Model Railway Forum

Well this was supposed to be an easy job but apparently not?

Have a Dapol Class 121 & a Bachmann Pannier, which are both fitted with a Lenz Silver + decoder and they will both happily shuttle up and down a branch line. Each end of the track has a Lenz BM1 fitted – so all works well.

The problem is that I have now purchased a Heljan Class 1361 loco and wanted to use this one on the branch line as well, so it was supposed to be a simple job – fit a Lenz Silver mini+ (different decoder as different plug), code it with the same cvs as the Pannier eg CV51 (3-1- value 10) (CV54 – value 15) and away we go!

No. The decoder works fine but neither the ABC or Shuttle function appear to be working. The loco will not brake after it passes the gap in the rail and ploughs into the buffers.

If I turn the power off before it hits the buffers the loco will stop. However, when turning the power back on there is a small delay (could be the timing set in CV 54) and the loco then moves forward. If I put into reverse – again a small delay but strangely the loco still moves forward? It will not change direction. The same happens at the other end of the line.

So the question is - am I doing something wrong, are the cvs wrong or is it the decoder at fault?

All help would be appreciated as this is driving me up the wall!

Clive

Hi
What acceleration and deceleration rates are in CV3 & CV4 ? If high these will cause the loco to continue on for some while and be slow to restart from rest. Suggest you set both to 1 and retest.
Also ensure CV51 has a value of 10 for shuttle mode or 2 if you just want plain ABC. What happens if CV54 value is lowered to say 4?

Brian - thanks for getting back to me.

So what I’ve done this morning is reset the decoder and the default readings are CV 3 = 6, CV4 = 5, CV29 = 14 & CV54 = 4. I’ve changed CV 51 to 10 as in my Pannier and yesterday CV29 was changed to value 2, so that only 14/28 step applied.

With these readings the problem remains.

If I change CV3 & CV4 to “1”, still no change. The loco doesn't stop.

I have changed CV51 to “2” – here the loco still doesn’t stop and when I do turn the power off and back on again the loco will not move either way.

I read that ABC doesn’t work with the shunting function in play, so I’ve turned Function 3 on & off again, just to check it wasn’t on by mistake.

It’s almost as if CV51 isn’t being recognised by the decoder at all or it's not sensing the asymetrical signal?

I have noticed that the decoder pins don’t go fully into the socket, but they won’t go in any further and the loco is running ok otherwise – it just won’t accept commands for ABC or the shuttle facility.

I’d be grateful to hear any other ideas that you might have to resolve the problem?

Clive

Hi Clive,

I don't think CV29 being at a value of 2 should allow 14/28 speed steps only? It normally means DC operation is Off and speed steps are 28/128 available?

Just a silly thought.... The lack of ABC apparently occurring is not due to the loco having a very large flywheel??

Other than what you've done I can't help, Sorry. I suggest you contact a DCC specialist like Coastal DCC who are extremely good at offering advice or your decoder supplier, if they are a specialist.

This is the standard CV29 calculator http://www.2mm.org.uk/articles/cv29%20calculator.htm which you adjust to give the value calculated to gain the operation needed.

https://www.coastaldcc.co.uk/index.php A phone call may be best.

Good luck with your quest.

The Lenz Silver mini 6 pin decoder is recommended for locomotives drawing less than 0.5 amp continuous.......Heljan locos have a reputation for having high draw motors so this might be the reason for the ABC not functioning.........HB

Does the Silver Mini support ABC - check the spec.