Wednesday, 26 November 2014

D/DA Class Diesel

DA (left) and D Class Test Models

First Test Print of D Class
Marbelup Models has finished the 3D design for a WAGR/Westrail D class diesel.  Test prints of all the 3D-printed parts have now arrived, and the test model has been assembled complete with Hollywood Foundry mechanism. The 3D design took approx 80 hours.

Thanks to Gav and Rob for helping out with photos and other prototype information.

The 3D design for the DA has also been completed.  The DA doesn't have dynamic brakes, so the short hood is fairly plain and also slightly lower.  The fuel tank is also shorter.  Test prints for the DA arrived on 19 December.

First Test Print of DA Class

Fuel Tanks - DA (left) and D (right)
D Fuel Tank with 7 layers of lead sheet installed.  166 grams in total.
Top 2 layers have a gap in the centre to clear the motor.
Test prints of D Class underframe and fuel tank
"Shop" bogies are dummies originally made for RA.  "Motor" is also a dummy.
The present models represents the D and DA class from delivery in 1971/1972 until the Westrail era.  In the late Westrail era (late 1990's), some of the DA locos were rebuilt into DAZ class.  Visible alterations included different cab windows, changes to various grilles on the body, and different brake cylinders on the bogies (on some locos).  Marbelup Models plans to produce a DAZ version as well.

Bogie Rendering
The D class uses a custom made drive mechanism from Hollywood Foundry.  Hollywood Foundry don't have the correct size wheels (15.7 mm) in their normal range, but the wheels are available from Northyard in New Zealand.  The minimum operating radius is 600 mm.

For DCC sound, the underframe includes mounting for a speaker.  The specific engine sound -EMD 645 Non-Turbo - is available in the Tsunami range of sound decoders from Soundtraxx.

The price for the 3D printed parts, i.e. body, underframe, bogie frames and fuel tank will be approx. $390 (subject to exchange rate variations).  The prices for individual parts are as follows:

Body: $170,  Underframe: $125,  Fuel Tank: $30,  Bogies (2): $65

Wednesday, 19 November 2014

D/DA Loco Assembly Tips

Please Note - This is a "work in progress" with the idea of recording information while I am working on the 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)
  • Air hoses - e.g. Detail Associates #6206 (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 D1071.  Limited quantities available from Marbelup Models.
  • Wheels - 12 x Northyard 401N - see below.
  • 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, e.g. K&S #9862 (5 x 300 mm lengths per pack)
  • Universal Joint set for 1.5 mm shafts (Hollywood Foundry)
  • Flexible coupling(s) for motor end(s) of drive shafts (Hollywood Foundry).  
  • 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
  • paint as desired
  • lead or other weighting material
  • Kadee couplers #156 ("scale") or #146 (normal size)
  • Kadee draft gear boxes #262
  • 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.
  • Fixing screws (optional) 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
  • Decals - Westland Models are developing decals for the original green WAGR livery and may also offer decals for later liveries.

Wheels


The correct size 15.7 mm wheels are available from Northyard in New Zealand.

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



Contact Northyard direct via email: northyard@xtra.co.nz for a quote for the wheels.  The current (December 2014) catalogue price is NZ$1.80 per wheel.

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 from Northyard and send them to Hollywood Foundry in conjunction with each order.

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.

Bogie Pivot Assembly


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 is also experimenting with 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

Brass rod 1.5 mm diameter is suitable for the drive shaft(s).  The required length is approx 72-73 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.

Couplers


The suggested couplers are Kadee #156 ("scale" head) or #146 (normal size head).  These 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.  The suggested draft gear boxes are Kadee #262 which available separately in packs of 10 pairs.  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.  

If the coupler height is a little too high, a styrene spacer can be added between the couplers and the underframe.  The bottom of the coupler opening in the end sill is only 0.5 mm thick, to allow it to be easily cut or filed if a deeper opening is required.  If a spacer of more than 0.25 mm is required, it may also be necessary to trim the bottom flange from the Kadee draft gear box to clear the top of the cowcatcher.




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.

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.  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, as low speed.  

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

If using dual drive bogies, there are areas marked on the lower, end wall of the cab which need to be cut out to provide clearance for the front drive shaft and bogie mechanism.  These are highlighted in yellow in the image below.


Handrails

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 started holes should be drilled out slightly larger, e.g 0.05 mm larger than the wire size.

One handrail is inside the recessed step nearest the top 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 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.

Photo by G Stallard
Starter holes are also provided on the end walls of the cab for the long handrails which run along the side of the loco - see below. 

Long 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.  

One option for the handrails is to solder each section of handrails from 0.6 mm brass wire.  Marbelup Models can supply a PDF template for the handrails on request.  

Note that the end walls of the cab have starter holes for the horizontal handrails.  Assuming 0.6 mm wire is used for the long handrails (and shorter ones at the front of the loco), it is suggested to drill the holes in the cab end walls slightly larger e.g. 0.7 mm, so the handrails are an easy fit.  Ideally, the handrails should be trimmed so that just enough extends into the holes (e.g. 0.5 mm) so they they appear to be attached when the loco is fully assembled.  If the handrails extend too far into the holes in the can, it will be more difficult to disassembly the loco.

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.)

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 D and A.  The A-line part numbers are D1071 (long) and D1071 (extra long).  The stanchions should be trimmed at the bottom to a length of 18.5 mm, measured from the top of the "loop".  For the handrails on the end platform, the stanchions should be trimmed to 17.5 mm.  After trimming, file off any rough edges from the cut end.

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).  Carefully insert each stanchion vertically into the drilled hole, taking care to align the loop perpendicular to the sides of the loco.  It is also suggested to orient all stanchions the same way, e.g. with the open side of the top loop inwards.  Make sure the bottom of each stanchion is level with the underside of the running boards.

Once the stanchions are installed, 0.6 mm brass wire can be threaded through the line of stanchions to complete the handrail.  Some custom bending will be required at the ends of the loco and where the height of the handrail varies.  The PDF template may be useful for this.

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 brass handrail can be secured to each stanchion with superglue and, if desired, the stanchions glued into the holes in the running boards.  Note that the short handrails in front of the cab should not be glued as they may need to be removed prior to separating the body and chassis, e.g. for maintenance.

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 rear wall of the cab (right side) and on the front wall of the cab (both sides).  Early photos show the front horn on the right side of the loco (as pictured below) and later photos show the front horn on the left side of the loco.  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 from the horn.

Photo courtesy of Rail Heritage WA.

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 D and DA 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.

A "conduit" has been provided in the roof of the cab to allow the headlight wires to be fed through into the short hood.

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






Thursday, 13 November 2014

Bettendorf Bogies and Bolsters

American Models Bettendorf Bogie
Marbelup Models 3D-Printed Narrow Gauge Bolster

As supplied, the American Models Bettendorf bogies are designed for S scale standard gauge, i.e. 22.5 mm gauge.  The Marbelup Models 3D-printed narrow gauge bolsters greatly simplifies the process of converting the American Models bogie to narrow gauge.

Prices:

  • American Models Bettendorf Bogies (standard gauge, no wheels)... $10* per pair
  • Marbelup Models 3D-Printed Narrow Gauge Bolsters... $14 per pair
  • Bogies plus bolsters... $22* per pair
* Limited quantity of American Models bogies available.

Assembly Tips


To install the 3D-printed narrow gauge bolsters, carefully remove the springs and separate the two side frames from the standard gauge bolster.

Tip: Work over a tray or shallow box to minimise the risk of losing springs.  The Kadee #241 manual uncoupling tool includes a “spring pic” which can be useful for removing and refitting springs.

Carefully remove the support structure from the 3D-printed bolsters using a sharp craft knife.  A knife with an Xacto No.11 blade is recommended.

If required, paint the narrow gauge bolsters and (optionally) the sideframes prior to reassembly.

Reassemble one sideframe of each bogie to a 3D-printed narrow gauge bolster.  Fit the second sideframe to each bogie but do not refit the springs at this stage.

Fit desired wheelsets by carefully twisting one sideframe with respect to the bolster.  Wheelsets must have 26 mm axles.

Refit springs to second sideframe of each bogie.

The pivot hole in the 3D-printed bolsters is designed for 2-56 (or 8BA) screws.


RA Loco Assembly Tips

Parts List


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)
  • 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.
  • Handrail Stanchions - see below.
  • 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, approx 65 mm long (cut to exact length) (Brass rod is suitable.)
  • 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)
  • Optic fibre 2 mm diameter for headlights.
  • LEDs (red and white) and optic fibre, if operating marker lights desired
  • paint as desired
  • decals - contact Westland Models.
  • 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 (December 2014) pricing for the required Hollywood Foundry parts is:

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

Dummy bogie - $45.10 (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.


Couplers


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


Unlike the chain handrails on the R class, the RA had solid handrails but with removable segments to allow the doors to be opened.

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.

One option for the handrails is to solder each section of handrails from 0.6 mm brass wire.  Marbelup Models can supply a PDF template for the handrails on request.  Note that the end walls of the cab have starter holes for the horizontal handrails.  These should be carefully opened out with a 0.65 mm drill bit to a depth of approx. 1.5 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.)

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 RA.  The A-line part numbers are D1071 (long) and D1071 (extra long).  The stanchions should be trimmed at the bottom to a length of 18.5 mm, measured from the top of the "loop".  For the handrails on the end platform, the stanchions should be trimmed to 17.5 mm.  After trimming, file off any rough edges from the cut end.

The holes in the 3D-printed chassis should be carefully drilled out to 0.75 mm to accommodate the stanchions (suggested drill size - test on some scrap plastic first).  Carefully insert each stanchion vertically into the drilled hole, taking care to align the loop perpendicular to the sides of the loco.  It is also suggested to orient all stanchions the same way, e.g. with the open side of the top loop inwards.  Make sure the bottom of each stanchion is level with the underside of the running boards.

Once the stanchions are installed, 0.6 mm brass wire can be threaded through the line of stanchions to complete the handrail.  

Where the handrails join onto the cab, there is a second, short handrail half-way up (See prototype photos.).  If desired to replicate this feature, a short length of brass should be soldered onto the inside of each stanchion nearest the cab.  Experience suggests the stanchions require light filing before soldering.

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 brass handrail can be secured to each stanchion with superglue and, if desired, the stanchions glued into the holes in the running boards.  Note that the short handrail in front of the cab (right side of loco only) should not be glued as it needs to be removed prior to separating the body and chassis, e.g. for maintenance.

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 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.

Headlights

The holes provided in the body shell for headlights are nominally 2.5 mm diameter, but typically slightly undersize due to the 3D printing process.  

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

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

At the rear of the loco, it is not practical to drill out the headlights to allow use of 2.5 mm diameter optic fibre, as the hole provided follows a curved path to allow for the high position of the headlights relative to the roof of the long hood.  The suggested method is to carefully drill out the first 2-3 mm of the hole to 2.5 mm diameter, but use 2 mm diameter optic fibre which can bendto match the curved shape of the hole.  The end of the optic fibre can be flared to approx. 2.5 mm diameter by holding it close to (but not touching) a hot soldering iron.  With a little practice, the amount of flare can be judged to give a lens shape 2.5 mm in diameter.  The same technique can be used for the front lights as well to avoid the need to purchase two difference sizes of optic fibre.

To attached 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.

For the dual headlights, it is simplest to wire the two LED in series as this simplifies 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.

Tuesday, 11 November 2014

Marbelup Models FAQ

Are the 3D-Printed Models Long Lasting?


Because the "Prime Gray" material which is used for most of the 3D-printed parts has only been available for only four or five years, the long term durability and stability of the material is unknown. The manufacturer (3D Systems) claims that the material is "tough" and "durable".   Marbleup Models has 2-year old printed parts which are in perfect condition.

i.Materialise suggest avoiding exposure of models to sunlight or other UV light sources, which can cause discolouration.  The material does soften at temperatures of 47C or above, so also avoid leaving models in hot cars and other places where high temperatures may be experienced.  If interested, you can read more about the Prime Gray material (trade name Xtreme) at materialise.com or 3D Systems web sites.

Do you sell "Ready to Run" models or complete kits?


No, Marbelup Models DOES NOT offer an assembly service, nor do we offer a complete "kit" of parts.  We just sell the 3D printed parts.  It will be up to the individual modeller to obtain the other parts required to complete the model, and to research prototype plans and photos to ascertain placement of detail parts, colour schemes, etc.

What level of modelling skill is required?


A degree of modelling skill is required to produce a finished model.  Typically, the modeller must remove support structures from the 3D printed parts, assemble the major parts, fit wheels/bogies, couplers, and detail parts, and apply paint and decals.  Online instructions are available for each model with more information on construction and what other parts and materials are required.

Are special paints or glues required for the 3D-printed models


No, normal hobby paints, both enamels and acrylics work fine.  Some modellers have reported that some brands of superglue don't work well with the 3D-printed material.  Selleys Quick Fix Single Shot works well.  It is available in packs of five small tubes from hardware stores.

Why are the models in S scale when HO is more popular?


Since about 1980, railway modellers in Western Australia have been using Sn3½ scale to model the local narrow gauge rail system and there is now an active community of over 50 modellers.  Initially, Sn3½ was chosen because it allowed the use of many HO parts such as wheels, locomotive mechanisms and track.  Sn3½ was and still is popular in New Zealand and many parts can be obtained from there.

The 1:64 scale means that the models are about 30% larger than HO models, giving the correct "narrow gauge" look.  The larger scale also allows more detail to be included in the models as many of the models were and still are made by hand or from basic cast resin kits.

Although HOn3½ has become more popular in recent years, particularly for modelling the Queensland narrow gauge rail system, Sn3½ remains the most popular scale in Western Australia for modellers of WAGR narrow gauge.

Recently (mid-2015), Marbelup Models has started producing some models of WAGR/Westrail standard gauge rolling stock in HO scale.  This will allow modellers to obtain some authentic HO scale model to run with the L class diesel locos being produced by both Haskell Co and Southern Rail Models.

Where can I find more information about modelling Western Australian railways?


The WASn3½ Blog is a good starting point.  It has links to many other sites with relevant prototype and modelling information, photographs, etc.  

The Australian Model Railway Association (AMRA) WA Branch also has an active S Scale Special Interest Group which meets monthly at the AMRA clubrooms in Bayswater, WA.

There is also a "Western Australian Model Railways" group on Facebook.

Where is Marbelup?  Are you based there?


No, Marbelup Models is based in Perth.  Marbelup is a townsite near the south coast of Western Australia about 16 km west of Albany.  It lies at the intersection of the South Coast Highway and the Perth-Albany railway line.  Although designated as a townsite, it never developed into a town so the name remains for the locality.  I chose the name for my Model Railway around 1997 and decided to use the same name in 2013 when I started Marbelup Models.

Why is the date on the Marbelup Models Home Page up to one month in the future?  Is this a mistake?


No.  Blogspot always displays the most recently-changed page when someone "visits" the http://marbelupmodels.blogspot.com.au/ address.  Manually setting the publication date to the end of the months ensures that the Home Page displays by default.


Saturday, 27 September 2014

NH ENH QA HA Hopper Wagon Assembly Tips

TT3 (left) and S scale models with supports attached.

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 end steps and the ends of the hopper doors where there are fine pull rods.

Note:  Sometime, contrary to instructions, i.Materialise remove most of the support structures in the factory.  Marbelup Models prefers that the supports structures are left attached in the factory as they help protect delicate parts of the models during handing and shipping.

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 door operating mechanism 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, e.g. around the door actuating mechanism, 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.  Another option is to sharpen the end of the spring steel wire to a chisel point, and secure the wire in a pin vice to form a tiny chisel.

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.  A hobby knife with a chisel type blade (Exacto #17 or similar) can also be useful for smoothing flat areas, such as the underside of the underframe,

Bogie and Coupler Mounting Holes


For HO and larger versions, the mounting holes for the couplers and bogies have been printed at 1.8 mm diameter to suit 2-56 or 8BA 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.

The coupler mounting holes for the HO version do go right through the floor due to the limited material thickness available.  The holes should be tapped for HO versions only.

For S and O scale verions, the mounting holes are "blind".  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.

Grooved holes used for S and O scale versions.  Tapping is not required for these holes.
For TT3 versions, the mounting holes for the couplers and bogies have been printed at 1.2 mm diameter to suit the size 0-48 screws typically supplied with Kadee HOn3 couplers.  These holes should be cleaned out with a 1.2 mm drill but don't need to be tapped.

Bogies


Various options are available for bogies for the different scales.  Some packing will most likely be required, depending on the bogies used, to achieve the correct wagon height above rail level.

TT3n½ Scale (10.5 mm gauge)

MicroTrains HOn3 Bettendorf bogies #00502020 were used on the Marbelup Models test model and fit well, although they represent an early 20th century design rather than the more usual mid-20th century Bettendorf style.

Blackstone Models HOn3 Bettendorf Trucks #B370110 are potentially suitable, but have not been tried.

HOn3½ Scale (12 mm gauge)

Marbelup Models used Wuiske Models QRB008 Modern QR bogies on test models.  They fit the NH and ENH models but don't suit the Tasmanian QA.HA version as they are fairly long wheelbase and the inner wheels foul the extra door stop parts.

Caintode Flats produce a range of bogies for QR and Tasmanian models, and the shorter wheelbase Bettendorf style bogies may be suitable, but have not been tested.

Sn3½ Scale (16.5 mm gauge)

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 has 3D-printed bogies of the correct design for the WMC/WMD available for sale which are pretty close for this model.  Please refer to the WMC/WMD Assembly Tips for more information on these bogies.

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.

Marbelup Models WMC/WMD Bogie

On3½ Scale

Marbelup Models is not aware of any specific bogies which are available.  Potentially, On3 or S scale standard gauge bogies could be suitable.  Also, the Marbelup Models 3D-printed bogies for the WMC/WMD hopper wagon could potentially be printed in O scale, depending on the availability of suitable wheelsets.

Couplers


As with bogies, there are various coupler options depending on the scale of the model.  Because the models are 3D-printed "on demand", it is possible to customise the coupler mountings to suit specific requirement of individual modellers.

TT3n½ Scale

The TT3 version is currently designed to suit Kadee #711/#712 HO 3/4 size couplers set at a height of 7.8 mm to match the prototype coupler height.  These couplers are the same as Kadee #713/#714 HOn3 couplers, other than having a longer trip pin to suit HO standard gauge models.  For TTn3½ use, the trip pin on the #711/#712 will need to be shortened by about 2 mm to match the 7.8 mm coupler height.

Kadee #713/#714 couplers can also be used at the intended HOn3 height, which requires a shim of approx. 0.6-0.7 mm to bring the couplers down to the HOn3 height (7.14 mm).

HOn3½ Scale

The HO models are designed for Kadee HO "whisker" couplers at the HO standard gauge height (9.9 mm).  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 are narrower and have been used because they provide more clearance for narrow gauge wheelsets.  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 HO couplers.

Sn3½ Scale

The S models are designed for Kadee HO "whisker" couplers at the HO standard gauge height (9.9 mm).  Either the #158 (scale size) or #148 (normal size) couplers can be used, with #242 draft gear boxes which are the ones normally supplied with the whisker couplers.  The reason for using the #242 draft gear boxes is that the mounting screws are closer to the end of the wagon (compared to #262 boxes) to avoid a clash with the outer axles.

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

On3½ Scale (1:48 and 7 mm scale)

The 7 mm scale model is design for the Kadee #805 O Scale couplers or other Kadee couplers with the same mounting holes.  If requested, the 1:48 scale model can also be configured for these couplers.

Handrails and Brake Handle


Small starter holes have been provided to locate the L-shaped handrails on each end.  One end also has a brake handle.  These parts can be formed from brass wire and fixed in position with superglue.  The hole for the vertical leg of the handrail is located near the corner of the underframe, and the hole for the horizontal leg is located just above the second rung of the ladder.  Carefully drill out the starter holes - see below for drill sizes.

The suggested wire sizes and dimensions for the handrails for each scale are as follows:

TT3: 0.4 mm wire, 0.45 mm drill, horizontal: 4.5 mm, vertical: 8.5 mm
HO: 0.4 mm wire, 0.45 mm drill, horizontal: 5.5 mm, vertical: 9.5 mm
S: 0.6 mm wire, 0.65 mm drill, horizontal: 7.5 mm, vertical: 12.5 mm
O 1:48: 0.8 mm wire, 0.85 mm drill, horizontal: 10 mm, vertical: 16.5 mm
O 7 mm: 0.8 mm wire, 0.85 mm drill, horizontal: 11 mm, vertical: 18.5 mm

Note:  The above measurements are a suggested starting point.  Feel free to make adjustments as required.

Handrail and Brake Handle

The brake handle is also an L-shape, with the shorter, horizontal portion fitting in a hole just above the centre of the handbrake mechanism.  The suggested wire and drill sizes and dimensions for each scale are as follows:

TT3: 0.4 mm wire, 0.45 mm drill, horizontal: 1.5 mm, vertical: 6 mm
HO: 0.4 mm wire, 0.45 mm drill, horizontal: 2 mm, vertical: 7 mm
S: 0.4 mm wire, 0.45 mm drill, horizontal: 2 mm, vertical: 9 mm
O 1:48: 0.4 mm wire, 0.45 mm drill, horizontal: 2.5 mm, vertical: 12 mm
O 7 mm: 0.4 mm wire, 0.45 mm drill, horizontal: 2.5 mm, vertical: 13 mm

Painting


Either enamel or acrylic hobby paints can be used to paint the finished model.  The test models have been painted with Revell Hobby Enamel No.83 "rust" which seemed a good match for the faded red/brown of the original NAR NH hoppers.

Monday, 15 September 2014

NH ENH QA HA AHAF Hopper Wagons

NH Hopper S Scale after Painting
The latest 3D design from Marbelup Models is a little different, in that it is of a wagon which didn't originate from WA although some did find their way to WA in 2003.

These wagons were originally built in 1966 and 1968 to carry iron ore on the North Australia Railway from the Mount Bundey and Frances Creek mines to Darwin.  In the late 1970's, they were relocated to Port Lincoln in South Australia for use on the Eyre Peninsular Railway, carrying superphosphate, ballast and, later, Gypsum.  Some were relocated to Tasmania to carry coal and superphosphate.  Then, in 2003, approx 20 were shipped across to WA and refurbished for use on the Mt Gibson iron ore trains to Geraldton.

So, it seemed a good opportunity to build a model of these wagons which have served in 4 states/territories for well over 30 years, all on the 3' 6" (1067 mm) narrow gauge.  At this stage, Marbelup Models has done the 3D design for the original NT, SA and Tasmanian versions.  We will consider the WA AHAF version is there is any interest from modern image modellers.

NH Hopper TT Scale after Painting
A further difference is that the model can be 3D printed in various scales, including TT3n3½ (1:101.6), HOn3 or HOn3½ (1:87), OO (1:76.2), Sn3½ (1:64) and On3½ (both 1:48 and 7 mm scales), to cater for the various scales used by Australian narrow gauge modellers.  Bogie and coupler mounts can also be customised for the various scales.  The model can also potentially be used for HO standard gauge, although it is quite a small wagon compared to most HO wagons.

The photos, below, of the unpainted models include added handrails and brake handles formed from brass wire.  Starter holes are included in the 3D print for the wire details.  See assembly tips for more information on finishing and detailing.

NH S Scale, Unpainted, A End

NH S Scale, Unpainted, B End
Original NH/NHA as running in Northern Territory 
NH/NHA "late" version as running in Northern Territory and also in
South Australia circa 1978-1984, prior to entering gypsum traffic.
QA and later HA as running in Tasmania
ENH/ENHA as running in gypsum traffic in South Australia.
The ENH/ENHA is also available with brackets for hungry boards, but without hungry boards.
AHAF as running to Geraldton, WA
The approximate cost for this wagon (body only) will be approx. $30 in TT3 scale, $40 in HO and $80 in S scale.  The cost will vary slightly for the different versions, and is subject to the usual exchange rate variations.