That odd looking gear is for strain release so if the locomotive suddenly stops or starts quickly it has a bit of spring to it to to help not break any teeth, they were used in larger form for a fair amount of large equipment. Hope that helps clarify that odd looking gear. :)
@@SMTMainlineI got a fp40 amtrack (sorry if it is misspelled) from a hobby shop probably from the I really don't know it had a broken contract you had to wriggle it on the track to make it go yeah that's all. happy new year
That gear at 10:30 is a shock absorber type of gear, the hub absorbs shock and tugging forces which helps prevent cracking other gears or stripping teeth
It’s an earlier phase of SD40-2, back when the body was much smaller than the frame on both ends. For a model that was first released in 1983, Bachman was certainly trying to add more details and features to attract the hobbiest market, though it was still very toy-like compared to Atlas and Athearn. The directional lighting and LED beacon were a nice touch that impressed me at 11 years old even if the plastic hand rails, thick shiny paint and odd number font would turn me off. I remember lusting after the DD40-AX even though it was huge, but I saw a few of them with their underpowered pancake motors and only a few driven axles and knew they’d be outperformed by an Athearn Hustler, but the directional lighting, horn and blinking beacon made them seem impressive. Kitbashing an Athearn drive & frame with the Bachman body and electronics did produce an equally impressive looking and performing model.
Your describing a clutch. This design is a cushion,shock absorber style that would "strip" gears when it reaches its commpession directional limit. A clutch can prevent said "stripping of gears" by utilizing multiple parts assembled.
These Bachmann SD40-2’s were pretty innovative for the time. One of the first HO units with directional lighting and an operational beacon, crude but it worked
RIGHT when a Notification pops up I click it right away for your videos I love trains and your videos KEEP UP THE GOOD WORK! And A little tip: if you can’t get the right parts for the end either go to the hobby store and see if I can find somebody who works in the train section to get it fixed. And then in your Christmas video if you saw the comment of all those cool items I got like the white bus that drives on train track and all that new stuff if I told you about that free N scale stuff that I got The engine I got still runs and it’s 50 years old or more! And that engine in your video reminds me of my N scale engine! And great video SMT Again!
Glad you enjoyed it. I do sometimes bring locomotives to my local hobby store for spare parts but I find that it's rare for them to have the part I need.
harrison: they have the sideframe pair for $9.51 in the b'mann parts dept. if you need the truck- they are about $24. if you need the powered truck/motor about $42. they have a lot of shells for them in diff liveries. i think youre right about the torque-seal glue in the screwheads- warranty void if disassembled.
The reason they used white incandescent lights rather than white LEDs is because white LEDs were not invented until 1995! This engine is likely from much before then. Also, you were correct in identifying the diodes and the capacitors.
What?!?!? That is totally not true. LEDs were invented in 1962 and become commercially available to home hobbyists in the 1970s. They were prevalent in Model Railroader magazine projects during the 70s.
@@TheSwitchList Yes, we had red, yellow and green LEDs in the 1970s, but not white ones (or anything that was reasonably "white-ish"). That's because practical blue LEDs were only available in the early 1990s (the inventors won a Nobel Prize), and they were necessary to be effectively combined with the other primary colors to form various shades of white (warm white, cool white, daylight, etc.). I remember even in the late 1990's white LEDs for hobbyists were very expensive, especially ones that were small enough to use as an HO scale headlight.
Great job working on this oddball from the 80s . yes on that board is a 3 leg transistor 2 resistors and 2 green capacitors with the 2 diodes 1 in front and 1 in rear. I honestly never seen one like this. Oh the red resin is for Bachmann warranty so they have proof of screws being tampered with so they can make the warranty claim void or not . i think my lifelike fph40 has it on screws ill check but I doubt it. At 15:13 yes mine did on my lifelike fph40 it lit up the commutator like a sparkler and smoked a bit like on fire but cleared itself it runs fine no damage but yes nobody oil that commutator! I'm gonna get a fiberglass scratch pencil I just gonna try either Amazon or eBay. The link from last video was based in amazon Canada but I didn't try at home yet maybe can get one for U.S. still great product I gotta get one.
I had three of the N-scale versions, which I custom painted for my own free-lanced railroad. The original paint was garish, but eye-catching, nontheless, and the N-scale version also had the blinking light. A profile view shows that the metal electrical conduits caused the body to sit way above the wheel sets, but I really liked the N-scale Bachmann SD40-2s. They were the only Bachmanns with nylon gears that actually ran smoothly, especially if one used a Tech ll power pack with low-speed Pulse Injection. The old metal geared Bachmanns (1970s) may have sounded like grandpa's electric razor, but they were great running locomotives and far superior to Bachmann's 80s offerings, (nylon geared) which ran in a jerky, erratic fashion. Something about the wheel spacings, though, would lead to derailments on switches at high, unprototypical speeds. I replaced the original couplers with shorter versions, which made the engines look more prototypical and not so stretched out when coupled with other engines or freight cars.
The weird looking drive gear is called a shock absorbing gear, so the motor doesn't take to many sudden jolts which can crack the motor housing on the motor.
That’s an SD40-2 if I’ve ever seen one! Great job at getting the right model! SD40-2s were made in the ‘70s so this was made 10 yrs. after the SD40-2s were made.
Hi, Harrison, I have one of these and swapped the position of the axle that has the traction tyre with the other outer axle so that you have more pickup wheels, currently the rubber tyred wheel has pickups which is kinda useless. Great content as usual!
Very good, nice to see the old ones saved and make them a runner again. 👍 I have two old Marx train sets (1 HO gauge & 1 O gauge) from the late 50's early 60's put back in service... I am old! lol
SMT does a great job with all the mechanical and electrical stuff on his loco fixes. That said I do wish he'd use an NMRA gauge to check the wheels before putting the engine in service. That is model RRing 101 to do. Since there are alot of newbies and 1st timers in his subs, that would be a good habit to promote. Eliminates one problem point. No one likes stuff that derails. Also suggest he move the cover from the non-powered truck to the powered one as the non-powered one is not dirt sensitive. If the covers are the same. Then he'll have a coupler on the rear then too. Pull some cars. Wish I had a power truck to send him.
I need to order one of those gauges at some point. I might end up moving the cover if it will work, the question is if those front wheels will stay in place.
That loose metal piece inside the engine is a reverse flux multiplier. There’s a small magneto that has a sensing unit that will allow it to send a signal to the anacromic distributor. The end result is a smoother runner.
7:02 that little black cylinder shaped thing next to the led with stripe on it is the diode, but yes it does same as led ie current can only pass through one way not the other
Hi SMT. I have the very same engine in Santa Fe. It was fancy looking, Kato had a later version of it. Sorry the snap on under side frames are missing, this happens on the majority of BACHMANN engine fleet engines. Fairly good runner I have to work on the remaining one. I wish I had the one similar to the one you repaired in Union Pacific. Meanwhile I'll keep tuning in. 😀
It's too bad that this one is missing parts but as you said it's fairly common to find them this way. Not much you can do although I don't feel too bad about it just as long as it didn't cost much.
@@SMTMainline I inherited a Chessie EMD f9 that was clicking and then stopped running. Instead of fixing the pancake motor, I put the shell on a metal chassis with all wheel drive. It is such a better locomotive now.
Looking at the loco as you have it in the video...the two blue pieces are capacitors - probably there for smoothing out voltage spikes to make the lights look more stable. They aren't using diodes per see. The little black square "thing" on the left and the black round one on the right - those are bridge rectifiers, which will only conduct current in one direction, no matter which direction the loco is traveling. What's weird is that there ARE diodes for current direction as well. Whoever did this - I don't know WHAT they were thinking.
This circuit uses a Bridge Rectifier (Round Black thing) to turn AC to DC voltage, then uses Caps + Resistor to make a RC Timer that turns that Transistor (the black square thing) on and off. The Glass Diode that is RED is a Zener Diode, it's job is to keep the voltage below a certain level if it goes above that level say 5V it sends the extra voltage to ground. It looks like it may also be doing a low voltage half rectifier (with the black diodes) to turn the light on till full voltage is applied.
I don't think I've ever seen one of those that I remember. Kader in Hong Kong made that for Bachmann, or maybe China, production moved and I'm not sure what year. The reason it uses bulb lights is you really didn't have white LEDs in the 1980s. Red, yellow and green were it. Probably the goofiest thing is it uses the same shell mount lugs as an Athearn and looks to copy the one just ahead of the fuel tank, but instead of that being a mount point there's one further ahead of it. That gear looks like if you stopped the wheels from moving it would let the motor turn a bit more. Like someone else was saying a bit of spring to it.
As far as I know Kader was originally just the company who made trains in Hong Kong, primarily for Bachmann but at some points for AHM and Lionel HO as well. Bachmann's GP30 was tooled up for Lionel about 1975 and that same shell continues today on the latest Bachmann DCC models. I believe today Kader owns Bachmann. Wikipedia might have better details.
I have a Santa Fe version of this loco. Motor was toast. Turned into a dummy. Left the electrical pick ups so the lights all still worked. If memory serves me, I cut the truck mounted couplers off and installed body mounted coupler boxes.
I've heard of people repurposing locomotives with poor drives as dummy units. It's certainly a creative way to keep older stock rolling without compromising performance.
SMT - Like Bob Wozniak said, the black parts with the white or silver bands are diodes. Those diodes direct electricity to the correct light, depending on the polarity of the rails. The glass part with the black band is also a diode; I am guessing it regulates the voltage going to that light circuit. The blue parts are capacitors; they are probably there to remove static produced by the motors. The tan parts with the color bands are resistors. The square part on the left is probably an integrated circuit for the beacon flasher. The black cylinder on the right may be a bridge rectifier.
Thanks for sharing your knowledge on this. I was wondering what those capacitors where there for. I thought that maybe it was part of a "Keep alive" system for the motor but your idea makes much more sense.
@@SMTMainline - You may be right about the capacitors acting as a " keep alive " system; they are charged to track voltage and provide some momentum to prevent stalling on a plastic switch ( or " turn-out ") frog by continuing to energize the motor & keeping the locomotive moving. Power packs with a " momentum switch " use a large-capacity capacitor to discharge & gradually lower the track voltage, slowing down the locomotive.
Bachmann locomotives were too light to pull any sort of train over 7 cars. Adding extra weight helps a lot. The extra motor housing is a good idea if you want to convert the unit to a dual motor set up for extra power. That swirling gear looks like it might help with heat build up and lub spreading I think. I think this model was Bachmann's "space age" model - lol.
It would be interesting to see what kind of performance you would get from a duel motor system, I'd imagine it would be similar to something like an AHM.
That’s a pretty neat engine right there yeah sometimes Like I said bachmann’s quality could be off though unfortunately but they’re pretty nostalgic though. I might find this on Engine at train show or so sometime. It looks pretty interesting.
2 things, 1 you are right, the black cylinder with silver stripe around it is a diode, the blue cylinders are capacitors (to probably smooth out the power from non constant contact with the track or motor causing pulsing). 2; if you want to figure something out I'd be happy to 3s print you another side frame for your trucks. Maybe from a few pictures and measurements or if you did "photogrammetry" to get a 3d picture of it.
The reason is twofold: 1.) The HT-C truck (motors facing the same direction) is physically longer than the SD truck (one motor reversed) and so more space was necessary. 2.) The SD38-2, SD40-2, and SD45-2 all share the same frame. The SD45-2 has a longer hood to accommodate a 20-cylinder engine.
I have one of these engines and the light turns on but the motor doesn’t turn. I opened it just like you did in this video. I also cleaned all the parts. However when I tried manually turning the gears with the motor in place, the gears nor the motor turned. Does this mean the motor is bad?
Those things inside it are fishing weights. The previous owner was probably trying to make it to scale weight. Sometimes model railroad rolling stock isn't at the right scale weight and it is recommended to modify them to be to scale weight. The reasoning is that if you have rolling stock that is to scale weight on either side of cars that aren't to scale weight, the difference in scale weights can pull the cars that are too light off the rails on curves causing a derailment problem, and if you didn't think about the cars scale weight you wouldn't know what the cause could be and you'd keep trying to make changes to the track in a futile attempt to stop the derailments. The NMRA has an article about it, I can't link it so just look for the NMRA website, or google ho scale model weight, the article also has a conversion chart so you can check your rolling stocks scale weight and know how to adjust them accordingly. According to their chart an HO scale rail car should have a 1 oz initial weight with 1/2 oz added for every inch of car, so a 3 inch long car would be 1 oz + 1.5 oz (1/2 oz X 3) for a total scale weight of 2.5 oz. I've never found a conversion chart for locomotives, but it is recommended to add some weights to a scale locomotive if it is having traction problems, the added weight will help the wheels grip the rails better, of course if you overdo it with the weights you could burn out the motor.
Thanks for sharing your knowledge on this. I'd imagine the original owner was just trying to add some extra traction to their model but it's hard to tell sometimes what people are aiming for. In this case the weights don't look great however they don't seem to be causing any issues.
@@SMTMainline You're welcome. Yea they are probably for extra traction, and they don't look great, but hey, they are covered by the shell so they don't need to be pretty, just need to do the job they were installed for. As long as they aren't interfering with the operation of the loco I'd leave them, if it were my project, that many aren't going to be much of an extra drag on the motor.
Hey, SMT! I’m looking for a cheap-ish Tyco locomotive of any type of motive power, and I don’t know which one to get. Can you think of any that you can recommend to me?
You seem to have put the traction tyre fitted wheelset into a position fitted with pick ups? Wouldn't it run better if first and third wheelsets were swapped?
The spiral GEAR in the motor provides TORQUE relief in case the motor stop instantly the gear will flex and keep from damaging the motor or busting the motors casing, all that torque has to go somewhere when it's stopped all of a sudden!!! (Gear is like a SPRING)
You could cast some new detail covers for the rear truck. Micro mark sells the stuff you need. There is lots of videos on the internet on how to do it. That would make for a good video for you to do a how to.
Yea thats a sd40-2 but the beacon later in the years were changed for ditch lights .and some of sd40-2 were changed for tunnel motors and they were a demand from southern pacific and rio grande and sd40t-2 were made to cool down in sp snow sheds and tunnel. And some sd40t-2 were changed back to sd40-2 and i think some are still in services. But its a cool sd40-2 you got there smt
Have you ever tired resin casting the parts you missing on the back wheels by copying the front wheel covers? I do it with my gundam models and it works fine for me to hold up over time
I would suspect the motor has a rather pulsed power delivery. That weird gear is to absorb the pulses and smooth it out. You'll find this a lot in the rear hub-to-wheel connection on single-cylinder motorcycles. Those strange lead weights are likely 1oz fishing weights.
My suggestion - swap the truck cover (bogie cap?) from the front bogie to the rear, if it will fit. You will at least have a coupler on the correct end until you can find another truck cover.
they put led in it for more weight which translates to more pulling power, it happens all the time and is one of the most b basic and important modifications that can be done to an old locomotive. Lead also isn't very hard to work with, you can put it in a pot and melt it with a blow torch. With enough weight added, a locomotive that would struggle to pull 6 cars can be made to pull 12+
You might find them listed as spudgers as that is what they used to be. Used for moving wires around. Note I looked for you real quick on ebay and saw a ton of assortments using my tech term.
That odd looking gear is for strain release so if the locomotive suddenly stops or starts quickly it has a bit of spring to it to to help not break any teeth, they were used in larger form for a fair amount of large equipment. Hope that helps clarify that odd looking gear. :)
Haven't seen one before but it's an interesting idea.
I think so too...to reduce the sudden occurring force of acceleration and stopping on the gear wheels. actually quite smart.
Someone must have modified it to pull some heavy cars. It's a smooth tork gear, added weight for grip and a solid hookup point.
I agree, it's for shock load.
@@SMTMainlineI got a fp40 amtrack (sorry if it is misspelled) from a hobby shop probably from the I really don't know it had a broken contract you had to wriggle it on the track to make it go yeah that's all. happy new year
it's a spring gear that gives smoother performance between the large diameter gear to the small diameter gear
Interesting, thanks for sharing.
It was their cheap version of flywheels!
Super. One of few locomotives that could easily be converted to twin motors and twelve wheel drive. 💙 T.E.N.
That gear at 10:30 is a shock absorber type of gear, the hub absorbs shock and tugging forces which helps prevent cracking other gears or stripping teeth
That body shell looks like it was drawn up by a guy who had never seen a SD40-2 in person, but had somebody describe it to him over the phone.
Well seeing as Bachmann is a Chinese company that assessment would most likely be 98.9999% correct ;) Kinda funny when ya think about it too.
It’s an earlier phase of SD40-2, back when the body was much smaller than the frame on both ends. For a model that was first released in 1983, Bachman was certainly trying to add more details and features to attract the hobbiest market, though it was still very toy-like compared to Atlas and Athearn. The directional lighting and LED beacon were a nice touch that impressed me at 11 years old even if the plastic hand rails, thick shiny paint and odd number font would turn me off. I remember lusting after the DD40-AX even though it was huge, but I saw a few of them with their underpowered pancake motors and only a few driven axles and knew they’d be outperformed by an Athearn Hustler, but the directional lighting, horn and blinking beacon made them seem impressive. Kitbashing an Athearn drive & frame with the Bachman body and electronics did produce an equally impressive looking and performing model.
The guy on the phone said "six axle North American diesel locomotive, 1970s" and then hung up.
wat
Cleaning the wheels always improves performance on older locomotives, nice work
It’s the first thing I do and it usually does the trick
That gear is for stress relief incase you grab it while running so it doesn't strip the gear it will let the gear slip rather than break.
It probably makes it run a bit smoother as it works as a circular spring..
Your describing a clutch. This design is a cushion,shock absorber style that would "strip" gears when it reaches its commpession directional limit. A clutch can prevent said "stripping of gears" by utilizing multiple parts assembled.
These Bachmann SD40-2’s were pretty innovative for the time. One of the first HO units with directional lighting and an operational beacon, crude but it worked
The chip next to the flashing LED is probably a 555 timer chip, set up as a flip flop in order to flash the LED.
You are correct on the electrical components, resistors, capacitor, and diode. Diodes always have a white stripe on one end.
RIGHT when a Notification pops up I click it right away for your videos I love trains and your videos KEEP UP THE GOOD WORK! And A little tip: if you can’t get the right parts for the end either go to the hobby store and see if I can find somebody who works in the train section to get it fixed. And then in your Christmas video if you saw the comment of all those cool items I got like the white bus that drives on train track and all that new stuff if I told you about that free N scale stuff that I got The engine I got still runs and it’s 50 years old or more! And that engine in your video reminds me of my N scale engine! And great video SMT Again!
Glad you enjoyed it. I do sometimes bring locomotives to my local hobby store for spare parts but I find that it's rare for them to have the part I need.
harrison: they have the sideframe pair for $9.51 in the b'mann parts dept. if you need the truck- they are about $24. if you need the powered truck/motor about $42. they have a lot of shells for them in diff liveries. i think youre right about the torque-seal glue in the screwheads- warranty void if disassembled.
That is a really good locomotive,especially from the 80s
The reason they used white incandescent lights rather than white LEDs is because white LEDs were not invented until 1995! This engine is likely from much before then. Also, you were correct in identifying the diodes and the capacitors.
What?!?!? That is totally not true. LEDs were invented in 1962 and become commercially available to home hobbyists in the 1970s. They were prevalent in Model Railroader magazine projects during the 70s.
@@TheSwitchList Yes, we had red, yellow and green LEDs in the 1970s, but not white ones (or anything that was reasonably "white-ish"). That's because practical blue LEDs were only available in the early 1990s (the inventors won a Nobel Prize), and they were necessary to be effectively combined with the other primary colors to form various shades of white (warm white, cool white, daylight, etc.). I remember even in the late 1990's white LEDs for hobbyists were very expensive, especially ones that were small enough to use as an HO scale headlight.
@@billlauretti7963 ahh I missed the specific reference to white LEDs. Thanks for the information!
The guy who in liked hit the wrong button, also I’m a big fan and your an inspiration to the young kids of model railroading
I like those transverse motors. Nice design.
Great job working on this oddball from the 80s . yes on that board is a 3 leg transistor 2 resistors and 2 green capacitors with the 2 diodes 1 in front and 1 in rear. I honestly never seen one like this. Oh the red resin is for Bachmann warranty so they have proof of screws being tampered with so they can make the warranty claim void or not . i think my lifelike fph40 has it on screws ill check but I doubt it. At 15:13 yes mine did on my lifelike fph40 it lit up the commutator like a sparkler and smoked a bit like on fire but cleared itself it runs fine no damage but yes nobody oil that commutator! I'm gonna get a fiberglass scratch pencil I just gonna try either Amazon or eBay. The link from last video was based in amazon Canada but I didn't try at home yet maybe can get one for U.S. still great product I gotta get one.
Thanks Matt. Usually cleaning the commutator fixes the smoke issues unless one or more of the coils has gone bad.
@@SMTMainline yes that is true. I just left it alone since it doesn't smoke since that one flair up lol
From SMT, who's likely handled more locos than any 2 of his subscribers combined: _I can't tell, I'm no expert on this stuff…._
Modesty personified.
the metal pieces you found inside the engine were weights for fishing
Sinkers?
@@JBofBrisbane yep
I had three of the N-scale versions, which I custom painted for my own free-lanced railroad. The original paint was garish, but eye-catching, nontheless, and the N-scale version also had the blinking light.
A profile view shows that the metal electrical conduits caused the body to sit way above the wheel sets, but I really liked the N-scale Bachmann SD40-2s. They were the only Bachmanns with nylon gears that actually ran smoothly, especially if one used a Tech ll power pack with low-speed Pulse Injection. The old metal geared Bachmanns (1970s) may have sounded like grandpa's electric razor, but they were great running locomotives and far superior to Bachmann's 80s offerings, (nylon geared) which ran in a jerky, erratic fashion. Something about the wheel spacings, though, would lead to derailments on switches at high, unprototypical speeds. I replaced the original couplers with shorter versions, which made the engines look more prototypical and not so stretched out when coupled with other engines or freight cars.
The weird looking drive gear is called a shock absorbing gear, so the motor doesn't take to many sudden jolts which can crack the motor housing on the motor.
That’s an SD40-2 if I’ve ever seen one! Great job at getting the right model!
SD40-2s were made in the ‘70s so this was made 10 yrs. after the SD40-2s were made.
My old Bachmann 611 is evidence that you're right about their quality in the 80's...
LOVE IT!! GREAT PROJECT! KEEP THE PROJECTS COMING!
i got three of the sd40-2's back in 1980 they still run today
SMT in getting to be the shop manual of the hobby👍 good job 🚂🚃🚃🇨🇦
Wow that’s some nice detail for the 80’s
Ebay has those Bachman truck covers all the time.
FYI Red wire (+) Engineer side
Black wire (-) Fireman side
great video 🚄👍
wOah! Fun fact: Amtrak’s Piedmont service uses ex-go transit locomotives, and coaches from some circus
I have a Walther’s train it has withstood the test of time without any oil and other stuff and it still runs like a charm gift from my grandfather.
What a beautiful video
Hi, Harrison, I have one of these and swapped the position of the axle that has the traction tyre with the other outer axle so that you have more pickup wheels, currently the rubber tyred wheel has pickups which is kinda useless. Great content as usual!
That's wise. I've seen some get rid of the traction tires all together which has its benefits.
Very good, nice to see the old ones saved and make them a runner again. 👍
I have two old Marx train sets (1 HO gauge & 1 O gauge) from the late 50's early 60's put back in service... I am old! lol
I think I got caught up in the front wheel drive craze of the 80s.😎 The front is a dance floor. It looks like the back may have a dance floor also.
SMT does a great job with all the mechanical and electrical stuff on his loco fixes. That said I do wish he'd use an NMRA
gauge to check the wheels before putting the engine in service. That is model RRing 101 to do. Since there are alot of newbies and 1st timers in his subs, that would be a good habit to promote. Eliminates one problem point. No one likes stuff that derails.
Also suggest he move the cover from the non-powered truck to the powered one as the non-powered one is not dirt sensitive.
If the covers are the same. Then he'll have a coupler on the rear then too. Pull some cars. Wish I had a power truck to send him.
I need to order one of those gauges at some point. I might end up moving the cover if it will work, the question is if those front wheels will stay in place.
If memory serves Bachman manufactured their trains offshore to NEM standsrds,.If so the flanges are slightly different than NMRA standards.
@@SMTMainlinewhere can I buy motor carbon brushes for my tyoc engine
@@robertnielsen2461I have couple of old Tyco engines.Do you where I can get motor brushes. Thank you so much. Rick
I used to have one, thanks for the video.
me too. from like 1988
The SD40-2 looks really cool, but jeez the front 😅
It's an anti-climber but it's poorly tooled.
I would be more inclined to say it was Bachmann's attempt at a very rudimentary SnowPlow/Pilot combo.
@@Don_ECHOguy No, it's just an oversized anticlimber. Not going to plow snow 5 feet off the railhead.
I read that EMD designed the SD-40 frame to accept the next version (like the SD-50?) and also for better traction. It's called the front porch.
@@jim874 huh, I thought they extended the frame so that they could fit all of the axles into that one frame
Can you take the front axle cover off and put it on the rear to cover the drive axles and gears?
"I have a rule with buying junk engines"
That's a rule that seems to get broken a lot.
His rule is "Buy 'em!" 😄
looks like a cushion gear for smooth starting? love the fishing weights lol
That loose metal piece inside the engine is a reverse flux multiplier. There’s a small magneto that has a sensing unit that will allow it to send a signal to the anacromic distributor. The end result is a smoother runner.
Very nice 👌 👍 👏 😀
Interesting loco
Bachmann sells parts on its website. Similar truck covers are around $9.60 (probably plus shipping) US.
I doubt they will still be making spares for something of it's age but I might have a look.
I wonder - would the cover from the front axle fit on the rear to cover the gears and give a working coupler?
7:02 that little black cylinder shaped thing next to the led with stripe on it is the diode, but yes it does same as led ie current can only pass through one way not the other
Hi SMT. I have the very same engine in Santa Fe. It was fancy looking, Kato had a later version of it. Sorry the snap on under side frames are missing, this happens on the majority of BACHMANN engine fleet engines. Fairly good runner I have to work on the remaining one. I wish I had the one similar to the one you repaired in Union Pacific. Meanwhile I'll keep tuning in. 😀
It's too bad that this one is missing parts but as you said it's fairly common to find them this way. Not much you can do although I don't feel too bad about it just as long as it didn't cost much.
i appreciate you showing how to work on this. I give you credit, I don't bother with a pancake motor, I put the shell on an updated chassis.
I tend to agree, the motor isn't high performance but I don't think the shell is worth a better drive to be honest.
@@SMTMainline I inherited a Chessie EMD f9 that was clicking and then stopped running. Instead of fixing the pancake motor, I put the shell on a metal chassis with all wheel drive. It is such a better locomotive now.
HO scale SD40-2 Union Pacific.
Good job in repair to the locomotive.
I don't have SD40-2 in N scale, Bachmann.
Looking at the loco as you have it in the video...the two blue pieces are capacitors - probably there for smoothing out voltage spikes to make the lights look more stable. They aren't using diodes per see. The little black square "thing" on the left and the black round one on the right - those are bridge rectifiers, which will only conduct current in one direction, no matter which direction the loco is traveling. What's weird is that there ARE diodes for current direction as well. Whoever did this - I don't know WHAT they were thinking.
It can be tricky to tell what people were aiming for sometimes with modifications like this.
it's either an anti-backlash gear or an adapter for a 45 rpm record.
This circuit uses a Bridge Rectifier (Round Black thing) to turn AC to DC voltage, then uses Caps + Resistor to make a RC Timer that turns that Transistor (the black square thing) on and off. The Glass Diode that is RED is a Zener Diode, it's job is to keep the voltage below a certain level if it goes above that level say 5V it sends the extra voltage to ground. It looks like it may also be doing a low voltage half rectifier (with the black diodes) to turn the light on till full voltage is applied.
congrats on 25K
Thank you!
I don't think I've ever seen one of those that I remember. Kader in Hong Kong made that for Bachmann, or maybe China, production moved and I'm not sure what year.
The reason it uses bulb lights is you really didn't have white LEDs in the 1980s. Red, yellow and green were it.
Probably the goofiest thing is it uses the same shell mount lugs as an Athearn and looks to copy the one just ahead of the fuel tank, but instead of that being a mount point there's one further ahead of it.
That gear looks like if you stopped the wheels from moving it would let the motor turn a bit more. Like someone else was saying a bit of spring to it.
I've been trying to figure out the full history of Bachmann and Kadar.
As far as I know Kader was originally just the company who made trains in Hong Kong, primarily for Bachmann but at some points for AHM and Lionel HO as well. Bachmann's GP30 was tooled up for Lionel about 1975 and that same shell continues today on the latest Bachmann DCC models.
I believe today Kader owns Bachmann. Wikipedia might have better details.
I have a Santa Fe version of this loco. Motor was toast. Turned into a dummy. Left the electrical pick ups so the lights all still worked. If memory serves me, I cut the truck mounted couplers off and installed body mounted coupler boxes.
tycotrain.tripod.com/ bachmannhoscalelocomotives/ id63.html
Remove the spaces and that is link to info about that loco
I've heard of people repurposing locomotives with poor drives as dummy units. It's certainly a creative way to keep older stock rolling without compromising performance.
Turns out I did not body mount the coupler box. Do you know how to mold and cast replacement parts?
Looks like fishing weights added for more pulling power but the clutch gear would be a problem i would thing with too heavy a train.
I don't see that ever pulling more than 10 cars
I wonder whether Nerf-Cat has an opinion on this one? Great repair and maintenance. I love the UP color scheme
SMT - Like Bob Wozniak said, the black parts with the white or silver bands are diodes. Those diodes direct electricity to the correct light, depending on the polarity of the rails. The glass part with the black band is also a diode; I am guessing it regulates the voltage going to that light circuit. The blue parts are capacitors; they are probably there to remove static produced by the motors. The tan parts with the color bands are resistors. The square part on the left is probably an integrated circuit for the beacon flasher. The black cylinder on the right may be a bridge rectifier.
Thanks for sharing your knowledge on this. I was wondering what those capacitors where there for. I thought that maybe it was part of a "Keep alive" system for the motor but your idea makes much more sense.
@@SMTMainline - You may be right about the capacitors acting as a " keep alive " system; they are charged to track voltage and provide some momentum to prevent stalling on a plastic switch ( or " turn-out ") frog by continuing to energize the motor & keeping the locomotive moving. Power packs with a " momentum switch " use a large-capacity capacitor to discharge & gradually lower the track voltage, slowing down the locomotive.
Bachmann locomotives were too light to pull any sort of train over 7 cars. Adding extra weight helps a lot. The extra motor housing is a good idea if you want to convert the unit to a dual motor set up for extra power. That swirling gear looks like it might help with heat build up and lub spreading I think. I think this model was Bachmann's "space age" model - lol.
It would be interesting to see what kind of performance you would get from a duel motor system, I'd imagine it would be similar to something like an AHM.
Hello SMT Greetings from southern Maine!
That’s a pretty neat engine right there yeah sometimes Like I said bachmann’s quality could be off though unfortunately but they’re pretty nostalgic though. I might find this on Engine at train show or so sometime. It looks pretty interesting.
I had one of those with those gears... I thought it was weird too.
2 things,
1 you are right, the black cylinder with silver stripe around it is a diode, the blue cylinders are capacitors (to probably smooth out the power from non constant contact with the track or motor causing pulsing).
2; if you want to figure something out I'd be happy to 3s print you another side frame for your trucks. Maybe from a few pictures and measurements or if you did "photogrammetry" to get a 3d picture of it.
Would it be possible to 3D-print the part you need, using the one that is already on the unit as a template?
Spiro gears are installed for armature cooling
That loco is really neat I wonder why they made the front and rear decks so long
I read there were two reasons. To spread the trucks for better traction and to use the frame on the next model. The SD-50?
The reason is twofold:
1.) The HT-C truck (motors facing the same direction) is physically longer than the SD truck (one motor reversed) and so more space was necessary.
2.) The SD38-2, SD40-2, and SD45-2 all share the same frame. The SD45-2 has a longer hood to accommodate a 20-cylinder engine.
@@ErickC EXACTLY!
Thx
So do you fix and repair trains.. i have a couple gp50 athearn blue box that have engine and lighting issues.. i need to have them fixed.
Stmtrains Can I ask you something I have a train engine that’s making a tricky noise?
Since this engine has quite a bit of weight could the strange plastic gear made like that to absorb shock?
That seems to be what a lot of other people are saying.
I have this same engine just southern Pacific scheme, it runs great and I love the strobe light, it cant pull a whole lot of cars
Hi there that looks like a torque tension gear to me with those gaps in it the reason for that is to help with torque towards the wheels ext 👍
I have one of these engines and the light turns on but the motor doesn’t turn. I opened it just like you did in this video. I also cleaned all the parts. However when I tried manually turning the gears with the motor in place, the gears nor the motor turned. Does this mean the motor is bad?
No but it might mean something is locking things up or something is out of place.
Those things inside it are fishing weights. The previous owner was probably trying to make it to scale weight. Sometimes model railroad rolling stock isn't at the right scale weight and it is recommended to modify them to be to scale weight. The reasoning is that if you have rolling stock that is to scale weight on either side of cars that aren't to scale weight, the difference in scale weights can pull the cars that are too light off the rails on curves causing a derailment problem, and if you didn't think about the cars scale weight you wouldn't know what the cause could be and you'd keep trying to make changes to the track in a futile attempt to stop the derailments. The NMRA has an article about it, I can't link it so just look for the NMRA website, or google ho scale model weight, the article also has a conversion chart so you can check your rolling stocks scale weight and know how to adjust them accordingly. According to their chart an HO scale rail car should have a 1 oz initial weight with 1/2 oz added for every inch of car, so a 3 inch long car would be 1 oz + 1.5 oz (1/2 oz X 3) for a total scale weight of 2.5 oz. I've never found a conversion chart for locomotives, but it is recommended to add some weights to a scale locomotive if it is having traction problems, the added weight will help the wheels grip the rails better, of course if you overdo it with the weights you could burn out the motor.
Thanks for sharing your knowledge on this. I'd imagine the original owner was just trying to add some extra traction to their model but it's hard to tell sometimes what people are aiming for. In this case the weights don't look great however they don't seem to be causing any issues.
@@SMTMainline You're welcome. Yea they are probably for extra traction, and they don't look great, but hey, they are covered by the shell so they don't need to be pretty, just need to do the job they were installed for. As long as they aren't interfering with the operation of the loco I'd leave them, if it were my project, that many aren't going to be much of an extra drag on the motor.
Hey, SMT! I’m looking for a cheap-ish Tyco locomotive of any type of motive power, and I don’t know which one to get. Can you think of any that you can recommend to me?
First one you see that works, unless it's one of the fantasy line liveries, e.g. Silver Streak, Chattanooga, Comin' Round The Mountain, etc.
Ok, thanks!
Tyco power torques are pretty much all the same drive system wise so it's more a matter of look preference.
@@SMTMainline okay, thanks!
You seem to have put the traction tyre fitted wheelset into a position fitted with pick ups? Wouldn't it run better if first and third wheelsets were swapped?
The spiral GEAR in the motor provides TORQUE relief in case the motor stop instantly the gear will flex and keep from damaging the motor or busting the motors casing, all that torque has to go somewhere when it's stopped all of a sudden!!! (Gear is like a SPRING)
I have worked on one too. I think it’s a cool mechanism
also you put the traction axle on the pickup side so i doubt that axle is picking anything up with the rubber
I believe that gear allows a certain part to move one way but not in the other... maybe like a mechanical diode for AC power?
I have a locomotive that comes through my town to do road switching, it is heritage Burlington northern, it's also a gp40-2
Bachmann would probably faint on the spot if they saw that loco! Compare this one with one of Bachmann's more recent models!
Hey smt, can you do a collection video on your life like locomotives?
You could cast some new detail covers for the rear truck. Micro mark sells the stuff you need. There is lots of videos on the internet on how to do it. That would make for a good video for you to do a how to.
Or 3D print those covers.
SMT also has some steam locomotives are are missing smokebox front covers, so the casting kit would be useful for fabricating replacements.
I will have to look into it.
BTW...that coupler screw on a rear of the loco? If you have a Dremel, you can use a cutting disk and cut that sucker off.
I need that antenna stand
Hi
Yea thats a sd40-2 but the beacon later in the years were changed for ditch lights .and some of sd40-2 were changed for tunnel motors and they were a demand from southern pacific and rio grande and sd40t-2 were made to cool down in sp snow sheds and tunnel. And some sd40t-2 were changed back to sd40-2 and i think some are still in services. But its a cool sd40-2 you got there smt
Interesting history, thanks for sharing.
Nice modelI modernised one of theese with a new sd40-2 from bachman
Are you still missing the truck cover on the rear?
y u no reinstall rear coupler
Can u send me an ho scale freight locomotive 🥺
Have you ever tired resin casting the parts you missing on the back wheels by copying the front wheel covers? I do it with my gundam models and it works fine for me to hold up over time
I would suspect the motor has a rather pulsed power delivery. That weird gear is to absorb the pulses and smooth it out. You'll find this a lot in the rear hub-to-wheel connection on single-cylinder motorcycles. Those strange lead weights are likely 1oz fishing weights.
Doesn't seem like too bad an idea.
I have one I gave up on, couldn't get it running again
My suggestion - swap the truck cover (bogie cap?) from the front bogie to the rear, if it will fit. You will at least have a coupler on the correct end until you can find another truck cover.
Or he could do a proper body mounted coupler on both ends.
That gear is like a clutch.
interesting.
Love your vids keep it up
they put led in it for more weight which translates to more pulling power, it happens all the time and is one of the most b basic and important modifications that can be done to an old locomotive. Lead also isn't very hard to work with, you can put it in a pot and melt it with a blow torch. With enough weight added, a locomotive that would struggle to pull 6 cars can be made to pull 12+
Hey smt I love your channel
A fiberglass pencil? May be useful for cleaning up more than just ho scale motors. Where did you get yours?
ebay
They are super useful. You can find them cheap on Ebay and Amazon.
You might find them listed as spudgers as that is what they used to be. Used for moving wires around. Note I looked for you real quick on ebay and saw a ton of assortments using my tech term.