Alco C-855 R-T-R Build – Part 3.5 – Chassis Prep Extra

This week I have an extra post to slip into my step-by-step build of an N Scale A-B-A Ready-To-Run set of Alco C-855 locomotives.  Back in July I posted part 3 which covered the chassis preparation procedure, you can find it here.  However I missed something so in this post I’ll cover what it was and how to do it.  My apologies to anybody who has been following this build along with me.  I will update part 3 which will make this post redundant but for now here it is.

You may have noticed I regularly recommend test fitting things as you go and I should take my own advice.  The chassis below has been prepped to fit into a C-855 A unit and at the cab end you can see how the top chassis section has been notched to fit into the narrow nose.

But the lower section doesn’t fit all the way in and a test fit before I assembled the chassis would have told me that.  In the picture below I’ve removed the lower chassis section and placed it into the shell.  As you can see the inside corners of the nose clip the shell.

However this is easily fixed by cutting two notches in the chassis section as marked below.  Each notch is 3.5mm (0.1377“) wide by 2mm (0.0787“) deep leaving a nose of about 6mm (0.2362″) wide.

I cut these out using my Dremel tool and cutting disc.

The bottom chassis section now fits into the shell.

This extra notching is not required for the C-855B chassis as it doesn’t have a nose.  Next, as I have disassembled and resembled the chassis, I’ll test them for running smoothness and any binding in the drive shafts. Then it’s on to the shells which will be in a later post.

Alco C-855 R-T-R Build – Part 5 – Fitting DCC Decoders

This week’s post will be a continuation of my step-by-step build of an N Scale A-B-A ready-to-run set of Alco C-855 locomotives.  And this post will be concentrating on fitting DCC decoders to the modified chassis.  You can find part one of the build here.

Although this post is aimed at DCC installation the first part is also relevant to DC operators.

The chassis, as you can see below, is held together by vertical bolts which clamp the top and bottom sections together.  But the bolts also do more than that.  Instead of a nut on the bottom the bolts screw into the plates which hold in the trucks, and in turn convey the power into the chassis.  The bolts nearest the front of the picture and on the left hand side of the locomotive connect the left power pickup to the top chassis section.  The bolts furthest away and on the right hand side are isolated in plastic sleeves and connect the right power pick up to the lower chassis section.

When these models were new they had a grain-of-wheat bulb connected to the front bolts which was used for the headlight, and illuminated the cab!  But we can now use these as power connections for the DCC decoder.  The original bulb had a diode attached so it wouldn’t operate in reverse.  Con Cor soldered the bulb wire to a tab plate under the bolt head and twisted the stiff diode wire under the other.  As I want to ensure good contact between the chassis and decoder I’ve made another solder tab for the other bolt as can see below.   I made it from an old axle wiper taken from a scrapped locomotive.  The decoder, also shown below, is an N scale sized chip from Gaugemaster but any DCC decoder will work as long as it fits.

Now, before we start with the decoder some electrical bridges need to be added.  This is the part which also needs to be done for DC operation.  In the picture below you can see I’ve linked the two right hand side bots together as well as the left.  This is because where the chassis has been cut and extended the new glued joints can form an isolating barrier.  So if the decoder was simply connected to the two front bolts it wouldn’t receive any power from the rear truck.

The center sections will also be isolated and as the motor used to collect power by having the contact simply touching the chassis, it’ll no longer work.  So the motor wires I’m about to install for DCC will also need to be connected for DC but just back to the solder tabs.

For the DCC decoder the red and black wires are cut short and soldered directly to the solder tabs. They should now be linked to both sets of trucks.

The chip can then be folded in and secured with Kapton tape.  Kapton tape is ideal as it’s isolating, thin, strong and designed to withstand heat in electrical situations.

The gray wire is the bottom motor feed and runs outside the chassis and is soldered onto the bottom motor tab.

There is a wire channel printed into the chassis extension for this wire as you can see below.  This wire, once fitted can be covered in a piece of Kapton tape or glued in.

The orange wire runs halfway down the other side and connects to the top motor tab. It could go through the hole in the top but I like to do it this way.  The blue and white wire are for the headlight so stay at the front.  If you wanted to add a rear light the yellow and another blue would need to be run to the back but as these will run in an A-B-A consist the rear light is not necessary.  With all the wires connected, except for the head light wires which I’m going to cover in a later post, they can now be fixed down.

Again I used Kapton tape to hold the wires down.  It’s important to position the wires in the middle of the chassis as they run from one end to the other as the shell has feet which sit on top of the chassis.  But there’s a gap in the middle of the foot to allow the wires to pass.  The two strips of Kapton tape are where the feet sit.

The chassis is now ready for DCC testing.

The next step is to fit the shell and for that I have to finish painting it which I’ll cover in a later post.

 

Alco C-855 R-T-R Build – Part 4 – Chassis Assembly

This week’s post will be a continuation of my step-by-step build of an N Scale A-B-A Ready-To-Run set of Alco C-855 locomotives.  And this post will be concentrating on assembling the chassis.  You can find part one of the build here.

Now the chassis sections have been extended it’s time to reassemble all the parts.  And for this build I’m also going to upgrade all the motors to newer Kato drives.  In the picture below you can see all the original parts plus the new Kato motor in the top left-hand side.

For this post I’m going to assemble the second chassis which you may remember from last week is for the B unit but the process is exactly the same for all three locos.  To start with I add the black plastic isolators into the pockets on the underside of the lower chassis section followed by the metal truck fixing.  Both are held in place by a countersunk screw, the shortest ones, which only pass through the lower chassis section.

Next, and this in an important one not to miss, the first new 3D printed part needs to be added.  It’s the small square screw fixing which holds on the fuel tank.  In the original the lower chassis has a threaded hole to receive the screw but as this section has been replaced by the stainless steel chassis extender a new fixing is required.  Threading the hole would require more work and it’s much easier to drop in this plastic part.

The square part simply presses into the square hole.

It will stay in place by friction and once the motor is fitted it can’t fall out.

The motor sits in a plastic cradle; this is to isolate it from the metal chassis.

The cradle has a peg on the bottom which fits into the hole in the chassis to ensure it’s in the right way around.

Next comes the motor.  Although I’ll cover this here I’ve written about this procedure before in a bit more depth which you can find here.  The new Kato motor doesn’t come with any gears on the drive shafts so the original ones will need to be removed from the old motor.

This is actually fairly easy to do.  I use a pair of needle nose tweezers, simply grip the shaft behind the gear and push it off.  Just don’t do it too fast or the gear will ping off behind the work bench!

To fit the gears to the new motor simply press them on with your fingers.  They want to go on so far that the shaft pokes out the other side but make sure the gears are not tight to the motor body and the motor can spin freely.

The next 3D printed parts are the drive shaft extenders.  These are toothed parts which fit inside the existing cup gears making them longer.

I used to glue these in but as my fellow modeller Mike Musick pointed out, they work better when left free with a bit of movement.  You can read Mike’s views on this here.

Also, as you may remember from last week’s post, Con Cor have over the years made a few changes to their chassis and one of those changes was to this cup gear.  The very first design had a different number of teeth in the cup.  This means the extender won’t fit.  But don’t panic, firstly these early chassis are now getting rather rare but if you are using one for you C-855 build you can get drive shaft extenders which will fit here.

The motor is now ready to be added into the chassis.  But first it’s very important to make sure the new drive shafts spin freely without any rubbing on the chassis. Across all the Con Cor chassis I’ve converted I’ve noticed that the drive shaft length varies; I have no idea why.  I’ve supplied the drive shaft extender for the more common shorter lengths I’ve come across.  This does mean that if you have longer ones the drive shaft will now bind against the chassis extender.  To overcome this pop the drive shaft back out and file down the 3D printed part on the cup side.  Running the part up and down a file will do this.  But be sure to make the reduction even.  I would also recommend doing a bit at a time and test fitting as you go as you don’t want to make them too short.  If you do you can get more here.  Once everything is good this would be a good time to add a tiny amount of light oil to each bearing, just a drop.

There may also be one more issue to resolve if you’re using the latest Rail Barron version of the chassis.  Con Cor updated the motor casing and added the curved notches you can see in the picture below.  And therefore added some material into the motor cradle so it’s a nice tight fit.  But this means the Kato motor won’t fit!  It fits fine in all the others.

These extra plastic parts need to be removed to get the new Kato motor in and I find the best way to do it is with a with a small burr bit in a Dremmel style tool.

All four corners will need to be removed to allow the new motor to fit.

Also, and this apples to all the cradles, a shim needs to be added to the base of the cradle as the new Kato motor is slightly shorter than the Con Cor one.  Before you glue the shim in a test fit is required because if it’s too thick it will create uplift on the cup gears which will be noisy and wear out the motor.

The motor fits in to the cradle with the motor contacts at the end with the larger hole.

You’ll need to lift the drive shafts in order to fit the motor in.

Once fitted and you’re happy that everything spins freely, and the motor turns both drive shafts, it’s time to add the rest of the chassis.  There are two plastic separators which also hold down the drive shafts, these get fitted next.

Then the top section of the chassis can be fitted and the other screws fitted between the top section and the metal truck fixing. The longest screws with a plastic insulator are used on the right hand side.  The medium screws are used on the left without insulators.

With the trucks installed the extended chassis should look like this.

At this point, using wires from a DC controller, I do a basic test to make sure everything runs well.  If it’s noisy, won’t run, or sounds like it’s struggling, STOP,  there are a few things to check.

  • Can you easily turn the motor with your finger?
  • Are the drive shafts seated properly?
  • Check the drive shafts are not too long and binding on the chassis.
  • Check the gears on the motor have been pushed on far enough but not too far.
  • Is the shim under the motor too thick forcing the gears up into the cup gears?
  • Are the gear towers in the trucks jammed?

Hopefully everything runs okay with all the checks done and any issues corrected.

The next step is to wire up the chassis, I will be doing this for DCC but I’ll cover DC as well and it will all be in the next post on this project.

Alco C-855 R-T-R Build – Part 2 – Grab Irons

This week I’ll be continuing my step-by-step build of an N Scale A-B-A Ready-To-Run set of Alco C-855 locomotives.  And this post will be about the first details to be applied to the shells; the grab irons.  You can find part one of the build here.

The grab irons or hand rails are small parts but form an important detail.  For these models I’ve made them from etched brass rather than a part of the 3D printed shell.  I could make them a part of the shell but they would be extremely fragile and probably couldn’t withstand being handled without breaking.  The other option’s to make them a solid piece of the shell but I find that makes them look too bulky.

The grab irons are located in the etched brass frets as shown below.  There are two sets for the A units and one for the B unit.

Each 3D printed shell already has the holes to locate all of the grab irons, and other parts.  Below you can see the cab of the A unit with the various holes.

And the rear also has holes for the four grab irons which create the ladder to the top of the locomotive.  Both ends of the B unit are the same as the rear of the A.

There are two types of grab iron.  Straight and folded down and in the A unit fret there are eight of each, although you only need 7 of the straight ones.

The straight ones have half etched sections where they are connected to the main fret to allow them to be easily cut out with a sharp knife.

One thing I strongly recommend is to test fit each grab iron.  If the hole is clogged or the grab iron is slightly bent the wrong way and you attempt to glue it right in, one leg will stick and the other will bend and you’ll be left with a wonky grab iron.  Each grab iron fits into a pair of holes which are either all the way through the shell or just the right length. So if you’ve cut them out too close to the fret and they are too long they may stick out too far.  This is another good reason to do a test fit.

The folded down version also has half etched sections on the rear just after the corner.   This allows the grab iron to easily be folded down in the right place.

I find by using a pair of wide tweezers I can hold both the legs and simply bend the fold down section into place with my finger.  When I tried it the other way round it was hard to get both legs in the right place.

I tend to get all the grab irons ready together, but I keep the two types separated.

To secure them in place I use superglue.  This is a great choice, not only because it sets very quickly but it is a type of acrylic and so are the 3D printed shells so there’s no danger of a chemical reaction damaging the shell.  I wouldn’t recommend trying to apply superglue directly to the shell; that normally ends in a sticky mess.  The best way is to pour some onto an old box lid or something similar, then gently dip the tips of the grab iron into the superglue just before you place it into the holes.  After you have test fitted it of course.

The straight grab irons fit in the A unit cab in six locations; I know there are only five shown below, I forgot one but it will appear shortly.  There are two in the roof above the number boards, two in the face of the cab above the outer windows, one in the side of the nose, above the step area, and finally, although not shown yet, one on the top of the nose.

The seventh fits in the top of the shell at the rear. The last one is simply a spare.

Three of the drop down grab irons fit into the side of the nose under the straight one.  These are the only three which don’t fit into two holes; the rear leg of each grab iron does but the front simply glues onto the front of the nose.  There is small sections of the 3D printed shell which stick out to locate the grab irons which sit on top of them. There is a fourth fold down grab iron under one of the windows.

When complete the fronts look like this. The B unit front is the same as the rear.

And the rears look like this.

The B unit fret has eight fold down grab irons and two straight ones.

So why have I only fixed the grab irons and not the rest of the etched brass parts?  Well these are the most delicate to do and also these need to blend in when the locomotives are painted. All the rest will be fixed after painting as they either fixed to several different parts or will make painting the shell harder to do if fitted first.

These shells will now go in for painting and while that’s happening I’ll turn my attention to the chassis which I’ll share with you next week.

Alco C-855 R-T-R Build – Part 1 – All the Parts

As promised in an earlier post I’m going to share with you the process of building an N Scale A-B-A Ready-To-Run set of Alco C-855 locomotives.  And this post is the first one covering all the parts.

I released the C-855 kit back in the beginning of 2016 and have made a few since then but as a fellow modeller has asked me to make a complete set for him, two A units and a B, I decided to document the whole thing to help others, as this build is a bit more tricky than normal.

So where to start?

I guess the best place is to show you all the parts you will need.  This will include 3D printed parts, donor parts, new parts and etched parts.

The 3D printed parts, as shown below, are all supplied by Shapeways in their Fine Detail Plastic material; originally called Frosted Detail Plastic.  This material is available in two quality levels; smooth and smoothest. The difference is the layer thickness, Smooth being 29 microns and Smoothest being 16 microns.  The Smoothest option takes longer to print and is therefore more expensive.  Since releasing these models Shapeways have also introduced their option to set the orientation of prints so the best detail can be achieved in the areas where you want it.  However, this also comes at a higher cost and as these engines are so big it did make a considerable difference to the price.  So I offer them in orientated and unorientated versions.  To find out more please see the C-855 page here and the C-855B page here.

The parts 3D printed in Fine Detail Plastic, starting from the top, are:

  • C-855 Locomotive Shell
  • C-855B Locomotive Shell
  • C-855 Locomotive Shell
  • 3 Fuel Tanks & 6 Drive Shaft Extenders
  • 18 Sand Boxes
  • 4 Special Sand Boxes, 4 Crew, 3 Sets Of Horns, 4 More Sand Boxes & 3 Fuel Tank Mounts

Since arriving from Shapeways all the parts above have simply been rinsed under warm water, soaked for twenty-four hours in Goo Gone, rinsed again in warm water, left to dry for forty-eight hours and finally run over lightly with a brush in a Dremel style tool as shown below.

I use this tool as any residue left over from the print process turns to powder after contact with the Goo Gone; once dry the brush simply knocks it off.

The next set of parts is the chassis.  For these locomotives, if you want them to be powered, you will need to get a donor chassis from a Con Cor U50 or turbine.  This is the only thing currently available which is even close to the C-855 chassis.  However it is too short and needs to be lengthened.  I will cover that later.

The parts for the chassis, starting from the top, are:

  • 3 Con Cor U50/Turbine Donor Chassis
  • 3 Sets of 3D Printed Stainless Steel Chassis Extenders
  • 3 New Kato Motors

The chassis extenders are also 3D printed by Shapeways and can also be found on the C-855 page here and the C-855B page here.

The new motors are not necessary for the build but the old Con Cor motor, although reliable and strong, is rather noisy by modern standards and this particular Kato motor works well as a replacement.  You can read a post about swapping them here with and an update here.

The last set of parts, well almost, is the etched brass parts as shown below. These are etched in 12 thou brass to give strength to the long parts.

Each etched set of C-855 Additions, as shown below contains:

  • 7 Handrails
  • 16 Grab Irons
  • 4 Ladders
  • 3 Walkway Platforms
  • 2 Sun Visors
  • 4 Windscreen Wipers
  • 4 MU (Multiple Unit) Hoses
  • 2 Miscellaneous Pipe Sections

The etched set of C-855B Additions, as shown below contains:

  • 8 Handrails
  • 10 Grab Irons
  • 4 Ladders
  • 3 Walkway Platforms
  • 4 MU (Multiple Unit) Hoses
  • 2 Miscellaneous pipe sections

The only other thing I’ll need for this build is three DCC decoders, LEDs for headlights and relevant wire but I’ll come to that in a later post.  I’ll also start working on the preparation of the parts leading up to the assembling of the locomotives.

This week I’ll finish off by saying I, along with my club members and club layout ‘Solent Summit’, will be at the Great Central Railways model railway exhibition from the 15th to the 17th June 2018.  You can find our more here.  And if you time it right you’ll see an A-B-A set of C-855s running on the layout.

A Different Way to Resurrect A Shelf Queen

As promised in last week’s post this week I’ll show you a way to give some new life to old steam engines, or any locomotive which has became a ‘Shelf Queen’.

The phrase ‘Shelf Queen’ is normally used in model railroading to describe a locomotive which looks great but just doesn’t run well and spends all its time on the shelf.  This could be because it has a broken part, it doesn’t pull well or simply runs so roughly or erratically it’s frustrating.

I have several of these which I kept telling myself I would get around to fixing, but time marches on and I now find myself with newer locomotives which outstrip my ‘Shelf Queen’ to the point that if they where good as new they would still disappoint.

So what to do with them?  The answer is make them into a scrap train.  Now I know I said “give some new life to old steam engines” and sending them for scrap is sort of the opposite!  But it’s a model, so they will forever be on their final trip to the scrap yards, and will be running on the layout once more.

I have several engines to do this with but the first three, as pictured below, are a pair of original Bachmann 4-8-4 steamers with long haul tenders and a Con-Cor 4-6-4 streamlined Hudson. (The Hudson in the image is not the actual locomotive, this one is good runner.)

The first thing to do is to remove any motors, drive shafts, wires, connectors and pickups.  Both of these locomotives have gears between the drive axles which I’ve left in to ensure equal turning of all the wheels.

Once this has been done and the locomotive has been reassembled it’s very important to ensure it’s free running.  That is to say when pulled, or pushed by another locomotive all the wheels freely rotate and any side rods and valve gear don’t stick.

Often when steam locomotives are transported like this the connecting rod, which links the piston to one of the driving wheels, and the eccentric rod, which drives the valve gear, is disconnected or removed.  This prevents damage occurring to the cylinder as it is normally lubricated by oil in the steam.  However these are going for scrap and Bachmann only linked the rear three driving wheels together with a side rod; this is the horizontal rod linking all the driving wheels, probably to save material as it can’t be seen behind the connecting rod.  But with the connecting rod removed it just looks wrong so I left them on.

It’s also a good idea to sort out any couplings at this stage so the effect of ageing the locomotive is all over.  New shiny couplings stand out.

To transform these locomotives into rolling wrecks on their last journey I handed them to my friends at Model Railway Solutions who went to town with a mixture of weathering powders, paints and a few secret ingredients.

And now they look like this.

Once these have been weathered to this severity all moving parts will need to be re-checked to ensure they still run free.  Areas like the valve gear are particularly susceptible but simply running the locomotive vigorously up and down your hand will free most of it up.  The biggest issue is paint and material on the running face of the wheel.  This will cause the loco to bump down the track; in real life they would be smooth as they weigh hundreds of tonnes.

However once it’s all ready the effect is fantastic, here are three powerful modern locomotives taking two giants on their last trip.

The Hudson still had some crud on the wheels so even these three diesels struggled to pull all the steamers, however in the last frame of the video it’s on the back of the train.

I intend to extend the train with some of my other ‘Shelf Queens’.  Some of these will have the connecting rods removed, maybe a tarpaulin over the cabs, rusted holes in he tender and maybe the word ‘scrap’ painted on the side.  Something else to consider: a lot of steam engines come with coal molded into the tender; of course this would not be here and the coal bunker would be empty.  Also the side rods and parts would still go to scrap so these could be on a flat car trailing behind.  Of course the scrap yard may not be the destination, they could be heading for preservation.

Next week, once I’ve recovered from this weekend’s exhibition in Bristol, I’ll share some of the show with you.