Zimo MX660 in an NW2 (video added)

[jdcolombo]

Hi folks.

Bryan Vianco sent me a Zimo MX660 sound decoder (full specs on Bryan's site here: http://store.sbs4dcc.com/ZIMOMX660MicroDCCSoundDecoder-UniversalBoard-styleHardwirewithLa.aspx ) with a good-natured challenge to see if it would fit in an NW2.

I took the challenge.

Results:

Here's a video of the final result:

Here are photos:

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The speaker is an 8x12 with a "double deep" enclosure as sold by Bryan.  I haven't yet wired up headlight/rear light (waiting for info from Bryan on whether I need a dropping resistor if I use the pads on the very front and rear of the decoder meant for the headlight and rear light), but it should be no problem - there's plenty of space both in front and in the cab above the speaker for a 603-size LED.  The only frame mods were cutting off the "nubs" that held in the original decoder, some slight modification of the motor brush connectors, and cutting a small groove in the front of the frame to route the red and black pickup wires to the pickup strips.  I may re-think how I did the pickup, but this seemed to be the most straight-forward way to do it.  I did not use any keep alive caps (no place to put them, unless I use a shallower enclosure for the speaker and sit them under the speaker enclosure), but so far I haven't noticed any dropouts. 

I'll take a video when I'm completely done, but I've run it, and it works - with the legendary Zimo motor control making it run much smoother than it ever has with the Digitrax decoder it had before.  Note that the shell is NOT the original Kato shell, but in fact a shell from a LifeLike SW9 that I had previously painted for the NKP.  I'm also going to try the original Kato shell to see how that fits, but I'm not anticipating any problem.  I'm not wild about Zimo's interpretation of the 12-cyl. EMD567, but they improved their 16-cyl 567 file, and if we asked, they might apply the same treatment to the 12-cyl file.

And it is really a pretty easy conversion - took me about an hour.

For those of you looking to put sound in a small switcher, this might be the ticket.  I suspect it will also fit the Atlas S2 for those of you who have non-sound units that you would now like to put sound in (the original decoder ESU made for that engine is not sold at retail), and the VO1000 would be another candidate for this kind of conversion.

John C.

[peteski]

Looks good!  Just yesterday I was discussing this install with Bryan.  The MX660 (with all the components located on one side of the circuit board) will come in very handy for many small diesel installs.  What  is also nice about this decoder is that it has 6 function outputs for activating all sorts of lights on the model. Plus being a ZIMO decoder it also has a great motor control.

As for the headlight function outputs, as I understand (from some info I was given by ZIMO design engineer), the outputs are designed for driving LEDs directly and have built-in current limiting to 5mA per output.  They are basically a constant current sources. So you should be safe to hook up the LEDs without any resistors (but if you add a resistor, that will not hurt the circuit either).  I have one of these decoders too, but no time to play with it yet.

[jdcolombo]

Hi Peteski.

Yes, Bryan just confirmed that the light pads (the two center pads on the very front and rear of the decoder) do not need resistors for LEDs.

Going to try to finish this up with 603's front and rear and then take a video.

I'm not wild about Zimo's interpretation of the 12-cylinder 567 prime mover and unlike their improved 16-cyl file, this one doesn't have a playable horn.  The default horn also is a multi-chime that's not really appropriate for a switcher, so I'll have to see if I can change that.  I wish they'd fix those things on all their US-prototype sound files.  But the sound itself is excellent, and of course the Zimo motor control is legendary.  And as of right now, this is pretty much the only choice for sound in something like an NW2 without hacking the frame to pieces.  I'm curious to run it more and see if it really can do without a keep alive.

John 

[RBrodzinsky]

Oh dear!  A whole other set of locos that may need conversion.  The SW1500 and the 77-tonner are probably still out of the question.

John, did you purchase the Zimo programmer?

[tehachapifan]

Awesome! Looking forward to seeing how the original shell fits as there is the different hood step-down section in front of the cab on the Kato shell. Wonder if the low, flat part of the step-down might cause more of a clearance issue.

[peteski]

Oh dear!  A whole other set of locos that may need conversion.  The SW1500 and the 77-tonner are probably still out of the question.

John, did you purchase the Zimo programmer?

I looked at my Life Like SW1200 (same chassis as the 1500 and unfortunately the large vertically-oriented motor goes all the way up to the top of the shell. No clearance for the decoder, and the motor can't  be lowered.  I thought of replacing the motor with one of the 10 or 12mm diameter coreless motors, but since the worms are right on the motor shafts, that would be a very difficult (if not impossible) conversion. Another option might be to replace the Life Like motor with the small motor Kato uses in the NW2 and orienting it horizontally (like in the NW2), but the worm alignment problem remains just as difficult.  Kato cleverly designed the NW2 drive train where the worms are integral with the trucks and the entire assembly is very low-profile (where SW1200/1500 uses what I would call a standard N scale truck design).

[jdcolombo]

Original shell works fine - I had to remove the rear light pipe assembly and the front cab window glass, but I think the front glass issue was largely because I didn't have the speaker in exactly the right position to fit between the Kato glass.  If I were doing the original shell, I'd mount the speaker in the cab, rather than gluing it to the frame, to make sure it fits properly.  I think it will fit between the front and rear glass if you use Bryan's enclosure (with the speaker glued to the top of the enclosure, rather than inset in a slightly wider and longer enclosure).  But the Kato plastic "glass" inserts are pretty thick . . .

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Added the headlight.  Actually, the LED is too bright, and bleeds through the shell.  Some black paint on the inside of the shell should take care of that. I'm probably not going to mess with the rear light, since this was mostly a "proof of concept" project.  Maybe later.

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The sound file itself needs tweaking.  For some reason, the headlight starts to blink (like a Mars light) when I blow the horn or turn on the bell.  I'm sure this is simply a programming issue.  The top speed is too high, and I vaguely recall from my other Zimo sound decoder experiment that I can't use CV5 for this; I have to adjust a different CV relating to the BEMF circuit to bring the top speed down, or else the decoder won't give me the full 8 speed step sounds.  Will also need to mess with the volume of the horn/bell/prime mover.  Might take me a day or two, but I'll eventually post a video of it in operation once I get the kinks worked out.

But . . . this proves it IS possible, and in case Bryan is reading this thread, I declare the challenge met

John C.

[jdcolombo]

Oh dear!  A whole other set of locos that may need conversion.  The SW1500 and the 77-tonner are probably still out of the question.

John, did you purchase the Zimo programmer?

Hi Rick.

No I didn't buy a Zimo programmer.  I like Zimo's products, but right now ESU leads the way for sound (their sound files are simply better and more wide-ranging), and I have all the sound-equipped units I need.  I did this NW2 project more out of curiosity than a real desire to put sound in these locos; the NKP yard at Bellevue used FM H10/44's and H12/44's along with some Alco S2's for switching duties, so I'm holding out for Atlas to release an NKP version of the S2 and for SOMEONE to do an FM switcher in the future.  I do have two VO-1000's that I use in my steel mill (both US Steel roadnames), but I've already converted them to sound using a standard wired ESU Micro.  So I'm pretty much done with sound installs.  I think I did my part in pushing this phase of the hobby forward - time for you young guys to take over!

John C.

[RBrodzinsky]

^always great to be referred to as young.

[Steveruger45]

Might be able to get two of these 220uF x 20v poly tantalum caps in if needed.  They are only 7.3mm long x 6.1mm wide x 2mm tall, so side by side they have about the same footprint as the speaker and it looks like there is more than 2mm available still, in height, inside the cab. 
https://www.mouser.com/ProductDetail/AVX/TCN4227M020R0100?qs=sGAEpiMZZMs9%2fSpGH%2fyc7NXwm7g2VEM4%252bnHoDv2KkmqizAB1vjad0w%3d%3d

Funny thing is I was thinking along the same lines just last night, so very timely John.  Thanks

[Jim Starbuck]

I looked at my Life Like SW1200 (same chassis as the 1500 and unfortunately the large vertically-oriented motor goes all the way up to the top of the shell. No clearance for the decoder, and the motor can't  be lowered.  I thought of replacing the motor with one of the 10 or 12mm diameter coreless motors, but since the worms are right on the motor shafts, that would be a very difficult (if not impossible) conversion. Another option might be to replace the Life Like motor with the small motor Kato uses in the NW2 and orienting it horizontally (like in the NW2), but the worm alignment problem remains just as difficult.  Kato cleverly designed the NW2 drive train where the worms are integral with the trucks and the entire assembly is very low-profile (where SW1200/1500 uses what I would call a standard N scale truck design).

Peteski,
I’ve got a Lifelike SW9 on my bench right now with a LokSound Select Micro in it.
I remotored it with a slender coreless and the decoder fits above. I’m just working out the smaller diameter worms to retain the stock truck height. Work has kept me gone all week but the project is looking very promising. There will be room for three caps on the front where the original light board was.  There has been very minimal frame modification. It has an 8x12 speaker in a Shapeways enclosure in the cab and sounds very good.

John,
Excellent and inspiring work as always! Thank you

Jim

[narrowminded]

I thought of replacing the motor with one of the 10 or 12mm diameter coreless motors, but since the worms are right on the motor shafts, that would be a very difficult (if not impossible) conversion. Another option might be to replace the Life Like motor with the small motor Kato uses in the NW2 and orienting it horizontally (like in the NW2), but the worm alignment problem remains just as difficult.  Kato cleverly designed the NW2 drive train where the worms are integral with the trucks and the entire assembly is very low-profile (where SW1200/1500 uses what I would call a standard N scale truck design).

I know a guy who could make the necessary conversion pieces if it would be viable otherwise.  The gear fitted to the shaft and a motor sleeve affair to align the motor seems doable if it would accomplish the need.  PM if you're up to the effort.

[peteski]

I know a guy who could make the necessary conversion pieces if it would be viable otherwise.  The gear fitted to the shaft and a motor sleeve affair to align the motor seems doable if it would accomplish the need.  PM if you're up to the effort.

I appreciate the offer, but with my project-load I'm not about to start another fairly complicated project.  I was just thinking out loud here, in case someone else was to tackle the Life-Like mechanism conversion.
It would be much easier (but pricey) to just use the NW2 mechanism under the SW1200 shell, like John did.  If someday I'm ready to tackle this project I'll be sure to ask "that guy" for assistance. Thanks! 

[tehachapifan]

John, which EMD 567 12cyl file did you use? I see two files listed for the NW2 and only one has a sound sample. Looking forward to seeing a video of this install to see and hear it!

[jdcolombo]

John, which EMD 567 12cyl file did you use? I see two files listed for the NW2 and only one has a sound sample. Looking forward to seeing a video of this install to see and hear it!

Bryan loaded the file, so I don't know.  But I only see one file on the Zimo web site. 

Meanwhile, I added the video I took this morning.  Still have the multi-chime horn, but I fixed the headlight going into ditch-light mode.  The horn can be changed; I just haven't done it yet, and thought people would like to hear the multi-chime anyway.

John C.