Building a locomotive from the frame up using A-Line


ICG/SOU

ICG/SOU

HO & O (3-rail) trainman
I'm looking at repowering an older (1980s) SW7 Athearn by buying a new frame (the Mashima motor I have doesn't fit without milling the frame), power trucks, and drive line. I was thinking after looking around on the site of building up a couple of SD40s or a GP38-2 with one of the powered chassis, but they are out of some of the powered chassis and just have parts.

How easily is this done? Did you like the results?

I saw they had some Front Range GP7/GP9 parts, and wondered if anyone built up one of these into a working locomotive. If so, how did it work out?

I'm asking because I'm looking for a project, and even though I can buy most anything off the shelf, and perhaps with better details, I wanted have a crack at building one.

Thanks in advance.
 
I have a front range GP9, though I hope to replace the unit with a new Genesis version when they come out.

Decent, well running considering it has a donor motor from a P2K SD60, Athearn trucks...
 
Josh, they've arrived at Athearn according to their facebook page. They said that the engines look amazing. I'm not sure if they're pre-pro models or the main release, but they are painted.
 
I'm excited. I got my PPW order yesterday, and now have a new frame, motor, and power trucks for my 1980 made Athearn SW7. I've got to mount the motor and hook up everything, and then get the shell back to start work on the LEDs and Tsunami install. This loco is my very first one, and has a lot of sentimental value.

I also did order a new motor for my 1987 Athearn GP38-2. I can't wait to work on that one either.
 
The last time I built a locomotive from the ground up was probably a Hobbytown Alco RS3 that was cast in heavy metal and had an open frame motor. The project went slowly, with a fair amount of flash to remove from all the metal casting, but the finished locomotive ran smoothly and was good for about 25 cars up a 2% grade.

More recently, there was a CF7 project using Athearn, Railpower Products, and Smokey Valley parts, and a heavily reworked Walthers GP15-1. It's fun having a locomotive unlike any other out there, that you built yourself.
 
I took the frame to the shop to mill down the cast coupler pockets. I drilled and tapped the frame for the new Kadee pockets for #14s. Frame is now painted black.

Now I have to do some research for the details.
 
What are Kadee #14s? I remember seeing them at the LHS, but Kadee's current #14 is a bulk pack of #148s.
 
I've found that the prototype SW7s I have found online have different end rails, and some sort of hump on the deck just aft of the step (which I have to put on). The end rails that come with the SW7 I have look more like what you'd see on a SW9.
 
So I got the motor in it, the new drive lines, and lightly lubed the gears, the motor bearings, and set it on the track and it sounds like poopoo. It has a growl to it (more than normal) and sounds like the wheel flanges are hitting the molded spikes, but they're not, because it is Code 100 track and the wheelsets are new NWSL.
 
A-Line modified Athearn SW7 frame with the lead cradle
Mashima SW motor with tapered flywheels and the motor is attached via Scotch brand foam double stick tape. Flywheels attached to motor via Blue Loctite (removable 242).
New A-Line Universal drive set set up like the Athearn was.
New Athearn SW7 power trucks with NWSL wheelsets. Worm gear and all gears (2 axle, 1 idler) lubed with NG Jel gear lubricant.

I've got rollers at work that I will see about just running the loco to break it in. Will post this afternoon if the sound goes away.

The knocking noise reminds me of a split gear sound, but they shouldn't be, since I checked them all when I put the NWSL wheelsets in.

I did notice that the shaft on the worm gear on the rear truck didn't perfectly line up with the shaft on the motor when I test fit everything.
 
Check the gear alignment and also check the gears for burrs or flash.

The double stick tape doesn't do much to dampen the vibrations from the motor. If I were you, I'd screw it down with an Athearn Mashima motor mount (the ones they use on the SW and MP series) or secure the motor with silicone or something.
 
ICG/SOU said:
...
Mashima SW motor with tapered flywheels and the motor is attached via Scotch brand foam double stick tape...
Click to expand...

diburning said:
Check the gear alignment and also check the gears for burrs or flash.

The double stick tape doesn't do much to dampen the vibrations from the motor. If I were you, I'd screw it down with an Athearn Mashima motor mount (the ones they use on the SW and MP series) or secure the motor with silicone or something.
Click to expand...

I have to agree with Eric on this. I stopped using double foam tape for mounting anything heavier than a decoder.

I personally prefer hot glue caulk. Its a type of latex "caulk" designed for hot glue guns, but its getting hard to find. I also use plain hot glue. I use a heavy duty glue gun that turns the glue almost liquid, and the glue bond is very hard to break, but it also gives you some time to adjust the positioning before it hardens.
 
I got it on the rollers today, and lubed it up some more. I seems to run a little better, and the growl noise is gone. There is a little vibration in the drive line, so I may need to tinker with it some more tonight.

I'll also do something about the attachment method. Would latex adhesive caulk work? I've heard of some folks using silicone, but the Devcon stuff we have at the shop for speaker enclosures can be peeled away easily with little effort.
 
Finally got back to it today. I removed the sticky tape and replaced it with silicone adhesive (like you use in a fish tank). I also took a little more time adjusting the drive line components, as it seems it is easy to have them bind the motor. It sounds and runs better now (no noises).

I'm going to do the other repower kit in my Athearn GP38-2 tonight, using the Athearn drive if it fits the first time.

I'd like to get both these running well, because there are other locomotives I may want to work on (older Atlas F7A) as well as build up a GP35 and GP30 (that I can't get right now with the right features).
 
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