Improving Kato UniTrack HO Points for DCC Operation

Kato UniTrack is a very good product and allows reliable trackwork to be assembled quickly without the need to cut and solder track.  Most Kato turnouts, including N scale, have the ability to be switched between power routing and non-power routing, but the No.4 HO turnout, as pictured below, doesn’t. So in this week’s post I’ll show you how I modify Kato UniTrack No.4 turnouts for use with DCC.

But what does power routing mean?  Below is an extract from www.dccwiki.com showing how the turnout isolates different routes depending on how it’s set.

For DC operation, power routing is very useful as power is delivered only where you want the train to run.  The other route is isolated so any trains on that line won’t move.  However for DCC all the tracks want to be powered so the turnout ideally wants to be non-power routing.  As I said earlier most Kato turnouts can be switched between power routing and non-power routing but the HO No.4 can’t.

In the No.4 box you get the actual turnout and associated track parts.

The actual turnout has an all metal frog shown in green, electrically linked blades shown in yellow and switched rails shown in blue.  The stock rails are marked red and black; these have the incoming power.

Between the frog and the switched rails is a plastic insulator.  It’s these two rails which ideally need to be electrically connected permanently for DCC operation.  However the frog changes polarity depending on how the turnout is set so you simply can’t solder the switched rails to the frog.

On the underside of the turnout are five screws holding on the base plate.

Under the base plate you can see the electronic switch and the solenoid which changes the turnout.  In the image below the turnout is set for the straight route. The ‘T’ section in the center of the switch is connected directly to the frog and bridges power from the right side to the left.  This connects the frog and the relevant exit rail or switched rail back to the black stock rail.

In the image below the turnout is set to the diverging route and the ‘T’ section connects the switched rail and frog back to the red stock rail.

To make the turnout non-power routing is a fairly simple fix.  I use two short sections of wire, as shown below.

These two wires are soldered to the copper plates as shown below.  The upper wire links the red stock rail to the diverging switched rail.  The lower wire links the black stock rail to the straight switched rail.

And that’s it.  This modification also makes the turnout even more reliable as the power is transferred through the new wires rather than the contacts in the ‘T’ sections.

With the base plate replaced the turnout is ready for use on a DCC layout.  It can still be used on a DC layout, the turnout simply won’t act as a power router. Also, if you’re not into soldering, this modification can be done away from your layout at a model club or possibly a local hobby store as the Kato turnouts will remain self-contained.

Pennsylvania Railroad (PRR) F22 Flatcars & Naval Gun Load

Several weeks ago I posted about the N Scale Architect’s new kit for a set of Pennsylvania Railroad F22 Flatcars & Naval Gun Load.  This kit, which was still in development, was announced at the Amherst Railway Society Show 2018, in West Springfield, Massachusetts.

And I spoke about it again two weeks ago as the sample came to the Bournemouth N Trak convention here in England.

Well, this kit is now complete and it looks amazing.

Here is what the N Scale Architect has to say about them:

“The Naval Gun Load kit is based on the Mark VII Naval Gun designed in 1939 and first used aboard Iowa-Class Battleships during World War II.  Measuring 16” in diameter, these guns could fire a 2,400 lbs projectile up to 24 miles. Each of these 68 foot guns weigh nearly 270,000 lbs and were shipped (breech first) across two(2) heavy weight flatcars with a third flatcar used as an idler. Many of these guns were manufactured by Bethlehem Steel in Pennsylvania and transported via the Pennsylvania Railroad across three(3) F22 flatcars. This kit comes complete with Frosted Ultra Detail (FUD) 3-D printed parts, full-color illustrated instructions, sixteen(16) inches of phosphor bronze rod and a ‘DO NOT HUMP’ placard sheet.

The Pennsylvania Railroad (PRR) F22 Flatcar 3-Pak Kit builds three(3) of these wood-decked 30 foot heavy-duty flatcars which had a loading capacity of nearly 200,000 lbs when upgraded to the Crown 2F-F1 cast steel trucks modeled in this kit. These flatcars were originally designed in 1913 and, at their peak in the 1940’s, there were over 100 in use on the Pennsylvania Railroad (PRR) roster with some of them surviving into the 1960’s. This kit comes complete with Frosted Ultra Detail (FUD) 3-D printed parts, full-color illustrated instructions, photo-etched stirrups & cut-levers, brass car weights, Micro-Trains brake wheels & body-mounted couplers, Fox Valley metal wheel sets and a PRR F22 decal sheet that features nine(9) verified road numbers, pertinent car data and prototypical reporting marks.

The ‘Naval Gun Load’ kit (#20100) retails for $39.95, the ‘Pennsylvania Railroad (PRR) F22 Flatcar 3-Pak’ kit (#20101) retails for $69.95 and the ‘Box Set’ (#20102) retails for $89.95… a $20.00 Savings !!!  These kits are available exclusively at the THENARCH.COM.  Additional 3-D printing material options are available at our Shapeways Shop: https://www.shapeways.com/shops/the-n-scale-architect.”

This was a project I really enjoyed working on as it’s such unique load. It was great to get everything correct from the trucks to the length of the gun barrel. The lack of restrictions, which are often caused by donor chassis and other parts that I have to use when designing a locomotive, are what made this easier to do. Only the wheels and couplings are bought in items.

As The N Scale Architect says the kits are available direct from their website or via their Shapeways shop if you want to order them in Frosted Extreme Detail (FXD).  If you do purchase a kit from Shapeways don’t forget to contact the N Scale Architect via their website (THENARCH.COM) or e-mail (thenarch.com@gmail.com) to obtain the additional pieces and instructions needed to finish the kit.  Be sure to include your name, mailing address and Shapeways order number in this message. These items will be mailed to you at no additional charge (including international orders). Please allow 7 to 10 business days for delivery (international orders may take longer).

For me it’s back to the virtual drawing board and on with my current projects, and I hope next week to have some more progress to share with you.

Union Pacific Rotary Snow Plow 900081 – Part 3

In this week’s post, as promised last week, I’m going to share with you a bit more progress on with my UP 900081 Rotary Snow Plow kit.

A major part of a rotary snow plow is the fan at the front and for my kit not only do I want it to be functional but I also want it to look right.  And the UP 900081 has a very complex fan.

The red sections look smaller than the silver parts, however, they are the same.  Each blade has wings which fold out to alter the size of the blade.  All the red ones are folded in.  In the close up photograph below you can see the wings on blade number 6.  Blades 5 and 7 have had the wings removed.  You can also see the circular chute the snow is forced down behind the wings. The chute slopes away from the center of the fan towards the back of the fan chamber.  As the blades cut the snow it’s forced down these chutes and as each chute reaches the top of the rotation the snow is blasted out through the hole on the top of the fan chamber.

It would be very easy to simply make a flat disc and add details to the front but I wanted to replicate this detail as closely as I could, particularly the blades and the circular chutes.  3D printing gives me the ability to make this complex shape and maintain strength at a 1:160 scale.  In brass at this scale it would be a very difficult task.

The fan will be printed in one piece with a shaft at the back.  This will pass through the shell bulk head and be connected to a gear which will be driven by the motor.  The fan will also be a separate part from the main body to allow easy painting of both the fan and the fan chamber.  In the render below you can see the fan located in half of the body shell.

The exit chute is directly above the fan.  Above the exit chute will be the directional cover which will force the snow either to the left or right.  This cover will probably be made from etched brass as a 3D printed part will appear to be too thick. The actual wings on the fan haven’t been drawn yet either but I do intend to add this detail.

Because the fan is modeled fairly closely to the original you will be able to see the end of the circular chutes through the exit chute.  However in order to retain strength the circular chutes don’t go back as far as the original.  As a compromise I have added a cut out detail in the side of the fan which you will see as it rotates.

My next task, once the fan and exit chute is finished, will be to work out a reduction gear system so the motor speed is reduced in order to spin the fan at a slower speed.  And in order to do that I need to complete the power chassis and that’s something I’ll share with you in a later post.

Follow-up on New Releases

Again this week’s post will be a short one.  Although I was at the Bournemouth N Trak Convention over the weekend I have a sprained wrist, having clumsily falling over in the snow, so things are moving a bit slower than intended.  But I’m hopeful that I’ll make a full recovery soon and then I’ll be back to modeling and 3D printing as normal.

Due to my wrist I didn’t take any photos this year at the N Trak Convention but there was one item that I wanted to share with you.  A few weeks ago I showed you the N Scale Architect’s new kit for a Pennsylvania Railroad’s F22 flat car set and Navel gun load.

Well, it made an appearance and did several laps of the Black Diamond’s layout behind a UP S2.

I will have more on this kit soon and will share a link once it is available on the N Scale Architects website. (These photos were kindly shared by the N Scale Architect.)

Although I won’t be there myself if you are in the Abingdon area of the UK this coming weekend you can see my club’s US N Scale layout, Solent Summit, at the Abingdon Model Railway exhibition.  A link to the exhibition can be found here.

Next week I’m planning on showing you some progress on the UP Rotary Snow Plow project.

New Axles for a Bachmann HO 4-8-4 Northern – Part 2

Last week I shared with you my designs for a set of replacement Bachmann HO 4-8-4 axles as shown below.

The locomotive was tested and ran smoothly with new axles fitted: the set of four axles are available in my Shapeways shop here.

One thing which I wasn’t sure of last week was one of the original axles has a square center section rather than circular as the other two.  I have since been informed by a fellow modeller that the orignal version of this locomotive also had smoke but the smoke unit had a section which was driven from this square axle to create the puff effect.  As the model was improved this feature was removed but the square axle was never updated.

This coming weekend, 9th to 11th March 2018, is the N Trak convention in Bournemouth, England and again it’s at The Trouville Hotel.  You can read a bit more about last year’s convention here and the 2014 convention here.  I’ll be there over the weekend if you are in the area and want to come by and say hello.

New Axles for A Bachmann HO 4-8-4 Northern

I often get asked to have a look at damaged locomotives and see if there’s anything that can be done to repair them.  And I’m happy to say most of the time there is.  So this week I have another 3D printed part made specifically to repair a locomotive to share with you.

Bachmann make model locomotives in many scales and I normally work in N Scale but this time it’s HO and it’s a lot bigger than N!

This locomotive has a motor in the rear of the boiler which drives the rear axle.  The other wheels, just like the real thing, are driven by the connecting rods on the side.

However this particular model suffers from cracked axles causing an issue with the quartering. But what does that mean?

Well, as each driving wheel picks up power from the rails the axle needs to be electrically isolated to prevent it from shorting and this is done with a plastic axle.  Each metal wheel has a peg at the center which fixes into the plastic axle.  Below you can see the chassis upside-down with the base removed.  Between each driving wheel you can see the plastic axle and between the rear wheel set is an axle with a gear which is driven by the motor.

This all works well untill the plastic becomes weaker with age and the pressure of the wheels turning causes it to crack.  In the photo below you can see the crack line running through the original axle.

When it’s cracked like this the peg on the wheel will not be fixed tightly into the axle and the wheel can move differently to the wheel on the other side of the axle.  And it’s this which causes the quartering issue.  Quartering is a name given to the positioning of each wheel relative to the cylinder and piston.  In the image below you can see all the wheels are connected to the connecting rod at the same point.  Half way around the wheel on the left hand side, or at the 3rd quarter point.  And the piston will be all the way to the front of the cylinder.

At the same time on the other side of the locomotive the wheels are all connected at the top of the wheel or the 1st quarter point.  And the piston will be in the middle of the cylinder.

All steam engines are offset like this, although some are a bit different if they have more cylinders, but it’s this offset which ensures one cylinder can always push on the wheels no matter where the locomotive stops.  If both side rods were in the same position and the locomotive stopped with the cylinders in the middle of a stroke, it would be nearly impossible to get it going again.  So either side of an axle a driving wheel is positioned a quarter of a turn apart.   But if the axle doesn’t grip the wheels then they get out of sync, the side rods get jammed up and the locomotive stops moving.  And that is exactly what has happened to this locomotive.

However, there is a simple solution.  I have drawn a replacement set of axles and 3D printed them in Shapeways Frosted Ultra Detail material which is accurate and hard-wearing, so ideal for this replacement part.

Yes, I know the original had a square section in the middle but out of the three I’ve changed only one of them did and I don’t know why. The other two had round sections and as I could see no reason for it being square I made them all round. If anyone does know why, please get in touch.

And as you can see in the image of the chassis the axles fit well.  The wheels push in with a tight fit and stay at the correct quarter spacing.

I’ll be making these axles available soon in my Shapeways shop so if you also have a Bachmann HO 4-8-4 with spit axles you’ll be able to fix it and keep it running.