Drawbars For Yosemite Valley Railroad Log Cars

As it’s been a while since I released a new product, and I’m still working through the Shapeways material changes, I thought this week I would finish up a project from a few months ago.

Back in February of this year I shared with you my designs for a 3D printed drawbar for my Yosemite Valley Railroad Log Cars, you can find the post here.  The drawbar was fairly simple and the test prints worked well; I just wanted to give them a proper test before I made them available.  Well, they’ve now done lots of miles on our modular exhibition layout, ‘Solent Summit’, so I’m happy to make them available; they can be found here. They can be ordered in either white or black.  This material stains or paints very well, so if you prefer a different colour I recommend getting the white.

As I said in the original post I had wondered if these would be any use for conventional freight cars.  I did some tests using boxcars fitted with N Scale Micro Trains body mounted couplers and right away I ran into a problem with length.  As these were designed to replace Z scale couplings the distance between the mounting holes is too small to use with the N Scale screw holes.  But I think adding 6mm will do the trick so I will be ordering a test set of longer links soon and I’ll share them with you when they arrive.

Fitting DCC to Wrenn OO Locomotives – Vertical Motors

Last week’s post was all about converting Wrenn OO locomotives with horizontal motors to DCC; you can find the post here.  This week I’m going to share with you how to convert the vertical motors.

The vertical motors were used in the City & Duchess 4-6-2s, A4 4-6-2s, 0-6-2 tank engines, Royal Scott 4-6-0s and Bullied Pacific 4-6-2s.  The two engines I’m converting are the ‘City of Birmingham’ and ‘Sir Nigel Gresley’.

To remove the all-metal shell simply remove the screw located at the front and it will come away from the chassis.

As with the horizontal motored locomotives the wiring is very simple.  The black wire goes to the right side pickups and connects to the isolated motor brush at the front of the motor.  The brown disc is the capacitor which acts as a suppressor to prevent interference with televisions etc.  The other wire from the capacitor connects to the chassis and the left side pickup.

All the wires are removed except the black feed from the right side pickup.  The brush at the rear of the motor is not isolated from the chassis and, as with the horizontal motor, it’s this one which gives us a problem.

The steel cap covering the brush simply pulls out to reveal a spring and a brush as below.

The cap fits into a brass sleeve which guides the brush and spring to the armature.  In order to isolate the brush from the chassis this sleeve will have to be removed and replaced.

It’s very unlikely the sleeve will push out; you may be lucky but chances are it will need to be drilled.  Before you do this the armature will need to be removed to prevent damage and metal filings getting where you don’t want them.  In the picture above you can see I’ve removed the magnet and side plates: this is done by removing the main bolt through the motor.  The front brush should also be removed by pulling the end cap out.  Then the top nut above the armature can be loosened and unscrewed.  Note there is a small ball bearing in the cap. The grease should hold it there but be prepared for it to fall out. Then the armature can be removed, normally from the right hand side.  There’s also a small ball bearing in the fitting at the bottom of the armature. Again, it should stay in place but be ready just in case.  The chassis should then look like this.

Using a 5mm drill the old sleeve can be drilled out and the hole made ready for the new 3D printed sleeve; you can see the new sleeve in the bottom right of the image above.  Once the hole has been drilled, clean and remove any burrs from the hole and remove any metal fillings from the chassis.  Before you fit the new sleeve make sure the brush fits through without any resistance.  It should be able to fall through if tipped up.  If it sticks there may be some 3D printing residue inside which can be removed with a drill bit or round file.  The new sleeve can now be fitted and, if necessary, held in place with a little glue.

Then simply reassemble the motor.  Before you put the armature back in check to make sure the ball bearing is still there.  The top nut should be screwed down so the armature spins freely but has no vertical movement; only then should the nut be tightened.  With the brushes refitted, a continuity test should be done with a volt meter to double-check that both brushes are isolated from the chassis.  Then the wires can be added for your DCC decoder.  The red goes to the black wire, the black goes to the chassis, the orange goes to the front motor brush and the gray goes to the rear as below.

Once a DCC test has been performed the shell can be refitted and the loco is good to go.

So where can you get these 3D printed isolating brush holders? They’re available here:

Two Wrenn horizontal motor isolating sleeves.

Four Wrenn horizontal motor isolating sleeves.

Two Wrenn Vertical motor isolating sleeves.

Four Wrenn Vertical motor isolating sleeves.

Two Wrenn Vertical & two horizontal motor isolating sleeves.

I will also keep a few in stock so please drop me an email or message me through the contact page.  If you have a different locomotive which needs a special part to isolate the motor for a DCC conversion I’d be happy to look into it for you.

Drawing a Dummy Chassis & Trucks for an N Scale EMD SD50 Part 3

Recently I shared with you my designs for a dummy chassis.  It was designed to be used with an Atlas N Scale SD50 shell, as shown below, and you can read the post here.  In this post I’ll show you the outcome and where you can get one.


As I mentioned in that post, and as you can see below, the fuel tank was a little bit low.  This has been corrected in the 3D model, raising the tank connection points on the chassis and adding a tiny bit of height to the truck towers.

emd-sd50-dummy-chassis-mk2-7With the fuel tank and trucks painted in acrylic ‘locomotive black’, the loco looks the part and spent some time last weekend running around our club layout behind other locomotives.


This dummy chassis kit will also fit an Altas’ SD60 and SD60M shell as all three locomotives use exactly the same chassis.  The kit is available in both Shapeways’ Frosted Ultra Detail and Frosted Extreme Detail materials and can be found here.

If you want to use the original light board with the chassis this can easily be done with my ‘Dummy Chassis Circuit Board Mount’ as shown below.  The actual mount is printed in Shapeways’ White or Black Strong and Flexible material and can be found here.


In order to add power to the circuit board, power pickups need to be added to the trucks.  This is done in exactly the same way as with my C-628/C-630 dummy chassis trucks and will look similar to the example below. You can read how to do it in this post.


Each truck will need three Fox Valley 36″ metal wheel sets (FVM3611), which are not included in the kit. If you don’t want power pickup then Micro-Trains 36″ plastic wheel sets will also fit but I recommend the metal ones as they add weight to the trucks.  The trucks on their own are very light and more weight helps them run smoothly.

The trucks are HT-C type trucks which EMD used from 1970 to 1994 on their three axle  trucked locomotives, the noticeable feature is the center shock absorber on each side.


As these trucks have been used for such a large range of locomotives I have also made them available on their own.The kit consists of two HT-C trucks and two bolster pins. These can be found here.

Next week I’ll have some more 3D printed products to share with you.

A New Tender Draw Bar for a Marklin 4-6-2 – Part 2

Happy New Year and welcome to 2017, and as promised in last week’s post I have a new product to share with you this week.  Back in November of 2016 I posted about a replacement tender draw bar design for a Marklin 4-6-2, you can read the post here.

The locomotive, as pictured below, is tender powered and the link from the engine to the tender is sprung.  This adds a visual softness to the acceleration and deceleration of the engine by helping to disguise any sudden movements when the locomotive starts and stops.


The original draw bar was badly damaged and so attempting to glue it together wasn’t very practical.


A new draw bar was drawn up and 3D printed in Shapeways Frosted Ultra Detail material.


The picture below shows the original springs fitted nicely into the new part.  The raised strip on the left of the part is to stop the spring moving too far when the draw bar is under compression.  The same detail’s on the right but it’s on the underside.


Test fitting the part went well, as you can see below.  The system fits by locating the loop in the spring around the peg in the locomotive; there is a bolt in the tender which act in the same way.  As the powered tender moves forward the springs compress untill the force matches the strength of the sprung steel.  Then the engine starts to move.


With the loco body fitted there’s a nice close fit between the tender and engine, possibly a little better than the original draw bar as the new one is ever-so-slightly shorter.  Also, because of the spring system, as the locomotive navigates a corner the gap opens up preventing the tender and engine from binding or locking up.


The draw bar also pivots at both ends.  The bolt at the tender end is visible near the front of the tender.  The other end pivots under the front of the cab.


The last thing to do was remove the new draw bar and paint it black.  Once it had dried and been refitted the locomotive was ready for use.


The replacement Marklin 4-6-2 tender draw bar is available from Shapeways here.

Next week’s post will be about another new 3D printed part and I look forward to sharing it with you then.

Capping Off the Chimneys

As well as model train parts I also get asked for building parts, although they are usually for model railway buildings, so this week’s post is about just that; a detail part for the Bournemouth West Station building, to be precise it’s the chimney vents on the top.

Bournemouth West was the terminus station of the Somerset & Dorset Railway which came down from Bath via some spectacular scenery.  I was because sadly the station is no longer there.

The station at Bournemouth West,  as shown below courtesy of Ben Brooksbank on Wikipedia, had some interesting chimney vents.

EPSON scanner image

There are some more photos of the chimneys on John Evans’ Flickr photo stream here and Alwyn Ladel’s Flickr photo stream here.

I was able to get some closer photos of the vents and, by measuring the images using the bricks in the chimney as a scale, I was able to produce a computer model.

Cimney Fins S&D Bournmouth West - Render

These have been designed to be printed in Shapeways’ Frosted Ultra Detail and Frosted Extreme Detail materials for OO/HO scale buildings, and that’s just what I did.

Cimney Fins S&D Bournmouth West 1 Cimney Fins S&D Bournmouth West 2 Cimney Fins S&D Bournmouth West 3 Cimney Fins S&D Bournmouth West 4

The model of the station is being built by Roger Sunderland as are most of the other buildings, and I was able to grab a few shots inbetween the building process.
I’ve made the chimney fins available in a pack of 20 which can be found here.  If you are modeling the S&D this is a difficult detail which can now easily be added to your station.  Once the layout of Bournemouth West is up and running I will give you all a guided tour as it’s going to be a fantastic layout.
I hope once I’ve caught up-to-date with my other projects I’ll be able to add more architectural products to my shop.

Geared Up and Ready To Go

At the beginning of June I shared with you some drawings for a replacement cup gear to be used with a Con-Cor U50/Turbine chassis.  That post can be found here. In this post I’ll show you the 3D printed result.

This new gear is a part used to extend the chassis for use with my Alco C-855 kit.  And this particular gear was designed for the rarer chassis made by Sekisui which has 26 teeth in the gear.  The normal one has only 20 teeth.

Below you can see a render of the two gears.

Alco C-855 Extra Gear

And below you can see the actual 3D printed gear.

New C-855 26 Tooth Cup Gear 1

In truth there isn’t much to see.  The priority was to make sure it fitted into the existing gear and matched the motor teeth, which it did, but it was a very tight fit.  So I decreased the diameter of the tooth section by just a fraction and reprinted the gear.  Now, as you can see below, it fits into the cup gear.  It’s a nice gentle fit and the motor teeth matched the other side.

New C-855 26 Tooth Cup Gear 2

So the last thing to do is to tell you where you can get them, and as usual it’s through the Shapeways shop.

Here is a link to the set of two 26 tooth cup gears for Sekisui-made U50/Turbine chassis.

So, a nice short post this week!  I’ll have something a bit bigger to share with you next week.