Friday, 29 December 2017

Marbelup Models - Available for Immediate Purchase

The following models are available from stock for immediate purchase:

  • Sold - 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) 
  • 1 x CXB Sheep Wagon... $95 (sheep also available).  More CXB's available to order.
  • 2 x SXT Bogie Sheep Wagon... $195 each (sheep also available).
  • Sold - 1 x FD Louvre Van... $75
  • Sold - 1 x DC Van (no diagonal braces)... $85 each
  • Sold - 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.  More on order.
  • 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):
  • More roofwalks for DC vans.
  • 1 x CXB sheep wagon

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.


Tuesday, 12 December 2017

WMC/WMD Construction 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 brake hoses and end steps.

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, for example, around the brake cylinders and other detail items.  An Exacto type hobby knife with a sharp pointed blade (Exacto #11 or similar) is quite useful for getting into the nooks and crannies.  For some parts around the brake cylinders where even a fine knife blade won't reach, a piece of wire (e.g. 0.8 mm spring steel wire) can be used to push against the support attachments and break them off.

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.  Clear out the holes with a 1.8 mm drill in a pin vice, but it is preferable to NOT drill through the floor to avoid the screws being visible on the finished model.

Due to the difficulty of tapping the blind holes, 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.

Bogies


The bogie mounting points are designed to be 10 mm above rail level.  Depending on the bogies used and the height of their bolsters, it may be necessary to add washers or similar so that the coupler mounting surface is 11.5 mm above rail level.

Marbelup Models WMC/WMD Bogie
Marbelup Models has 3D-printed bogies of the correct design for the WMC/WMD available for sale.  Similar bogies, although of slightly different shape, are available from Black Diamond Models in Queensland.  The Black Diamond bogies are cast in white metal and are supplied fully assembled with wheels.

Assembly of 3D-Printed Bogies



The Marbelup Models WMC/WMD bogies are printed in two identical halves.  A set contains four pieces to make one pair of bogies.  As with other 3D printed parts, the first step is to removed the supports structure and clean up the small supports in the holes in the bogie sideframes, around the springs, etc.  Take care around the brake shoes to avoid breaking them.

The bolster section of each bogie half contains two holes intended for M1.4 screws (which are supplied with the bogies).  The larger hole nearest the narrow end of the bolster is a "clearance" hole and should be cleaned out with a 1.4 mm drill.  The smaller hole, nearest the bogie sideframe, should cleaned out with a 1.1 mm drill and tapped with an M1.4 tap.  (Drills and taps are available from North Yard in New Zealand.  The M1.4 tap is part No. 3014.  Refer to Page 5 of the North Yard Catalogue.)

An alternative to M1.4 screws is to use 1.5 mm x 6 mm self tapping screws, which are available from DCC Concepts - Part No. DCS-PH156.  If using self tapping screws, the smaller holes should be drilled out to 1.1 or 1.2 mm.  If the screws seem tight with 1.1 mm holes, try 1.2 mm, especially with bogies printed in Standard Resin (clear yellow rather than grey), which is somewhat less flexible.  The clearance holes should be drilled to 1.5 mm.

The bogie sideframes contain holes for fitting brass pinpoint bearings (available from Railwest Models).  These holes should be cleaned out with a 2 mm drill bit, after which the bearings should press fit into place.  The bogie is designed for 12 mm wheels with 26 mm axles.

When assembling the two halves, it may be necessary to trim the narrow end of the bolster by approx. 0.25 mm to get good alignment of the fixing holes and centre pivot hole.  (Later production will be made slightly shorter.)  After assembly, clean out the centre pivot hole with a 2.2 mm drill bit to suit 2-56 mounting screws.  (2.2 mm provides adequate clearance without excessive slop.)

Couplers


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 WMC/WMD is also available with correct scale coupler height for WAGR/Westrail narrow gauge, in which case #252 draft gear boxes are used.

The draft gear boxes supplied with the couplers do not fit as they have a different mounting hole position.  The #262 draft gear boxes 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.

Note that the height from rail level to the coupler mounting surface should be 11.5 mm, the standard for Kadee couplers.  The 2-56 6.35 mm (1/4") long screws commonly used for couplers are slightly too long for the blind holes.  Options are to shorten the screws by 0.5 to 1 mm, or to add a flat washer between the head of the screw and the coupler.  Railwest Models sells suitable washers with a 2.2 mm hole diameter.  If using scale coupler height, the height to the coupler mounting surface should be 13.8 mm. 

Stiffening Rods


The WMC/WMD 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.

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.

Drill location for stiffening rod
The rods should be a maximum of 2 mm diameter and 140 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. 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.

Handrails


Small starter holes have been provided to locate the various handrails.

The WMC has just two handrails on opposite corners.  These can be formed from 0.6 mm brass wire.  Viewed from above, the handrail is an L-shape, with the horizontal portions about 6.25 mm long.  The height from the floor to the top of the handrail should be about 9.5 mm.  The vertical post nearest the coupler can be cut about 2 mm over-length to provide a secure (glued) fixing into the floor.  The vertical post near the side of the wagon should only be over-length by just 0.5 mm so the end of the wire is not visible from the side.

In addition, the WMD has 3 handrails on each end of the hungry boards.  Thinner brass wire, e.g. 0.4 mm should be used for these.  The hole centres for each handrail are 4.75 mm.  The WMD also has wire handrails/steps across the tops of the "chutes" at each end of the hopper.  The 3D print includes small notches for locating these, and the length of the wire should be 9.5 mm (8 required).

Note that the position of handrails and other details varies between different members of the WMD class.  The model depicts the most common arrangement, based on photos of various prototype wagons.

Door Lock Shafts


As part of the locking mechanism for the bottom discharge doors, there are two shafts which have to added using brass wire, either 0.5 or 0.6 mm.  The length of each piece of wire is 40 mm, although it is probably easier to feed a longer length of wire through the holes provided, then trim it to length with fine wire cutters after it has been glued into place.

Location of Door Lock Shafts

Brake Levers and Chains


The handbrake ratchet assembly on the end of the wagon includes a vertical groove to house a 10 mm length of 0.4 mm brass wire, to represent the handbrake lever.  Superglue is recommended for attachment of the wire.

A distinctive detail of the WMC/WMD are the chains running across the floor which connect the handbrake mechanisms with the brake linkage underneath the vacuum cylinders.  North Yard (NZ) make a suitable fine chain which is available from Railwest Models.

Threading the fine chain through the three guides at each end is a bit tricky.  It helps to use a piece of fine but soft wire as a "needle".  The 0.25 mm diameter inner conductor from "wire-wrap" wire used for electronics is suitable.  (If you ask nicely, you might be given a piece with your WMC/WMD!)  Once threaded through the guides, one end should be glued into the small notch provided for the purpose in the horizontal "angle iron" underneath the vacuum cylinder.  Once that end is fixed, the other end should be threaded through the support bracket for the handbrake which has a tapered keyhole-shaped hole.  When gently tensioned, the free end of the chain can be glued into the tapered hole to secure it, and the excess chain trimmed from underneath with fine wire cutters.

Weighting


With the Black Diamond (metal) bogies, the completed wagon weighs around 72 grams.  The "desirable" weight for a wagon of that length (140 mm) is around 95 grams to ensure optimum operation including operation of Kadee couplers.  (See the Sn3½ blog for more information.)

If requred, additional weight can be added by gluing lead shot or small pieces of sheet lead between the various frame members of the underframe, e.g. either side of the hopper doors, where it would not be seen in normal operation.

Painting


Either enamel or acrylic hobby paints can be used to paint the finished model.  The model pictured has been painted with Revell Hobby Enamel.

WSH/XM Ballast Wagon Instructions

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 and the handwheels underneath the side of the wagon.  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.

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

Bogies


HO Scale - 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.  Note that the depth of the blind holes is 3.4 mm for the HO model.  If using Kadee bogies, the supplied screws may need trimming to avoid damaging the floor of the wagon.

Sn3½ Scale - Marbelup Models makes specific bogies for the XM wagon, representing the prototype's standard gauge bogies with narrow gauge wheelsets.  The wheels should be larger than is normal for narrow gauge wagons.  Suitable wheels (14 mm diameter, 26 mm axles) are available from North Yard (NZ) and DCC Concepts.  Please note the gauge of the DCC Concepts wheels is slightly greater compared to  the NMRA RP25 standard, which can cause problems with the wheels "picking" point frogs.  It is suggested the DCC Concepts wheels be tested with your trackwork before purchasing in quantity.

The method of assembly for the bogies is the same as for the WMC hopper wagons except that the holes for the fixing screws are inclined at 10° above the horizontal so that the axles do not get in the way of the screwdriver.

Couplers


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, although the normal size couplers are more appropriate.  Couplers are also available from Kadee in bulk packs without draft gear boxes.

The draft gear boxes supplied with the #148 or #158 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.

For the HO model, the coupler fixing screws should be trimmed to about 3.8 mm so the top of screw is flush with the deck of the wagon.  One option is to use a metal 2-56 screw to form the thread in the plastic material, then use a Kadee Nylon 2-56 screw for the final installation, which is easier to cut to length.

Since mid 2017, the design for the XM has been modified so that the couplers are at the correct height for WAGR standard gauge, i.e. 13.75 mm (measured to the centre of the coupler).  Note that the corresponding height from rail level to the top of coupler mounting surface should be 15.4 mm.

If desired to fit couplers at the Kadee standard height for HO (9.9 mm), the couplers should be shimmed down by approx. 3.75 mm.  An alternative, is to use a Kadee "overset" coupler which reduces the height by approx. 1.25 mm, although a shim will still be required to match the HO coupler height.

Note that the prototype XM wagons retained their standard gauge coupler height.  When used with narrow gauge "chopper couplings", the wagons at the end of a rake were fitted with "gooseneck" couplers to reduce the coupler height.

Wire Details


There are quite a few details to be added from brass wire.  The following sequence is suggested:

Discharge Doors Mechanism


Note that the eight 4-spoke handwheels have been printed as part of the model.  In addition, some spares have been printed at the end of each of the discharge hoppers.  Carefully cut away the spare handwheels using a sharp knife, and retain in case of any breakages.  Smooth off any remnants of the attachment points on the ends of the hoppers.


The longitudinal shafts are shown in blue on the diagram above.  Suggested sizes are as follows:

  • HO, Outer Shafts: 0.6 mm wire, 25.75 mm long (4 required)
  • HO, Inner Shafts: 0.6 mm wire, 27.5 mm long (4 required)
  • Sn3½, Outer Shafts: 0.8 mm wire, 35 mm long (4 required)
  • Sn3½, Inner Shafts: 0.8 mm wire, 37.5 mm long (4 required)

The transverse shafts are shown in red on the diagram above.  Suggested sizes are as follows:

  • HO: 0.4 mm wire, 12.75 mm long (4 required)
  • Sn3½: 0.5 mm wire, 16.5 mm long (4 required)

Before installing the various shafts, clean out the holes in 3D-printed material with a pin vice and drill bit fractionally larger than the wire size, e.g. 0.05 - 0.1 mm larger.  Drill carefully to avoid breaking any of the parts from the model.  For the longitudinal shafts, another option for cleaning out the holes is to cut a spare piece of wire, say about 100 mm long, at an angle with sidecutters, so as to leave a slightly ragged edge.  By holding this wire in a pin vice, it can be used as a crude drill to ream the three holes for each shaft.

Secure all the wire pieces in position with superglue.

Brake Rods


The are five brake rods to be formed from brass wire.  Suggested sizes are as follows:

HO Scale:
  • Rod A - 0.4 mm wire, 24 mm long, bent 90° one end
  • Rod B - 0.4 mm wire, 19.5 mm long, bent 90° one end
  • Rod C - 0.4 mm wire, 11.75 mm long, bent 90° both ends *
  • Rod D - 0.4 mm wire, 6.4 mm long, bent 90° one end
  • Rod E - 0.4 mm wire, 36.5 mm long, bent 90° one end
S Scale:
  • Rod A - 0.4 mm wire, 32.5 mm long, bent 90° one end
  • Rod B - 0.4 mm wire, 26.5 mm long, bent 90° one end
  • Rod C - 0.4 mm wire, 20 mm long, bent 90° both ends *
  • Rod D - 0.4 mm wire, 9 mm long, bent 90° one end
  • Rod E - 0.4 mm wire, 50 mm long, bent 90° one end
* Fixing hole for "chain" end of Rod C is marked by a dimple on the underside - drill through from underneath.

Secure all the wire pieces in position with superglue.

Brake Rods - Top View (Hopper hidden for clarity)

Vertical Handrails


Each of the vertical posts at the corners of the hopper has a vertical handrail, which can be formed from 0.4 mm brass wire.  The distance between the hole centres is 10.5 mm for HO, and 14.25 mm for S scale.

Corner Handrails


Small starter holes have been provided to locate the handrails near the handbrake at each end of the wagon..  The handrails can be formed from 0.4 mm brass wire.  The holes should be drilled out, e.g. with a 0.45 mm drill bit.

Viewed from above, the corner handrails are L-shaped, the longer leg of the "L" being parallel to the side of the wagon.

For HO, the horizontal legs of the "L" are 3 mm and 2.5 mm long.  The vertical legs of the handrail should be 5.5 mm long, including an allowance of  0.5 mm to be glued into the fixing holes.

For S scale, the horizontal legs of the "L" are 4.5 mm and 3.5 mm long.  The vertical legs of the handrail should be 7.5 mm long, including an allowance of  0.5 mm to be glued into the fixing holes.

Ratchet Handbrake Lever


A short length of 0.4 mm brass wire can be used to simulate the lever of the ratchet handbrake on each end of the wagon.  The length of the wire should be approx. 5.5 mm in HO and 7.5 mm in S scale.Glue the wire into the vertical groove in the handbrake assembly.  The bottom of the wire should be level with the bottom of the groove, with the remainder of the wire projecting upwards.

Uncoupling Levers


A spiggot with a vertical fixing hole has been provided underneath the wagon, next to 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 diagrams below show the approximate shape to aim for, but feel free to adjust the measurements to suit your model.

After positioning the uncoupling levers, check that the coupler can swing freely and is not obstructed.  After fixing the uncoupling levers in place, it should still be possible to remove the coupler and draught gear box, e.g. for painting the wagon, by sliding it out towards the end of the wagon.

S Scale - Approximate Measurements
HO Scale - Approximate Measurements




Air Brake Hoses


Small brackets are provided next to the couplers on each end of the wagon for air brake hoses.  Cast plastic hoses in HO scale are available from Detail Associates, part number 6206.  In lieu of equivalent hose in S scale, the HO ones could be used also.  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.


Cross Braces

The top of the hopper had small notches on the inside to accommodate 7 cross braces cut from 0.75 x 1 mm styrene strip.  The HO, the length should be 31 mm and, for S scale, 42 mm.  The braces should be pushed to the bottom of the notches so that the top of the braces is slightly below the top of the sides, as indicated by prototype photos.

Photo from Weston Langford collection showing cross braces.

Weighting


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

Painting


Either enamel or acrylic hobby paints can be used to paint the finished model.  

Monday, 19 June 2017

DB Loco Mechanism Options

As an aid to deciding which mechanism to use for Marbelup Models DB Locomotive, the following summarises the main features of the Hollywood Foundry (HF) and ViTrains (VT) mechanisms.

Comparison of ViTrains bogie (left) and Hollywood Foundry bogie (right)

Bogie Wheelbase


Prototype: 3810 mm = 59.5 mm in S scale
HF Bogie: 59.5 mm
VT Bogie: 58 mm

Wheel Diameter


Prototype: 1016 mm = 15.875 mm in S scale
HF Bogie: 15.7 mm
VT Bogie: 14.8 mm Note: Upper part of wheels is largely hidden by bogie sideframes

Flange Depth


HF Bogie: 0.65 mm (RP25)
VT Bogie: 1 mm - operates on Code 70 or larger rail

Cost (for drive bogies and motor):


HF Single Bogie Drive: Approx. $200
HF Double Bogie Drive: Approx. $250
VT Drive: $140

HF Mechanism Features


  • Choice of 6-wheel (single bogie) or 12-wheel (dual bogie) drive
  • For single bogie drive, cab area is clear to allow for interior detailing
  • Worm gear on each driven axle, with dual belt drive from bogie input shaft

VT Mechanism Features


  • 8-wheel drive (centre axles are idlers and lightly sprung)
  • Twin flywheels included
  • Smoother operation
  • Quieter operation
  • Cab area is clear to allow for interior detailing
  • Worm gear on each bogie with spur gearing to powered axles
Back to Marbelup Models Home Page

Friday, 9 June 2017

DB Loco Assembly Tips

Please Note - This is a "preliminary" version and subject to change during construction and testing of the development models.

Parts List (Preliminary - subject to change)


In addition to the 3D printed parts, the following parts must be obtained separately by the modeller:
  • Brass wire for handrails, etc. (0.4 mm, 0.6 mm - 3 x 300 mm lengths)
  • Air hoses - e.g. Detail Associates #6206 - 12 required.  (Vacuum brake hoses are included.)
  • Handrail Knobs (4) for uncoupling levers - e.g. Markits 1.5 mm (short) - available from Railwest Models.
  • Handrail Stanchions (optional) - A-Line D1070 or D1071.  Limited quantities available from Marbelup Models.
  • Vi-Trains Class 47 mechanism.  Limited quantities available from Marbelup Models,
    OR
  • Hollywood Foundry mechanism, with NorthYard Wheels and Mashima 1833D motor - see below for details.
  • DCC decoder and speaker (both optional)
  • Light Emitting Diodes (LEDs) for headlights 4 x 3 mm (sunny white) and optic fibre (2 mm)
  • LEDs (red and white) and optic fibre, if operating marker lights desired
  • lead or other weighting material
  • Kadee couplers #146 for scale coupler height,  #149 for HO coupler height (see below)
  • Kadee draft gear boxes #262 (supplied)
  • Fixing screws for body, couplers and fuel tank:
    2-56 x 19 mm, 4 required for central body fixing screws
    2-56 x 6 mm, 8 required, for remaining body fixing screws and couplers.
    2-56 x 12 mm, 2 required for fuel tank.
    Kadee #256 nylon screws can be used for the fuel tank, couplers and end body fixing screws.
  • Fixing screws for motor (ViTrains mechanism only) 2-56 x 25 mm (1"), 4 required - to be trimmed to required length.
  • 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.
  • Fixing screws for bogie sideframes - self tappers, 1 mm dia. x 3 mm long (8 required).  Suitable screws are available from DCC Concepts - Part No. DCS-PH103
  • Fixing screws for nose - self tappers, 1 mm dia. x 5 mm long (2 required).  Suitable screws are available from DCC Concepts - Part No. DCS-PH105
  • Paint and decals, as desired.

Underframe Preparation


Remove the support structure from the 3D-printed underframe.  Take particular care around areas with delicate detail, including the vacuum hoses and ... (details to be added).

Clean out the indicated holes with a 1.8 mm drill bit and tap with 2-56 thread.  Note that the four holes closest to the motor cutout are for the ViTrains mechanism only.  If desired, the coupler mounting holes can be drilled right through as the top surface of the underframe will be hidden by the loco body.

Underframe Holes to be Tapped 2-56 (viewed from below)
If intending to fit couplers at HO height, file out 1 mm from the bottom of the coupler mounting holes, as per diagram below.  The headstock is only 0.5 mm thick in this region.  Up to 1.25 mm can be removed, if required, to accommodate fine adjustment of coupler height.

Headstock Modification for HO Coupler Height

Bogies and Drive Train


There are two mechanism options: Hollywood Foundry and ViTrains.  The DB loco underframe is specific to each mechanism, so the choice of mechanism must be made at the time of ordering.

See comparison of the mechanism options.

Please refer to the separate assembly tips for:

Couplers


The coupler height of the DB loco has been set at the correct scale height for WAGR/Westrail narrow gauge rollingstock, i.e. 12.2 mm (above rail height) rather than the HO coupler height (9.9 mm) which is commonly used for most Sn3½ models.  This has been done because the correct height "looks better" for modern locos and rollingstock.  For correct scale coupler height, use Kadee #146 couplers.  

Provision has been made in the underframe design to lower the couplers to match the HO coupler height by using Kadee #149 couplers which have an "overset" shank together with a spacer approx. 1 mm thick between the coupler box and mounting pad.  The bottom of the coupler openings in the headstocks is only 0.5 mm thick, and this thin section needs to be filed 1 mm deeper to allow for the lower coupler mounting height.

The #146 and #149 couplers are both "long shank" style which avoids the problem of the "glad hand" on opposing couplers from fouling the cowcatcher.  The suggested draft gear boxes are Kadee #262 (supplied).  Kadee suggest assembling the coupler so that the main part of the draft gear box is on the bottom and the lid is on top.  The draft gear boxes simply snap together.  

Due to the length of the DB loco and long end overhang, coupling of 4-wheel wagons next to the loco is not recommended on curves of 850 mm radius or less.  The loco itself will operate on curves of 700 mm radius, or slightly less, but the coupler overhang is probably the limiting factor.


Underframe Details

There are four large air pipes to be added to the air reservoirs on the underframe, as highlighted in yellow below.

Underframe Air Piping (viewed from below).
These can be formed from 0.8 mm brass wire, and glued into the holes provided in the air reservoirs and underframe.  

Approx. dimensions for the L-shaped pipes are as follows:
  • Front left: 5 mm + 8.5 mm
  • Front right: 13 mm + 8.5 mm
  • Rear left and right: 34 mm + 8.5 mm.
Note that the front right pipe should have a gentle upwards bend, about midway along the longer part, to match the height of the hold in the underframe.

DCC and Sound


The underframe 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.  

The underframe speaker mount include four holes, nominally 1.1 mm diameter, which are suitable for M1.4 fixing screws, 6-8 mm long.  Ideally, the holes should be tapped with a M1.4 thread, but the screws can be inserted without tapping.  (DCC Concepts sell suitable screws - part number DCS-NB14x6 or as part of an assortment DCS-Nbset.)

The recommended sound decoder is the Soundtraxx Tsunami EMD 645 Non-Turbo.  The Tsunami "AT" style decoder model 828048 is suitable and slightly cheaper than the TSU-1000 style model 827109.  More recent equivalents are also available in the Soundtraxx Econami and Tsunami 2 ranges.

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


Body Preparation and Details


Take care when removing the support structure from the body, especially around the cab windows to avoid damaging the vertical dividers between the windows.  

Once the body has been "cleaned up", it is also necessary to remove the two temporary braces which link the fixing posts near the centre of the body, as highlighted in yellow below, as well as another one just behind the cab.  These have been included to protect the body during production and shipping, and must be cut away to provide clearance for the motor, etc.  These can be cut with a fine-toothed razor saw or a cutting disk in a rotary tool, at low speed.  

The ten fixing holes in the body shell and nose should be tapped with a 2-56 thread.  If necessary, clean out the holes prior to tapping using a 1.8 mm drill bit.


Nose Assembly

The nose is a separate 3D-printed part.  This has been done to avoid stepping on the sloping top surface of the nose from the 3D printing process.  Once the supports have been removed from the nose, a light sanding may be required on the bottom surface to remove the slight stepping present there.

Small holes have been provided to secure the nose to the cab with small screws, e.g. 1 mm dia. x 5 mm long.  The screws should be inserted from inside the cab, into the nose.  The holes are angled so there is some hope of reaching them with a small screwdriver.

Once satisfied with the fit of the nose, it can be superglued onto the cab, preferably from the inside to avoid traces of glue on the visible surfaces.


Handrails on Body


Starter holes are provided on the body for three handrails which can be formed from brass wire (e.g. 0.3 or 0.4 mm).  The starter holes should be drilled out slightly larger, e.g 0.05 mm larger than the wire size.

One handrail is inside the topmost recessed step on the left side of the loco, next to the radiator grilles.  The spacing between the holes is 3.5 mm (centre-to-centre).

Photo by G Stallard
The other two handrails are on the roof, adjacent to the recessed steps.  The spacing between the holes is 8.5 mm.  Photos indicated that the bends in the top handrails should have a radius of approx. 1.5 mm.  Radiussed corners can be formed by bending the wire around the shank of a drill bit, or using special pliers with round jaws made for wire forming.

Photo by G Stallard
Starter holes are also provided on the sides of the long hood for the handrails for the rear steps, and on the nose for the front handrails. - see below.

Handrails on Cab Front


Two handrails either side of central window:
  • Right side: 7.5 mm between hole centres
  • Left side: 7.5 mm + 12 mm between hole centres, with 65 degree bend between straight segments to match slope on nose.

Handrail on Top of Nose

  • Left side, on top step notch: 4 mm between hole centres
  • Left side, on sloping section: 8.75 mm between hole centres
  • Right side, on sloping section: 11 mm between hole centres*
* Front hole for this handrail is missing from some nose prints, but can be easily be marked and drilled.

Handrails on Underframe


The 3D-printed chassis incorporates holes approx. 0.6 mm diameter to house the vertical handrail posts, typically cut from 0.6 mm brass wire.  There are also starter holes on the rear steps, and on the headstocks, for the end handrails.

One option for the long handrails is to solder each section of handrails from 0.6 mm brass wire.  Marbelup Models has developed a PDF template for the handrails which can be downloaded and printed.  Ensure it is printed at 100% size - check the scale on the bottom of the template to ensure the scaling is correct.
Handrail Diagram - Download PDF for Accurate Dimensions

Handrail Diagram (PDF)

On the real locos, the rear handrails and the rear end of the long side handrails have 2 fixing points near the rear steps.  Holes been provided in the underframe for the additional fixing points, if desired, which would entail soldering additional short lengths of wire to the respective handrails.  The vertical spacing between the upper and lower fixing points is 8 mm.

Use of A-Line Handrail Stanchions


An alternative, which is potentially easier than soldering, is to use preformed steel handrail stanchions available from A-Line (Division of Proto-Power West, USA).  These are available from various online hobby shops and/or eBay.  (Marbelup Models has limited stocks of these stanchions available at $15 per pack of 35 stanchions.  Each loco requires 16 stanchions.)

A-Line Handrail Stanchions
Although these stanchions are intended for HO locos, the two longest sizes are sufficiently long to be trimmed to the correct length for the DB .  The A-line part numbers are D1070 (extra long) and D1071 (long).  The stanchions should be trimmed at the bottom.  After trimming, file off any rough edges from the cut end.  

The number and lengths of stanchions required are as follows:

  • 21 mm long, 8 required - left side
  • 18.5 mm long, 7 required - right side
  • 16.75 mm long, 1 required - right side, rearmost stanchion.
Note that the length should be measured from the top of the "loop".  When installed, the bottom of each stanchion should be flush with the bottom of the running boards.

The holes in the 3D-printed chassis should be carefully drilled out to accommodate the stanchions (suggested drill size: 0.75 mm  - test on some scrap plastic first).  

After preforming the long handrails as per the PDF template, test fit each handrail without stanchions.  Once satisfied with the fit, remove each handrail and thread on the 8 stanchions.  It is suggested to orient all stanchions the same way, e.g. with the open side of the top loop inwards.  For the right side handrail, ensure the single, short stanchion is at the rear.

Carefully insert each stanchion vertically into the drilled holes.    It is probably best to insert the stanchions part way initially, then go along and press them down to the full depth, and also insert the ends of the handrails into the holes in the underframe.  Make sure the bottom of each stanchion is level with the underside of the running boards.

Once all the stanchions are in place and the long handrails threaded through, check that all the stanchions are vertical and make any necessary adjustments.  Then, the stanchions can be glued into the holes in the running boards and the handrails glued into the holes in the underframe.  It is optional whether to glue the handrails where they pass through the loops in the stanchions.

Separately form the U-shaped handrails on the side, and the end handrails from 0.6 mm wire, as per the template.  Install and glue the U-shaped handrails into the underframe.

Temporarily fit the loco body to the underframe in order to test fit the end handrails, the top ends of which locate into holes in the loco body.  Only glue the bottom end of the end handrails, to allow for future removal of the body.  It is suggested that the top end of the handrails should protrude approx. 1 mm into the body, to allow them to be sprung out slightly when the body is removed.


Horns



Four horns are included as part of the 3D-printed underframe.  Carefully remove them from the underframe, leaving the spigots attached to the horns intact as much as possible.  Only two are required, with two spares.

(Alternate horns can be source from detail parts suppliers e.g. in brass, if greater robustness is desired.)

Starter holes are provided for the horns on the front wall of the cab (right side) and on the left side of the long hood, just behind the vestibule door.  Consult photos appropriate to the era being modelled to determine correct horn placement.

Drill out the starter holes to suit the diameter of the spigot on the back end of the horns.  Carefully trim the unwanted spigot (projecting sideways or lengthways) from the horns.

Headlights


The holes provided in the body shell for headlights are nominally 1.8 mm diameter, but typically slightly undersize due to the 3D printing process.  The headlights should be 2 mm in diameter, so drill the holes out to 2 mm taking care not damage the thin surround around the hole.

(The holes are deliberately undersize because the thin surround would not print otherwise, as the minimum detail thickness is 0.5 mm. and the outside diameter of the surround is 2.8 mm.)

One method of lighting the headlights is to use a short length of optic fibre together with a 3 mm LED (Light Emitting Diode).

The DB locos had "sealed beam" headlights for which "sunny white" LEDs are a suitable approximation.  (Many older locos had larger diameter headlights with replaceable bulbs which tended to have a more yellow appearance, similar to "golden yellow" LEDs.)

Note: Incandescent (filament) lamps are not recommended due to their high operating temperature which may damage the 3D print material.

To attach the LED to the optic fibre, 3 mm black heatshink tubing is recommended.  With the use of a hot air gun, the heatshrink tubing will shrink to form a snug fit over the optic fibre.  However, the hot air may well be hot enough to melt the plastic optic fibre, so the trick is to shrink the tubing over the shank of a 2 mm drill bit, them slide the drill bit out and slide in the optic fibre.

Typical steps are:

  1. Cut heatshrink tubing to length, e.g. 8-10 mm.
  2. Hold 3 mm LED in a small vice by its legs, with the clear lens uppermost.
  3. Push the cut length of heatshrink tubing over the clear lens of the LED.
  4. Hold the shank of a 2 mm drill bit inside the heatshrink tubing while applying heat from a hot air gun.
  5. When it has cooled, withdraw the drill bit and insert the desired length of optic fibre.  For the rear of the loco, you will probably have to feed the non-flared end of the optic fibre through the curved hole provided (from the outside) and attached the LED with attached heatshrink tubing on the inside.
CAUTION: Do not used the hot air gun or other heat source to shrink the heatshrink tubing in close proximity to the loco body or other 3D printed parts as they may distort due to the heat.

For the dual headlights, it is simplest to wire the two LED in series as this reduces the wiring and avoids the need for two separate resistors.  A resistor of around 2K2 (2,200 ohms) is a suggested starting point for LEDs powered from DCC decoders.

Marker lights can also be drilled out and illuminated if desired.



Sunday, 4 June 2017

DB Loco Hollywood Foundry Underframe Assembly Tips

Hollywood Foundry Drive Components


It is up to the modeller's individual preference whether to fit two drive bogies or a single drive bogie plus a dummy bogie.

Drive bogie specifications: G16.5/B29.8+29.8/W15.7-110/22:1DUALBELT/NOBOL
Dummy bogie specifications: G16.5/B29.8+29.8/W15.7-110/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 should purchase the wheels, 15.7 mm diameter, from Northyard in New Zealand and send them to Hollywood Foundry in conjunction with each order.  Marbelup Models has a limited quantity of Northyard wheels available for purchase for $35 per set of 12 wheels.



Contact Northyard direct via email: northyard@xtra.co.nz for a quote for the wheels.  The current (September 2016) catalogue price is NZ$1.95 per wheel (not including postage).

Each loco requires 12 x 401N wheels, as illustrated in the following extract from the Northyard Catalogue:



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

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.

Total price for two drive bogie configuration is $218.14 (plus approx $10 postage)
Total price for single drive bogie configuration is $171.94 (plus approx $10 postage)

Please not that the above prices set by Hollywood Foundry and are subject to change.

As of late 2016, Mashima Motors are no longer in production.  Marbelup Models has designed the chassis to accommodate other motors including Canon, which are available from some hobby shops in the same size as the Mashima M1833D.  Marbelup Models also has limited stock of another alternate motor which will fit in the space available.


Bogie Pivot Assembly (Hollywood Foundry)


Note:  Prior to assembling the Hollywood Foundry bogies to the underframe, place each bogie on a flat surface (glass is ideal) and check that the bogie doesn't rock from end to end.  Some bogies have been found to have the centre axle set a fraction of a millimetre too low, which means the outer axles don't properly contact the rails and could cause derailments.  If you are unlucky enough to experience this problem, contact Hollywood Foundry for repair or replacement under their Lifetime Warranty.

The underframe is designed for a nominal thickness of washers/packing of 1 mm between the top of the bogies and the mounting surface on the underframe.

The Hollywood Foundry bogies are supplied with two plastic shouldered washers, a formed phosphor bronze spring, a flat steel washer and an M1.4 machine screw. 

For assembly to the 3D-printed underframe, it is recommended to discard the flat steel washer and upper plastic shouldered washer.  This should result in the correct loco height from the rails and the phosphor bronze springs (at both ends) should minimise side-to-side rocking of the loco while allowing some movement to cope with uneven track.

Secure the bogie with the M1.4 screw provided, but don't tighten it fully so as to allow some for and aft rocking movement of the bogie as well.

To check the loco height, fit the underframe and body together, with couplers attached, and check the coupler height against a Kadee HO coupler height gauge.  Be aware that the 3D-printed underframe is somewhat flexible on its own, and relies on the rigidity of the body to keep it straight and level.  The top surface of the footplate should be 26 mm above rail level.

If the loco sits too low, a spacer should be cut from styrene and added above the phosphor bronze spring (or glued to the bogie pivot on the underframe).  The spacer needs to be large enough, e.g. 8 mm square, so that the phosphor bronze spring is effective in minimise rocking.

If side-to-side rocking is still a problem, Marbelup Models can provide details to fabricate a mounting plate from brass sheet and wire which can be fitted to the top of the rear bogie, to provide a "3-point" suspension.  Marbelup Models has also produced a 3D-printed version of this mounting plate which is printed in high-detailed stainless steel at a cost of approx. $16.

Drive Shaft Assembly (Hollywood Foundry)


Brass rod 1.5 mm diameter is suitable for the drive shaft(s).  The required length is approx xx mm.  Check the exact length required from your model.  Allow some "end play" in the universal joint at the bogie end to accommodate movement of the bogie on curves or uneven track.

Hollywood Foundry have published an instruction sheet on the basic assembly. One end of each shaft requires a "flat" to be ground or filed to accommodate the male end of the plastic universal joint.  Grind or file a flat on the shaft with a minimum length of about 2 mm.  The depth of the flat should be 0.3 mm, so that the measurement over the remaining shaft is 1.2 mm.  Don't force the joint onto the shaft if it is very tight, as it may split later.

Hollywood Foundry can supply silicone tubing (free on request with each order) for the motor end of each drive shaft.  The tubing is sufficiently flexible to fit both the 1.5 mm drive shafts and 2 mm motor shaft.

The drive shaft for the front bogie of a loco with both bogies driven must pass through the "tunnel" in the speaker housing.  One technique is to attach the drive shaft to the motor before installing the motor, then pass the drive shaft through the "tunnel" to engage with the universal joint on the bogie and, finally, fix the motor in position with the short M2 screws provided with the motor.  The rear drive shaft can be attached to the motor last, as there is no "tunnel" to get in the way.

For a loco with one powered bogie, it is suggested to install the powered bogie at the rear to avoid the "tunnel" and leave the cab free for interior detailing, if desired.