Trainorama and DCC

 
  TheBlacksmith Chief Commissioner

Location: Ankh Morpork
Yeah, but then what else would you expect from a fellow electronic dingbat Razz

Aside from the DCC aspects, which everyone seems to want to focus on, the fragility of the core-less motor when overloaded, even running DC, is an aspect that is not often considered. Indeed, the can motor itself is a culprit, because it is poor at dissipating heat compared to the older open frame motor that are now 'so yesterday'.

A pity really, because the modern can motor is simply an open frame motor that someone put in a tin can. They are, conventional or core-less, no better in any respect except for their ability to keep dirt and stuff out. And is some respects, a step backward in terms of ability to dissipate heat or clean the commutator or replace the brushes.

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  Gremlin Assistant Commissioner

Yeah, but then what else would you expect from a fellow electronic dingbat Razz

Aside from the DCC aspects, which everyone seems to want to focus on, the fragility of the core-less motor when overloaded, even running DC, is an aspect that is not often considered. Indeed, the can motor itself is a culprit, because it is poor at dissipating heat compared to the older open frame motor that are now 'so yesterday'.

A pity really, because the modern can motor is simply an open frame motor that someone put in a tin can. They are, conventional or core-less, no better in any respect except for their ability to keep dirt and stuff out. And is some respects, a step backward in terms of ability to dissipate heat or clean the commutator or replace the brushes.
TheBlacksmith
So with the open frame/can motor in mind, is it possible to re-motor old brass with an open frame motor that sticks out the back of the model with a newer and/or smaller open frame motor that will fit inside the body?  Or are we all stuck win can motors unless we wind our own Smile
  TheBlacksmith Chief Commissioner

Location: Ankh Morpork
If you are talking about new motors, then it appears you are stuck with can motors these days, as I cannot find any open frame motors of new manufacture. However modern motors can develop more power in a smaller package these days than the old motors because of the use of Neodymium magnets that are stronger and smaller.
  Gremlin Assistant Commissioner

So....Aaron (and others)

If my understanding of the discussions is correct (and it would be the first if I was!), for new/recent models produced as DCC compatible/ready/something....that come with a DCC plug, there is no need to hunt down the capacitor(s)/coil(s) that may exist *somewhere* on a PCB as either the PCB and/or the DCC decoder should be able to cope with real/imaginary/theoretical transitory spikes etc.

For old/non-DCC-ready models, remove capacitor(s) across motor leads.

Yes?  No?  Take more medicine Smile?
  TheBlacksmith Chief Commissioner

Location: Ankh Morpork
So....Aaron (and others)

If my understanding of the discussions is correct (and it would be the first if I was!), for new/recent models produced as DCC compatible/ready/something....that come with a DCC plug, there is no need to hunt down the capacitor(s)/coil(s) that may exist *somewhere* on a PCB as either the PCB and/or the DCC decoder should be able to cope with real/imaginary/theoretical transitory spikes etc.

For old/non-DCC-ready models, remove capacitor(s) across motor leads.

Yes?  No?  Take more medicine Smile?
Gremlin
If it comes down to a straight decision, I would remove any of the capacitors or chokes fitted to a model, providing you can properly identify them. If not, you may be removing the wrong components.
  Gremlin Assistant Commissioner

Thinking (typing?) out aloud...

I guess I would have to cut capacitors but replace coils with wire - to keep the circuit intact for the coil as I assume that the capacitor/coil are doing something inductive and therefore the coil "line" is required to remain.....well past my electronics knowledge from years ago.

I wonder if anyone has identified the *correct* capacitors/coils on Australian DCC-ready locomotives?  I have searched and apart from two or three, I can't find details for each PCB that exists.  Mind you, I haven't approached the vendors, maybe that is the next step and it could become a sticky?

Of course a better solution would be to place the circuitry on the NMRA dummy plug so that, when removed, the problem goes away Smile
  Aaron Minister for Railways

Location: University of Adelaide SA
I would leave the suppression in, unless running qualities with the components in are bad, in which case I would remove them.

To remove them, snipping one lead of the capacitor will effectively remove it from the circuit, and simply placing some form of conductive link across the coil will remove this component from the circuit too.

There's a reason why the suppression components are not a part of the dummy plug that being when you have an EMI source, every piece of wire that signal travels down becomes an aerial and will aid in propagating that signal. The EMI suppression components therefore need to be as close as possible to the source (the motor brushes/commutator) in order to prevent that signal being propagated. The NMRA socket is simply an impractical distance from the source.

I believe there is possibly one other small reason, for not placing said EMI suppression on the dummy plug, that being it's a tacit 'hope' that these components will be left behind by the user installing DCC. As I posted earlier, many DCC equipped products have factory fitted EMI suppression AND DCC decoders, I think even without other electrical knowledge, that tells me enough.
  Gremlin Assistant Commissioner

I would leave the suppression in, unless running qualities with the components in are bad, in which case I would remove them.

To remove them, snipping one lead of the capacitor will effectively remove it from the circuit, and simply placing some form of conductive link across the coil will remove this component from the circuit too.

There's a reason why the suppression components are not a part of the dummy plug that being when you have an EMI source, every piece of wire that signal travels down becomes an aerial and will aid in propagating that signal. The EMI suppression components therefore need to be as close as possible to the source (the motor brushes/commutator) in order to prevent that signal being propagated. The NMRA socket is simply an impractical distance from the source.

I believe there is possibly one other small reason, for not placing said EMI suppression on the dummy plug, that being it's a tacit 'hope' that these components will be left behind by the user installing DCC. As I posted earlier, many DCC equipped products have factory fitted EMI suppression AND DCC decoders, I think even without other electrical knowledge, that tells me enough.
Aaron
Aaron....that is exactly my thinking in relation to the DCC-compatible locos - if the suppression devices are on the PCB in a way that makes identification and removal exceptionally difficult, then as the devices were *designed* with DCC operation in mind, surely part of the electrical design was efficient and/or acceptable running with a decoder installed?

Since starting this thread, I have installed 17 decoders in DCC ready/compatible locos.  As noted earlier, the *only* difference I have seen is that in my case, in *every* loco in which I installed an NCE decoder, slow speed crawl at setting 1 on an NCE ProCab was impossible.  Replacing the decoder with a TCS then had the locos crawling at setting 1.  I have not removed capacitors or coils from any loco and they all crawl at setting 1, appear to work perfectly fine at a scale running speed and don't appear to be heating-up or melting or stuttering or....well, anything abnormal.

Pure personal opinion, highly subjective and only supported by watching the loco operation over a period of about an hour (each), going around a 10m oval track crawling at setting 1.
  Albert Chief Commissioner

I have NCE and TCS decoders in my Trainorama locos and they do the same as you describe Gremlin
  Captain Underpants Train Controller

Aaron....that is exactly my thinking in relation to the DCC-compatible locos - if the suppression devices are on the PCB in a way that makes identification and removal exceptionally difficult, then as the devices were *designed* with DCC operation in mind, surely part of the electrical design was efficient and/or acceptable running with a decoder installed?

Since starting this thread, I have installed 17 decoders in DCC ready/compatible locos.  As noted earlier, the *only* difference I have seen is that in my case, in *every* loco in which I installed an NCE decoder, slow speed crawl at setting 1 on an NCE ProCab was impossible.  Replacing the decoder with a TCS then had the locos crawling at setting 1.  I have not removed capacitors or coils from any loco and they all crawl at setting 1, appear to work perfectly fine at a scale running speed and don't appear to be heating-up or melting or stuttering or....well, anything abnormal.

Pure personal opinion, highly subjective and only supported by watching the loco operation over a period of about an hour (each), going around a 10m oval track crawling at setting 1.
Gremlin

Gremlin... with the NCE decoders you will need to increase CV2 (Start Voltage), CV 116 (Torque compensation kick rate) and CV117 (Torque compensation kick strength) in order to get the loco crawling at setting 1.NCE decoders use Torque Compensation for slow speed performance while TCS uses BEMF which helps them crawl at setting 1.
Increase CV2 by 5 at a time until the loco maintains slow movement at setting 1. Just keep increasing it until you are happy.  CV116 and CV117 can be adjusted to increase kick rate and strength to get the motor smoothly turning at slow speeds. You will find all the info in the instruction manual that came with the decoder. Just play around with these CVs until you are happy with slow movement. Try a few different numbers for them and you will notice the difference in the way the loco runs at slow speed that way you will understand how these 3 CVs work. (Hint: write down the values for these CVs when you are happy with movement before experimenting with them that way you can always return to your happy numbers.)

Good luck

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