Hey all.
While I was playing with my other Shay, it occurred to me that a speaker is just about the same size as the DZ126T I used in the last install.
The ins and outs of the Shay were still fresh in my head and I thought I would go ahead and see if I could cram Loksound into one. Well as it turns out I was able to. While the Shay is small, there is a surprising amount of vacant space in there.
Here is what I was hoping to accomplish: Loksound decoder (ESU has a Shay file on the website), capacitance, LED lighting, and finally the biggest speaker possible.
Decoder:
My first stop was the ESU website to look at the specs on the Loksound Micro V5. Strangely, ESU only lists the length (21mm) and the width (10mm). I found the height (3.8mm) in the sbs4dcc.com website. My idea was to locate the decoder in the cab/oiltank. A measurement of this area yielded a total length of 24.64mm from the front of the cab to the oil tank screw, and a width of 10.6 mm. The depth of the oil tank is 4.62mm. Therefor I was confident that if I removed the front wall of the oil tank and the back wall of the cab, it would fit. It then occurred to me that I have a V4 decoder in my stock. It was purchased second hand a while back and was pre-loaded with 8-40CM sounds for use in a project I was building. Fast-forward to last week when I impulse bought the Rapido -8, which came with a Micro V5, all of a sudden I have a surplus decoder. Select Micro V4 it is! The Select Micro V4 comes in at 25mm long, 10.6 wide, and 3.8mm high. With the extra 5mm length and the additional .6mm of width being exactly what the oil tank allowed, it was going to be a very tight fit now! Here is the decoder inside the loco.
Capacitance:
Having never done a sound install before I know only what I've read here. Thanks to the stunning array of Loksound installs shared here I had access to everything I needed. It appears commonly accepted that the use of two 220uf caps in parallel to produce 440uf is the goal to aim for. A while back I bought some 16v caps on eBay but have yet to use them. I opted to test them first, again as recommended here, and above 14v they self destructed. I was advised that 20v or higher is preferred, and the higher value caps are on the way. They are the same package size as the caps I was testing so at least I can confirm fit. I opted to put the speaker on the left side below the oil tank so this left the right side of the loco for caps.
Lighting:
As in the first Shay install I chose to use 0402 SMD LEDs. They worked well inside the light housings. This time though I wouldn't have room for the physically large resistors, so I opted to use SMD resistors here. The ones I'm using are 1/10 watt which is quite a small package size, however I prefer to use large resistor values, in this case 4.7k, so the power draw is very low.
Speaker:
In my stock of speakers I have a dozen Knowles Fox 9mm x 16mm speakers that I bought a while ago. Since this is what I had on hand, I tried to make it fit. It does but it is really tight. I mean I had to use a .003" shim which was the difference between the worn gear rubbing on it's surface and not. It made it really difficult to assemble so were I to do this again I think I would try to find a size smaller. This one had to be mounted at an angle as, on it's side, it was too tall. A smaller speaker may not have this issue which would really simplify things. This one measures .354" (9mm) wide, .630" (16mm) long, and .119" (3mm)_ thick.
Building it:
Speaker construction:
I started by poking around the model to see if the speaker and caps would fit. Satisfied they would, I started building the speaker enclosure. I decided to put the enclosure on the left as that's the side of the decoder the speaker wires attach to. I settled on .005" styrene as my material of choice for the enclosure as it's really the only thing that would fit. Thicker would be ideal but in this case I just couldn't make it work.
I wanted the speaker to use the maximum amount of space, without contacting the worm or the drive shaft. Due to the height of the speaker, it had to go in on an angle. It fit here fine during exploration, but I knew that the walls of the enclosure would move the speaker in towards the worm. I needed to find this final position so I stuck shims to the bottom, rear, side and top of the tender. In my my experience, styrene never really seems to sit flat and the air between it and the surface its being squished a against has a measurable thickness. To accommodate for this I used .010" stryene as a shim, instead of the .005" I intended to use when i made the enclosure.
In this photo I have the speaker in its final position, pushing back against the shims.
The tolerance is so tight, the worm actually uses the void created by the speaker cone, and I had to file away a section of the plastic trim on the right front of the speaker to allow the driveshaft to turn freely. I also filed angles on the top and bottom edge of the speaker to get it to nestle back away from the worm. Finally, to clear the flywheel, I filed the non contact end of the speaker down to .596. A difference of .034".
I test ran the loco at several points during this process and by now there was no rubbing. With the speaker glued into place, I built the enclosure around it.
When the enclosure was complete, I installed it in the tender. It's a friction fit and the compression of the tender to the chassis hold it tightly in place. Still I wanted to be sure it was as far back as it could be, so while the glue dried I shimmed it against the drive shaft with a piece of .010" styrene.
Further testing showed that the install was good and there was no rubbing. I pulled the enclosure out now for final tweaking, which consisted of sealing the edges with Bondic and then sanding all of the sides flat. Even the smallest burr could push it out and foul the mechanism.
It's not going to win any beauty contests, but it works.
The final step before moving on was to test it with audio. For this I used a 1 watt amplifier kit that I purchased from eBay a while back.
I connected my phone and started with Money For Nothing by Dire Straights which sounded terrible but also awesome. And finished with some steam train videos on Youtube. Any concerns about damage due to my modifications and manhandling were put to rest and it was time to move on the to the next phase.
Lighting Installation:
Next I installed the LEDs. I soldered 0402 LEDs to magnet wire and set them in the housings with Bondic. In this build I wanted to keep the resistors out of the back end of the loco as space is at a premium back there. The resistor for the head lamp is coated with liquid connector coating and located in the sand dome...
...and the resistor for the tender is located in the corner on the right side of the tender. This spot has open space whereas the left side, where the light is located, is occupied entirely by speaker enclosure.
Loco modifications:
There are a few modifications that need to be made to shoe horn the decoder in, and make room for wiring. First, in the shell, I carved out the front wall of the oil tank and the back wall of the cab...
next I had to remove the oil tank screw holder in the oil tank and the legs that hold it in behind the cab. The tank will be glued in place with Krystalclear....
finally, to get the Select Micro V4 to fit in the oil tank, it had be widened inside. Thankfully there is plenty of material in the walls...
The decoder itself needed to have the wires removed. I saved them for later as they would be used during the install.
The last modification was to the motor. As in the last shay install, I removed the extra contacts so that wires could be soldered directly to the motor tabs. On these ones you can see that the copper has oxidized. I imagine this would have caused performance issues years down the road and I have zero interest in tunneling my way into this motor again.
Wiring:
With those contacts removed, the motor wires are soldered to the motor. (This time with the colours on the correct tabs - I got them back wards in the last Shay install). This time I soldered the top orange wire to the BOTTOM of the top motor tab so that I wouldn't need to modify the motor bracket any more. At this time I also soldered the red and black wires to the chassis as well.
With these modifications complete it was time to work my way out of the locomotive. The motor goes in first. The grey and orange wires are routed over and under the shaft to the right side of the chassis, bent at a 90 degree angle and then run along the chassis to the rear. They are joined with the right rail wire and Bondic is used to hold them in place.
on The left side I ran only the left rail wire as the speaker enclosure rests here and there isn't much space. I didn't try running the grey wire over on the left. I just figured I best keep that spot as free of clutter as possible. By gluing all of the wires into place as I go, I can ensure that nothing will move and I won't have to go back in. This is like closing Pandora's box
With all of the wires run to the rear, I bent them upwards at a 90 degree angle for the run up the back of the tender to the decoder solder pads.
Decoder installation:
Next the speaker enclosure is placed in position. I held it there with two sided tape. This decoder came with the shrink wrap removed which is just as well. I would have had to take it off anyway. However I was concerned I'd let the magic smoke escape when I jammed it in the metal cab so I wrapped it in Kapton tape. Prior to the Kapton wrapping I soldered a wire to the negative cap terminal at the front front of the decoder. This wire is under the Kapton wrap. One speaker wire is also soldered to the bottom of the decoder as it's not accessible once it's in. The decoder is then set on top of the motor and taped in place.
You can see the void on the right side where there is room for caps to sit.
Next the cab goes on. The wires are gathered at the back right of the tender as there is a little square of space there that's just big enough for all of the wires. The brown wire is the one that I used for the negative capacitor wire and it should have been left inside the shell where the caps would go. I'll fix that later when I install the caps. With the wires dressed it was time to secure the tender with screws. I started them but didn't tighten them. First I got the tip of a knife inside and made sure the enclosure was settled as far back and to the side as it could be. Once in place I tightened the screws to make the sandwich. It took two tries to get the speaker enclosure in properly. The second time it didn't rub when I tested the motor.
at this point there is only the wire connections left to do before I could see if this whole things was going to work. Under magnification I care fully trimmed and soldered each wire starting at the farthest pad on the left. I carefully lifted the back of the decoder and tucked each completed wire under it. I left the rear light disconnected as I'll have to remove the tender shell to install the caps. At that time I'll pull that rogue brown wire in and then when the rear light wires are trimmed and installed, I'll be able to re-fit the oil tank.
So that's where I am right now. it's running and it sounds pretty good, albeit odd with the 16 cylinder diesel sounds. a 4000hp Shay! I'll fix that when I can get access to a programmer.
Soon I'll post a link to a short video of it running:
Thanks for reading.
That's all for now.
Craig
