Upgrading Bachmann HO motor?

Edgar Feb 26, 2020

  1. Edgar

    Edgar TrainBoard Member

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    Firstly, I'm still quite new to both model railroading and TrainBoard, please pardon my severe ignorance and I do apologize ahead of time, if I'm posting this in the incorrect location.

    I did my due diligence by first searching around a bit both on this forum and other sites to find a solution. I didn't find anything, but then again, my wife says I couldn't find my keys if they were in the car I was driving.

    I'm about 2 months into the hobby and have my DCC++ system up and running. My Kato SD40-2 runs perfectly, and it's probably at least 10 years old. It uses a flywheel design that stops and starts smoothly and superbly.

    I also have a Bachmann loco that came with my RTR set that someone gifted me this Christmas. It's the Thoroughbred HO set. I started working on this loco and hard wired in a Digitrax decoder and it works fine, but after having experienced the smoothness of the flywheel design in my Kato, I would really like to upgrade my Bachmann. I'm not very familiar yet with all the different types of motors, but the Bachmann has no flywheels, just little tiny cylinders that extend out to the front and rear trucks, via little plastic drive shafts.

    Would it be possible for me to even try to swap out my Bachmann motor assembly with a flywheel motor assembly? I think I would need different drive shafts, but not sure. Would I need new trucks too? Anyone out there ever attempt a motor swap and if so, any advice or guidance would be greatly appreciated!

    Thanks very much for your time!
     
  2. gmorider

    gmorider TrainBoard Member

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    Not my area of expertise. Just keep asking and digging until you are confident enough to move forward. The only bad question is one that is unasked.(y)
     
  3. minesweeper

    minesweeper TrainBoard Member

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    I did one on a lima railcar from the 80s, you do not need new trucks unless you want also to replace them.
    Check the diameter and length of the shafts, you would have something the same size.
     
  4. Edgar

    Edgar TrainBoard Member

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    Thank you Maurizio, I will do those checks.
     
  5. fordy744

    fordy744 TrainBoard Member

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    Welcome firstly.

    Secondly anything is possible, with the right tools and parts. A good question is "is it worthwhile spending the time and money to do it?". The answer to that question will vary from person to person. You can buy decent sized Canon/Sagima/Mashima motors and big brass flywheels. driveshafts can be modified or adapted or replaced entirely. NWSL do UJs and sets to replace drivelines etc. basic tools of screwdrivers, pliers, soldering iron etc.

    Without seeing the actual chassis I suspect some modification to the frame would be required to fit a new motor and flywheels. Milling machines are nice but not essential. A hack saw and vice would be sufficient.

    At the end of the day it would be a learning experience and you will have to solve problems in mounting and adapting etc so will set you well in the hobby.

    When buying locos it's not the age that is important, it is the quality (reflected in the price when new too). Kato and Atlas have the best drives in my opinion. Kato drive Atlas locos from the 70s run better than entry level models nowadays. Also for all Athearn bluebox locos from 70s/80s etc have flywheels, but they have open frame motors so slow speed smoothness isn't as good as others. but newer Athearn Genesis locos have can motors and flywheels.

    Good Luck
     
    gmorider likes this.
  6. Sharky_McSharknose

    Sharky_McSharknose TrainBoard Member

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    Do you have any photos of the mechanism you're working with?
     
  7. Mr. Trainiac

    Mr. Trainiac TrainBoard Member

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    Is this a Bachmann f7? The last Bachmann model I opened up was a GP40. Since you have already done a DCC install, you know what it looks like inside. My old GP40 has no flywheels either. The main problem is how the motor is mounted to the chassis. Mine has a cradle as part of the frame with two rubber washers on each end of the motor that sit in grooves. The hard part will be finding room for a flywheel. As soon as it gets to frame milling, I am usually done. I do not attempt it. What might be easier than a flywheel installation is a conversion from a 3-pole to a 5-pole motor. That will give you a partial upgrade without a ton of work.

    Replacing trucks is out of the question. Each manufacturer has their own design, so you would really only be able to replace Bachmann parts with more Bachmann parts.

    Keep in mind cost too. Buying all these parts (motor, flywheel, the decoder you already purchased) and the effort it takes to do this project may not pay off. If you do not have the tools to mill out a space for a flywheel, you would have to pay a machine shop to do it. The Bachmann model is a starter-set locomotive, while the KATO is a good model with a nice drive train. Look at higher-quality models like Athearn Genesis or Intermountain F units. If the cost of your project is about equal with a new model, it would be easier to just buy a new one.
     
  8. acptulsa

    acptulsa TrainBoard Member

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    You made me go look Bachmann Thoroughbred up. An EMD F-7a locomotive seems to be what you mean. Realistically, the F-7 was near the end of its service life when the SD40-2 was introduced in the early 1970s. Do you want to model the early 1970s? Is that level of realism even important to you? Do you like the little old streamliner?

    The reason I ask is because making certain Bachmann products run is difficult and expensive. Yes, you can get what you need to hop it up from Northwest Short Line (which is what...
    ...stands for) if they've reopened for business. And you can learn a lot about miniature mechanicals and the hobby in general along the way.

    Or you can chuck it in the trash and get any of about ten thousand HO scale diesel models that run right out of the box, some for less than a hundred bucks. And you don't have to worry about those Bachmann gears you don't replace wearing down or splitting when you apply more power.

    I'm not saying, don't tackle it. The dealerships are full of new cars, but hot rodders still build their own. Just make sure you really like that particular EMD F-7 before you invest that much blood, toil, tears and sweat into this marriage.

    Especially since you'll know it's an extra special full custom street machine, but because literally every manufacturer which has built any model locomotives at all since 1949 has built EMD F-2, F-3, F-7, F-9 and/or FTs, no one else will be able to tell.
     
    Last edited: Mar 15, 2020
  9. Mr. Trainiac

    Mr. Trainiac TrainBoard Member

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    I found and opened my Bachmann F7. It came from the Challenger starter set in Union Pacific colors. I’m assuming your model has the same chassis since they are both from the starter sets. There is actually a lot of room in here and may be an easier modification than expected.

    The motor itself is pretty standard but is mounted differently than I was expecting from the GP40. If you take out the plastic cradle, you could install any motor. You may need to design a custom mount, but there is adequate room for almost any 12V motor. The flywheels may be a bit harder. They are limited in diameter by the screw pass-throughs the hold the shell on. The drive shaft is also kind of close to the floor of the chassis. If you did cut it out to allow for a larger flywheel, you would see it from the bottom of the model. Mounting the new motor a bit higher is an easier solution. As long as the universals still connect, you should be fine.

    The more I look at it, the more technically feasible it seems. It is not an impossible project, but the question is still, do you want to do it? If you love the KATO drive of the SD40-2, look into a Stewart F-7. Their drives were designed by KATO, so they run well. They are not super expensive and are a bit better detailed too.
    image.jpg
     
    gjslsffan likes this.
  10. Sharky_McSharknose

    Sharky_McSharknose TrainBoard Member

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  11. Edgar

    Edgar TrainBoard Member

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    I apologize for the delayed reply. I work in IT and we've been scrambling to adjust to all of the covid 19 stuff.

    To Mr. fordy744, thank you for the guidance.

    To Mr. Sharky, I was had taken photos a week or two back and was going to upload them, and now I see a reply which contains my exact loco. Also, thank you for the website!

    To Mr. acptulsa, thank you for the input. I am interested in taking on the project as a way to get a bit more technical and learn more about the mechanical aspects of the motors, and like you stated, it will be a custom street machine. :)

    To Mr. Trainiac!!! Yes that is my chasis and I thought the same thing, that there's plenty of room! I also considered the exposed flywheels underneath but I think I can fabricate something or maybe get something 3d printed (haven't got one of those yet but maybe I have an excuse now). Thank you for opening up your loco and taking the time to post. Appreciate that! I'll see what I can find on the Stewart F7!

    Thanks all and hopefully as work stuff levels out, I'll get more time to tackle. I'll try to post progress from time to time.
     
  12. minesweeper

    minesweeper TrainBoard Member

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    I have one and it runs beautifully

    Inviato dal mio BLN-L21 utilizzando Tapatalk
     

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