Wednesday, 31 May 2017

Marbelup Models Home Page

High quality 3D-printed models of Western Australian trains in Sn3½ Scale (mostly) and HO Scale.

New: Westrail DB Loco Project.

For information about pricing and availability of any of these models, please send email to

Thursday, 18 May 2017

R Class Loco Assembly Tips

Parts List

In addition to the 3D printed parts, the following parts must be obtained separately by the modeller:
  • For pre 2017 Models only - 2 brass I-beams (Special Shapes Part No. B-6-3)
  • Brass wire for handrails, etc. (0.4 mm, 0.6 mm)
  • Brass chain (40 links per inch) if modelling original version with chain "handrails" e.g. North Yard CH40 (2 packs required per loco)
  • Air hoses - e.g. Detail Associates #6206 (Vacuum brake hoses are included.)
  • Handrail Posts (4) for uncoupling levers - e.g. Markits 1.5 mm(short - available from Railwest Models.
  • Bogie drive mechanisms - see below (Hollywood Foundry)
  • Motor - Mashima 1833D Flat Can (double shaft, 2 mm diameter, includes fixing screws) (Hollywood Foundry)
  • Drive shaft(s) - 1.5 mm diameter, 65 mm long (cut to exact length) (Hollywood Foundry)
  • Universal Joint set for 1.5 mm shafts (Hollywood Foundry)
  • Flexible coupling(s) for motor end(s) of drive shafts - suggestion is to use model aircraft fuel tubing, approx. 1 mm ID, 4 mm OD.  
  • DCC decoder and speaker (both optional)
  • Light Emitting Diodes (LEDs) for headlights 4 x 3 mm (sunny white)
  • LEDs (red and white) and optic fibre, if operating marker lights desired
  • paint as desired
  • lead or other weighting material
  • Kadee couplers #156 ("scale") or #146 (normal size)
  • Kadee draft gear boxes #252
  • Fixing screws for body, couplers and fuel tank e.g. Kadee #256 - 12 holes are included correct size (1.8 mm) ready for tapping 2-56.
  • Fixing screws for speaker M1.4 x 6 (slightly longer is OK) - 4 holes are included correct size (1.1 mm) and screws should make their own thread, tapping shouldn't be required.  Suitable screws are available from DCC Concepts - Part No. DCS-PHB156 or in assortment DCS-PHBSet.  Although described as 1.5 mm, the DCC Concepts screws are actually M1.4 thread. Note:  DCC Concepts now supplies pan-head and countersunk screws interchangeably, so you can't be sure of getting one or the other.

Bogie Drive Mechanisms

The bogie drive mechanisms can be ordered direct from Hollywood Foundry. The ordering specifications are as follows:

Drive bogie specifications: G16.5/B28.6+25/W14-110/15:1DUALBELT/NOBOL
Dummy bogie specifications: G16.5/B28.6+25/W14-110/NOBOL

To order the above bogie configurations, please use the special order page on the Hollywood Foundry web site and copy and paste the above codes into the Product Description field.  

The modeller has the choice of fitting two identical drive bogies or one drive bogie and a matching dummy bogie, depending on the required hauling capacity.  

If a single drive bogie is fitted, this would normally be placed at the rear to keep the cab free for interior detailing if desired.  However, the drive shaft is quite low above the footplate level, so there is minimal intrusion into the cab when two drive bogies are fitted.

The current (February 2016) pricing for the required Hollywood Foundry parts is:

Drive bogie - $91.30 (same price as Bullant In-Line 3-Axle)

Dummy bogie - $52.80 (same price as Bullant 3-axle Dummy)
    Motor: Mashima M1833D - $31.35

    Universal Joint Set for 1.5 mm shafts (set contains parts for 4 joints.  1 joint is required per drive bogie, but it is recommended to purchase 1 set per loco to allow for some "spares".) - $4.19 per set

    Drive shafts are available from Hollywood Foundry although the required 65 mm length is not a standard product. Check with Hollywood Foundry for availability.  Alternatively, 1.5 mm brass or steel rod can be used.

    Silicone Tubing - used for flexible coupling between motor and drive shaft(s).  Supplied free by Hollywood Foundry if requested when ordering other parts.  Tubing will fit both 2 mm motor shaft and 1.5 mm drive shaft. 

    The prototype 3D-printed chassis showing central motor, Tsunami AT-style DCC sound decoder, drive shaft, belt drive and speaker "duct" with tunnel for drive shaft.
    The chassis does not have provision for a flywheel.  The main reason is that the motor is mounted low down, partly in the fuel tank, to get a "straight line" drive shaft alignment.  Also, the speaker is very close to one end of the motor, which was necessary to avoid the narrow part of the body just behind the cab.

    DCC and Sound

    The chassis is specially designed to accept a 23 mm square high-bass speaker (Soundtraxx 810129 or equivalent) if a sound decoder is to be installed.  The speaker faces downwards on a "sound duct" which has a "tunnel" through it for the front drive shaft.

    Although the choice of specific sound decoder is very subjective, the Soundtraxx Alco 244 Tsunami decoder sounds similar to the English Electric diesel engine in the prototype, and is probably the closest available "off-the-shelf" decoder.  The Tsunami "AT" style decoder model 828043 (pictured above) is suitable and slightly cheaper than the TSU-1000 style model 827104.

    Note: The above links are for the SoundTraxx web site.  SoundTraxx do not sell direct but their products are available from many retailers.


    The suggested couplers are both "long shank" style which avoids the problem of the "glad hand" on opposing couplers from fouling the cowcatcher.  The choice between normal and "scale" size is up to the individual modeller.

    Also, the suggested Kadee #252 draft gear boxes should be mounted upside down (as per the photo on the right on the Kadee web site). The round boss on the upper side needs to be trimmed away to allow the assembled coupler to slide into the headstock opening.

    Other types of couplers can potentially be installed by modifying the headstock and/or coupler mounting pad.

    Handrails and Chains

    As delivered, the R class had round handrail posts with chain between them rather than solid handrails.  This was a feature of the R class and was necessary to allow the doors on the side of the long hood to be opened.

    Later, the chains were replaced with solid handrails but with removable segments to allow the doors to be opened.

    The 3D-printed chassis incorporates slots intended to house 2 mm x 0.25 mm brass strip soldered to the bottom of each handrail post, of which there are 25.  This approximates the prototype bracket arrangement and allows the handrail posts to be positioned right at the edge of the footplate.

    The handrail posts can be made from 0.6 mm brass wire and should be 16.7 mm high.  The brass strip should be soldered to the bottom of each post, with 1.1 mm overlap, and project a maximum of 1.8 mm below the bottom of the handrail post.  A suggested construction method is to leave the brass wire and strip as long lengths, and tape them down to a heat resistant surface with the  required overlap, then solder the joint and trim both to the required length.  The brass strip will probably require filing to remove any rough edges prior to insertion into the slots in the chassis.

    Suitable chain is available from North Yard in New Zealand, part number CH40 (300 mm length).  Two packs are required per loco.  Railwest Models normally stock this chain also.

    Chassis - Removal of Support Material

    Carefully cut away the support materials from the delicate areas highlighted in the drawing below which are:
    • Bolsters with bogie chain brackets approx. 6 mm in from edge of footplate (2 per side)
    • Triangular footplate supports (4 per side)
    • Sandboxes (2 per side)

    Once these areas have been done, the remainder of the support material can be gently torn away by wiggling a section of it to break the fine attachment points.  

    The remnants of the support attachment points should be removed with a sharp hobby knife, filing or sanding on all visible areas, including the bogie attachment points.

    Chassis - Assembly of Brass I-Beams (Pre 2017 Models Only)

    From 2017, the I-Beams are included in the 3D-printed chassis.  The brass I-Beams are not required.

    The underside of the chassis includes two longitudinal slots which are designed to provide a secure attachment for the brass I-beams.  The brass I-beams add some weight and rigidity to the chassis, as well as replicating the appearance of the steel I-beams in the prototype chassis.

    Cut the brass I-beams to a length of 236 mm, or a fraction under.  The I-beams should fit between the inside of the headstocks with a small amount of room at each end so that they do not exert any outward pressure on the headstocks.  Keep the offcuts as they will be useful for checking the fit of the I-beams in the mounting slots.

    At this stage, it is advisable to cut 3 notches in the lower inside flange of each I-beam to facilitate later access to the fixing screws which attach the chassis to the body.  The suggested shape of the notches is highlighted in yellow below.

    The diagram below is a cross-section of the footplate, with the I-beams highlighted in yellow.  The intention is that the I-beams are inserted into the slots, then slid outwards so that the flange on the I-beam engages in the groove to provide a secure attachment.

    Once the support materials have been removed from the underside of the chassis, it will be necessary to do some cleaning up of the I-beam slots.  Firstly, check for any remnants of supports materials on the inside surfaces of the slots and, in particular, in the narrow groove. Cut away any remnants with a sharp hobby knife.

    After filing any burs from the cut end of an offcut of I-beam, test fit it to see whether it will slide into the groove at various locations along the length of the chassis.  Moderate pressure with a screwdriver will probably be required to encourage the I-beam to slide sideways into the groove.  If there are tight spots, don't force it at this stage, as the groove will probably require cleaning out.

    It may be necessary to make a tool from metal strip approx. 6 x 0.5 mm, by bending the first 3 mm from the  end of the strip at right angles.  Insert the bent end of the tool into the groove and slide it along to find and remove any remnants of plastic support material which may be obstructing the groove.  Be careful not to damage the triangular supports under the footplate, the bolster ends or sandboxes.

    Once the groove has been cleaned out so that the offcut of I-beam fits at any point along it, insert the full-length I-beam and gently slide it sideways to engage in the groove.  When satisfied that the I-beam is fully engaged in the groove along its full length and the notches in the lower flange are aligned with the fixing screw locations, it can be glued in position.

    Chassis Height

    The finished height of the footplate should be 23 mm.  Spacers with a nominal thickness of 1 mm are required between the Hollywood Foundry bogies and the underside of the footplate.  The thickness of the spacers can be varied slightly, if required, to adjust the coupler height to match a Kadee coupler height gauge.

    Friday, 30 September 2016

    Marbelup Models Home Page

    High quality 3D-printed models of Western Australian trains in Sn3½ Scale (mostly) and HO Scale.

    New: Westrail DB Loco Project.

    For information about pricing and availability of any of these models, please send email to

    Sunday, 11 September 2016

    AQNY AKZY Assembly Tips

    Parts List

    • Bogies: e.g. Kato 31-602 Barber S-2 Roller Bearing Bogies with 840 mm (33") wheels. 
    • Couplers: Kadee #148 or #158
    • Coupler boxes: Kadee #252 (supplied)
    • Air Brake Hoses, e.g. Detail Associates #6206 or Kadee #438.
    • Brake wheel e.g. Kadee #2025 or similar
    • Brass wire: 0.3 mm and 0.4 mm for handrails, and brake piping
    • Fixing screws: (see below)
    • Glue, paint, decals
    Marbelup Models has limited stocks of the Kato bogies for sale.

    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 and delicate parts.  Take particular care around the bottom of the steps, and the triangular bracing inside the centre portion of the wagon.

    The following image highlights the more delicate parts, some of which are only visible once the outer layers of supports have been cut away.

    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, on the end ribs and bogies bolsters.  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.

    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 3.3 mm.  The bogie fixing screws may need trimming to avoid damaging the floor of the wagon.

    The wagon includes projections from the bolsters, to match the height of the Kato bogies, and provide "3-point suspension" to minimise side-to-side rocking of the wagon.  If fitting other types of bogies, these projections may need to be modified or removed.

    The holes for mounting the couplers are also blind, but should be drilled right through the floor with a 1.8 mm drill to obtain a strong fixing.  These holes should be tapped 2-56.  Note that one end of the wagon has two blind holes for couplers.  The one closest to the end of the wagon is for a Kadee coupler and the hole closest to the bogie fixing holes is for the rotary coupler option.

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


    The suggested bogies are Kato 31-602.  These are pretty much "exact", differing only in having 2 springs visible at the bolster ends rather than 3. Note that the Kato bogies have the correct size wheels 840 mm (33") which are smaller than those fitted to most other Westrail standard gauge wagons.

    Note that the depth of the blind holes for the bogies is 4.3 mm.  The fixing screws may need trimming to avoid damaging the floor of the wagon.  Do not drill the bogie mounting holes right through, as they will be visible on the finished model.

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


    Because of the thin floor section, the model has been designed so the coupler and draft gear box slide into a recess 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.

    You will need to remove the cylindrical projection from the top of the Kadee #252 draft gear boxes - highlighted in red in the diagram below.

    The draft gear box will probably be a snug fit inside the mounting recess.  A hole has 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 3.9 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.

    Kadee nylon 2-56 screws are available from good hobby shops.

    Brake Piping

    The brake piping can be formed from 0.3 and 0.4 mm brass wire.  There are long, angled pipes at each end, and short 90 degree pipes connecting to the brake valve/cylinder assembly.  The main pipes running along the inside of the wagon frame are printed in place.

    The diagram below shows the approximate dimensions for forming the brake piping.

    The shorter pipe to the brake cylinder is 0.4 mm as is the long pipe at the same end.  The other 2 pipes should be 0.3 mm.

    Small starter holes have been provided for attachment of the brake piping.  These should be opened out with a small drill bit or broach.  (Sets of tapered broaches are available from good hobby shops.)


    The wagon has short handrails at each corner, and an L-shaped handrail attached to the brake wheel supports.  These can be formed from 0.4 mm brass wire.  Small starter holes have been provided to locate the handrails, which should be drilled out, e.g. with a 0.45 mm drill bit in a pin vice.

    The holes for the horizontal four handrails are 4.3 mm apart (centre to centre).  These handrails should be bent with an inside radius of approx. 0.6 mm (e.g. using a 1.2 mm drill bit).  The total height of the handrails should be approx 2.5 mm and, when installed, the top of the handrail should be 1 mm above the wagon deck.

    The L-shaped handrail should also be bent with a inside radius of approx. 0.6 mm.  The horizontal leg should be approx. 6.5 mm long, and the vertical leg approx. 7.5 mm long.

    All handrails should be fixed into position with superglue.

    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.

    An alternate (cheaper) brake hose is the Kadee #438.  These have a rectangular mounting pin which requires the holes to be drilled out to approx. 0.8 mm.  It is suggested to drill the holes out in a number of stages, using successively larger drill bits, to avoid over-stressing the brackets.

    Uncoupling Levers

    Notched brackets have been provided at both ends of the wagon for the uncoupling levers, together with a longitudinal hole just below the coupler.  The uncoupling lever can be shaped from 0.4 mm brass wire.   The diagram below shows the approximate shape to aim for, but feel free to adjust the measurements to suit your model.

    After positioning the uncoupling lever, check that the coupler can swing freely and is not obstructed, prior to gluing it into position.

    Handbrake Wheel

    A 0.5 mm spigot has been provided on the handbrake assembly, to which the wheel can be glued.  If necessary, open out the central hole in the handbrake wheel with a 0.6 or 0.7 mm drill bit to fit over the spigot.


    With the suggested Kato bogies, the completed AQNY weighs approx. 24 grams.  For this length wagon, the NMRA recommended weight is 125 grams, although some modellers feel that the NMRA weight recommendations are excessive.  A total weight of somewhere between 100 and 115 grams is probably about right.

    Due to the "skeletal" design of the wagon, there is not much scope to add weight where it can't be easily seen.  Weight can potentially be added to the container "load".  If using the Marbelup Models BIS sulphur containers, provision has been made to fix weights inside the containers.  It is suggested that any added weight be concentrated over the bogie ends of the containers, to avoid causing the wagon to sag in the long term.


    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!)  A white undercoat (e.g. Testors Model Master 2748 enamel) is recommended to enhance the yellow colour.  

    Wednesday, 31 August 2016

    Marbelup Models Home Page

    High quality 3D-printed models of Western Australian trains in Sn3½ Scale (mostly) and HO Scale.

    New: Westrail DB Loco Project.

    For information about pricing and availability of any of these models, please send email to

    Tuesday, 5 July 2016

    Marbelup Models - Available for Immediate Purchase

    The following models are available from stock for immediate purchase:

    • 4 x WW Standard Gauge Wheat Wagons (HO Scale)... $80 each.
    • Sold - 6 x WO Standard Gauge Iron Ore Wagons (HO Scale)... $40 ea., $35 ea. for 5 or more.
    • 1 x WF/WFDY Standard Gauge Flat Wagon (HO Scale)... $55 each
    • 1 x WFW Standard Gauge Flat Wagon for Iron Ore Containers (HO)... $55 each
    • 3 x Iron Ore Containers for WFW (HO Scale)... $55 per set of 3.
    • Sold - 1 x AGWY Standard Gauge Wheat Wagons (HO Scale)... $75 each.  
    • Sold - 1 x WBC Standard Gauge Brake Vans (HO Scale) ... $90 each plus 3D printed bogies... $30 per pair (bearings included, wheels not included) 
    • Sold - 1 x CXB Sheep Wagon... $105 (sheep also available). More available to order.
    • Sold - 1 x FD Louvre Van... $75
    • 1 x DC Van (no diagonal braces)... $85 each
    • 1 x DC Van (flat diagonal braces)... $85 each
    • 1 x VG bogie louvre van... $110.  More available to order.
    • Roofwalk only for DC Van... $10 for 2.
    • Sold - 1 x WMD Hopper Wagon... $85 plus 3D printed bogies... $30 per pair (bearings included, wheels not included)
    • Sold - 3 pairs American Models Bettendorf bogies with 3D-printed narrow gauge bolsters... $20 per pair (wheels not included).  - trying to order more from American Models.
    • 5 x WAGR Water Columns, extended version: $15 each.
    Available soon (currently on order from i.Materialise):

    Note:  This section will be updated when items are sold or new items become available, so check in from time to time to see what is available.  Any other item from the Marbelup Models catalogue is available to order in approx. 2-4 weeks.

    Friday, 1 July 2016

    Marbelup Models DB Loco Kit Project

    The Marbelup Models project to produce a 3D-printed "kit" of the Westrail DB diesel locomotive in Sn3½* scale is going ahead!

    Basically, the "kit" will consist of 3D-printed parts for loco body, underframe, fuel tank and bogie sideframes,   The general construction will be similar to the Marbelup Models D and DA locos.

    The expected "kit" cost will be about $350 per loco.  (Actual cost subject to variation due to exchange rate variations against the Euro and/or prices increases in 3D printing.)

    To complete the loco, the purchaser must also source a mechanism as well as some detail parts, screws, couplers, DCC decoder (if required), paint, decals, etc.  Assembly instructions will be available online.

    One option for the mechanism is the "inline" drive bogies available from Hollywood Foundry, as have been used for the D and DA locos,  Other mechanism options are also being explored.

    Some modellers have paid a $100 deposit as per the initial invite for "expressions of interest" published in May 2016.  Those who have paid a deposit will take priority as the kits become available.  Additional kits will be available after the initial orders have been fulfilled, and there is no fixed limit to the number of kits produced, due to the 3D-printing process which allows additional kits to be produced "on demand".

    Deposits are still being accepted, which will secure a place in the "queue" for delivery.  A $100 deposit per loco can be paid by PayPal (to or Bank Transfer.

    Expected delivery time: 1 year, i.e. by end of June, 2017.

    Deposits refundable only if Marbelup Models unable to deliver, for any reason, after 2 years, that is by end of June 2018..

    You can pay the $100 deposit using the PayPal link below:

    Specify Scale and Gauge*

    Please email Marbelup Models for bank details if you wish to pay by Bank Transfer.

    Please note that complete ready to run locos will not be available from Marbelup Models, although it is possible that "third parties" may offer an assembly and/or painting service at additional cost.

    * The DB loco kits proposed in HO and HOn3½ scale will not be produced at this stage, due to lack of paid deposits from HO modellers.  The idea of producing kits in HO scale may be revived at some time in the future but only if there is strong interest.