OO Gauge Fixed Link Couplings – Part 6

As promised in last week’s post I’ve been busy getting all the OO Gauge Fixed Link Couplings ready and uploaded onto Shapeways, and the Short series are now ready to buy.

The Short series will work for the majority of rolling stock and I’ve added a page which describes all the couplings and sample packs in detail, and that can be found here along with the links to buy each product.

The Medium and Long couplings will be available soon.

I’ve been asked if these couplings can be used for coaches as well.  The short answer is ‘yes’, but they are not very prototypical, as coaches normally have different couplers from freight stock.  But don’t panic as I also have a new and simple coach NEM coupler which is designed for exhibition and home layouts.  It will allow close coupling of coaches without the chance of uncoupling on the layout, but, and this is the good bit for exhibitions, when lifted from the layout the coaches separate straight away, making for a quick pack away after the show.  I’ll be sharing this with you, hopefully next week.

OO Gauge Fixed Link Couplings – Part 5

This week’s post will be short as I’ve been busy getting the new OO Gauge Fixed Link Couplings ready for the Shapeways shop.

As well as the sample sets I made available last week (see the post here) Types 1, 2, 7 & 8 are now available in packs of 4, 10 and 25.  As a reminder as to which couplings they are, please see the table below, which you can click on to make bigger.

Hopefully by next week I’ll have the rest up on the site as well.  If there’s a specific combination of couplings you would like please feel free to get in touch.

OO Gauge Fixed Link Couplings – Part 4

This week I have some good news for my OO Gauge Fixed Link Couplings.  All the designing is done and the sample packs are ready.  If this coupling project is new to you, you can read more about it in the previous post here.

All of the different types of OO Gauge Fixed Link Couplings can be seen in the table below.  The main couplings are numbers 1, 2, 7 & 8. These should work for the majority of models.  However as I described in part 2 of this project some manufacturers have set their NEM sockets at different heights so I have also supplied adaptors to cover all situations.

The first fifteen are the shortest and designed to give 18mm between each NEM socket.  Should your layout have tight curves or you have a model with the NEM socket set further back then all the couplings have been repeated for 19mm and again for 20mm.  The extra distance on tight curves will avoid buffer lock which can derail wagons.

Both the 5.5mm Step Up and the Loose 3 Link couplings were a special request from a fellow modeller so I have included them in the range.  Please note that the 5.5mm Step Up will require any existing molded hook to be removed from the wagon but it will put the coupling at a more prototypical height. Also the Loose 3 Link only has the center link loose, both outer links are fixed; this means there will be some slack in the coupling but it’s only good for pulling rather than shunting.

Given how many different types are on the table I’ve made five different sample packs available.

NEM OO 3 Link & Instanter Couplings – Basic Sample

This contains one of each coupling types 1, 2, 4, 5, 7, 8, 10 & 11.

NEM OO 3 Link Couplings – Sample Set

Containing one of each type: 1, 4, 7, 10, 16, 19, 22, 25, 31, 34, 37 & 40.

NEM OO Instanter Couplings – Sample Set

Containing one of each type: 2, 5, 8, 11, 17, 20, 23, 26, 32, 35, 38 & 41.

NEM OO 3 Link & Instanter Couplings – Sample

Containing one of each type: 1, 2, 4, 5, 7, 8, 10, 11, 16 ,17, 19, 20, 22, 23, 25, 26, 28, 29, 31, 32, 34, 35, 37, 38, 40 & 41.

NEM OO 3 Link & Instanter Couplings – Advanced Sample

Containing one of each type: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 & 15.

The packs containing lots of the individual couplings are currently being uploaded and will be available by next week.

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.