IZNF, "I have a problem"

[Per Olsen]

Hello.

I have tried for several days to solve this, but now I think I will have to ask for help, sorry

I am using IZNF (very useful/powerful feature, I like it a lot !!).  But I am having problems.....

This time I have calibrated 3 different Motor Coaches for use with IZN.  They are all smaller than 60cm long.  2 of them have axels in one end without feedback.  So (for this purpose) I only run them with end 1 first, to be sure of good feedback from the front wheels.  I calibrated their speeds and "Bremsekorrektur", all was done in a station-area where I have more than 3m straight track, symmetrical around the middle of the track.  All were calibrated to stop exactly at the middle.  In this track, all the 3 trains stop exactly at the middle every time, also when entering from the other side.  So I am pretty sure they are correctly calibrated...?

So the problem is not at this station.  But in all other tracks in all other stations, I have a problem to make them stop in the middle.  Some places they all stop at different distances from the middle-point, and at different places on different tracks at the same station.  I have tried to manipulate with changing the speed, and the length of IZNF, but I have not found any solution that works with all trains at the same time.  It drives me crazy...

I have been very careful to measure all tracks and distances very careful, so I am pretty sure that they are correct.  All feedbacks work 100%.

Can anyone offer some general help?

Best regards,
Per.

[Stefan Lersch]

Helle Per,

have you turned off the deceleration of the decoders (set it to 1)? Have you set the deceleration in WDP to 18? Are the entries for length and the distance to the first axle correct in the database? If you are running AC you might have to enter the distance to the slider and not to the axle.

Could you please fill in your personal profile in the forum? I always forget what you are running.

[Per Olsen]

Hello again, Stefan.

Yes, I have tried to set braking to off in decoders, not much difference.
Yes, it is 18 in all locos.
Yes, I have checked and re-checked the distances to first axle, they are correct.
Yes, I am running AC (Maerklin C-tracks).  Distance to the slider does NOT matter, feedback is only from the wheels.

I also checked and re-checked all measured distances of tracks.  All are correct.

I tried to fill in the profile now, will see if it works 

Best regards,
Per.

[Stefan Lersch]

Hello Per,

how big is the difference between the place they stop an where they should stop? Is the sequence of the feedback contacts correct in the iZNF?

[Per Olsen]

Hello again.

I did not measure exactly (will check more today).  But the middle of the train should stop at the middle of the platform.  And so it does, always, on the track where I did all programming.

Other stations, I would guess +/-  0-15cm. 

But they seem to always stop at the same place (although it is the wrong place).  Of course, +/- a couple of cm is (for me) acceptable.

Regards,
Per.

[Stefan Lersch]

Hi Per,

can you please provide me with a current backup? Please give me an example: a iZNF where they stop too late and the range. Do all of your trains stop there too late or only the above mentioned?

[Per Olsen]

Hi again.

I did some more carefule measuring and testing right now.  I have included a current backup.

All locos has been calibrated for speed.  All locos has been calibrated for "Bremsekorrektur" using Fahrtsrasse no 435 from NesIn3v to Nes3f with "Stop am Signal".  Signal is 20cm from the end of track.  All locos has been adjusted to stop exactly at signal (buffers).

Using the same route, with "Stop in Bahnsteigmitte", results in:
Loc 69 stops +1cm from middle.
Loc 50 stops +1cm from middle.
Loc 61 stops +2cm from middle.

(These are for me acceptable values).

Next, I test the route 420 from Min0a to Str1b.  
First I test with IZNf only with RMK 537,544 and 543.  This may be a bit short, but the result is anyway:
Loc 69 stops +1cm from middle.
Loc 50 stops -1cm from middle.
Loc 61 stops +12cm from middle.
Lok 69 and 50 is acceptable, but lok 61 is not...

So I make the route longer, including 30,7cm without feedbakc, and RMK 479.
But the result is exactly the same.

As it is sunday, and I also have other things to do    I did not have time for more tests now.  I know that there also is big differences at station Sol, but this I have not had time to test more carefully yet.

Best regards,
Per.

[Per Olsen]

Hi.

I am beginning to believe there must be something wrong when I calibrate each loco for speed and Bremskorrektur?  All locos stop correctly at the calibarting-track, but almost everywhere else in my layout, most locos stop at different distances from the "correct" stop-point.

As they stop on the same spot in the calibrating-track, they should stop at the same spots in every track/station.  What can I have been doing wrong..?

Best regards,
Per.

[Stefan Lersch]

Hello Per,

on my layout I don't have such problems. Where I calibrate the Bremskorrektur the locos stop 3 mm exact. At other places they stop 1 cm exact which is fine for me.

I will now have a look at your backup.

[Stefan Lersch]

Hello Per,

the middle of the train should stop 127 cm away from the beginning of the turnout #161. Where does it stop?

[Per Olsen]

Hello.

Sorry, I sent you the wrong backup  Please look at the one included here..

Platform should be 278,5-80-10=188,5cm
Middle of the platform should be 188,5/2=94,25cm.
So the trains should stop at 94,25+10+30 (or 80-40) =134,25cm from start of turnout #161.

I think that should be correct.

Loc 69 stops +5cm from middle.  Or 139,25cm from start of turnout #161
Loc 50 stops +5cm from middle.  Or 139,25cm from start of turnout #161
Loc 61 stops +13,6cm from middle.  Or 147,85cm from start of turnout #161
Loc 52 stops +2,8cm from middle.  Or 137,05cm from start of turnout #161

I cannot understand why.  Can you ?

Best regards,
Per.

[Per Olsen]

Hello again.

Any more hints/tips?  I am stuck here...

Best regards,
Per.

[Stefan Lersch]

Hello Per,

maybe someone running Marklin could help you here. I still think it's a problem of your loco and not a WDP problem. That's because only one of your locos has this problem and nobody else mentioned something similar. Which loco is it (# of article)?

[Per Olsen]

Hi.

Well, one of them is extra wrong.  I have chaanged to another loc-decoder, and will re-calibrate that one.  But as you see, all of the others are around +5cm from the middle in the mentioned route at Strandby station.  I have not calibrated in any other stations (yet).

Yes, it may well be a problem here, but I cannot find it !

At the calibrating station, all trains stop exactly as calibrated.  In all other stations, that have an offset from the middle of the station.  This is what I do not understand.  If all is calibrated well, in a long station with long tracks, the should stop correctly at other stations, at least when I use around the same length of the IZNF track...?

Best regards,
Per.

[Adrian L]

I don't know if this will help, but I have one Marklin loco that would not give a consistent result during calibration. In the end, I had to clean the wheels (using a LUX 9305.7) and very lightly oil the gears. Since then, the loco now produces a clean calibration graph with 15 points..