@rem5142

A nice step by step of your procedure to dress up the engine would be interesting to follow.

Bernd

Looking forward to this

if you were to break this down into a cost only analysis it probably wouldn't make a whole lot of sense given what is currently available as RTR or even newer variants than the venerable blue box. But I love that fact that despite all the doom and gloom we often read about the demise of hobby and that no one models anymore people still manage to make something old something great again. Please keep us informed of your progress 

Simon

Melbourne Australia  

"if you were to break this

    It's  like restoring or hot rodding old cars, they are not gonna replace the new stuff but some folks still enjoy their ride. I still have my old Athearn engines and if I ever build another HO layout I'd certainly run them....DaveB

Cleaning and stripping the shells

I have been curious if this is more cost effective that getting some nice P2K SW9s. I suspect that this will be more expense. Perhaps I'll try to account for all of the associated costs when I get a better picture of what all is required to get these models to my standards.

I'm still not settled on much of the plan beyond new cabs and see through grills (more for sound than appearance). 

Lets focus on getting the shells clean and the mechanisms working before I start delving into changes to both.  

I had to clean the the shells just to see how much damage they had. This shell had the cab and all of the handrails crudely glued.  

So I soaked them in warm water with dish soap. 

An old tooth brush cleaned sticky grime off very well leaving the paint exposed.  

Then it was time for the paint stripper, 91% isopropyl alcohol, which works for most factory paint.  

I like to soak mine in a gallon freezer bag, I find that it requires the least amount of alcohol and can change size to accommodate most shells.  However, the cheap bags don't hold alcohol well. After 2 or more days, the alcohol will start leaking from one of the seams. A small plastic tote keeps the mess down and keeps the soaking shell safe. 

Add the alcohol until it covers the shell while the bag is being held upright.

Squeeze the air out of the bag and wrap it up so the alcohol is in contact with as much of the paint as possible. 

I learned this trick from Alton Brown. It's just like marinating salmon, except on a longer time scale, and not good eats. Flip it once or twice a day and let it soak.  

Some paint comes off after a few hours, some has to soak for days. Anything applied to the old paint (dullcote, weathering washes, ect) can effect how easily it comes off. Even different production runs from the same manufacturer can strip differently.

These are both in factory PRR paint with the same yellow and silver paint applied but one shell cleaned up much easier than the other. Two days versus the better part of a week, and that shell still wasn't clean enough to kit bash with. Later, I'll cover a second wash that really gets everything clean. 

Gently rub the paint through the bag, when it smears off it's time to drain off the alcohol and start scrubbing the paint with a toothbrush. I keep the alcohol and reuse it.   

Closing the bag up around the brush handle will keep this from getting too messy. Keep cleaning the brush in the alcohol at the bottom of the bag helps wash the plastic off. Periodically wash the shell off with alcohol or water to get a good look at tough spots and corners like step wells.

A trusty dental pick works wonders on thick paint. If the paint doesn't scrape off, lightly scratch the surface to open the paint up to the solvent.

Alcohol can also loosen up glued on parts as the glue or the paint beneath it is dissolved. After a day I was able to pull most of the handrails out with a pair of small hemostats and a glued on cab was freed from the shell.

At this point you should have plastic that is clean sans some seemingly burnt on crud that really doesn't want to let go. It clings on to any nooks and crannies it can.

A second bath in purple degreaser gets all but a few bits of paint off. For petroleum based paints like Floquil, skip the alcohol and go straight to super clean.

I find that super clean eats though the bags much quicker than alcohol so I soak it a hard plastic container. It also might attack some plastic so keep an eye on it. 

For similar reasons, I wear nitrile gloves when I handle purple degreaser.

 1:1 degreaser to water works well. Again, soak, move to a bag, scrub with a tooth brush and scratch with a pick. I don't worry so much about cleaning parts of the shell that I know I will later cut or file off.

Cleaning both shells took almost 2 weeks. At first I only soaked the tough shell but once I saw how clean it came out of the super clean, I was eager to get the easier shell just as clean.

Next post, I'll clean and tune the Athearn drives.

Plastic Bag Trick

I like that freezer bag trick. Looks like you would use less alcohol too. Neat.

Bernd

Sometimes the cost is priceless

Cleaning The Motor

I wanted to write a how to blog on a blue box Athearn because they are so prevalent and a very good engine for someone new to the hobby. Old Athearns are common and inexpensive at train shows, hobby shops and ebay.

They aren't the best runners in the world but they can be tuned to run smoothly. Many people have engines that need dcc decoders added. If you have to take the drive apart in order to add a decoder, you might as well lube the motor and clean the gears.

This is possible using common tools. A soldiering iron and a Dremmel tool are the biggest tools needed and they are two of the most useful tools you'll ever own. Small screw drivers and a dull exacto knife are excellent for prying the trucks apart; a good pair or two of tweezers are priceless. 

If keeping the costs below that of a rtr model isn't a of concern to you, Mashima can motors and NWSL nickel silver wheels are a solid upgrade. The Mashima motors are arguably as smooth or smoother than anything else, it all comes down to well conditioned gears.

Of the two switchers, one drive is clean and running nicely with the stock wiring and the other is missing a worm gear and doesn't work on track power. The nicer drive will get its motor tuned after I work on its gears. The other engine needs to work well on track power before I do anything else to it.   

This is definitely the worst drive I've ever tried to fix up. I'm not even sure if it will work acceptably well once I clean and lube it. But it's worth a shot. The motor is covered in grime but spins freely so it will need to be taken apart and cleaned. Luckily one of the hobby shops near me has a stock of replacement parts so I found another worm gear. Parts are very easy to find for these drives. 

To get the motor free from the frame, remove the silver metal clip from the top the motor that connects it to the trucks. Then gently work the motor until the white rubber motor mounts slip out of the frame. Some times poking the mount pegs with a dull point is needed to free the motor. The linkages between the motor and the gear towers should pull right off. The trucks on these switchers are held in by tabs. These trucks will make it out of the frame without removing the worm housing. 

I used a 9v battery and some wire to test the motor. It spins but it's rough. Everything appears to be in good shape, just covered in grime. The copper windings on the armature are not shorted or worn. If the armature is bad, the motor isn't worth saving. 

All Athearn motors are pretty much the same. They only differ in length and flywheels. The long metal clip can go, it's not necessary to keep it since the motor will get wires soldiered on for a decoder. The motor mounts may or may not slide off easily. They don't always age well and can crack or warp so make sure they are in good shape. 

Pull the flywheels off by twisting them until one starts to slide off. To get the other off, hold the drive shaft with a pair of plies. Be careful not to mar or bend the shaft. The brass clips hold the black plastic ends and magnet can together. Pry the clips off but be sure not to lose the spring and carbon brush underneath. 

It looks like rust from the steel long clip has made its way into the motor. This is probably half the reason it runs so poorly.

The plastic ends pull right off, this will expose the magnets and armature. Take note as to how the magnets are arranged in the can. 

Also check for 2 pairs of thrust washers on the drive shaft. They rusted quite a bit on this motor so they will either be cleaned and polished or replaced. Keep small parts like the washers, springs and brushes safe, put them in a small container where they won't get lost. I like to put parts in old film canisters or prescription bottles.

​Needle tipped tweezers make working with tiny parts and springs bareable. 

I cleaned the motor parts with dish soap and a toothbrush. Everything cleaned right up. The magnets weren't dirty so I left them on the work bench. 

Polishing the commutator can make a motor much smoother. The drive shaft will fit in a Dremmel chuck. Then a small piece of fine (600 or higher) sandpaper will take off any burs or oxidation as it's held gently against the spinning copper contacts. I have a fiber abrasive buffing wheel and it really gets the copper shinny. Just watch magnet wires that are soldered to each pad.

I used a c-74, a backwards clothespin, to hold the armature. Then I took it out side and cleaned it really well with a can of contact cleaner. It gets all the dust off the windings and commutator with out damaging the enamel insulation on the wires.   

The thrust washers cleaned up with a qtip and rubbing alcohol. They aren't flat. They are a little convex, these convex sides oppose each other on the drive shaft when they are put back on. 

Interesting fact, the holes on the bottom of an Athearn motor are the perfect size to be tapped for a 2-56 screw. While the motor is apart, I like to tap them in case I decide to rework the frame air tanks and fuel tank to replace the poorly detailed SW7 undercarriage.  

I've previously used Athearn motors and trucks on frames scratch built from K&S brass stock. These drives are adaptable if you are creative. 

Clean the motor bearings with alcohol and a qtip. These bearings sometimes go bad, when that happens, the motor, or at least that end, will need to be replaced. 

Use a light, plastic safe oil. I picked up this stuff from an rc and slot car shop. The proprietor says he bottles it himself so I assume that it is some kind of synthetic motor oil. Put one thrust washer on and then put a tiny amount of oil on the shaft and then put even less on the washer. Put on the second washer. 

Getting everything back together is tricky. One magnet refused to stay in the can, so a I used a little drop of ca glue to hold it in place. The motor ends held it until the glue cured, assuring me it was in the right spot.

The flywheels need to be pressed on. Put the tighter of the two on first, that way the second wheel will have less friction holding it back than the attached wheel and it will slide on easily.  

To reduce drag on the commutator, cut the springs a little shorter. This improves slow speed performance. If you cut one too short, just stretch it a little.

I cleaned up the clips with my Dremmel and a wire brush. Normally I would bend the prongs down on the bottom clip to prevent it from contacting the frame, however, I will wait to isolate the motor from the frame. I still want to use dc power to break in the gears. 

Once the brushes and springs were put in and the clips reattached, I used my Dremmel to spin the motor fast, but not so fast as to make the motor vibrate. A very small bit of CRC 2-26 on the commutator prevents it from oxidation.  The spinning will spread it out. Too much will make the 2-26 sticky as it collects dust from the brushes. The graphite rubs off onto the copper and works as a dry lubricant. Spin the motor one direction for a minute or two and then turn it around and spin it in the reverse direction. This will fit the brushes to the commutator. 

The motor turns nicely hooked up to 9v. This motor is ten minutes and a soldering iron away from being ready to connect to a dcc chip but I want to clean the trucks up and run them with a fine abrasive to polish the plastic gears. This will quiet the Athearn growl. I don't want to go through the trouble of soldering on a chip if its not the final decoder for this locomotive. 

I may make some heavy changes to the stock frame so that it better represent an SW9 under carriage. I could probably find air tanks, leaving the fuel tank and piping to be scratch built. It might make for an interesting build but it may also not be feasible. I haven't decided yet, it needs more thought.    

Almost

It almost looks like it's supposed to now (now that the yellow paint is gone). I saw a lot of these growing up as a kid in Southwest New Jersey. Most of the time in a three unit consists, cab end first.

Charlie

Rebuilding

Wow, what a nice post this is!

Looking forward to see more.

Sideframes...

Thank you very much for posting this info and pictures.  I see some things that I can definitely do/use.

I purchased a used Athearn SW/7 Cow at a local club sale that someone had started to modify for DCC and had given up on.  Have got it back running but it was missing the sideframes when I bought it.  Our local go to Train Shop had shells and some misc parts BUT no sideframes.  The parts sheet that was with the loco shows a sideframe set Athearn part # 41021.  Do you (or anyone else) know where I can get these or is it better just to wait & hope I can find another used loco (with sideframes) at a sale that I can use for parts?  There seems to be another type of truck on my SW/1500 cow that has the wheel/axle bearings in the sideframes rather than inboard between the wheel and the axle gear.  The local Train Shop had the axle gears (plastic) and I already have replaced one that was cracked (I understand this is a common problem).  Would this 2nd type of truck fit into my frame?  It looks like the part numbers are the same?  (41023 rear & 41024 front)

Noticed in one of your photos that you mentioned tapping the bottom of the motor for 2-56 screws.  Do you do this for the 4 holes?  Does this allow you to not use the white motor mount pad?

John

Sideframes and Motor Mounts

Athearn makes 3 different kinds of sideframes for the switcher truck. The AAR truck with journal covers (Bottom) is the most common, it comes on the SW7/9. The second kind is the Flexcoil sideframes (Top) that are common on SW1500 and later EMD switchers.  

Athearn also makes a second variant of the AAR truck with exposed roller bearings. I found 2 full sets of the AAR journal cover side frames at a hobby shop and picked them up a few weeks ago before I found out about the AAR roller bearing. Conrail converted most of their SW7s, SW9s and SW1500s to the roller bearing trucks in the early 80's. A few ex-Reading SW1500s (not to be confused with the ex-Reading MP15DC's) kept their flexcoil trucks but they were rare. The bluebox SW7/9 and the SW1500 share the same trucks. Somebody correct me if I'm wrong but I think the new rtr 1500's also have the same truck. So, the sideframes are all interchangeable. If there is a difference between the front and rear sideframes, I haven't found it yet. Switcher side frames appear on ebay quite often and are available on other websites and at train shows. They usually go for less than $10 for a set of 4.    

I tapped all 4 holes for a 2-56 screw. On the SW7 frame as well as the SW1500 frame, the hole for the mounting peg interferes with drilling holes to screw mount the motor. The screws are too close/the hole is too large. I may cut the fuel tank portion of the frame off and fabricate a new tank out of brass. Then I'll use screws to attach the motor to the new frame assembly.

I took a look at a blue box GP38-2 frame and motor I had on hand and it appears that with some styrene and washers, the motor can be screw mounted to the frame. This probably applies to the other blue box GP's and SD's.   

Nice work

I appreciate the fact that you are modeling.  Like you, I still enjoy working to turn a now dated model into something special.  Ya we could just buy a newer model with better detail and more accurate castings,  but I don't see this as modeling but collecting. 

Attached [I hope] is a shot of an Athearn BB SW that I tricked into an SP SW1200.  I still need to do the roller-bearing trucks. 

Pat

Great thread

im really enjoying this thread, and although my initial message may not have implied it I think it's great what you are showing can be done with the venerable BB loco.

unless I missed it what are you using for the abrasive to prepare the gears?

Simon

Unpowered sideframes

Took apart an Athearn unpowered/dummy loco I picked up out of the one dollar each box at our last train club open house in the hope of getting some useable sideframes.  No joy here!  So will have to keep looking.  Not complaining since the shell & frame are easily worth more than the dollar I paid.   Here (I hope) are picture(s) of these sideframes.  It is my 1st time posting images on this site so hope all goes well here.

First photo is the unpowered loco with one truck taken apart & other truck still in the frame (41018)

Unpowered sideframes 2

Here is the 2nd photo showing the SW7 loco I want to put the sideframes on.  Measured the eyelet hole on the loco and it is about 0.1" - a #39 drill bit goes in & a #38 does not.  The sideframe post in the photo that would have to go into the loco eyelet hole measured 0.132" (no way that will happen).  Also these sideframes have two smaller posts where the loco trucks have black plastic protruding posts (one side needs posts & other side needs holes).  So these unpowered truck sideframes are completely different in their mounting (back) side although on the front side they look just fine.  So will look at powered trucks for suitable sideframes.

Looking at my SW1500 again, it looks like these sideframes might fit there although I need to take apart a truck from the SW1500 to be sure.  Would need to replace the black plastic wheel/axle bearings with a bronze ones for powered usage.

Re: Unpowered side frames

Are those sideframes metal? 

I've seen an sw7 with metal sideframes, from what I remember, it was an older model. I took the motor out to put a dcc decoder in it but I didnt take the engine apart too much as it ran well on dc.

I suppose there are 2 phases of switcher trucks.

You may be able to put the gears in the gear towers that fit the sideframes. 

AAR sideframes with exposed roller-bearing caps

Dear MRHers,

Seem to recall an old Dave Bontrager article in MR about kitbashing Ath sideframes (DRGW SD50s?) to add exposed roller-bearing caps salvaged from RB freight trucks? A similar kitbash to the Ath SW AAR sideframes might be do-able, assuming one could source the RB caps...

EDIT Tichy says https://www.tichytraingroup.com/Shop/tabid/91/c/trucks/p/3080/Default.aspx 

Happy Modelling,
Aim to Improve,
Prof Klyzlr

sideframes

The older metal sideframes are a completely different truck than the newer plastic sideframes. The plastic ones have more detail but even the wheels are different with the bearings being inside instead of in the metal sideframes. These should be easy to find at swap meets or ebay if you look carefully at the type of drive. I may have spares if you determine which type of truck you would like to use. I am allmost certain I have the newer plastic sideframes.      Mark

Blue box Athearns

were the mainstay for most layouts for decades. While they don't measure up to the details of todays engines, they are virtually bullet proof. And as this thread will attest, easy to work on! In the late 90s I found new homes for all my BB diesels and moved up to P2K and Kato offerings. I have a neighbor who rebuilds BBs with Ernst gearing. He has a huge DC layout running 60 to 70 cars trains with 3 SDs or GPs on the point.

I swear, working on locomotives.................

.............can be a hobby in itself.  I am building a layout (O scale) but I always seem to drift back to working on locomotives, mostly brass because I love the challenge and it's fun making a silk purse out of a sow's ear!  The OP's very illuminating post reinforced all I go through to get these to look and run well with sound, led lighting and in my case, new motors as most in the older brass were junk, not worth trying to resurrect.  Some needed new gears as they were cracked.  Most steam needed torque arms installed and a lot of diesels needed new drive shafts.  Unfortunately it takes a lot of layout building away, but hey, it's all fun, right.

REM5142, thanks for sharing.

3 of my reworks below.  The 8 wheeled chassis is for a 2-8-2T Toby Minaret shows the new Faulhaber motor and torque arm testing for noise and slow speed.  The 2-4-4-2 was stripped, modified to oilburning, new motor and drive, QSI stereo sound (smokebox and tender speakers) and painted.  The Witcomb was re-motored, QSI stereo sound (2 speakes, one for each engine) and painted.

Peter

Dismantling the Trucks

Thank you for the support. I know I'm not the only one who is still heavily kit bashing locomotives. I've been inspired by a lot of other peoples photos, writings and videos. When I got into the hobby, I learned a lot by reading forums and blogs. I still learn a lot from seeing what other modelers have done. 

The trucks were packed with entirely too much grease and the metal pieces were a bit rusty. So, it needed to be cleaned to get reliable electrical contact before I could assess how smooth the drive was. 

The trucks are held together by the worm gear housing, a clip on the bottom and a small clip on the top. The clips can be pried off with a dull exacto knife or small screw driver.

I laid everything out on a paper towel, keeping the gears oriented to each other the way they were inside the tower. I figure keeping the gears in the same order will take advantage of existing wear. Each gear has a smooth side and a side with some remnants from the casting process so it isn't that hard to tell which way they face after they are cleaned.

At this stage, I wasn't worried about getting all the grease off, just the vast majority of it off so to scrub everything, I used a toothbrush and some dish soap. 

For rust and grime on metal, a dremmel with a wire brush works wonders. The receiving slots for the brass journals really need to be cleaned to promote good electrical contact. With some finesse, you can get the bristles in there without grabbing the whole part. The top plate where the frame rests also needs to be polished. The electrical towers will probably get clipped but I shined them up so soldering will be easier.

Wire brushes often shoot tiny pieces of sharp wire as they spin so find somewhere safe to do this and wear safety glasses.  

Athearn used sintered iron for the BB wheels which gives the wheels good adhesion to the rail but collects grime and rusts. Ideally I would replace these wheels with nickel silver (Cu Ni Zn) but that's not in the budget at this time so I'll use a drill to spin the wheel while the dremmel scrubs the tread with a wire brush. 

That dark crud is fairly thick and needs to come off. The shaft immediately behind the wheel is an electrical contact point so get that nice and clean too. 

The wire brush not only cleans but also polishes the wheel. I used 2 brushes, a nice rough steel brush and a softer brass brush. 

Brass is rather soft so by spinning it very fast and in opposing rotation to the wheel, the brass will rub off onto the sintered iron due to friction. It isn't as smooth as a quality nickel silver wheel but the brass fills the porous surface enough to give the wheel tread a golden color. This layer of brass will wear off with use showing the iron again so this process improves the wheel but it will still need to be cleaned from time to time. 

I suppose a nickel silver brush would be a bit better.  

I reassembled the axles only to find that the center gears were cracked. This is vary common in these gears. It's visible in the picture below. The gears split where there is a square gap in the shaft. The replacement gears from Athearn don't have the faulty slot in their molds. 

Split or warped axle gears can cause an engine to have a bit of a wobble as moves slowly down the track. If they break badly enough, they will jam.

Proper gauge is a necessity so use an NMRA Gage to check them.

Look for any burrs in the plastic before putting everything back together.  

Once the frame is cleaned up I'll wire the motor up for dc and break in the gears. I haven't been able to find Pearl Drops locally and I don't really want to order a large bottle from the UK. I'm still looking for a suitable abrasive. Some people have suggested tooth paste but I'd like to find one that is extra gritty. I have a stick of buffing compound that might work if I shave some off and soften it with water or alcohol. If the loco was running in the first place, I would only clean the gear towers once. But this was an unusually dirty engine.

Polishing Ath sintered iron wheels

Dear MRHers,

Just a by-the-by, Polishing Athearn sintered iron wheels to a smooth electrically-superior surface is not difficult, esp if you follow the directions posted here onlist some time ago...

http://model-railroad-hobbyist.com/node/16333

Better and cleaner results than Dremel-brushing, and arguably less harsh/damaging on the wheel surfaces...

Happy Modelling,
Aim to Improve,
Prof Klyzlr

SW-8

These posts have been enjoyable to follow and have inspired me to create a dynamic brake equipped Lehigh Valley SW-8 "Pup" from the Athearn SW-7 model.  Still have a fair amount of effort to complete, but the little monster is starting to take shape.  

Fantastic Thread!!

This is one of the most helpful threads for me I've seen yet. Everything else I've seen on tuning up blue box locos has been an overall of related more to the electrical side. I will definitely be using this guide for a metal flywheel sw7 and some F-units, all blue-box locomotives. Will definitely be referring to this thread as I go!!