Class 27 DCC problems

[SHerr]

I hope somebody can help,

 

I've just purchased a second hand Heljan class 27 no. 27 034 in blue - I think it's one of the earlier releases.

 

When I have fitted the decoder, it barely moves. Applying a bit of pressure seems to help but not much. I don't have any problems with my 2 class 26's although I believe they are later releases.

 

I vaguely remember having similar issues when they first came out and having similar issues (I had completely forgotten until I bought this done).

 

I know that Heljan locos draw a lot of power, does anybody know if there are certain makes of decoder that help the issue - or any other solutions?

[charliepetty]

How does it run on DC

[BrushVeteran]

It maybe that the pins on the decoder are shorting out on the metal chassis underneath.  Try putting a strip of insulation tape under the circuit board where the decoder socket sits. I had a similar problem and this fix sorted it out so it's worth a try.

[SHerr]

It maybe that the pins on the decoder are shorting out on the metal chassis underneath.  Try putting a strip of insulation tape under the circuit board where the decoder socket sits. I had a similar problem and this fix sorted it out so it's worth a try.

Many Thanks, will give that a go tomorrow.

[SHerr]

How does it run on DC

It seemed ok, only gave it a quick go.

[RFS]

What brand of decoder are you using?  For example, the Hornby R8249 does not work well in Heljan locos as they need more power than the 0.5amp that the Hornby supplies.

[SRman]

The other thing that may apply to early releases is the brass wheels may need a thorough cleaning. That may not apply here but I would still suggest that in the trouble-shooting routine.

Check also the lights are not shorting out - I had one Heljan locomotive that had this problem (not a 27). Once I traced the short, it ran superbly.

[Matt]

I have 27034 and have same problem. Has been sitting in the too hard pile for a while... Likewise ok on dc and my many 26s are fine... With same decoders I think. None are Hornby for sure as never owned one... May be Bachmann or gaugemaster.

M

[SHerr]

Tried a few things this evening.

 

1. Can't get anything under decoder housing to insulate.

2. Definitely fine on DC, good full power.

3. Decoder definitely not Hornby, I'm pretty sure I went through that when I first had one a few years ago and was told then that they can't hope with Heljan locos as they draw too much power.

4. Swapped decoder from a 26, it now moves but starts sticking on anything other than straight and flat. Lights don't work very well if at all and this affects performance. The decoder for this one is a fairly new Bachmann one.

5. Tried decoder from 27 in the 26, performance very sticky, I've also tried decoder in other locos and it works ok - not sure of make, code comes up on NCE Powercab as 089?

 

After watching it run, stick on curves and points, this is definitely how my original one ran, and possibly had similar issues on a first release green 26. My current 26s are the second release Railfreight and blue without tablet catchers etc, so I'm assuming the pcb must have been updated.

 

Still not really great, and not much fun to operate so any thoughts on best decoders for Heljan would help.

[MrB]

Tried a few things this evening.

 

1. Can't get anything under decoder housing to insulate.

2. Definitely fine on DC, good full power.

3. Decoder definitely not Hornby, I'm pretty sure I went through that when I first had one a few years ago and was told then that they can't hope with Heljan locos as they draw too much power.

4. Swapped decoder from a 26, it now moves but starts sticking on anything other than straight and flat. Lights don't work very well if at all and this affects performance. The decoder for this one is a fairly new Bachmann one.

5. Tried decoder from 27 in the 26, performance very sticky, I've also tried decoder in other locos and it works ok - not sure of make, code comes up on NCE Powercab as 089?

 

After watching it run, stick on curves and points, this is definitely how my original one ran, and possibly had similar issues on a first release green 26. My current 26s are the second release Railfreight and blue without tablet catchers etc, so I'm assuming the pcb must have been updated.

 

Still not really great, and not much fun to operate so any thoughts on best decoders for Heljan would help.

 

Heljan have the most simple PCB of all model railway manufacturers, I doubt that would be the problem. All Heljan incandescent bulbs are dull, but this is more prototypical then the very bright ones with LEDs fitted.

For my Heljan locos I'd use a decoder with a current of more than 1amp, not sure if the Bachmann one would be up for the job.

 

Regards

 

Roy

 

 

(Edit: spelling)

[Guest 40-something]

I use the Bachmann decoders (3 function) in my HJ 26 & 27 (in fact they are the standard I use in all my 8-pin loco's) and I dont have a problem.  However, try taking the wheelsets out, cleaning the back of them and the wheel treads, and remove as much of the white grease as you can.  Failing that you can alter the starting voltage for the decoder.

 

If its the black-wrapped 2 function Bachmann decoder you are using, swap it for at least the 3 function one (blue circuit board), I've found the 2 function ones are useless in anything but a steam loco, even then they arent too good.

[SRman]

One other idea has occurred to me: it could be a BEMF problem with the particular motor/PCB combination.

Try turning off the BEMF facility in the decoder.

 

Also, remove any capacitors around the motor/brushes.

[SHerr]

Many thanks to all for your suggestions. A bit of an update:

 

I purchased a Gaugemaster decoder today rated 1 to 1.8 amps. Installed in loco without doing anything else so I could assess the impact. It worked a bit better than Bachmann one (black wrapper so 2 function - but works ok on 26's), still really struggling on curves but lights working more frequently.

 

I went to clean wheels and noticed that on one bogie the contact strips were not touching the wheels, I bent these in and a bit improvement on straights, it now manages to get round curves but quite sticky. Lights work better again - including when they are switched off!!! More cleaning required tomorrow I think.

 

In summary, higher rated decoder helped and contacts improved too so probably a number of issues. Still not happy with overall running though.

[MrB]

Many thanks to all for your suggestions. A bit of an update:

 

I purchased a Gaugemaster decoder today rated 1 to 1.8 amps. Installed in loco without doing anything else so I could assess the impact. It worked a bit better than Bachmann one (black wrapper so 2 function - but works ok on 26's), still really struggling on curves but lights working more frequently.

 

I went to clean wheels and noticed that on one bogie the contact strips were not touching the wheels, I bent these in and a bit improvement on straights, it now manages to get round curves but quite sticky. Lights work better again - including when they are switched off!!! More cleaning required tomorrow I think.

 

In summary, higher rated decoder helped and contacts improved too so probably a number of issues. Still not happy with overall running though.

Cotton buds soaked in Alcohol on the back of the wheel and tyre are a good way, but be warned you may go through a load of cotton buds.

[pheaton]

Heljan are famous for drowning the gear towers in grease, this finds it way not only on the wipers but also the inside of the wheels.....do the 27s have nickel silver wheels like the 26 or do they have brass wheels?

 

if they are brass i would recommend replacing them with nickel silver....if they are nickel silver then the advice Mr B gave you is spot on.....but also clean the inside of the wheels and the brass contact strip....thoroughly as this is just as important as the tread, i had a 58 that had similar problems....remember DC is raw power DCC is instructions much more susceptible to dirt....if the instruction doesn't get through the loco wont move properly.

[Matt]

Finally tackled my problematic 27034 today. Removed decoder and barely ran on dc. Tried cleaning wheels and omg they are the worst I've seen... This loco has not done much running since new - could this be result of brass wheels tarnishing? How does one go about sourcing and replacing the wheels? Noticed the pickups were out of line too which will tackle when change the wheels. Any advice gratefully received on where to get replacement wheels...

 

Cheers,

Matt

[kevpeo]

Howes of Oxford for the replacement wheels. Last page of the Heljan OO spares list. Often not in stock though! Kev.

[Matt]

Howes of Oxford for the replacement wheels. Last page of the Heljan OO spares list. Often not in stock though! Kev.

Thanks kev, will take another look - couldn't see in class 26/27/33 section but am guessing might not be in that section?

Cheers,

Matt

 

Edit: found them in general section and, yes, out of stock. Will keep an eye on whether they come back in. Any alternative suggestions?

[dasatcopthorne]

Thanks kev, will take another look - couldn't see in class 26/27/33 section but am guessing might not be in that section?

Cheers,

Matt

 

Edit: found them in general section and, yes, out of stock. Will keep an eye on whether they come back in. Any alternative suggestions?

 

 

I agree with all the above posts but;

 

I have a number of Heljan locos 33 & 47. I use Locsound V4 on all.

 

However the poor performance on curves is a really good indication that the brass pickups are not always in contact with the back of the wheels.

 

Take the sideframes off, remove the keeper plates and clean most of the grease off everything. Then bend the pickups right outwards.

 

If you have the old brass-coloured wheels, clean them.

 

Put everthing back together.

 

On you Powercab adjust CVs 2,3,4,5, and 6.

 

You need to know your chip type to be able to get 3,4,5, and 6 right, I'm afraid.

 

Best of luck.

 

Dave

[Matt]

Finally put some proper time into 27034 tonight and she's now running like a dream. By a process of elimination the main problem was excessive grease form the gear towers getting onto the pickups. One of the pickups also not making contact and was remedied too. When I started the process I was struggling to get her to even turn a wheel on dc but she's now completed 30 mins on DCC without missing a beat. Thanks for the guidance on here.

M

[SHerr]

Mine also running much better, a combination of bending contacts in as described above and a decoder above 1 amp - the latter definitely helps as I tried it back with a lesser one and works but quite jerky.

 

Glad to see my predicaments also helped others.