Friday, April 21, 2017

HO Scale AHM GP18 total rebuild Part 1

HO Scale AHM GP18 total rebuild Part 1

Stripping the paint and making some parts

We're going to take an old school AHM GP18 and totally rebuild this guy and make some 3D printed detail parts to pimp out our build.

The AHM GP18 from back in the 1970's was many kid's first locomotive, mine included.  I've always loved this model for that reason.  They are super easy to find for very little money, but have a reputation of being unreliable.

There are 2 reasons for the unreliability.  First, this toy was meant to take abuse at full power being reversed at full speed over and over again.  For that task, this engine was pretty good.  The motor takes a lot of full power abuse.  It wasn't expected that it would be used for slow speed switching with short moves and delicate situations.  The motor likes to get lots of power to get going and stay going.

This leads to the second weakness, power pickup is poor, using small wipers.  The wipers are on alternate sides, so you don't get power from all the wheels.  Dirty wheels and wipers lead to jerky operation and no real slow speed ops to speak of.

We're going to do a real budget build on one of these to include a new motor with good slow speed and low power operation. We'll also fix the power pickup problem.

We're also going to make a couple 3D parts from scratch and handrails from brass wire make this an interesting locomotive.

Hopefully by now you have the skill to tear this thing down to bare bones.  Carefully remove the 3 screws you will find on the underside, 2 by the cab and 1 on the fuel tank and take it apart.  Remove the sideframes and truck clips carefully with a small flat head screwdriver without breaking anything.  Pinch the motor clip from underneath carefully to release the moter.  Cut all the wires since we're rewiring it anyways.

You should be taking pictures before you do stuff so you know how it was in case you need to put it back together, but I'll have pictures and instructions here to help you.

Take apart the trucks without breaking the tabs.  Use very gentle pressure on the plastic tabs and clips to do this.  You might have one that was oiled with something that made the plastic brittle and things break off.  DO NOT PANIC.  We'll deal with broken parts later.

Use Dawn dish soap to wash everything to remove all oil, dirt and grease.  Don't lose any gears down the sink.

OK, you can see it apart.  That yellow motor is the possible replacement from ebay for about $2.  Don't know if that one will work yet, but we're trying it.  I started cutting off the handrails.  There are side pieces that will be glued to the shell.  They are removed by gently scoring the line where they meet the frame many times with a knife.  After each score, bend slightly back and they will eventually come off nicely.

We'll go in depth on the gears in another part, for now we want to strip the paint.

This paint is tough to remove, so I used the EZ strip method from the previous blog post.  Go review the 5 methods before stripping the paint.  On this particular shell, the yellow is very tough to remove, so EZ strip was the way that worked.  There were 2 spots where I left the stripper in place for about 5 mins and it started to melt the plastic.

DO NOT USE EZ STRIP ON THE FRAME.  It melted a section of the walkway right away.  The rubbing alcohol method works on the frame, but it takes 2 days or a little more.

I'm going to make some beefed up fans and exhaust mufflers using the 3D printer.  We'll save that for another part of this project.  At this point I glued on 2 of the battery box covers I cut off the frame, but the 3rd piece has nothing to attach, so we'll make something to glue it a little later.

We'll get to the paint in another part, so at this point you should have your shell ready for painting.  Make sure to wash it with both the tooth brush and a soft cloth with soap to get all the stripper off.

Stripping paint from Model Trains and Locomotives 5 Methods

Stripping paint from Model Trains and Locomotives 5 Methods

How to remove paint from models

There are several methods to remove paint from models.  Each method has it's own risks and effectiveness.

I strip a lot of old locomotives and a few freight cars - here's how I do it:

Method 1 91% Rubbing Alcohol

I use a tub with a top, tupperware is good for this.  Pour in as many bottles as it take to submerge the shell you want to strip.  Highly effective on newer paints that are much thinner than the old school toy paint jobs...
Let soak for as long as you need to, sometimes days or weeks, but in the case of modern paint jobs it can be as short as an hour or 2.

I had a locomotive that was primered with gray auto primer in there for a few weeks.  I noticed that the paint wasn't coming off, but it was bubbling a bit.  I took it out and placed it in front of a fan and the fast drying action caused all the primer to flake off.  That would be a rare case, but you never know unless you try it.

The rubbing alcohol method usually leaves the plastic intact with no damage, but I have has shells that developed striations, very rare though.

It must be 91% rubbing alcohol.  Use this method first unless you know the paint really well and know it won't work.

Method 2: 8% (or higher) pine oil

Pinesol will NOT work for this, it doesn't actually contain real pine oil.  Fortunately the bargain brands at Walmart say on the bottle that they contain about 8-9% pine oil and they are much cheaper.

I use a 5 gallon tote box to do this.  This method can take weeks to work, but sometimes overnight will do the job.

I keep the oil, which is very heavy, in the tote and on top of a 4 wheel dolly.  Even with the lid on, I put a large bath towel over the box to keep it from stinking up the place.  This method works pretty good on toy type paint jobs, but takes quite a while.  The make it work faster, clean the shell each day with dish soap and a stiff tooth brush and put it back in.  I often put future projects in here and leave them for sometimes months until I'm ready to use them.  I haven't noticed and plastic damage from this method.

Method 3:  Brake Fluid

For really tough paint jobs, brake fluid soaking can often do the trick.  There are shells that can be attacked by the brake fluid, but in general it works pretty good.  I've soaked many shells for weeks in brake fluid and it will remove some of the toughest paint I've ever encountered.  But, try method 1 and 2 before you resort to the brake fluid.

I double bag the shells and don't submerge the shells, I let the fluid spread through the bags.  I place the bags in a tupperware container, but don't seal it up.  Just roll the bags shut around the shell.  Check within in the first hour, then everyday until you are comfortable with this.  Works best on toy paint.  Frequent cleanings help, but this method increases the risk of melting a shell.

Method 4: EZ strip

I got this stripper at Home Depot.  There are many others that will melt the plastic, especially the citrus strippers.  EZ strip will also melt the plastic so you have to actually sit down and do this one by hand a little at a time with a tooth brush.  Frequently spray with a soap and water mix like 409 or spray and wipe and then wash in dish soap with a tooth brush.  Many small applications will do the job.  Don't turn your back on any section with this stuff applied or it will melt the plastic.

Many washings with dish soap in between small area applications of EZ strip.  Very effective, but very high risk.

Method 5:  Oven Cleaner

This is how we did it back the 1980's.  I say don't use this method, I've melted shells many times doing this. But, if you must know how, then what you do is heat the oven to 100 and use a cookie sheet.  Spray the shell with oven cleaner and put it in the oven for a couple mins at most, take it out, wash it and do it again.  Takes off most paint, but melts plastic more than 50% of the time.  You can do it without using the oven in a plastic bag, but that almost always leads to striations in you plastic.

Bottom line:  don't use the oven cleaner method, too much risk.

There are also model products you can buy to remove paint, I don't use them, but I've seen that they are generally very good and effective.

So why go through the trouble of these other methods?  Simple, they are much cheaper and the first 2 are just fire and forget methods - drop the shell in and come back when you're ready for it.  Otherwise, you can buy the good stuff and do it right now.

Thursday, March 30, 2017

Use LED lighting quick and dirty simple step by step

LED Quick & Dirty Step by Step

Explaining how to use the Light Emitting Diode

Make an LED Ring tool

Quick & Dirty LED's...

Using your power pack, you can connect the DC or AC or Track Power DC to a string of LED's and get them to work reliably.

Make an LED Ring Tool so you don't have to memorize how to do LED's and have a tester for brightness.

We're going to keep it as simple as possible. If you can get these things, you can light up your LED's in a matter of minutes.

Tools needed:
1. Solder Pencil/Iron/Gun - a simple $10 solder pencil from the auto parts store (or Home Depot, Lowes, Menards) will work for most things you do.

2. Solder - electrical rosin core is what I use (Home Depot, Lowes, Menards) about $4

3. Rosin Soldering Flux Paste - I use RadioShack, at Grainger it's $2. You CAN use most kinds of flux, but rosin is best for electrical.
We'll explore different kinds of flux later, for now get what you can to make this project work today.

4. Bridge Rectifier - Radio Shack (if you still have one) or ebay or Amazon. You might luck out and be able to find one at some other store near you. on ebay $7 for 10 600 volt, pretty good deal.

5. 1k resistor - online or some auto parts stores, on ebay 100 1/2watt are $3.48. Sometimes I use 1 watt and sometimes 1/4watt, if you pop an LED, then you know it was the wrong resistor.

6. LED of your choice. Brightness is measured in MCD. I have some that are 700mcd, 7000mcd and superbright at 24000mcd, almost like a surefire flash light. We'll play with brightness later.

We need to make this ring so we can test LED's to see if we like them in our projects.

Once you have a working ring, you can then add new LED's to see how bright they are compared to others that you already know.

Here is a useful note: A 5mm led is just a little too big for an Athearn blue box Trainmaster headlight and a 3mm is too small.

Make the ring:
1. Tin your parts. This is where you pre-solder the parts leads so they are easy to join to another part.

2. Join the "+" lead (which is marked on the bridge rectifier) to the resistor. The GOLD STRIPE IS toward the next part. You are soldering the "+" to the side of the resistor without the gold stripe.

3. Look at the pictures below - inside the LED is a big piece and a little piece, solder the gold stripe side of the resistor to the small side of the LED.

4. Put more LED's in the same direction, small side always points back to the gold stripe.

5. Solder a black wire from the big side of your final LED to the "-" lead on the bridge rectifier.

6. Connect power from you power pack and light them up.

I like yellow for the inside of building and some headlights. You can use the AC accessory on your power pack to do this.

Remember those old power packs you have somewhere? You can use those to light city blocks.

In locomotives without DCC, you can use this LED ring to do you lights. DCC already has circuits that deal with lights, so this isn't for use in that situation.

Passenger cars, EOT - end of train, all that is possible from this.

This is only the beginning. You can get much more complex but adding other things to your ring, but you'll always have an example of the basic working LED.

Saturday, March 25, 2017

HO Scale Bachmann Pancake Motor Rebuild Part 3

HO Scale Bachmann Pancake Motor Rebuild Part 3

1980's U36B motor restoration

Here's the final part...  The motor works, the gear repair holds and we get it up and running again...

Thursday, March 23, 2017

Rebuilding an HO Scale Bachmann U36B pancake motor Part 2

Rebuilding an HO Scale Bachmann U36B pancake motor

Part 2

Pancake motor rebuild

Here's the next episode....

Rebuilding an HO Scale Bachmann U36B pancake motor

Rebuilding an HO Scale Bachmann U36B pancake motor

Part 1

another total rebuild of a pancake motor

Here are the first 2 parts of a short series of rebuilding a pancake motor from an old Bachmann U36B.  I like doing these because they are good practice for building the skills you need for more complex rebuilds.  You can really dig into these projects without fear of ruining a $300 locomotive...

Friday, March 17, 2017

Repairing Cracked Gears with Baking Soda and Super Glue

Repairing Cracked Gears with Baking Soda and Super Glue

HO Scale Bachmann Old School Pancake Motor Repair

I've been advocating gear replacement a lot lately.  That is the preferred method, but sometimes you just need to repair and existing gear.

You may have heard the legend of the baking soda and super glue repair method.  If you haven't, then it goes like this:  you can combine baking soda and super glue into a paste that can be used to repair gears that are impossible to find a replacement for....

That is mostly correct, but how you actually do it is to fill the crack with a fine dusting of baking soda and apply a tiny drop of super glue and it will create a super strong weld.

While rebuilding another pancake motor from a Bachmann U36B, I did discover 2 cracked gear and decided that it was time that someone demonstrated the legend.....

Here is a video demonstrating: