hi again,
as I move through my diesel roster I am reaching further and further back in time.
Next on the list is an ancient Proto GP18 that I don't think was ever out of the box--already checked, it has all the OEM cracked gears so some Athearn gears are on the way.
I've done a search here for decoder installs and also on the modifications needed for modifying the locomotive weight. Best I've come up with so far is this thread http://cs.trains.com/mrr/f/88/p/209704/2295137.aspx#2295137 where Chad used a milling machine to remove a sizable chunk of the weight on the long hood side of the chassis.
My question is this, and partly because that's almost a three-year old thread, is there a recommended practice in terms of where to cut the weight? meaning on one end, in the middle, wherever the most weight is? Alternatively, I know decoders get smaller and smaller every year, is there a decoder that could go in the center where the diode bundle is? and skip the hacksaw work on the weight. Just looking for a basic non-sound dcc install.
And apologies if this ground has been worked over before, I'm sure it has, I just didn't see anything obvious in the archives. thanks.
Jim T
When I do milling of the weights - I usually try to remove just enough weight to clear the decoder.
I usually use the Atlas or Kato type boards as they are the flattest decoder so I don't have to remove too much weight.
They are long and narrow which make them well suited to fit in most GP type engines.
Just because they are listed for Atlas or Kato - doesn't mean they can not be made to fit.
Also the new N & Z scale decoders would be an alternate choice - go to the MFG of choice and they will usually list the size of their decoders and then find one that may fit the area in your engine now!
If none - then cutting out the frame will need to be done!
BOB H - Clarion, PA
Is that the already modified version or is that what it looks like stock? For just a motor decoder, there should be plenty of room there at the back, or even in front just behind the front truck - basically, where the black marks are.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
cmrproducts Jim T When I do milling of the weights - I usually try to remove just enough weight to clear the decoder. I usually use the Atlas or Kato type boards as they are the flattest decoder so I don't have to remove too much weight. They are long and narrow which make them well suited to fit in most GP type engines. Just because they are listed for Atlas or Kato - doesn't mean they can not be made to fit. Also the new N & Z scale decoders would be an alternate choice - go to the MFG of choice and they will usually list the size of their decoders and then find one that may fit the area in your engine now! If none - then cutting out the frame will need to be done! BOB H - Clarion, PA
good point, just miked that space, roughly .455" x .660. Will see what's available. I have a bunch of different decoders on hand but they're all on the largish side.
rrinker Is that the already modified version or is that what it looks like stock? For just a motor decoder, there should be plenty of room there at the back, or even in front just behind the front truck - basically, where the black marks are. --Randy
Randy,
this is stock, and actually I think you're right--I should have pulled the shell out and looked at it more closely. The black marks on the weight are where they painted the weight so it wouldn't shine behind the ventilation grills, and the weight at those locations goes right up against the top of the shell's interior.
On the cab end, however, the weight does not go all the way up to the shell surface [on edit: DUH, it's a high nose engine], there seems to be about .20" of space above the weight where a decoder could go before it hits the light tube for the headlight. So I think that's a possibility? I would have to route the wires past the headlamp bulb if that's where it ends up.
alright, so here's a new question. One of the power leads from the trucks wasn't soldered very well and broke off. So I take off the weight to re-solder it. Of course the weight is glued to the power lead for the headlight bulbs (yellow wire below), and in the course of pulling the weight off the insulation on the yellow wire gets damaged enough I want to swap it out now.
Only problem is how to remove the motor so I can access the soldering point beneath the flywheel? I've got the exploded diagram and it doesn't look like the motor is screwed onto anything, but seems to be held in place with a couple of rubber clamps? I don't want to force the motor out of the clamps and risk more damage; is there a trick for removing the motor? Or should I just pull the trucks off and remove the flywheel to get at that spot?
thanks again, and I appreciate your patience with my rookie mistakes.
Note looking at that it is an identical clone of Athearn Blue Box, just with the red wire on top instead of the metal clip from truck to truck. Basically, proceed as such. HOSeeker may have the parts diagram that came with them showing an exploded view. Witht he one red wire off, you're halfway there to freeing up the motor. I haven't look at an early P2K lately to remember if they have a screw underneath holding the motor or if it just uses the press in nylon mounts like Athearn, in which case you just pull up on the motor.
rrinker Note looking at that it is an identical clone of Athearn Blue Box, just with the red wire on top instead of the metal clip from truck to truck. Basically, proceed as such. HOSeeker may have the parts diagram that came with them showing an exploded view. Witht he one red wire off, you're halfway there to freeing up the motor. I haven't look at an early P2K lately to remember if they have a screw underneath holding the motor or if it just uses the press in nylon mounts like Athearn, in which case you just pull up on the motor. --Randy
that's what I thought as well, here's a pic of the nylon mounts, yes? (the screws go into the weight.) I'll try pulling them out as you suggest--but they are really in there tight.
ok, that did it--thanks Randy. I ended up having to get a nail punch and pushing them through from underneath. Never having disassembled one of these before, wasn't sure how those rubber mounting blocks were configured. Really appreciate the guidance.
Little late now, but, you should have removed those screws first - look in the pic showing the busted wire, you can see the ends of the screws coming up through the motor. Probably broke off the little nubs under the commutator. As long as it didn;t break the plastic supporting the lower brush you're ok.
Edit - hmm, hard to tell, maybe they don't go into the motor. Might just hold the fuel tank on.
rrinker Little late now, but, you should have removed those screws first - look in the pic showing the busted wire, you can see the ends of the screws coming up through the motor. Probably broke off the little nubs under the commutator. As long as it didn;t break the plastic supporting the lower brush you're ok. Edit - hmm, hard to tell, maybe they don't go into the motor. Might just hold the fuel tank on. --Randy
actually those screws simply screw the frame onto the weight and provide the electrical contact for the motor ground to the frame. The fuel tank is simply a press fit onto the frame. Nothing seems to have broken, but I will say that the original design of the power supply to the motor from the frame connection (blue wire below) strikes me as a bit unreliable. That connection broke off as well, so I temporarily soldered it back to the straggling copper strands that remained pinched under the black pin holding it all to the weight. I'll redo that when I do the decoder.
I didn't have anything suitable on hand, I did have an NCE N141P that would certainly fit, but I'll save that as a drop-in for one of my Stewart switchers that has an 8 pin connection. Haven't looked up which decoder I'll order for this geep yet though.
This was one of those days where one thing leads to another--kind of another snowball effect afternoon. I don't know if you guys know the Patrick McManus essay on "Sequences" . . . it's well worth reading. Reminds me of that essay.
(found that essay online here, unfortunately no paragraph breaks, but you'll get the idea.)
It's one step up from Athearn which just uses a tab on the bottom brush retainer to rub against the bottom of the chassis for the contact. And the RTR series still relies on the truck bolsters get to power from the (left? if all your pictures have the front of the loco the same way, the big tabs on the trucks are the right rail) to the frame, then they pus a ring terminal on a wire and pinch it between the frame and PC board to tab a wire off to feed the board. Your best bet will be to solder some small flexible wire to the metal side of the trucks, the side than bends over the top where the pin connects the truck to the chassis. Solder wires to the big tabs, and you have your 4 truck power inputs. Solder a wire to each of the motor clips (one at a time, it's an Athearn clone so if you take both out the motor will literally come apart). Also make sure to prop the motor up so the spring under there and the brush don;t fall out. Solder one, put it back on, do the other. I'd also put a layer of kaptop tabe in the slot where the motor nestles in (or around the bottom clip) so nothing makes contact with the chassis. Now you have your main wires to connect a decoder to. Headlight option depends on how they had it set up, if it's all through a light pipe or it was just a fire in the cab look. If you model is a high nose, there should be plenty of room in the nose to mount and LED right up against the headlight lenses, and same in back.
rrinker It's one step up from Athearn which just uses a tab on the bottom brush retainer to rub against the bottom of the chassis for the contact. And the RTR series still relies on the truck bolsters get to power from the (left? if all your pictures have the front of the loco the same way, the big tabs on the trucks are the right rail) to the frame, then they pus a ring terminal on a wire and pinch it between the frame and PC board to tab a wire off to feed the board. Your best bet will be to solder some small flexible wire to the metal side of the trucks, the side than bends over the top where the pin connects the truck to the chassis. Solder wires to the big tabs, and you have your 4 truck power inputs. Solder a wire to each of the motor clips (one at a time, it's an Athearn clone so if you take both out the motor will literally come apart). Also make sure to prop the motor up so the spring under there and the brush don;t fall out. Solder one, put it back on, do the other. I'd also put a layer of kaptop tabe in the slot where the motor nestles in (or around the bottom clip) so nothing makes contact with the chassis. Now you have your main wires to connect a decoder to. Headlight option depends on how they had it set up, if it's all through a light pipe or it was just a fire in the cab look. If you model is a high nose, there should be plenty of room in the nose to mount and LED right up against the headlight lenses, and same in back. --Randy
Randy, thanks as always for your description of what I'll need to do. I ordered an M1 decoder which should get here Tuesday, and I plan on swapping out the incandescents for LEDs with resistors. I'll keep the existing light pipes right where they are, unless there's a reason to want the LEDs closer to the headlight lenses?
I follow the general idea of getting a power wire to the left rail side of the trucks, but not exactly sure I can visualize where you're saying the solder point is ("Your best bet will be to solder some small flexible wire to the metal side of the trucks, the side than bends over the top where the pin connects the truck to the chassis")? If you could point me to a photo possibly of what you're describing, that might help; although I can search for that as well.
Funny you should mention the brushes and brush springs! I spent an enjoyable 20 minutes this afternoon on my hands and knees searching for what I thought was a lost spring . . . turns out it had slipped underneath my cutting mat on the bench. I've got to work with a magnet on the bench to keep stuff like that from rolling away.
Anyway, looking forward to finishing this up once the decoder shows up. For a 20 dollar locomotive, I sure spent a lot of time futzing around with it this afternoon!!
JimT I follow the general idea of getting a power wire to the left rail side of the trucks, but not exactly sure I can visualize where you're saying the solder point is ("Your best bet will be to solder some small flexible wire to the metal side of the trucks, the side than bends over the top where the pin connects the truck to the chassis")? If you could point me to a photo possibly of what you're describing, that might help; although I can search for that as well.
alright, I did some searching online, and I think I've got the idea. (I've never worked on Athearn locomotives, so I guess I didn't realize most of the tips for improving the power on these Protos comes from Athearn tuneup pages.)
here's a photo lifted off of another board, basically the idea is to hit that metal plate between the sideframe and the truck tower/wheelsets (black wire)? any tips on how to route that wire so it doesn't pinch or bind on anything?
In that one, they've bent the tab where the red wire attaches, but with that in its normal position, if you bring the black wires up outboard of that, the tab should shield the wire from the gears. just tape it to the tab - tape on the tab, then wire, then another layer of tape just to be sure. On the right side of your assembled picture there is a channel conveniently located. There's one on the left side, but at the end it tapers over right to the middle of the drive train.
Only reason to mess witht he light pipes is if you need more room in the middle. On slightly newer models like my Geeps, there are two protrusions of the weight with plastic caps on top of them, under which sat the original light bulbs, and a T3 size LED fits perfectly there, and the stock light pipes line up perfectly. Looks like on these older ones they just stuffed everything in almost randomly - like the diodes for the directional lighting just bundled together like that.
hadn't noticed those channels on the weight--wonder how it was they included those in the design but ended up not using them? I'll loop the wire over the tab with tape as you suggest and then use those channels to route them to the motor. you're right about them just stuffing things in the middle--I don't pretend to understand that diode bundle, so I'd just as soon take it all out and start again from scratch. And the LEDs sound like a plan, there's plenty of room for them in the existing center grooves along with the resistors.
Stuff should be here by Wednesday, I'll try to take a picture of the finished installation.
JimT hadn't noticed those channels on the weight--wonder how it was they included those in the design but ended up not using them? I'll loop the wire over the tab with tape as you suggest and then use those channels to route them to the motor. you're right about them just stuffing things in the middle--I don't pretend to understand that diode bundle, so I'd just as soon take it all out and start again from scratch. And the LEDs sound like a plan, there's plenty of room for them in the existing center grooves along with the resistors. Stuff should be here by Wednesday, I'll try to take a picture of the finished installation.
Ok, so here's where it stands, and I need some help with one of the LEDs.
I've included a photo below of the decoder installation--everything works exactly as it should except for ONE of the LEDs (the one on the left in the photo). This is also the second LED/resistor combo that I installed, thinking maybe the first one had a bad LED or resistor.
I can get forward, reverse, and the headlight on the right going forward. The LED on the left is not working going in reverse. I have included the TCS wiring diagram at the bottom, I *think* I have wired everything correctly. Or did I make a mistake? or is the reverse light something that needs to be programmed instead of coming on automatically?
And all the solder joints, etc. will be fully insulated with liquid tape, Kapton, or both by the time the shell goes on, and everything will get tucked away nice and neat. I just need some help before I go any further with this. thanks again for all your help!
Can't see the LEDs close enough, but are the resistors on the same side of each LED? The default for TCS is normally directional lights that come on with F0, so if one doesn't light, it's probably just hooked up backwards.
A little late, but about the weight...
I'd just leave the weight off completely. If you're like most of us you've got more engines than you can use anyway, so absolutely maximizing pulling power really isn't necessary. I tested my old-series Proto GP18, and with the weight removed it easily took 8 50-foot cars weighted to NMRA standard up a 2.5% hill.
Disclaimer: This post may contain humor, sarcasm, and/or flatulence.
Michael Mornard
Bringing the North Woods to South Dakota!
rrinker Can't see the LEDs close enough, but are the resistors on the same side of each LED? The default for TCS is normally directional lights that come on with F0, so if one doesn't light, it's probably just hooked up backwards. --Randy
well, I tried that also, I reversed the wires but that didn't do anything. The resistors are each on the anode side of the LEDs. All I can think is maybe the yellow wire coming from the decoder is bad, or has a bad connection to the board?
Bayfield Transfer Railway A little late, but about the weight... I'd just leave the weight off completely. If you're like most of us you've got more engines than you can use anyway, so absolutely maximizing pulling power really isn't necessary. I tested my old-series Proto GP18, and with the weight removed it easily took 8 50-foot cars weighted to NMRA standard up a 2.5% hill.
Michael, that's funny you say that, while hooking everything back up tonight, I was definitely cursing that weight. The way the whole thing is designed, you'd basically have to cut every wire to remove it and get at the motor. So we'll see. I swapped out the gears for Athearn gears, I'm still getting some grinding noise from the trucks, almost like something is dragging on the track ties. I read somewhere that the Athearn gears are not an exact fit for the Proto 2K worm, so I may end up swapping out the wheelsets for a full replacement set. We'll see.
Ah, my bad, I didn't look that closely at the photos. My GP18 is the old original-run brown-box version that they first did in the early 90s, and the weight is an add on piece that just lifts off.As a guy I knew said at a club I belonged to some years later (think Proto blue-box era) "Modern locomotives are so tightly engineered there's no room to do anything to them."
Also, maybe you can scavenge the worm from an old Athearn drive.
...I wonder if old BB Athearns at train shows would be a cost effective method of getting replacement axles and worms?
Alright, installation complete. Turns out I had shorted the first two LEDs (I'm guessing against the frame or the track somehow). Got myself a 9v battery and hooked them up, nada. Started with a fresh LED and made sure to insulate the bejeezus out of all of it. Works now . . . forward and reverse.
Have to say this seemed like a lot of effort for a cheap locomotive. The weight is a nightmare, the gears still grind, and that yellow wire that runs up the side of the weight is keeping the shell tab on that side from firmly clicking into place. Plus the coupler pocket design on this chassis is stupid. Next time I have the shell off I'll redo the yellow wire and install entirely new coupler assemblies--but for now, I am done with it! time to move on to bigger and better things.
JimT Have to say this seemed like a lot of effort for a cheap locomotive. The weight is a nightmare, the gears still grind, and that yellow wire that runs up the side of the weight is keeping the shell tab on that side from firmly clicking into place. Plus the coupler pocket design on this chassis is stupid. Next time I have the shell off I'll redo the yellow wire and install entirely new coupler assemblies--but for now, I am done with it! time to move on to bigger and better things.
You've pretty much covered most of the reasons why those locomotives are inexpensive to begin with!!!
And I actually think you missed a few more...
Congrats on the installation BTW.
- Douglas
That weight is a tight fit against the inside of the shell. You need to do one of two things .... either find a way to route the wire up through the inside of the weight, or - mill a slot into the side of the weight for the wire to recess into.
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
Mark R. That weight is a tight fit against the inside of the shell. You need to do one of two things .... either find a way to route the wire up through the inside of the weight, or - mill a slot into the side of the weight for the wire to recess into. Mark.
yeah, I almost milled the existing slot for that yellow wire a bit deeper and wider, but got lazy and just put the shell back on. Next time it's apart, that will happen.
one last followup on this locomotive--I didn't like the sound from the gears so ordered two sets of the Walthers Proto2K replacement geared wheelsets to see if there was a difference. More of an experiment than anything else, I was just curious. Anyway, those showed up this week, I switched them out today, and I am pleased to say that there is a fairly significant difference in the gear noise, which is now much reduced. The engine is still on the somewhat noisy side compared with more recent engines, but with the full-blown replacement wheelsets (versus Athearn gears on the original wheels) it is a much more smooth-running unit. Anyway, thought I'd add that.
davidmbedardHave you considered using the drive from a Stewart F unit? Minimal grinding of the frame and silky Kato goodness afterwards. I for one don't see a need for such a large weight. It was put there to compensate for the Blue Box electrical pickup scheme. A quick chuck in the garbage would have solved the majority of your headaches..... David B
gotta admit, this made me smile. You're probably right, there are likely several easier ways to go about this, but it was an engine I've had on the shelf for a long time, and there's always value in the learning experience. The big lesson here, however, is that despite how many of these locos are available on ebay or wherever for 20 or 30 bucks, it's not really worth it (to me) to pick them up and get them running. They don't come close to the later P2K offerings or to anything from Kato as you suggest. And I just don't love GP18s the way I like early diesel switchers or RS units. But again, most of the value to me is the puzzle-solving part of this, which I really enjoy.
David, I'm intrigued, do you have any photos with the shell popped off showing the drive? how much work do you have to do to the Proto chassis to get the Stewart motor installed? or do you use the Stewart chassis and modify the Proto shell? I am always open to good ideas and suggestions.