Friday, July 20, 2018

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.

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.....

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.

Tuesday, April 3, 2018

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.

Wednesday, March 21, 2018

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

Wednesday, January 31, 2018

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.