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Bachmann class 37 sound running slow and struggling up gradients


Jim

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Hi,

 

This maybe the wrong place to post this but, I've four baccie 37s with sound.

I have had them all re-blown with Howes sounds.

 

I program my engines to give a realistic acceleration, deceleration and top speed using cv3, 4 and 5.

What I've noticed is that all the models seem slow, when I gradually alter cv5 to 64 the locos stop getting faster arround value 50 and seem to struggle up gradients. If I programmed cv5 to 50 or 64 in the 47s they would be flying off the board!

I even looked at my NCE controller to see if it was providing enough amps.

The thing I dont understand is that the 37 chassis must be quite similar in design to the 47, so why does it seem slow?

The other thing I've noticed is that they all slow slightly on curves. This makes me think there is a "tightness" in the design. My 37s are well used and run-in.

It's funny that my baccie type twos can romp up gradients with a string on but the 37s struggle.

Any ideas on a fix?

 

Thanks

Jim

 

 

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It sounds to me like the load compensation isn't set up properly. When the loco goes around tight curves, or up gradients with a train on, the load on the motor increases. The chip should detect this and increase the drive to the motor to maintain a constant speed. There are four different CV's that control this. Most of the time the factory default values work fine but I suspect not in this case. Read and make a note of the values of CV's 53, 54, 55 & 56. The factory defaults (assuming these are v3.5 chips) are 56, 32, 24 and 64 respectively. I would suggest leaving CV56 at 64, but try varying the other 3 CV's in turn, one at a time and check the effect. Change them by 5-10 at a time and see if this improves things or makes them worse.

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Well a good try:(

I experimented with the CVs but didn't affect it much.

It's weird, even if I set the max power to 64 all the 37s seem to run out of straight line and level speed arround cv5 value 45.

If I have a lower speed selected on the throttle then the chip does seem to compensate up the gradient with load.

I even tried a gaugemaster controller with the same results.

It's like there's a piece of resistance restricting the motors.

It's all my 37s, all have 3.5s reblown with Howes, refurb and non refurb.

 

All the other types of engine run very well with power and speed to spare.

 

Ahhhh!

Jim

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Jim,

 

You say you have had the locos reblown so i assume they had other sounds previously. Was the problem evident before the reblows? What is the setting of CV29 - if it is set for CVs 67-94 the locos will not respond properly to adjustmens to CVs 3, 4 and 5?

 

Harold.

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Jim,

 

You say you have had the locos reblown so i assume they had other sounds previously. Was the problem evident before the reblows? What is the setting of CV29 - if it is set for CVs 67-94 the locos will not respond properly to adjustmens to CVs 3, 4 and 5?

 

Harold.

 

Thanks,

I'll look at that cv29 in the morning.

Unfortunately, I only ran one standard Bachmann 37 with sound when I had a shunting layout.

I bugs me, they just feel like there is something sapping power from them. One loco I could understand as a rogue or in need of some maintenance but all of them?

 

Thanks to both of for your suggestions, I will have a play tomorrow.

 

Jim

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Thanks again for the cv tips.

Well, I couldn't make much change adjusting the cvs but I had one of those "blindingly obvious" moments!

I swapped the decoders from a 37 and a 47.

The result was the fast 47 decoder in the 37 ran slow and the 37 decoder ran fast in the 47.

So, it must be something in the design. I lubed up the 37 but it didn't seem to need it. I lifted the motor chassis to have a look at the drive shafts and everything turned freely.

 

Anyone else noticed this kind of performance with their baccie 37s?

 

Jim

 

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There definitely seems to be something. My first loco was a sound Bachy 37/0 (nearly three years ago). After I acquired a Hornby Brit and a Bachy 108, I believed my 37 was going slowly and so lubricated it. That only made things worse so I cleaned everything up with marginal effect - track and wheels too. Eventually I took the 37 in to Trains4U in Peterborough where Garry tested it and declared it was running the same as his. I guess therefore that it is a relatively slow running model but it is odd that it does not respond to the higher speed steps. That became very evident when I was trying to speed match it with a class 25 for double-heading with the sound switched off. The model has very good pulling power though.

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