Wednesday, 29 July 2015

WF/WFW/WFDY Assembly Tips

Removing Support Structures

Carefully remove the support structure from the wagon.  It is suggested to use a sharp knife to cut the supports away from visible areas.  Take particular care around the steps.  Note that the steps have guards below them to protect them during production and shipping.  It is suggested to leave these guards in place until the majority of the finishing work on the wagon has been completed, to minimise the risk of damage during handling.

Once the majority of the support structure has been removed, carefully go over the wagon and cut away the small supports which typically extend from one part to another including, for example, inside the coupler housing.  An Exacto type hobby knife with a sharp pointed blade (Exacto #11 or similar) is quite useful for getting into the nooks and crannies.  

Go over the model and smooth off any remnants of the fine supports, expecially in the visible areas.  A sanding stick or small file can be useful for this.

Stiffening Rods (Optional)

The WF model includes provision for two metal rods to be inserted within the underframe structure to provide stiffness and guard against possible future warping of the plastic material over time.  Each of the transverse frame members includes two holes approx. 2.2 mm diameter, as part of the 3D print.  The metal rods also add a bit of weight to the wagon.

Location of Stiffening Rods

On the end sill, the hole for the stiffening rod is covered over by a 0.5 mm layer of plastic, opposite the handbrake assembly, as pictured below.  This can easily be drilled through for installation of the rod.  There is a corresponding hole on the diagonally opposite corner of the wagon.

Location of Hole for Stiffening Rod

The rods should be a maximum of 2 mm diameter and 188 mm long.  They can be of any strong metal, e.g. steel or brass.  One source of steel rod is threaded push-rods sold for radio controlled models by manufacturers such as Du-Bro, and available from many hobby shops.  These have a threaded section at one end, but the remainder of the rod is plain, about 1.85 mm diameter. Different lengths are available, e.g. Du-Bro #172 and #173.  Longer lengths are better as several pieces can be cut from it with less wastage.

Once the rod has been glued into position, the hole in the end sill can be filled with modelling putty and lightly sanded to restore the flat surface prior to painting.

Bogie and Coupler Mounting Holes

The mounting holes for the couplers and bogies have been printed at 1.8 mm diameter to suit 2-56 screws.  

Due to the difficulty of tapping the blind holes for the bogies, the 3D print includes vertical grooves in the sides of the holes to help the screws cut their own threads, so tapping the holes is not required nor recommended.  Note that the depth of the blind holes is 4.4 mm.  If using Kadee bogies, the supplied screws may need trimming to avoid damaging the floor of the wagon.

The maximum length for the coupler fixing screws is 4 mm.

Note: An economical source of 2-56 screws in various lengths is Little Bird Electronics.


The suggested bogies are Kadee #569 or #1569, the only difference being the width of the wheels.  Both Atlas and Athearn make similar bogies, but the advantage of the Kadee ones is that they add some weight to the wagon due to the use of a relatively heavy plastic material.


The WMC/WMD is designed for Kadee "whisker" couplers.  Either the #158 (scale size) or #148 (normal size) couplers can be used, with #262 draft gear boxes.

The draft gear boxes supplied with the couplers do not fit as they have a different mounting hole position.  The #262 draft gear boxes, which are available separately, are narrower and have been used because they allow details such as the brake hoses to be positioned the scale distance from the wagon centre line.  Also, the #262 draft gear boxes are easier to use as the lid snaps into position.

Because of the deep end sill on the WF series of wagons, the model has been designed so the coupler and draft gear box slides into a recess via a hole in the end sill.  Make sure that any remnants of support structure from the 3D printing process have been cleaned up from inside the coupler mounting recess.

The draft gear box will probably be a snug fit inside the mounting recess.  A hole had been provided for a 2-56 fixing screw to prevent the coupler from being pulled out.  Note that the maximum length of the screw is 4 mm, so it is likely the screw will have to be cut to length.  Provided a metal screw is first used to create a thread in the provided hole, a nylon screw (e.g. Kadee #256) can be used for the permanent fixing.  A nylon screw is much easier to cut to the desired length.

Note that the height from rail level to the top of coupler mounting surface should be 11.5 mm, the standard for Kadee couplers.


Small starter holes have been provided to locate the square-shaped handrail near the handbrake at each end of the wagon..  The handrail can be formed from 0.4 mm brass wire.  The holes should be drilled out, e.g. with a 0.45 mm drill bit.  The diagram below indicates the dimensions for bending the wire handrail.

Ratchet Handbrake Lever

A short length, approx. 7.5 mm, of 0.4 mm brass wire can be used to simulate the lever of the ratchet handbrake on the end of the wagon.  Glue the wire into the vertical groove in the handbrake assembly.  The top of the wire should be level with the top of the groove, with the remainder of the wire projecting downwards.

Air Brake Hoses

Small brackets are provided next to the couplers on each end of the wagon for air brake hoses.  Cast plastic hoses are available from Detail Associates, part number 6206.  Carefully drill out the starter hole provided in the supporting bracket to suit the diameter of the "pipe" on the air hose.  A suggested drill size is 0.65 mm.

Uncoupling Levers

A small starter hole has been provided underneath the coupler, as well as a notched bracket towards the left side of the wagon, when view from the end.  The uncoupling lever can be shaped from 0.4 mm brass wire, with a 90 degree bend for attachment into the central fixing hole.   The horizontal portion of the uncoupling lever should be approx. 14 mm long.  The diagram below shows the approximate shape to aim for.


If required, additional weight can be added by gluing lead shot or small pieces of sheet lead between the various frame members of the underframe where it would not be seen in normal operation.

Iron Ore Containers

Apart from removing any remaining supports from the 3D printing process, the iron ore containers require little preparation.

The HO version of the container includes two projecting pieces, highlighted in yellow below, which should be cut off and filed/sanded flush with the bottom of the slightly larger, angled projections.  The larger, angled projections are intended to fit into the recesses in the deck of the WFW flat wagon to position the containers.

The reason for the deeper projections is to prevent the angled projections from being sanded flat if the printing supports are removed in the i.Materialise factory.


Either enamel or acrylic hobby paints can be used to paint the finished model.  The model pictured has been painted with Testors Model Master Enamel colour "Gelb RLM 04".  (Gelb is German for yellow!)

Customer Photo Gallery

This gallery contains photos of Marbelup Models products built and painted by customers.

Tasmanian HA and HH hopper wagons by Simon Chandler in Sn3½ scale.
The 3rd wagon in the train is an HH, which was made from two HA's welded together.

Tasmanian HA and HH hopper wagons by Simon Chandler (Jul 2015)
Two FD's and two VD's by Adrian Gunzburg (Apr 2014)
VD van with custom decals by Adrian Gunzburg (Apr 2014)
FD van by Adrian Gunzburg (Apr 2014)
ZBA Brake Van by Stuart Mackay (Feb 2014)
Four CXB Sheep Wagons by Neil Blinco (Feb 2014)
Water Columns by Doug Firth (Feb 2014)
Two CXB's built by Adrian Gunzburg of Melbourne (November 2013)
R1903 Diesel Loco, built by LE from Perth (September 2013)