I am running in DCC, of course.
Thinking of adding a Proto 2000 PB unit to my PA. The P2K PB is typically a dummy unit.
Question #1 is power. I assume that there is a way to pick up track power thru the trucks. Any thoughts?
Question #2 is the motor, or lack thereof. My thought is, why bother adding a motor, just add a sound and lights decoder. Any thoughts?
Am I under thinking such a project?
Rich
Alton Junction
I've put Digitrax SoundBugs into a couple of dummies. They are sound-only, no motor, no lights. The engines I put them in were ancient Athearns. Some were always dummies, and some were gutted rubber-band drive units, but all were equipped with metal wheels and trucks, making the hookup job easy.
SoundBugs are very inexpensive, but the sound quality is strictly 8-bit. Digitrax also makes some sound-and-lights decoders, but those that I've tried have very low sound volume and I would not recommend them. Then again, those were all purchased some time ago, so the company might have better models available now.
It takes an iron man to play with a toy iron horse.
I've never seen a Proto dummy unit, so I have no idea how they supply the trucks on those. On the Stewar/Bowser dummy units I have, they have the same metal wheels and all as the power units, simply minus the motors and gears and it is a simple matter to solder wires to the trucks to get power. Worst case, you may have to rig some wheel wipers to pick up power if they leave out the pickups. It might be possible to purchase the pickups as spare parts and fit the standard powered unit pickups to the dummies, too.
No reason to add a motor, you'll have more space for a BIG speaker and enclosure. Fit the biggest thing you can, the sound will be that much better. To program though, you may need to fit a resistor on the motor leads. Use a 2-pin connector so you can take it out, there's no need to leave it in once the loco is programmed. If you DO leave the resistor installed, set CV 2,6,5 to 1,2,3 or set a speed table with all 1's across the range so little voltage gets applied to the resistor. This will keep it from getting hot. Lights and sounds should work just like it was installed in a regular powered loco.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Why would you want lights on a B-unit?
Mr. B.,
Thought that myself, but you could have a backup light and engineroom lighting.
Rich,
What I did was take the drive from a powered PB unit and used it. The first run of these had the high amp motor under the four-stripe shell, with the b unit being a dummy. The later run had the single stripe Rio Grande scheme, but both units were powered with the later, low amp motor. I had both, so swapped the chassis on the both units, got a four-stripe, powered PA-PB consist to keep and sold the other set on ebay.
Finding a powered single-stripe Rio Grande PB may be hard these days. But since what you really need is the chassis, any powered P2K PA or PB chassis with the low-amp motor will fix you up. Then you could sell off the dummy chassis with the extra shell.
Mike Lehman
Urbana, IL
I actually wouldn't put lighting in the B unit.
I just referred to the decoder as a "sound and lights" decoder.
A unit has the sound, lights, pickups and motor decoder, plus a speaker. The B unit has a motor, pickups, speaker.
Close coupled. Hardly notice the wires when running unless you look close. Rich
Close coupled. Hardly notice the wires when running unless you look close.
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
Very nice, Rich.
Those wires look like hoses.
I like it, a lot.
richhotrainQuestion #2 is the motor, or lack thereof. My thought is, why bother adding a motor, just add a sound and lights decoder. Any thoughts?
Texas Zepher richhotrain Question #2 is the motor, or lack thereof. My thought is, why bother adding a motor, just add a sound and lights decoder. Any thoughts? I agree with this thought and rrinker, A PB unit makes a nice great big speaker enclosure. I would forget the power (unless you need it for some reason) and just go sound.
richhotrain Question #2 is the motor, or lack thereof. My thought is, why bother adding a motor, just add a sound and lights decoder. Any thoughts?
I agree with this thought and rrinker, A PB unit makes a nice great big speaker enclosure. I would forget the power (unless you need it for some reason) and just go sound.
Bummer.
Got the dummy PB today, and the trucks are plastic, so powering it would be a challenge.
I may just keep it as an unpowered dummy and not worry about sound.
It's the wheels that matter.
I was looking at Gigi the GG-1 last night to figure out how to replace the couplers. The power pickups on the drivers are wipers that rub on the inside face of the wheels. This could be implemented with any set of metal wheels, on both sides so each truck would have pickup from both rails.
Or...I had an Athearn switcher apart last week. The wheelsets have those small square-block bearings on the ends. I have a trolley with the same kind of bearings. The bearings weren't making good contact with the truck frames, so I soldered a wire from the bearings to the frame. The trolley works great now.
I'm not sure if replacement wheels and axles come with the bearings. What I was thinking, though, is that these could be the same part as the infamous "cracked axle" wheelsets. If the replacements have the bearings, then you could use a set of the cracked ones for this, since you won't be driving them so the gears won't matter.
Looked 'em up. Athearn part 40029 is the axles with gears, wheels and bearings.
I think the wheels press-fit on to the axles, so you can pull them off and remove the bearings for soldering, then put them back together and re-gauge the wheels.
All (or virtually all) HO diesels have plastic trucks. Powered units have metal parts inserted that are used to pick up power. If you contact the manufacturer, you often can get the parts you need to electrify the truck - or just buy the entire trucks already set to pick up power.
All (or virtually all) HO diesels that come in A and B units use the same chassis for both, so you could just pick up a powered A unit and swap bodies with the B unit. Because it's designed to fit the A unit, the chassis will be cut down around the cab and low-nose of the A unit. When you put the B unit body on the chassis, it leaves a very large area there to fit a speaker in. I've done that with my Proto E8A - E7B set.
BTW B units often did have a rear headlight, often mounted to one side of the rear door. It was for back-up moves. It's something you rarely see modelled.
Thanks, Mister Beasley, you have given me something to think about.
Stix, thank you as well, more food for thought.
I just had a flash of inspiration, although I can't check it out just now. Suppose, just suppose, that the axle diameter for these is the same as that for a set of standard Intermountain or Proto 33-inch wheels. That would let us remove the locomotive wheels, slice-and-dice a standard rolling stock wheelset and re-assemble it as a powered wheelset for caboose lighting. I'm going to look into that over the weekend. Pack-rat that I am, I must have some cracked axle sets just lying around.
It's just a shame that the manufacturers of unpowered dummy units don't take the one extra step to add a provision for powering the trucks. OK, so there is no motor, but without powered trucks, it becomes difficult to add a sound decoder. In a dummy loco, with all that space, it is the ideal place to install a sound decoder and speakers.
Bowser dummies are easy to power, they use the same trucks minus the gears as the powered units. As long as there are metal wheels, all you need to do is provide some sort of wiper, which will probbaly have better pickup than the stock powered units anyway - Kadee coupler springs make a nice starting point to fabricate wheel wipers.
You could use the power pickups from the A unit and leave the B unit as is. Just solder a couple of wires to the track power wires in the A unit, feed the wires back to the B unit, and connect them to a sound-only 'piggyback' decoder and speaker in the B unit. I've done something like that with an A-B set of F-units. A convenient place to run the wires through is the window opening in the end doors at back of the A unit and one of the end doors on the B unit. You could wire in a mini-plug/receptacle like the tiny ones MicroMark sells, if you want to be able to separate the units easily. In my case, I ran a drawbar between the units, and used a diaphragm between the units that hid the wires.
wjstix You could use the power pickups from the A unit and leave the B unit as is. Just solder a couple of wires to the track power wires in the A unit, feed the wires back to the B unit, and connect them to a sound-only 'piggyback' decoder and speaker in the B unit. I've done something like that with an A-B set of F-units. A convenient place to run the wires through is the window opening in the end doors at back of the A unit and one of the end doors on the B unit. You could wire in a mini-plug/receptacle like the tiny ones MicroMark sells, if you want to be able to separate the units easily. In my case, I ran a drawbar between the units, and used a diaphragm between the units that hid the wires.
All of which prompts a question about a sound decoder in a dummy loco with only power pick up connections.
Without motor connections, how does the sound decoder know which prime mover sound to make such as acceleration, deceleration, braking, etc. ?
A sound-only decoder is listening to the DCC commands, not piggybacking on the motor.
MisterBeasley A sound-only decoder is listening to the DCC commands, not piggybacking on the motor.
No, the DCC motor speed command. The 'script' in the sound decoder is based on speed step from the DCC command, not the voltage.
richhotrain It's just a shame that the manufacturers of unpowered dummy units don't take the one extra step to add a provision for powering the trucks. OK, so there is no motor, but without powered trucks, it becomes difficult to add a sound decoder. In a dummy loco, with all that space, it is the ideal place to install a sound decoder and speakers. Rich
I think this is due to the fact that as sound became available, dummy units were on their way out. Very few dummies being made any more. Mfg's would rather you buy the package from them than invest in making provisions for it in a dummy. Just the way sharp-penciled manages look at things, I suppose.
richhotrain All of which prompts a question about a sound decoder in a dummy loco with only power pick up connections. Without motor connections, how does the sound decoder know which prime mover sound to make such as acceleration, deceleration, braking, etc. ? Rich
Not sure which decoder you're using, but if it's a standard motor control decoder, you may need to provide for it to see a load on the motor connections for it to work properly. I've read about people running into this problem. Think they added resistance to that part of the circut, but one the electronuic gurus is probably better placed than me to assess if this is an issue and how to work around it if it is.
I am probably not being very articulate about this, since I don't particularly understand it.
But, let me try to restate the question.
I have a powered Proto 2000 PA, motor, gears, the works, and it has an NCE D13SRP decoder installed.
I also have an unpowered dummy Proto 2000 PB, no motor, no gears, no power pickups.
So, if I wanted to install a sound decoder in the PB, which wires would I run to it?
The pickup wires and the motor wires?
If it was me, I'd put the decoder in the PA and the speaker only in the PB. Why? Then there are only two wires needed to connect between the two units.
Otherwise, you need to run, not only the pickup and motoer wires between the two, but also the lighting wiring, maybe 8 wires in all.
Not to nitpick -- I'm not Frank -- but the NCE D13SRP isn't a sound decoder. You adding that to it or ?
I'm assuming that you will be keeping the non-sound decoder in the PA, and adding a sound decoder to the PB, right?
The sound decoder only needs the two power leads from the track. It will then have two additional leads to the speaker. Some sound decoders have light outputs as well.
Mike reminded us: Not sure which decoder you're using, but if it's a standard motor control decoder, you may need to provide for it to see a load on the motor connections for it to work properly
Not sure which decoder you're using, but if it's a standard motor control decoder, you may need to provide for it to see a load on the motor connections for it to work properly
That's true. A sound only decoder should program without a motor, but if you're using a sound-and-motor decoder without a motor, you will need to provide one to program the decoder. I use an 80 ohm resistor for this. If you use one that's much larger than that, it won't work. I take the resistor out and tape the wires after programming. If you want to keep it in, you should set Vhigh (CV5) and Vmid (CV6) to zero so that no voltage will be applied to the resistor, or it will get hot and use power as well. On Soundtraxx Sound Value decoders, these values may be in CV63 and CV64 instead of 5 and 6.
You can either program both decoders to the same address, or give them different addresses and consist them when running them together.
MisterBeasley I'm assuming that you will be keeping the non-sound decoder in the PA, and adding a sound decoder to the PB, right?
I would just replace the decoder in the A with a sound/motor control Decoder, run the speakers wires back to the B connected to two speakers of the size that can reproduce better sound and forget about the other, he hawin' around with pick-ups and wheels n'such. But what do I know?
Thanks for the compliment Mike.
Take Care!
Frank