I finally finished repowering my old Bachmann DD40 with a better mechanism. Now that it's done and working, I thought I'd post a "how to" topic on how I repowered it.
The original 4-wheel-drive mechanism was a poor runner, no matter how much I did to make it better (it does run a little better than before, but still not great). I decided to repower mine with Athearn trucks and a pair of good quality (yet inexpensive ) Mabuchi motors with flywheels.
I had to completely cut out the sections of the frame where the old trucks were mounted, and make separate frames for each truck, kind of like an old Mantua diesel. The motors are mounted on each end of the fuel tank, using flipped over A Line stick on weights, which are glued to the frame. The tape on the bottom of the weights is the same as what A Line sells for motor mounting, so you don't have to worry about the motors coming loose.
I used parts cut off from the Bachmann sideframes and some extra brake cylinders to detail the Athearn trucks. It still doesn't look quite like the DDA40X trucks, but it's close enough to look good. You can also see what the home-made front truck mount looks like in the picture. All the Athearn wheels were replaced with NWSL 40" wheels, which roll quieter, look better, conduct electricity better, and grip the track more.
I had to move some of the parts on the PC board around just enough to clear the flywheel. Some were as easy as bending them out of the way, but the large black cylinder-shaped part had to be partially unsoldered and moved closer to the PC board.
To support the front truck, I had to put whatever I could in the bottom of the cab. The stick-on lead worked well for the large open area, and then I filled the steps with whatever I could find, which was some extra plastic from a model truck.
To make the DD40 look a little more realistic, I made the walkway in the middle of the hood out of some copper sheet and glued it in place, making sure it was properly lined up with the doorways in the shell. It really does make the engine look a lot better.
All assembled! Everything is held together by super glue, so it should hold together fine as long as I'm careful. I filled the front pilot, but the rear pilot was left open so it wouldn't drag cars off the track on curves. Some of the rear coupler box had to be cut off to clear the shell.
Since I used Athearn trucks, it's not a real quiet runner, but that should hopefully improve with some run time. Other than the noise, it's now an excellent runner. The speed control is excellent, it runs smooth at all speeds, it draws less than 0.2 amps running free (which surprised me), and with a weight of, I'm guessing, over 2lb. and 16 wheel drive, it should be one of my strongest pullers. I probably spent between $70 and $80 on everything, and the engine originally cost me only $5 at a train show. Even so, I'm happy with how it turned out.
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good job!
all my old pancake versions were retired long ago, replaced by the spectrum version, but if I run across any more, I'll know how to update them.
Larry
Conductor.
Summerset Ry.
"Stay Alert, Don't get hurt Safety First!"
Thanks everyone for your kind comments.
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.
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.
Working on things so they'll run better is one of the things I like doing in this hobby. Tonight, I just finished making my new AHM Big Boy run fairly smoothly. The boiler mounts had a LOT of slop in them, and it could hardly do anything without wobbling all over the place.
From one tinkerer to another; really kewl Darth! 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 (), 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.
Nelson
Ex-Southern 385 Being Hoisted
SteamFreak wrote: From one tinkerer to another; really kewl Darth! 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 (), 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.
Thanks.
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. 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!
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. 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.
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.
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.
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.
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.
Yes, CA does a great job of gluing the weights (and various body parts ) to the frame or shell.
So what are you planning to do with all of this Union Pacific mega-power, Darth?
GARRY
HEARTLAND DIVISION, CB&Q RR
EVERYWHERE LOST; WE HUSTLE OUR CABOOSE FOR YOU
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.
SteamFreak wrote:Just upload it to YouTube or Photobucket. They automatically compress it into Flash format.
That's pretty cool! 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¤t=BachmannDD40.flv
What, you re-powered it but didn't add a sound decoder?
Tisk tisk tisk.
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.
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.
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.
Darth Santa Fe wrote:Wow, it's been two months now since I posted this. I guess some topics were just meant to live.
Old threads never die...
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.
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. You're right, those motors are pretty silent.
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
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.
Ken
I hate Rust
Wow, I guess some topics were never meant to die! It's good to know people still find it interesting.
grayfox455I 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.
cudakenDarth, 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! 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.
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!
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.
"The true sign of intelligence is not knowledge but imagination."-Albert Einstein
http://gearedsteam.blogspot.com/
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
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!