting CV's, any help would be much appriciated. 

It's a process the DCC gurus call "Speed Matching". There are many good articles and videos on the subject if you Google search the term. American modellers have great experience with this as they often run several locos in a consist.

Basically the process involves adjusting 3 CVs.

CV2 which controls the speed of the loco at speed step 1 on the throttle.

CV5 which controls the speed of the loco at max throttle speed.

CV6 which controls the loco's speed at the middle speed step.

Bear in mind that some cheaper decoders will not allow adjustment of these CV's.

Hopefully you have a large loop on your layout as this makes the process much easier. Set the 2 locos up a couple of inches apart and run them both at speed step 1. Adjust CV2 so they are at the same speed. Then do the same with CV5 while the models are running at top speed. Once you have those set work on CV6, it's much easier when you have CV's 2 and 5 matched. You probably won't get them running identically but just try to get them as close as possible. Also try to adjust the CV's on only one loco, adjusting it to match the other one rather than fiddling with CV's on both locos at once. That can get very confusing!

[DJ Dangerous]

Warb recently posted a Barrow Street video of a 121 double-header, and he said that all he changed was the CV for direction, possibly CV29:

 

 

[Alan564017]

DJ, I managed to do that, there is instructions in the elite manual that describes how to change a direction of a loco (which must change a CV setting). The problem is the different speeds of each loco in the double header

[Billycan]

I had that question when putting my consist together.  When I was running in the two locos I realised that 125 needed to be at speed step 62/63 on an NCE PowerCab to keep up with the 131 running at speed step 60.  I take it that at reduced speed steep 31 on 125, then 30 would be corresponding on 131.  That's hardly worth worrying about and half a drop of oil might sort that, but it's too early to go there.  Using NCE the advise is to put the faster loco first and I've done that.  So, I set up the consist as per the NCE manual and all works fine (I didn't need to change the directional CV bit as the NCE system asks if the loco is running forward or reverse and sets up the consist accordingly.  I have a video record of them running in a consist at speed notch 50 and slowing to stop and the running is nice and smooth.  You can view that at  https://youtu.be/KXydwaGbzes

Hope that helps.

[Noel]

Curious how the Z21 can handle matching speed curves in consists

 

 

[irishthump]

58 minutes ago, Noel said:

Curious how the Z21 can handle matching speed curves in consists

 

 

Yes, but not a lot of help to the original poster as he isn’t using a Z21.

[Noel]

8 hours ago, irishthump said:

Yes, but not a lot of help to the original poster as he isn’t using a Z21.

Ok but as I said 'curious' how some DCC systems can aid speed matching. Interesting piece below, perhaps more relevant to US consisting as they ofter have more than two locos, often 3 or 4 whereas in the part of the world just a pair as with the 121s. Back to steam days up to 3 stream locos banked heavy trains up the hill out of Cork until the 800s.

https://dccwiki.com/MU_consisting/Speed_Matching

[Mayner]

The difference in speed between Alan's 121  may become less noticeable as the locos are run in and it may be a better option to operate on DC or leave the decoders at their default setting.

I found that it was more trouble than it was worth attempting to speed match consists of locos with different speed characteristics on an American layout, and ended up only consisting locos with the same characteristics usually with the decoder at its default setting.

I generally ran 3-5 loco consists, but ended up keeping Atlas, Bachmann and Kato locos in separate consists in order to reliably operate 20-30 car freights.

Funnily enough speed matching was less of an issue when I operated the layout on DC the main limitation was the 1 AMP rating of the H&M transformer.

 

[Noel]

1 hour ago, Mayner said:

The difference in speed between Alan's 121  may become less noticeable as the locos are run in and it may be a better option to operate on DC or leave the decoders at their default setting.

I found that it was more trouble than it was worth attempting to speed match consists of locos with different speed characteristics on an American layout, and ended up only consisting locos with the same characteristics usually with the decoder at its default setting.

I generally ran 3-5 loco consists, but ended up keeping Atlas, Bachmann and Kato locos in separate consists in order to reliably operate 20-30 car freights.

Funnily enough speed matching was less of an issue when I operated the layout on DC the main limitation was the 1 AMP rating of the H&M transformer.

Agree, two 121s once run in with the same decoder settings should more or less match up which has been my experience with 121s and consisting 141 pairs. Same chassis/motor and same decoder makes a huge difference. Also found TLCs a PITA if speeds slightly mismatched compare to knuckle couplings as when one loco is pushing the other the TLCs tend to slip and one rides over the other leading to a derailment on the next bend or paintwork. 

Clip below of three different steam locos (DCC converted wired decoders) with different decoders pulling and pushing a little but they could run together without derailing or much wheel slip. 

 

[Alan564017]

18 hours ago, irishthump said:

It's a process the DCC gurus call "Speed Matching". There are many good articles and videos on the subject if you Google search the term. American modellers have great experience with this as they often run several locos in a consist.

Basically the process involves adjusting 3 CVs.

CV2 which controls the speed of the loco at speed step 1 on the throttle.

CV5 which controls the speed of the loco at max throttle speed.

CV6 which controls the loco's speed at the middle speed step.

Bear in mind that some cheaper decoders will not allow adjustment of these CV's.

Hopefully you have a large loop on your layout as this makes the process much easier. Set the 2 locos up a couple of inches apart and run them both at speed step 1. Adjust CV2 so they are at the same speed. Then do the same with CV5 while the models are running at top speed. Once you have those set work on CV6, it's much easier when you have CV's 2 and 5 matched. You probably won't get them running identically but just try to get them as close as possible. Also try to adjust the CV's on only one loco, adjusting it to match the other one rather than fiddling with CV's on both locos at once. That can get very confusing!

irishthump, many thanks for the reply. Leaving one loco as is and the changing the other makes sense. I'm using a Hornby Elite, i've never tried to alter any CV's so im a little hesitant. The decoders are the lok-pilot (got them with the locos), so I presume the CV numbers you mentioned above still apply. 

If anybody knows or has advice on how to read/write CV's using a Hornby Elite, it would be much appreciated. 

[DART8118]

Alan, I did have a look at the CVs that needed changing for speed matching but the factory defaults are the same for both locos and as their speed difference was so small I left things at the defaults.  I also thought that a little running while in a consist formation would also help the running in process.  Setting CVs is nothing to be intimidated by and will soon become part of your DCC toolkit.  Does the Hornby Elite come with a manual?  That should explain how to set CVs in the first place and it should also explain how to set a consist.  I'm sure there must be some YouTube videos that also show you how.  

 

[irishthump]

3 hours ago, Alan564017 said:

irishthump, many thanks for the reply. Leaving one loco as is and the changing the other makes sense. I'm using a Hornby Elite, i've never tried to alter any CV's so im a little hesitant. The decoders are the lok-pilot (got them with the locos), so I presume the CV numbers you mentioned above still apply. 

If anybody knows or has advice on how to read/write CV's using a Hornby Elite, it would be much appreciated. 

If both decoders are LOkpilot you can use the Auto-Tune feature which may well improve things.

Just place the loco on a straight piece of track then programme CV54 to a value of 0. Then press F1 and the loco will take off like a rocket for a few seconds. (Make sure nothing is in the way!)

This reads feedback from the motor and stores it in the decoder. Do it with both locos and see how they run after that.

[Alan564017]

thanks for all the replies and advice. Im going to take the easy option and 'let them run in for a while', any thoughts on how long this should take?

my layout is temporary and unfortunately it has to be dismantled to get at the attic storage where the xmas decorations are!!! so it maybe a while before I get back to this. Some of the above questions will probably be asked again  

[Alan564017]

On 29/11/2020 at 4:53 PM, irishthump said:

If both decoders are LOkpilot you can use the Auto-Tune feature which may well improve things.

Just place the loco on a straight piece of track then programme CV54 to a value of 0. Then press F1 and the loco will take off like a rocket for a few seconds. (Make sure nothing is in the way!)

This reads feedback from the motor and stores it in the decoder. Do it with both locos and see how they run after that.

irishthump, im only getting to look at this now. just a quick recap, I have a Hornby Eilte, two 121's, same decoders, running at different speeds. Im currently trying to adjust the relevant CV's with limited success. 

Your comment above on CV 54, I dont have an F1 button!! (Hornby Eilte), I presume this should be done on the programme track (as per Eilte instructions). Adjusting other CV's on the programme track (which is currently a single length of R601) never moves the loco. If i adjust CV 54 while on the programme track will it move?

Will the CV 54 auto-tune feature aid speed matching (double header) and will it undo any adjustment thus far?

Many thanks in advance, 

[irishthump]

6 hours ago, Alan564017 said:

irishthump, im only getting to look at this now. just a quick recap, I have a Hornby Eilte, two 121's, same decoders, running at different speeds. Im currently trying to adjust the relevant CV's with limited success. 

Your comment above on CV 54, I dont have an F1 button!! (Hornby Eilte), I presume this should be done on the programme track (as per Eilte instructions). Adjusting other CV's on the programme track (which is currently a single length of R601) never moves the loco. If i adjust CV 54 while on the programme track will it move?

Will the CV 54 auto-tune feature aid speed matching (double header) and will it undo any adjustment thus far?

Many thanks in advance, 

Hi Alan,

You can set CV54 to 0 on the programming track but you must then press F1 while the loco is on the main track. It won't move on the programming track at all, that track uses a much lower voltage setting.

I'm a little confused when you say the Elite does'nt have a F1 button. I simply mean the no.1 button on the controller. 

Also if you use this feature make sure the loco has been ran for around 15-30 minutes before you do it. Also, do it 2 or 3 times to get the best result.

The auto-tune MAY help. If the motors have similar properties it may help them to match up more when running together. It also won't alter any adjustments you've already made, it changes CV's that you would'nt normally touch.

[Alan564017]

irishthump, thanks for that. I think I understand the F1 button, on the Elite its the controller 1 (a dial that is pressed to select). 

the locos have definitely been run in on both DC and DCC. From out of the box, B131 ran faster than B125, I put them on a simple loop on the 12 and 6 o'clock positions and one eventually caught up with the other.

I then put in the decoders, same thing, I swapped the decoders, same thing. I think this suggests this is either a mechanism issue or power delivery issue. 

Im playing with the CV's at the moment, I've read CV's 2, 3, 4, 5 and 6 on both decoders and they had identical values. I think I have CV5 max speed almost there by reducing the speed of the faster loco. CV 3 acceleration is proving difficult, im down to altering values by units of one, put its still not perfect. 

When you say altering CV 54 to 0 may have to be done two or three times, will it have to be reset to its original value and then set it to 0 again?

Again, all the help is much appreciated, not a road i've been down before 

[Alan564017]

irishthump, I tried CV54 to 0 on both locos, unfortunately no result, it did adjust some of the CV's I had previously altered. 

I've reset them to their original values (each decoder had identical values as you would expected).

Im going to give it one more go, its become a very frustrating exercise. Same locos, same decoders, a double header straight out of the box should have been possible as others have done.

Thanks for you help

[irishthump]

On 26/2/2022 at 12:12 AM, Alan564017 said:

irishthump, thanks for that. I think I understand the F1 button, on the Elite its the controller 1 (a dial that is pressed to select). 

the locos have definitely been run in on both DC and DCC. From out of the box, B131 ran faster than B125, I put them on a simple loop on the 12 and 6 o'clock positions and one eventually caught up with the other.

I then put in the decoders, same thing, I swapped the decoders, same thing. I think this suggests this is either a mechanism issue or power delivery issue. 

Im playing with the CV's at the moment, I've read CV's 2, 3, 4, 5 and 6 on both decoders and they had identical values. I think I have CV5 max speed almost there by reducing the speed of the faster loco. CV 3 acceleration is proving difficult, im down to altering values by units of one, put its still not perfect. 

When you say altering CV 54 to 0 may have to be done two or three times, will it have to be reset to its original value and then set it to 0 again?

Again, all the help is much appreciated, not a road i've been down before 

Alan,

You simply set CV64 to 0 then press F1. After the loco finished moving the process is finished. It is recommend you repeat this process a couple of times to get the best result. This process adjusts automatically CV's 51-56 which control motor BEMF and are quite fiddly to adjust individually.

BTW F1 on the Elite is this button;

 

 

 

Edited February 27, 2022 by irishthump

[Noel]

On 25/2/2022 at 11:28 AM, Alan564017 said:

irishthump, im only getting to look at this now. just a quick recap, I have a Hornby Eilte, two 121's, same decoders, running at different speeds. Im currently trying to adjust the relevant CV's with limited success. 

Your comment above on CV 54, I dont have an F1 button!! (Hornby Eilte), I presume this should be done on the programme track (as per Eilte instructions). Adjusting other CV's on the programme track (which is currently a single length of R601) never moves the loco. If i adjust CV 54 while on the programme track will it move?

Will the CV 54 auto-tune feature aid speed matching (double header) and will it undo any adjustment thus far?

Many thanks in advance, 

What decoders are you using?

[Alan564017]

7 hours ago, irishthump said:

Alan,

You simply set CV64 to 0 then press F1. After the loco finished moving the process is finished. It is recommend you repeat this process a couple of times to get the best result. This process adjusts automatically CV's 51-56 which control motor BEMF and are quite fiddly to adjust individually.

BTW F1 on the Elite is this button;

 

 

 

irishthump, I eventually figured it out, its picking function F1, and each loco tore off for about a meter. it didnt have much of an overall effect. I think I have CV 2 and CV5 almost settled. Im currently messing with CV6. 

6 hours ago, Noel said:

What decoders are you using?

Noel, im using LocPilot, got them with the loco

[Noel]

PS: Have both locos been run in both directions?

[Alan564017]

Noel, run in, both directions, DC and DCC. See the thread above for more detail.

[Noel]

3 hours ago, Alan564017 said:

Noel, run in, both directions, DC and DCC. See the thread above for more detail.

Apologies missed that, Then all I can offer is confirmation of Graham's suggestion for LokSound motor auto calibration which you have already done as far as I can see. Other than that adjust CV2,5,6 to manually create your own power curve to match the locos, CV5 having the most effect. Would one of the locos need a tiny bit of lube to free it up enough to match the other loco? Best of luck. I regularly double head (consist) MM 121 pairs but more commonly 141/181 pairs and 141+121 pair, sometimes with different decoder types. But most of my Locos have LokSound these days.

[Alan564017]

Noel / irishthump, I'm currently playing with CV's 2, 5 and 6 to develop a simple curve and get them to match. I've just read a more recent edition of the Hornby Elite manual, there is a section about CV 29. Through CV 29 bit 4, do I have to choose which type of speed curve I want to use (or alter)?