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Discussion Starter · #1 · (Edited)
This is a project I started a couple of years ago for a friend. I thought it would be ideal to practice a number of skills. It's taken a bit longer than expected, as areas have proved challenging and is now developing into a nice looking model.

The F Class locomotive originally was designed to haul suburban passenger consists in Adelaide, over time they also worked freight as well. They came into service from 1902 replacing the P class and other smaller locomotives,as the increase in passenger numbers and rolling stock was proving too much. Commonly and affectionately known as Dolly's which was a reference to a well known song of the the time called Dolly Grays.

Over a period of 20 years a number were built at Islington Workshops, James Martin and Perry Engineering and they lasted until 1969 in service. Most were scrapped although several have preserved with one still operating at Steamranger in the Adelaide Hills. I've provided a schematic and link to the National Rail Museum that provides extra details.

This is a model that will be a mix of 3D printing and scratch-built parts.

Line Drawing


SAR F CLASS 0
by taylorplains, on Flickr

 

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Discussion Starter · #2 · (Edited)
This presented a number of challenges in terms of sourcing parts, what needed to be modelled and what tolerances needed to print well. I needed it to be structurally strong while not compromising too much on operation / handling / details.

I scoured the internet for pics, plans, information as well as what commercial parts could I use. Was the loco going to be R/C battery or live rail powered? I settled on R/C control as having just fitted the Thomas with a RCS R/C unit, I was happy with using that system.

After several weeks of scouring manufacturers, model suppliers and forums I discoverered that the Bachman Annie had the closest dimensions of the 3 driving wheels. So I was fine with the millimetre larger difference. Even better was finding out they look very similar and the fact there was a blind drive wheel as on the prototype. I managed to purchase a donor unit off of Ebay - so the motor and drive wheels were at least sorted.

Sadly the donor frame and arrangement wasn't compatible and that meant designing from scratch the underframe. Lots of referencing pictures, plans, notes as well visiting the F Class on display in Gawler plus the one at the Rail Museum.The frame took a couple of weeks to design as I played around with motor placement (horizontal or vertical), wiring, the wheel spacings, how the motor was going to be held and a raft of other considerations.

I designed the underframe to support the motor, the cab, boiler, smokebox assemblies, as well as mounts for the front bogie and rear radial wheel. Plus provision for details to be added and the R/C system too.

Also another consideration was access to the motor and wheels for maintenance, hence the design of the bottom access cover.

View of the upper parts of the underframe.


SAR F CLASS 1
by taylorplains, on Flickr

View of the underframe from below.


SAR F CLASS 2
by taylorplains, on Flickr

View of the motor access cover.


SAR F CLASS 3
by taylorplains, on Flickr

View from the top of the motor access cover.


SAR F CLASS 4
by taylorplains, on Flickr
 

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A good starting point with a cost effective donor for the wheels even if the frame is not entirely suitable and I look forward to your build on this. I do like the broad gauge F class tank loco but when you finish this loco for your friend are you eventually going to make a narrow gauge Y (2-6-0) for yourself? That is something I would love to see hauling your own rolling stock.
Russell
 

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Discussion Starter · #4 · (Edited)
Oh yes - I need to finish the V class after this, make at least one of the T, Y, W and Z class narrow gauge locos. Not to mention the NB30, 700, 830 class diesels.
 

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Discussion Starter · #5 ·
The designing phase meant that I could work on other items and ensure I was able to pre-fit and assemble before making parts. Some items needed revision for ease of printing and budget.

Everyrthing was designed to slot in or be fixed place. Here are some of the initial developments.

Front angle view showing the placement of the Smokebox assembly, front coupler and rock / debris guards.

SAR F CLASS 5 by taylorplains, on Flickr

Side view showing placement of smokebox, air resevoir, splasher and coupler.

SAR F CLASS 6 by taylorplains, on Flickr

As I develop a model, just to reference the sub-assemblies I use different colours to distinguish them. I usually have a file dedicated to the construction so check off as I go and see the overall progress.
 

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Discussion Starter · #6 ·
I had the underframe, smokebox, motor cover and air resevoir printed in tough resin .05mm. As with every print, I critique the print quality, finish, accuracy and scale. There were a couple of unseen errors though and I went back over the design refining it.

The base of the underframe has a cover which allows access to the wheels and motor for maintenance. I designed it to have a curved piece to allow the motor gearing to move easily and not bind.

SAR F CLASS 7 by taylorplains, on Flickr

The underframe was quite a complex design, it worked better than I thought. There were some minor details that did not work as well. I noticed several problems with the frame in regards to missing a support part, some warping of the running board. bulging in the coal bunker / cab as well as some gaps where parts should hava solid seam.

SAR F CLASS 8 by taylorplains, on Flickr

A view of the underframe.

SAR F CLASS 9 by taylorplains, on Flickr

SAR F CLASS 10 by taylorplains, on Flickr

SAR F CLASS 11 by taylorplains, on Flickr

Side view showing the connecting base motor cover.

SAR F CLASS 12 by taylorplains, on Flickr

Front view of the smokebox on the underframe, showing just a little bit of adjusting is needed to fit the frame.

SAR F CLASS 13 by taylorplains, on Flickr

The engine mounts - as printed and the other as modified.

SAR F CLASS 14 by taylorplains, on Flickr

More to follow.
 

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Discussion Starter · #8 ·
Indeed, the majority of the colonial railways and early state railways had a very strong UK look to them. Although there were some German and American built / designs featured as well.

At times it was a mix of British, European, Amercian and home grown ideas to make a locomotive suited for local conditions.
 

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Discussion Starter · #9 ·
The challenge of making a combination complex model, is to ensure that the sub-assemblies fit and there is adequate support, not to mention being able to run well. The underframe must must be sturdy enough as well to cope with the following factors - pull / vibration / tension / compression and twisting / flexing of the model.

Shown is the underside of the main underframe with remediation work underway.

SAR F CLASS 15 by taylorplains, on Flickr

Remediation work
  • Gaps in the front and rear supports to fill,
  • Clearance for the axle support bearings,
  • Addition of a styrene strip to the footplate for strengthening and filling where the designed support did not print,
  • Drilling and tapping of the supports for the screw of the motor cover.

Upon test fitting of the motor I noticed there was binding of the gearing and needed to be remedied.

SAR F CLASS 16 by taylorplains, on Flickr

SAR F CLASS 17 by taylorplains, on Flickr

SAR F CLASS 18 by taylorplains, on Flickr

Pre-remediation picture of the printed components and donor motor unit.

SAR F CLASS 19 by taylorplains, on Flickr

More to follow.
 
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