Tenshodo Brass SD24 rebuild

Tenshodo SD24 Total Rebuild and Repower

I've been working on this old brass Tenshodo SD24 for a couple of years on and off.  My goal is to make it a decent running locomotive.

**UPDATE JUNE 2020**  This project is complete and turned out awesome check my blog entry from May and June 2020

I selected a high torque rare earth magnet motor with a 2mm shaft.  This motor runs around $6 each.  These types of motors are far superior to anything else out there.  They are very good on the low end, but at 24v, you never reach the top end so the locomotive may seem a bit slow.  If you run trains at low speeds, this is the type of motor you want.  The torque is very high, much more than you are probably used to.

I made the motor mount on the 3D printer just the right height so the motor shaft is aligned with the drive shaft on the gear tower.

Here's where the problem is located:  these locomotives used a 2mm rubber hose to connect their 2.3mm shafts to the old open frame motor.  I could save this hose and with a drop of glue make it work probably ok.  The hose takes away just a bit of freedom of sideways movement, and that little bit almost certainly adds up to frequent derailments on most track, unless you have huge radius and large turnouts.

Let's table the hose for now and move to more serious problems.

The motor shaft connects to a hose that connects to a drive shaft that connects to a bakelite gear on a gear tower that connects to another bakelite gear that connects to another bakelite gear that connects to a worm gear on a shaft connected to another worm gear connected to another drive shaft that connects to 2 more worms.  Each worm connects to an axle.  That's 3 bakelites, 4 worms, 5 total shafts.

The trouble starts with mating a bakelite gear to a metal worm.  Once worn a little, lots of binding will happen.

No I'm going to replace anything with another drive system.  In this shop, things get fixed, so let's figure out how to solve the problem.

Getting new hose is easy, but perhaps we can make couplings.  Gears are riveted on, but not impossible to replace and we have plenty of those around.

Fabricating a new gear tower is totally possible using aluminum and may be the way to go, plus I really want to make something like that anyways.....

This project has been given new life - I'm going to paint it by hand with a paint brush and it will be incredible.  Check May 2020 for a new entry.

Dual Motor Tyco C630 or SD24 total build and DCC prep

Dual Motor Tyco C630 or SD24 total build and DCC prep

Preparing Tyco Power Torque Locomotives to use 2 motors

Quite a while back I scored a Dual Motor Golden Eagle Super 630 from ebay.

Today I'm going to rebuild it and get it ready to accept a DCC controller.

Some of the considerations are:

1. Total rewiring and adding a small PC board where the DCC decoder will go.
2.  Making sure the motors are not fighting each and travel in the correct direction.
3.  All new interior wires.

Power Torques are very easy to rebuild.  They are far more robust and powerful than most people give credit to them.  They are often derided as being terrible motors, but the reality is quite different.

Wiring is quite simple, so this project was a total success.  It turns out that 2 motors on a Tyco are way better than just one.

Wheel weathering jig for locomotives

Make a simple wheel painting jig

 Take a piece of cardboard and poke a wheel into it trace it with a pencil and cut it out with your knife. Leave strip down the center open.

 Under the center you will place a leg to hold it up.

Wire Model Railroad Buildings with LED lighting

Wire Model Railroad Buildings with LED lighting

Part 1
Planning with pencil and paper

Step 1  State your Objective (your intent)

"My Intent is to have a cool lighting effect inside my building with LED lighting."

Step 2  List Specific Requirements

"LED Lighting"

Step 3  List the elements that are implied by the requirements

"a bridge rectifier and 1k resistor are necessary to LED lighting"
"an additional feature is that this method can use either AC or DC power"
"flexible wire of a gauge 26-30 AWG would be best for this porject"
"hot glue would be best for securing wires in place"

Step 4  Draw a simple diagram to show the plan

"a simple drawing on graph paper, not to any scale, but showing the approximate locations and directions of the elements"

Step 5  Gather the materials to include tools and support tools (tape, glue, rags)

Step 6  Prepare materials (such as tinning the wires and components)

Step 7  Do the construction

Make a locomotive fuel tank out of bondo

Make a locomotive fuel tank out of bondo

Sometimes you need a larger fuel tank, or in the case of the Athearn C44-9W I got for parts, there was no fuel tank at all so I had to build it from scratch.

Bondo is a product that is easier to use than you would expect.  Take a piece of card board from an old box and put some of the gray bondo in a glob with a plastic knife.  Then put about a cap full of the red hardener next to it and mix the 2 together.  It will turn pink.

You now have 3-5 minutes to glob it where you need it.  I use tape barriers most of the time, but be warned that too much barrier and you can't get the bondo to go where you want it.

As soon as it starts to get a bit sandy looking when you mix it up on you card board that means time is up for spreading it.

Now you have 5-10 minutes where you can take a flat blade x-acto knife and trim it.  You sculpt it as best you can carefully shaving it down.

At about 30 minutes in you can go to the disc sander and shape it like wood.  Sometimes you wait a bit longer, but rarely do you need to wait an hour.

You can get it very smooth if you want using finer and finer grades of sand paper.  Once you're done, you can paint it.  I don't always use primer, but primer can be used to make the surface even smoother.

How to clean HO Scale Wheels

How to clean HO Scale Wheels on Model Trains

There are a lot of methods to do this.  My experience shows that using metal polish is the best way whenever possible.

For brass, use Brasso, Simi-Chrome or Flitz.

For all others, you can use those three and Noxon is also very good.  I don't use Noxon for brass because I have Brasso, but it will work on brass.

The results are excellent.

I put the polish in a glob on a heavy duty micro fiber cleaning rag and just rub the wheels until clean, works really fast.  After that I use a tooth brush, dish soap and COLD water.

It is totally possible to put wheels in the drill press and do this, but you need to know how to get them back into gauge after you do that using the Tacky glue method I showed in the SDP40 rebuild video.  Once wheels are removed from their axles they tend to go out of gauge quite often.

There is another way to use the metal polish and that is to put it on the cloth wheel of a flex shaft moto-tool that has a slow speed and then put it in a bench vise.  This works very well on wheels that don't come off their axles - this is a future video.

Athearn C44-9W Northwest Short Line Motor Installation

Athearn C44-9W Northwest Short Line Motor Installation

The C44-9W project continues.... I understand why I got this locomotive for very cheap.  This project was abandoned due to a lot of technical problems.  The previous owner almost got it to work, but several faults cropped up making this a very frustrating project.

The drive couplings all have at least 1 pin sheared off.  This was a likely attempt to get smoother operating characteristics that ultimately lead to the couplings coming apart frequently.

I've change the position of the couplings and used a drop of super glue to hold them.  Most people aren't comfortable doing that in case there is a screw up, but if you use a tiny screwdriver and hit just one side of the shaft, you can remove it later if you need to.

I use Goop to hold the motor in place.  It does a very good job at cutting vibrations and can be removed if I make a mistake.

Athearn C44-9W Rebuild with NorthWest Shortline Can Motor

Athearn C44-9W Rebuild with NorthWest Shortline Can Motor

NWSL Wheelsets also

This next restoration is an Athearn C44-9W that I got "for parts or repair."

It has a NorthWest Shortline 163-4 Can motor and some NWSL replacement wheels.  It wasn't a successful conversion and the person who had gave up and stripped some usable parts and then sold it to me.

Confidence is high that we can rebuild it.

This is part 1 where we break down the trucks and get everything apart.

Bachmann Pancake Motor Repair Sideframe Removal

Bachmann Pancake Motor Repair Sideframe Removal

How to get the wheels out

Bachmann locomotives equipped with the pancake motor have 1 piece sideframes.  There are a couple different versions, but they all come off the truck the same way.

The sideframes are held in place by wedge shaped ends on each truck.  The sideframe has a cutout on the end where the wedges fit when the sideframes are on.

To remove the sideframes, carefully take your flat blade screwdriver to the end closest to the fuel tank, also known as the rear end or the back end of the sideframe.  Come in sideways as much as you can and give a twist with the blade and it should pop free.

DO NOT put the the flat blade in from the top and pry like you would a lever or you will break it.  If you do break it, once it is off use super glue to repair it.  NO OTHER GLUE will work.  For extremely broken parts, especially if you are replacing the broken part with something you fabricated, then use 2 part epoxy, that is the only thing strong enough to hold a new part in place.

I use PC11 epoxy, its expensive, but for model making, it will last many years and you don't end up wasting it like the kind that uses a plunger to dispense the 2 parts.  For about half price, there is a PC7 which is also supposed to be very good, but I don't have that one yet.  As soon as I do I'll review it here.

This shows the rear clip released

 Sideframe completely removed

 How it lines up coming off or going on

 Putting it back on or taking it off

They do have a proper direction, if you have a paint marker, put a dot on the rear end of each sideframe so you don't have to figure it out later.

Also, take a picture before you remove it, you'll notice on the U36 and BQ23-7 that those models have very easy to identify truck features that will help you get it back together again.

On the older models, those trucks are difficult to tell which way they go back, so mark them.  If you forget to do this and already have them off, then you need to carefully match the slots on the ends to the wedges that hold them in place, don't worry it's not hard.

Athearn SDP40 rebuild and repair

Athearn SDP40 total rebuild

I forgot to post my rebuild and floating axle video of the Athearn SDP40 blue box.

This is total rebuild with floating axle, DCC ready and excellent wiring.

Athearn SD40T-2 total rebuild

Athearn SD40T-2 total rebuild

rebuild, rewire and pimp my drive system

The Athearn SD40T-2 that I got in 1988 was a locomotive that I wanted sooo bad.  I got a snoot nose specially ordered for from the hobby shop.  Those were the days when I made everything Chicago & NorthWestern.

I hand painted this thing and bent grab irons with a pliers from piano wire.  I did hard wire it back then and coated the exposed metal with the graphite coating called Slip Plate.

The problem with this locomotive is that it's big with a long wheel base.  It's notorious for jumping the track on multiple turn outs.

So I was wondering what project to do next when a friend asked if I could do an SD40T-2.  I've got several of them and my first thought was to do this rust bucket I got for a couple bucks at the train show.  Then I saw my old set of tunnel motors, 1 a snoot the other a regular hood.

When CNW ceased to exist I was in shock and boxed up all my trains where they stayed for 20 years, almost exactly 20 years.  I setup a new workshop and promised myself that I would destroy or strip my 72 CNW locomotives, but preserve them.  I'm amazed at how detailed these locomotives were. Considering that I had all hand tools and not nearly what I have now, these locomotives look good.  They aren't great by today's standard, but they're certainly operating quality.

I spotted my tunnel motors in my lineup of old stuff and decided they needed this rebuild.  I remember dreaming about getting this locomotive.  I went ahead and did an in depth rebuild.

One of the most important modifications I made was the floating axle.  If you're familiar with Athearn locomotives, especially the SDP40 and SD45, then you probably know they tend to derail in yards a lot.  The tunnel motors don't just derail they also throw cars off the track.  The solution is to make the floating axle.

This rebuild was a total success and the floating axle negotiates multiple #4 turnout with ease now.

This is part 1 of the rebuild

HO scale horsepower measurements

HO scale horsepower measurements

Measuring scale horsepower for real

or what we really want to do

So how much pulling power do your locomotives really have?  How much more do you get when you add locomotives to get a consist?  Are newer locomotives better at pulling?

First things first: why do you want to know?  I can answer that for myself and that answer is because no one else is doing it or talking about it.

Practical answer is that when you are planning a steep grade, can you pull your train up that grade?  How can you keep statistics that will help you figure out that problem and record the information.

There is a simple tool called a Newton Spring Scale.  It's a tube with a spring and a hook that is used in physics to find out how much force is needed to drag objects across a surface or up an incline.

If you're looking at the various scales you buy for a couple bucks, the one you will want to have first is the 5 Newton scale, usually the green one.  The next one you want is the 30 Newton scale - you won't use that one a long until you have long trains to test.

In physics you generally hook on to something a drag is across a surface or up an incline and your partner reads the scale and you get a number in Newtons or grams.

On the model railroad, you use a twist tie and attach a dummy coupler to the hook.  Then you put a nail or screw in your test track and put the loop at the top of the scale over it so it's laying on the track with the scale visible and the dummy coupler available to attach to a locomotive.

Next, hook on a locomotive and give it some power so it can stretch the scale until it's wheels slip and that will give you a reading you can record.  Add more locomotives and start a horsepower chart.  Measure them separately and in groups or consists.  Reverse their directions and measure again.  Rearrange your consists and make more measurements.

You should find that an average locomotive pulls around 1 Newton and more powerful locomotives pull almost 1.5 Newtons.  Consider that 1.5 is 50% more power than 1 Newton.

Hook up a train of cars and use the scale to drag them.  This tells you how many Newtons are needed to pull that train.  Try it again on some grades and watch how much even a light weight train increases the force required dramatically.

We'll get into the conversions to change Newtons to torque and horsepower later.  But for your own use, I suggest using and recording the Newton reading directly because it makes things super easy.  Just so you know 1 Newton is about .22 pounds.

I made a video demonstrating an Athearn SDP40, GP50 and GP60 on the bench:

AHM C628 motor and broken parts replacement

AHM C628

replace the motor

replace broken parts with 3D printed parts

I love the AHM C628.  Over the years I've obtained about 10 working models and a few more that are in very rough shape, to include one that has a terribly deformed shell from sunlight.

Pretty much everything I say about the C628 will also apply to the GP18, C424 and FP45.  They all have the same mechanism.  Also, these models were sold as Model Power and Bachmann.

If you got any of these AHM or IHC or Model Power or Bachmann locomotives as a kid or on ebay or at at train show or anywhere else and find that they have broken parts or don't work at all then I have some very good news for you.

There is almost nothing too broken to fix on any of these models.  Did you totally crack off and break the motor clips or the couplers?

So I got this C628 and it had all kinds of broken and missing parts.  One of the motor clips was gone, the gear towers were missing the small clips that hold the two parts together (those always break off).  The couplers were broken off and the side frames wouldn't stay on.

First, sideframes.  Don't cut the couple pockets all the way off, leave a little bit so the sideframes stay on. But, since you probably know that after the fact now, you'll need to drill a tiny hole for a 2-56 screw to keep them on.  Problem solved.

You've got a huge hole to plug in the front and if you do it the old fashioned way of cutting a pilot out of styrene, which is a lot of work, you still need a platform to screw in the couplers.  The first thing I do is take my digital calipers and measure the open pilot and then make an insert on my 3d printer thick enough to screw in couplers.  I'm going to go into making pilots in an upcoming post.  Quickly, what you do is make a box the size of the opening and thick enough to screw in the couplers and make a 2nd box where you subtract the opening for the couplers.  If you've done any design, that will make total sense, if not, believe me when I say that is a 2 move 3d construction that is as simple as they come.

The motor can be replaced easily because it has a standard shaft size meaning that the couplings on the shaft will fit a new motor with no modification.  The motor is a 2mm shaft, so take a look on ebay and find the one you like.  I personally like the 24 volt motors because I know they won't burn out.  Remember that you can go higher voltage than 12 volts, but not lower.  24 is a good number because power packs that have pulse or older high power models can often crank out 20 volts or more which is very hard on 12 volt motors.  A 24 volt motor can take the abuse, the only downside is that it will be a bit slower than the 200mph original version you're used to.  Something with around 20,000 rpm at 24v will give you about half that much on your layout and will be a little slower than and Athearn Blue Box locomotive.

I like to shave the handrails off these locomotives and replace them with brass wire that I solder in place.  Just eyeball the size when you you're at the hobby store.  If you're not sure, .032" wire is best to use the first time before you go smaller.  Smaller wire is a lot less forgiving.

Shortly there will be a video on youtube that shows each of these fixes.  Don't give up on these locomotives no matter what you see under the hood.  Even the gears can be replaced if you know what to look for, but gear replacement is a whole other topic.