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How to repower a Bachmann HO DD40X (now with video!)

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Posted by railandsail on Monday, January 17, 2022 9:35 AM

I ran across this subject thread today when I was trying to find out about problems that might be encountered with the 4 axle trucks used on some of these big diesel locos. To my current knowledge there were not a lot (any) other HO model diesels that utilized 4 axle trucks??

Why would I be interested in such?

I'm playing with ideas of adding 'diesel power' to a 'disguised pusher car' to help out my single headed steam engines. In this particular case I am thinking of adding power to the tender of my Bachmann Northern engines that came with long-haul tenders that had two 4-axle trucks

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Posted by Combatmp on Wednesday, April 29, 2020 12:08 PM

Darth the thread is still helpful 12 years later. Although the video doesnt exist anymore. Just picked up an old pancake drive and was kicking around an athearn repower. Even debated using the athearn frame and stretching it. I like your approach for simplicity more than my frame stretch mod thoughts. Thanks for the info even though it is over a decade old

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Posted by Tonatiuh on Saturday, November 20, 2010 11:28 AM

Darth

I will take some photos of work i will try tu upload them ( if someone help me how to upload the photos) Big Smile

Saludos from Mexico City

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Posted by Darth Santa Fe on Friday, November 19, 2010 2:11 PM

I think this thread has returned more than any other I've ever written.

I'm glad my tips could help you! From what you've described, I suspect your chassis design is more sturdy than mine. It should last you a long time!

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Posted by Tonatiuh on Friday, November 19, 2010 1:27 PM

Thanks a Lot Darth!! your  post was so helpful for me to conclude this work of repowering this engine. Years ago I purchased a DD40AX with pancake motor, and a Friend recommended me the exchange of chassis but he did not tell me how, then i just use my imagination to do this work, I used the chasis of DD40 and Motors of Athearn, then I Split and, modified the chassises (2)  and when i tried to begin the electrical work, i saw your article, and then I applied your tips to conclude the repower of this beautiful engine.

Saludos from a UP fan in Mexico City

Esteban Tonatiuh

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Posted by Geared Steam on Thursday, December 17, 2009 10:21 AM

Darth 

Good threads never die, your contributions are appreciated. You've helped me several times and I appreciate it, your one of the "go to" guys on this forum. Bow

"The true sign of intelligence is not knowledge but imagination."-Albert Einstein

http://gearedsteam.blogspot.com/

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Posted by Darth Santa Fe on Thursday, December 17, 2009 9:58 AM

Wow, I guess some topics were never meant to die!Shock It's good to know people still find it interesting.Big Smile

grayfox455
I also am in need of my Athearn DD40 trucks needing rebuilt or replaced. I got some replacements a year ago but lost out just lately. Mine seem to stick at one point in their revolution but I cant seem to see what the problem is. Also would love to some advice on remotoring the buggers with more powerful DCC friendly motors.

Is it sticking in one revolution of the wheels? At may be that there's some flash in the gears, or one of the axles is poorly shaped where it rides in the bearing (which actually happened to me once). Or, one of the axles is badly warped, and every time it turns, it binds with the large gears. The easiest way to find the problem would be to take everything out of the trucks, and then put each axle and gear in one by one until you find the one that's the problem.

If you clip the frame contacts off the Athearn motors, then they'll be DCC friendly (unless you've got the old half-amp Jet 400 motors). But if you really need new motors, check with microlocomotion on eBay. I'd use the Canon EN22 (used by OMI in their recent brass) or 18x37mm coreless (which is a fantastic runner with low current draw). If you need double shafts, than this motor is the same one used by BLI, Rivarossi, and a few others. Or if your DD40 has more than 20mm of room widthwise inside, than a single one of these Pittman motors should do very well.

cudaken
Darth, boy you used a lot of weights!  Your layout looks like it is coming a long as well. To bad you don't live a closer, I sure like to pick your brain on some remoter projects. I know I can do the work, just don't know the In's and outs of it yet.

I did use a lot of weights in that DD40!Big Smile The thing was always so lightweight and weak before, so I wanted to make sure it would be a good, strong puller for if I ever got a layout that needed that kind of power.Big Smile

My layout's actually come along farther since I put that video up (more grass and ballast, more trees, and some Rapido phone poles), but it's still not finished. I actually only live a couple hours north of you, so who knows? Maybe well meet at a train show by some random chance!

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Posted by cudaken on Thursday, December 17, 2009 8:24 AM

 Darth, boy you used a lot of weights! Big Smile Your layout looks like it is coming a long as well. To bad you don't live a closer, I sure like to pick your brain on some remoter projects. I know I can do the work, just don't know the In's and outs of it yet.

    Ken

I hate Rust

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Posted by grayfox455 on Thursday, December 17, 2009 4:20 AM

This thread now has new life put into it TWO YEARS LATER!!!

Check with your local O'Reilly's Auto Parts store for 1/4 oz stick on weights. For $33 you get a whole lot of 'em.

I also am in need of my Athearn DD40 trucks needing rebuilt or replaced. I got some replacements a year ago but lost out just lately. Mine seem to stick at one point in their revolution but I cant seem to see what the problem is. Also would love to some advice on remotoring the buggers with more powerful DCC friendly motors. 

Bob

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Posted by Darth Santa Fe on Wednesday, November 28, 2007 8:50 PM

 SteamFreak wrote:
It sounds very quiet, Darth, even with all of those wheels and gears. The FK-130's are pretty silent.

It's actually kind of loud in person, but still not bad.Smile [:)] You're right, those motors are pretty silent.

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Posted by SteamFreak on Wednesday, November 28, 2007 7:03 PM

 Darth Santa Fe wrote:
Wow, it's been two months now since I posted this. I guess some topics were just meant to live.Big Smile [:D]

Old threads never die... Wink [;)]

It sounds very quiet, Darth, even with all of those wheels and gears. The FK-130's are pretty silent.

Now you just have to doublehead it with your new Big Boy. Big Smile [:D]

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Posted by Darth Santa Fe on Wednesday, November 28, 2007 5:49 PM

 Autobus Prime wrote:
Nicely done. It should be a real brute.  Where did you get your Mabuchi motors?

I got them from a very reliable eBay seller, the K4 Supply Company. Here's the link to his auction: http://cgi.ebay.com/Parts-Small-12V-Motor-for-Model-Train-Mabuchi-FK-130SH_W0QQitemZ190111687954QQihZ009QQcategoryZ484QQcmdZViewItem He's still got about 30 left.

By the way, what modifications did you do to the stock pancake drive?  I am very curious, because the weird layout seems like it would be really unfriendly to modifications.

I switched it to front wheel drive instead of the standard rear wheel drive, added a little weight (not much, because the old motor was too weak for anymore), and made sure everything was very clean and well lubricated. The only thing that could've made it run better was a second power truck and better tires.

Wow, it's been two months now since I posted this. I guess some topics were just meant to live.Big Smile [:D]

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Posted by Autobus Prime on Wednesday, November 28, 2007 5:18 PM

DSF:

Nicely done. It should be a real brute.  Where did you get your Mabuchi motors?  

By the way, what modifications did you do to the stock pancake drive?  I am very curious, because the weird layout seems like it would be really unfriendly to modifications.

 Currently president of: a slowly upgrading trainset fleet o'doom.
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Posted by Hoople on Wednesday, November 28, 2007 4:50 PM

What, you re-powered it but didn't add a sound decoder?

Tisk tisk tisk.

Mark.
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Posted by loathar on Monday, September 24, 2007 6:54 PM
Cool video Darth! I've never seen one of those beasts run. I would expect it to pull about 100 cars.
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Posted by Darth Santa Fe on Monday, September 24, 2007 6:40 PM

 SteamFreak wrote:
Just upload it to YouTube or Photobucket. They automatically compress it into Flash format.

That's pretty cool!Big Smile [:D] Thanks for letting me know about that, or I probably NEVER would have uploaded it!

(edit) Oops, that didn't work. Let's see if this works:
http://s9.photobucket.com/albums/a70/DarthSantaFe/?action=view&current=BachmannDD40.flv

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Posted by SteamFreak on Monday, September 24, 2007 2:27 PM
Just upload it to YouTube or Photobucket. They automatically compress it into Flash format.
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Posted by Darth Santa Fe on Monday, September 24, 2007 9:47 AM

Just thought I'd let you all know I've got a short movie on my computer now, but it's a 50MB mpeg for 1 1/2 minutes of video. I'll try and find a way to size it down before I post it, since it even runs slow on my computer.

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Posted by Heartland Division CB&Q on Saturday, September 22, 2007 6:40 PM
Cheers to you, darth.  i like the conversion. I think i'll show this to my friend who has one of those Bachmann clunkers.

GARRY

HEARTLAND DIVISION, CB&Q RR

EVERYWHERE LOST; WE HUSTLE OUR CABOOSE FOR YOU

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Posted by Anonymous on Friday, September 21, 2007 6:39 PM
Good question. A movie would be great!
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Posted by SteamFreak on Friday, September 21, 2007 4:04 PM
 Darth Santa Fe wrote:

I'll be sure to keep an eye on the lead tape. I've found that if it let's go, super glue does an excellent job of re-sticking it.Big Smile [:D]

Yes, CA does a great job of gluing the weights (and various body parts Shock [:O]) to the frame or shell.

So what are you planning to do with all of this Union Pacific mega-power, Darth?  Mischief [:-,]

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Posted by csmith9474 on Friday, September 21, 2007 12:45 PM
 Darth Santa Fe wrote:

 csmith9474 wrote:
That looks great!! I seem to remember that somebody was making an upgrade/repowering kit for the Bachmann "Centennials". Was that A-Line/PPW? I remember it being a heck of an upgrade kit, with the price to go along with it.

I haven't heard of a DD40 repower kit, but I do know that sometime last year I think? A Line got Bachmann to make a run of undecorated Spectrum DD40s for them. I don't know if they have any left at this point.

That is it then. It was an entire kit you could buy, and I think that it was well over $100.

Smitty
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Posted by Darth Santa Fe on Friday, September 21, 2007 12:22 PM

 csmith9474 wrote:
That looks great!! I seem to remember that somebody was making an upgrade/repowering kit for the Bachmann "Centennials". Was that A-Line/PPW? I remember it being a heck of an upgrade kit, with the price to go along with it.

I haven't heard of a DD40 repower kit, but I do know that sometime last year I think? A Line got Bachmann to make a run of undecorated Spectrum DD40s for them. I don't know if they have any left at this point.

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Posted by Darth Santa Fe on Friday, September 21, 2007 12:19 PM
 SteamFreak wrote:

From one tinkerer to another; really kewl Darth! Cool [8D]Thumbs Up [tup] Where did you finally locate those worm housings? Did you order them from my LHS?

One thing I would caution about is using the stick-on weights to support the shell. I've had that tape let go over time, in spite of degreasing the mounting surfaces beforehand. If you want to stick with tape (Whistling [:-^]), Scotch makes a heavy duty indoor/outdoor mounting tape that's more like the super strong servo tape I put in my RC car, but this can be found at Home Depot. I use it for motor mounting applications.

I second the motion for a video. Smile [:)]

Thanks.Big Smile [:D]

I got the worm housings from a brand-new condition (but pretty old) Athearn F7A I picked up at a train show for $12 last week.Big Smile [:D] Everything in that F7 was in completely un-used condition when I got it, so I'd say I got a pretty good deal on that one. The worms weren't even rounded off like in most of my other Athearns!Big Smile [:D]

I'll be sure to keep an eye on the lead tape. I've found that if it let's go, super glue does an excellent job of re-sticking it.Big Smile [:D] So far, the only time it's ever lost its stick is when I peeled it off of whatever it was stuck to (not an easy task!!).

I'll see if I can figure out how to use the new digital video camera this afternoon. If I do, I'll try posting a video for you all.Big Smile [:D]

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Posted by SteamFreak on Friday, September 21, 2007 11:44 AM

From one tinkerer to another; really kewl Darth! Cool [8D]Thumbs Up [tup] Where did you finally locate those worm housings? Did you order them from my LHS?

One thing I would caution about is using the stick-on weights to support the shell. I've had that tape let go over time, in spite of degreasing the mounting surfaces beforehand. If you want to stick with tape (Whistling [:-^]), Scotch makes a heavy duty indoor/outdoor mounting tape that's more like the super strong servo tape I put in my RC car, but this can be found at Home Depot. I use it for motor mounting applications.

I second the motion for a video. Smile [:)]

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Posted by Cox 47 on Thursday, September 20, 2007 10:17 PM
Congrats! Way to turn a dog into something to be proud of...Ahhh I have a Nscale Gp 38......?Cox 47
ILLinois and Southern...Serving the Coal belt of southern Illinois with a Smile...
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Posted by csmith9474 on Thursday, September 20, 2007 10:09 PM
That looks great!! I seem to remember that somebody was making an upgrade/repowering kit for the Bachmann "Centennials". Was that A-Line/PPW? I remember it being a heck of an upgrade kit, with the price to go along with it.
Smitty
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Posted by Darth Santa Fe on Thursday, September 20, 2007 10:00 PM

Thanks everyone for your kind comments.Big Smile [:D]

One thing I forgot to mention earlier is that the DD40 can only make it around a minimum 22" radius, instead of the 16"? radius the old drive could go around. Of course, most of you would want to run an engine this size on larger curves anyway, so I guess it doesn't matter too much.Big Smile [:D]

 BRAKIE wrote:
Darth,Good job!  Its nice to hear there are those that still like to tinker around improving drives and re-powering less then stellar performers.Thumbs Up [tup]

Working on things so they'll run better is one of the things I like doing in this hobby.Big Smile [:D] Tonight, I just finished making my new AHM Big Boy run fairly smoothly.Big Smile [:D] The boiler mounts had a LOT of slop in them, and it could hardly do anything without wobbling all over the place.

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Posted by Anonymous on Thursday, September 20, 2007 3:54 PM
Great! So maybe you can do that with some of my old locos.......Big Smile [:D]

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