jpendle

Aaarrggghhhhh!!!!!!! Or lost in translation. My ESU equipped CL90 90047 was running at 75mph max. I tried the ESU autotune and then it wouldn't run faster than 50mph. Read the fine print "sometimes auto tune can make things worse". Reset to factory defaults and set the address and CV29 to use a 3 point speed curve. Running at 75mph again. But this got me reading about the various motor tuning CV's. Specifically CV53, where the CV table in the manual says that if the loco doesn't run fast enough DECREASE the value. Tried that, it goes slower! Tried INCREASING the value in CV53 and it goes faster. On reading the actual manual page for CV53 it says INCREASING the value for CV53 will make the loco go faster. So at least the ESU manual is correct 50% of the time 😁 Now it'd be nice to find out if there's an equivalent CV in Zimo decoders. Regards, John P

Yes, my Rapido designed stuff (Pendolinos and CL92's) work fine at 14V. Every day's a learning day. Regards, John P

Hi Iain, Yes I still plan to tweek CV5, if I set CV57 any lower I still get the "bump" at the top end of the curve and top speed is lower. I am still very tempted to buy a decoder tester to see what the motor voltage looks like on a scope as CV57 is adjusted, but for now I've got a lot of loco's to profile. Plus, I was cutting twigs to 1" lengths to load my log train and after doing 24, worked out that I'll need more then 2000 to do the whole train, at least it'll give me something to do while I'm profiling locos. Regards, John P

Hello, My 24V 4A power brick arrived today and I duly set about measuring speed profiles for my CL68 68004 Rapid. First is the measured speed with the track voltage set to 16V, the eagle eyed will notice that this is a different CL68 but the original speed profile for 68004 was almost identical. No CV's have been altered so everything is set to Zimo defaults. Now we have 68004 with the track voltage set to 18V Top speed is now ~90mph but the curve still has far too much "wasted" at the top end. Next track voltage set to 20V. This is getting there, top speed in excess of 100mph, remember CL68's are rated for 100mph running. And finally with CV57 set to 90 (9V max at the motor) and CV2 set to 20. Still plenty of overhead with regards to max speed and a nice slow crawl at speed step one. Once this curve is applied iTrain will smooth out the top end. The only problem now is that I'll have to re-profile all my locos because they had their profiles captured with a 14V track voltage. Regards, John P

Once you have programmed a long address in a loco decoder then the value in CV1 is irrelevant, it doesn't matter if it's 3 or 33, that loco will only respond to it's long address. And, as others have said, in the Z21 app you don't select locos by typing in an address you scroll through the list of pictures/ descriptions and select that way. e.g. when I want to select CL68 Defiant on my layout, I scroll the list to the DRS section and then select the loco by it's picture and it's description/name. By default in the app locos are sorted by the order in which they are added to the list, but you can move them around to make it easier to find them. Regards, John P

Hi, You might want to reconsider, if it's not too late, and use 1/2" or 1" XPS instead. I've used that for my hone layout, it doesn't sag and I just glue my Tortoise point motors to the underside of the XPS. I'm planning on using MTB's when I extend the layout and I plan on just gluing these in place as well. Regards, John P

Thanks, yes I am aware of that. My yard uses 1.5A on the track bus and the rest of the layout uses another 0.5 at rest with half a dozen locos scattered around. When the time comes I may just buy a Roco Dual booster for ~$200 rather then the Booster Light for ~$100. That way I can spilt the yard into separate Up & Down districts. I also plan on adding another single ended set of sidings else where on the layout for my MU's or anything else that can be run in either direction like my Nuclear Flask trains topped and tailed with DRS CL68's. Regards, John P

Hi, I had this issue as my layout got bigger and more loco's were acquired, basically if the Z21 is asked to provide too much current ~>3A then the light will flash blue If it detects a short then the light will flash red. In my case the current draw on the layout, at rest, was 2.5A, if I left the Z21 switched on over night I sometimes came back to a blue flashing light. I split my accessory bus from the track bus using a Z21 Light Booster, this gave me a bout a 1.5A current draw on the track bus and I haven't seen the problem since then. After acquiring more sound fitted locos plus various lit LHCS items, current draw on the track bus is now about 2A, so I suspect that another booster will be on the cards later this year. Regards, John P

Hi, You haven't set a long address of 3716, you've set a short address of 37, on your first screen it shows #37 and on the second screen shot it shows address 37. A long address would need CV's 17 & 18 set to 37 and 16 plus bit 5 in CV 29 should be set to 1. Now, once you've successfully setup a loco in the Z21 app and got all it's function buttons sorted, then if you have a second loco with a different number you can just copy the first one in the app and then modify the address and name of the copied loco. That WILL copy over all of the function buttons. I haven't tried to set long addresses with my Z21 as I run diesels (5 digit numbers) and I find it's just as easy to select from a picture and desription, as it is from the loco numbers (most of which I can't see from a distance anyway). BTW I thought that if you specified a long address in the Z21 app it would automatically modify CV29, but I could be wrong. Regards, John P

I have had this issue on my iphone but I could never pin down a sequence of events that caused the issue. Some days I'd walk to the train shed and the phone app would connect, on other days it wouldn't. I ended up powering the phone down, and that would fix things. These days I don't see the issue and I assume that's because I always update my Z21 when new firmware comes out and that Roco have fixed some bugs. Regards, John

So armed with a 25V 1A bench supply I did some experiments this morning. First of all I disconnected the storage yards from the track bus, this reduced the current consumption from 2A to 0.5A. I then hooked up the supply to the Z21 and set it to 24V. With the Z21 track voltage set to 16V I ran a CL68 (Zimo MX618N18) over a fixed length of track and it took ~20 seconds. With the track voltage increased to 20V the same distance took ~ 10 seconds!! With track voltage reduced to 18V the loco still managed to do the distance in 14 seconds or about 40% faster than at 16V. I couldn't measure any speed profiles as the measurement tracks are in the storage yard area. However, it would seem that even with just a 2V change, a 42% speed increase should take my CL68 locos from 75mph to 105mph. I think it's also interesting to note that Roco no longer supply the 18V adaptor with the Z21 they supply 20V adaptors instead. I now need to get my hands on a 24V 4A adaptor or perhaps borrow another power supply from work. This one will do the job, it'll do 35V @ 6A but it's a bit of a beast. Regards, John P

Found a 25V bench supply as well, so I just need to make up a suitable cable to start testing the track voltage. They are only "apparently" sitting idle. If one went walkies it would soon be noticed. We also have lots of "apparently" empty cubicles and storage rooms, put something in one and you get an email within a week asking to get your junk out of someone else's space! John P

@spamcan61 The company I work for makes Oscilloscopes so there are plenty sitting around not being used in the office. @WIMorrison I went through my box of redundant wall warts this morning and not one of them goes above 16V 👎 I'll have a poke around in the office, I've got a very large system supply that'll do 24V @ 4A, but someone will probably have a suitable bench supply lying around. Regards, John P

Hi Iain, As I said, my Z21 came with an 18V DC power supply so I cannot get the track voltage any higher than 16V with my existing setup. Roco themselves do not sell a PSU rated at more than 20V DC. I can get hold of a suitable 24V PSU for $20 from Amazon, or $40 from Digikey, but there's probably not a great deal of difference in quality. I can probably borrow a suitable bench supply from work and try it out with that. With regards to designing drive trains to suit the loco, I have 7 Pendolinos, 4 have Loksound and 3 have Zimo MN180 decoders, all run quite happily at scale speeds. I also have 3 CL92's, reviewing the speed profile for one of these locos shows a straight line from 0 to ~100mph, with default settings for the speed curves, all these models are designed by Rapido, again fitted with a Loksound decoder, so it does appear that this can be done right! I'm modelling in N Gauge and I do have 20' straight sections, so I expect my express passenger trains to run at 100mph or above, and for the fast freights to run at 75mph. I think my next step is to source a 24V supply for my Z21 and then increase the track voltage to see what effect it has. I am also sorely tempted to buy an ESU decoder tester so that I can actually measure the PWM waveform supplied by the decoder to the motor. Regards, John P

Hi and a Happy New year to all, The maximum DC voltage with the CL68 running is slightly more than 14V, I’ve got a Z21 and it had been set to a track voltage of 15V, increasing this to 16V, which is as high as it will go, makes no difference. The Z21 came with an 18V power brick by the way, although I will double check that. Regards, John P

I am in the process of measuring the scale speed of all my locos as I am automating my layout using iTrain. I model in N Gauge and the majority of my locos have Zimo MX series decoders. Loco wise I am talking about Farish and Dapol CL66's, CL60's, and CL68's. Almost without exception the same thing happens when measuring scale speed on any of these loco's fitted with a Zimo decoder. First on my DC test track, with a Dapol CL68 fitted with a Zimo MX618N18 at firmware rev 40.1 I measure a top scale speed of ~150mph. With exact same loco on my layout controlled by my Z21 the loco only gets to a top speed of ~75mph. And, when I measure the speed of the loco using iTrain every 5 speed steps from 126 down to 1 the loco speed maxes out at 75mph at speed step 60. The speed then wobbles around 75mph all the way up to speed step 126. I have also discovered that I can set the max voltage delivered to the motor to ~6V (CV57 set to 60), with no effect on max speed. The speed curve looks better, but that's not what I'm after. Now, and this is important, I don't care what the measured speed profile looks like in relative terms, I can change CV's 2,5,&6 and mess with a 28 step curve if I need to. I have 3 questions. 1) Has anyone else noticed this kind of behaviour? 2) Does anyone know why this happens? 3) Has anyone been able to fix the issue? A few other random thoughts, the same happens with my ESU Loksound 5 equipped Farish CL90's. I'm using mine on intermodal trains so 75mph is just about good enough, but I wouldn't be happy if I were running with rakes of MK3 coaches. My Pendolino's with both Zimo and ESU decoders achieve prototypical high speeds, but as a result I haven't ever measured their speeds on DC. A user on the iTrain forum reported the exact same issue in 2021, but as this isn't an iTrain issue no conclusion was reached. Maybe this is just an N Gauge problem and HO or OO models with the same chips, but presumably bigger and more powerful motors don't have this issue. Regards, John P

I heartily agree. No one else will be attempting these, and I’d go for the TPE and Avanti ones. Of course it does mean that Revolution would then be free to build on their CAF expertise and do the CL195, CL331, and all 12 CL397’s 😀 Regards, John P

Thanks for all the replies. I know that 140mph isn't done these days, pity! Anyhow, the root of my question was in regards to signalling my WCML N Gauge layout. I'm playing around with 4 aspect signals in iTrain and it's going to be a steep learning curve. iTrain's Automatic signals are based on German speed signalling rather than UK route signalling. I currently have 1 working 4 aspect signal and a signal decoder. I doubt that I'm going to be buying any more stuff until I've been able to get head around signals in iTrain. Regards, John P

Smashing, thanks. John P

Hi, This is about colour light signals on todays railway. Let’s suppose a Pendolino is belting along at 140mph in a 4 aspect signalling area. The signal operator needs to send the Pendo into a loop or onto the slow lines, how is that done? Clearly there’ll be a feather on the signal at the junction itself but how are earlier signals set to tell the driver that they’ll be taking a diverging route and will need to slow down? Thanks, John P

Probably! I use stripped out CAT5E Network cable and I even bought a whole box of the stuff for the purpose. That cost me about $100 8 years ago and I still haven't run out! I get 4 different colours of single strand 26AWG twisted pair wiring out of each length of cable. Regards, John P

AWG is AWG regardless of the number of wire strands. So that looks like 28 or 30 AWG to me. It doesn’t matter if its single strand or multi strand AWG is all about the overall diameter. e.g. 28 AWG and 7/0.2 are about the same diameter, but 7/0.2 has 7 strands, 28AWG wirewrap wire is single strand. FWIW I use 26 AWG single strand wire for my DCC droppers. Regards, John P

For better or worse part of the experience is chucking it all away and starting again. My first layout was hinged against a brick wall in a lean-to using code 80 track with a CL47 and some bogie tankers, this lasted about 1 year and then we moved house. Layout 2 was in our garage, again with code 80, plus lots of issues with trackwork as I moved a bit further along the learning curve, that got demolished when we converted the garage. Layout 3, approx 25 years after number 2 was constructed, was in the basement of our old house here in the US. I started from scratch with Code 55 track and new locos and rolling stock, the 1980's vintage stock was consigned to storage. Lots of lessons learned here as well, such as CL66's don't like hauling 20 bogie coal hoppers up a 3% grade on a curve, I don't like crawling around under baseboards to attach point motors, and Peco slips are a nightmare to get working with Peco solenoid motors plus accessory switches. I bought 2 Tortoise motors and had the single slip wired and working in about 20 minutes, versus the many frustrating hours I'd spent before. I then converted it from DC to DCC and swapped all the solenoids for Tortoises (these days I'd take a look at the MTB range of point motors). Layout 4 is the latest and might be the last (famous last words there) and while I've got to a point where my construction methods suit me, I'm still a beginner in many ways. The space I have is actually a detached double garage with a sloping floor. I re-used all the baseboard frames from Layout 3 and replaced the baseboard tops with XPS. 3 or 4 years later I start to expand the layout and I realised that I'd laid the original boards on a slope heading down to the garage door doh! There's now lots of random offcuts wedged under the baseboard legs to get it level again. The point is that it's very big learning curve and I suspect that everyone on this forum has gone through 2 or more layouts before they've thought that they're finally getting there. Regards, John P

Hi, I use Peco code 55 track, laid on 1” thick XPS. I have around 40 short radius points in my storage yards and another 40 long radius points in the scenic section. I have just 1 single slip and no diamond crossings. With the exception of my 2 axle cement PCA’s, all my rolling stock has bogies, and all my locos are either Bo-Bo or Co-Co. I rarely get any track or point related derailments, and any wheel drop in frogs is only really noticeable with the PCA’s. But that doesn’t cause them to derail. I suspect that the smaller the wheelbase the worse this gets with Peco track, and it is certainly the case that the flangeways have relatively much larger gaps and drops than the equivalent OO track. The reason people “put up with this” depends what they’re layouts are for. Mine depicts the contemporary WCML, fast, long trains and no shunting in a 36’ x 28’ space. I’ll put up with a few wobbles rather than have to handbuild all the track. If my layout were meant to depict short wheelbase stock being shunted around in a relatively small space then I too would be pretty upset. BUT, I probably wouldn’t pick any brand of RTR N Gauge track as my starting point. Merry Christmas, John P

Where did the decoder get to? John P