On the Workbench

Do you have lifting corners?

Are you spending time on post print clean up?

STOP USING BRIM in your slicer!

This is a very simple part. It’s just a triangular prism but when you try to 3D print it, or more importantly print it at scale. There’s a number of challenges around these three corners that I will show you a solution for today.

So this type of part is a very simple part, this is a very simple example that we’re going to use but we’re looking at these sharp corners. 

Sharp corners when put down on the very first layer are not something that’s desirable, they cause dragging where the nozzle will reach out to a point and then drag the corner back with it. Which will cause a little bit of a warp or if you’re creating a very dense part if you were to print this totally solid, then these corners break up from the bed and you start to have a little bit of curling which is also not desirable. 

This error can come up a lot especially in mass production of a part like this, so we want to address it. Also there’s a lot of more complicated types of designs out there than this simple triangle. There’s things as simple as a gear where warping at corners can be an issue. 

Now the traditional type of solution to help with warping is to put a brim on this, where you have a single strip all the way around the outer side of the part. 

And that’s fine, but it doesn’t always work and it adds a lot of post-processing because that brim has to be removed from the entire exterior of the part. When really the only thing we care about are these corners, so the other problem is also that the brim is a print setting and you want the design to not be dependent upon the printer settings or the printer tuning itself. 

A good design can be manufactured basically with any printer at any time and at any scale. So how can we change this CAD so that it doesn’t need a software generated brim? 

Well these!

The most common solution is actually called mouse ears and mouse ears are these very simple circles that you place at very sharp corners. Which gives a round outline to the part, so that it doesn’t have the drag feature. And also creates a very high surface area for adhesion right here so that the corner is held against the bed very well.

The way you design them is you can place them on the corner and then you make them as thick as whatever the first layer would be. Generally 0.2 is a very good thickness for these types of features, so that the software can catch them. Most softwares will catch them very reliably this way, instead of having a brim all the way around that needs to be cleaned off, you have just a small area that can be trimmed off very quickly. 

But this can be optimized even more, this still has quite a bit of touch and can leave residue on that tip. So there’s an evolution to this that can be utilized. Which is to actually put kind of a sprue off the end of the corner. This way instead of having to trim two edges, you instead just literally snip off the tip of this. 

However this one has been exaggerated in order to show that sprue. This is a little bit far spaced and a little bit long, because what would happen is if this part was very dense and had a lot of warping or a lot of internal stresses it would start to pull up on this little sprue. It would kind of stretch it and it would still potentially warp. 

So you want to make sure that this surface area of the disc, is as close to the corner as possible. What we can do is edit our model and you’ll basically move it in, right to the edge. 

This is a very good sprue where you have a very tight controlled part, but again it snips off in a half a second. You can produce thousands of these inside of large print farms and not have to worry about a bunch of post-processing labor cost or additional cost.

That helps a huge amount with a part, because 3D printed parts are really just the cost of the machine time and the material. But then a lot more cost comes in with post-processing, so rather than using software generated brims or these kinds of basic designs of the mouse ears. You can create these sprue design mouse ears which will hold together sharp corners that have a high potential to warp or to fail in the first layer. They add very minimal extra post processing to the part.

Try these on your next 3D model with sharp corners!

Glenreagh Mountain Railway

So I’ve kick off the new year with my first work travel and sales meeting.

I must say it was a great meeting, I wasn’t shown the doors within the first five minutes. Instead the meeting lasted close to three hours! Very very productive meeting was had.

No I did not sell a damn thing but I did get a personal tour of the local historical railway in my customers town to which he was a board member of.

Glenreagh Mountain Railway, known as the GMR, was established in 1989 as a heritage tourist railway at Glenreagh, near Coffs Harbour, New South Wales, Australia. The GMR acquired the 35-kilometre section from Glenreagh to Ulong in 1999 from the State Rail Authority for $1 and began restoring this section of line as well as rolling stock, to enable the heritage tourist railway to operate.

Rolling Stock

GMR’s current rolling stock includes steam locomotive Z19 class 1919, 4-wheel watergin L568, TAM sleeping car, two heritage end-platform cars, S type carriages, ex-U set interurban carriages, and numerous trikes and track maintenance vehicles.

At the Glenreagh Mountain Railway Museum, you can view steam trains, diesel trains, 4 Wheel Open Goods Wagons, end platform cars and more.

We are open 7 days a week by appointment to the general public.  To book a tour, please  email us at secretary@gmr.org.au at least 2 days prior to your arrival. Group bookings are also welcomed.

A number of school excursions, rail enthusiasts, photography clubs, tour groups visit us here at the Glenreagh Mountain Railway Museum. 

Our current Rolling Stock includes, but is not is limited to: 

1. The Railmotor CPH 11

The Railmotor CPH 11 here at Glenreagh is one of the famous “42 Foot Rail Motors” of the NSW Railways. They were commonly known as “Tin Hares”, a title that owes its origins to the greyhound tracks of NSW between the two World Wars.

There were 37 in all of the CPH’s . The first one was introduced in 1923 and they rapidly revolutionised passenger transport on branch lines throughout NSW. When many of these lines were closed from the 1960’s onwards they were redeployed to non-electrified passenger lines in Sydney and Wollongong until the mid 1980’s. They are amongst the best known and most widely traveled rail vehicles in NSW.

CPH Rail motors were powered by a General Motors diesel engine generating 150hp. They have a driver’s compartment at each end, a central guard’s compartment and passenger accommodation at both ends. When they reached the end of their journey the driver simply locked up the cabin he had been using and walked up to the other end. No need for turntables or triangles with this handy little machine!

During 1970 CPH 11 was based at Richmond for use on commuter services to Blacktown. By the next year it had moved to Moree to run out on the Boggabilla and Mungindi lines. In 1974 it was running to Oaklands in southern NSW from The Rock.

Next year saw it based at Cootamundra to run out on the line to Tumut. In 1978 it was transferred back to Sutherland to work on Illawarra line services. Electrification of this line to Waterfall resulted in its transfer to Wollongong where it saw out its days until retired in the mid 1980’s.

CPH 11 was initially bought by the Dorrigo Steam Railway and Museum. Ownership passed to GMR in the late 1990’s. Its transfer to Glenreagh West did not occur until late 2003.

Its general condition can be described as fair at best.

Much work will be required to return CPH 11 to operating condition, but in time it will become a vital part of GMR’s operational fleet.

2. Locomotive 1919

The 19 class

Perhaps a little should be said here about NSWGR locomotive numbers. After a renumbering in 1924, all steam locomotives carried a 4 digit number. The first two digits indicated the “class” of the locomotive, while the second two digits indicated the number of the locomotive within the class. Thus, 1919 is the nineteenth member of the nineteen class. Nineteen class locomotives first entered service in 1877, with 1919 entering service in December 1878. Ultimately, seventy seven 19 class locomotives were employed, with the last entering service in 1890. Fifty nine of the engines were built by Beyer Peacock and Co. of Manchester, England, with the remaining eighteen being built locally by Henry Vale and Co. of Sydney.

When introduced on the NSWGR, the nineteen class were the big new goods power of the day, replacing many older and less powerful engines. They became the most widely used class of goods engine employed on the NSW system. In their early days the Nineteen class travelled all of the main lines of NSW hauling the “heavy” goods trains.

In their latter days they saw service on almost every branch line and industrial siding in the state. As built, the nineteen class weighed about 57 tons and were about 46 feet long, overall. They are diminutive when compared with the massive 57 class goods engines introduced some 52 years later in 1929, weighing 227 tons and of 87 feet in length. Although considered big in their day, they are very small engines by “modern” (1929!) standards.

The nineteen class locomotives had extraordinary long lives. While some were scrapped in the 1930s, many survived until the 1960s, giving them working lives of around eighty years. Eleven of the class, including 1919, remained in service until near the end of steam on the NSWGR in 1971, giving them working lives of up to ninety five years! While it was not uncommon for steam locomotives in NSW to have lives spanning forty, or fifty years, (or even sixty or seventy years in the case of the famous 32 class engines), the nineteen class engines were unique in their long life times.

The reasons for this lay in the light axle loads and short wheel base of the class. They could transverse lines where no other class could go. Several branch lines in NSW, notably the Oberon, Batlow and Dorrigo branches, were laid with steep grades, sharp curves, and light rails which were unsuitable for longer and heavier engines. While the Dorrigo line also permitted 50 class engines, only nineteen class were allowed on the former two branches. Ultimately, the wharves of Darling Harbour, and the Newcastle waterfront accounted for the retention of the class, for shunting at these locations. Sharp curves and light rails would only pass the nineteen class and while more modern engines, including the legendary 38 class, were passing to the scrap merchants, the old engines were still being overhauled at Eveleigh workshops. All but nine engines completed over a million miles during their varied careers.

1919 and the Glenreagh – Dorrigo line

During the years 1953 to 1958, engine 1919 was allocated to South Grafton Locomotive Depot, but spent most of its time at Glenreagh, which was a subdepot of South Grafton. During this period 1919 operated many trains on the line, and became a familiar sight between Glenreagh and Dorrigo. 1919 was the last of its class to work regular traffic on the branch. 44 and 48 class diesels were introduced from October 1957, and 1919 was withdrawn from South Grafton depot in October 1958.

3. “S” type 4 Wheel Open Goods Wagons

These 4-wheel open wagons were once the most numerous wagon on the NSW railways. Nearly every preservation group in New South Wales has a representative of this type of wagon in their collection.

The S truck design was originally introduced in 1901, but it was not until the late 1940s that a massive rebuilding programme saw the introduction of the modified design represented by wagons in the GMR collection.

The reconstruction programme continued until the end of 1958 by which time a total of 10,000 were built. Clyde Wagon Works undertook the massive task. New frames and bodies were built, but some parts were salvaged from the earlier designs.

The 4-wheel S truck has a wheel base of 10′-0″and an overall length of 18′-0″. This became the standard or equivalent length for measuring all trains in New South Wales. Crossing loops and refuge loops were stated as being equal to a certain length, for crossing purposes, and were measured in multiples of this standard 18′-0″.

S trucks lasted well into the 1980s, last seeing main line service on the wire traffic from Port Waratah in Newcastle to Ashfield & Rozelle in Sydney.

4. End Platform Cars

HFO 1260 and HFO 1595

This car was originally built in 1911 as a loose car i.e. not as a part of a particular car set but in July 1936 a set coded  LUB 36 of 8 cars was formed out of loose cars including 1595.

This set was officially condemned in Dec 1974 but unofficially continued to be used as the standby set at Newcastle, where it saw intermittent use to replace failed diesel railcars.

Placed into storage mid 1977 and then sent to Shell Harbor for further storage pending scrapping.

Built as a FA 1595 5/1911

Fitted with electric lighting June 1926

Converted to a brake end 8/1932 with a small guards/goods compartment.

Converted to HF0 3/1941

Condemned 12/1974

My Path To Remote Ops

Living in rural Australia and being of the younger NMRA generation does have its draw backs; Three hours to the closest model railroad club and very few peers of my age. However as the saying goes, you only get out what you put in. Being introduced to model railroading as a seven-year-old and only moving away from the hobby when girls and cars became of more interest, I quickly rejoined when I had a son of my own. In the space of ten years technology has taken a large leap. When trying to find answers to my questions and problems I instinctively turned to the internet.

In the world of DCC, open source software and microcomputers I am sure you have all heard of JMRI and a Raspberry Pi. My new layout build is in the early construction stage. By the end, I am aiming to have a multi deck layout with the ability to have eight to ten operators for a three to four-hour operating session. It was at this point I reached my first group of questions: how do I fit eight to ten people in a 6m x 3m area?, what DCC system offers the best solution for ops and user-friendly throttles? The answer to the first was easy! I would not overcome this without reducing my layout footprint. That was not going to happen! Second question was not so clear cut, with every DCC system having their own pros and cons. A fellow modeller here in Australia was assembling Sprog Pi’s and introduced me to the idea of having my Pi and eating it to.

The Sprog Pi system uses a Raspberry Pi 3B+ with a Pi-Sprog Hat (Hardware Attached on Top) from Sprog DCC. This takes care of the DCC throttles, with the added benefit of a computer that is running JMRI for as part of the Sprog system. As the Raspberry Pi is a minicomputer, you can attach multiple DCC systems via the USB ports. This enables the user to add block detection from one manufacturer and signalling from another as the layout evolves. Using JMRI as a building block has the added benefit that while building my Roster, Tables and Panels as I go the integration of other systems will be slice of Pi due to the groundwork already started.

The Sprog Pi comes as a plug and play system so I will not be covering the setup of this. The Sprog Pi comes pre-configured to operate your layout via WiThrottle in JMRI, the Raspberry Pi’s WiFi and a smart phone or device. With half the battle won, it left me pondering the notion of fulfilling my need for two person train crews whilst having less operators onsite. While tinkering within JMRI I found and used the “Web Server” to view my panels while testing the layout during track laying. Access was via a web browser and my local home network (all in house IP address). This had me thinking, if only half of my operators could access this while not in my train shed! Being part of the NMRAx team hosting and watching Dave Abeles clinic, I knew the technology was available, it was a matter of determining how and what settings to use.

Setting up JMRI to start and launch WiThrottle, My Panels and the Web Server is the first step. All of this can be completed from within JMRI’s Preferences. Under the “Start Up” tab, you can add files or parts of JMRI you want to start every time you open JMRI [img1].

 To Add a new start up item, click the add button [img2]. Here you can pick from several options [img3].

I like to run a pause between start-up and all items I have opening. This gives the Raspberry Pi time to complete the operation. I run the sequence of WiThrottle, My Panels, Web Server. Once you have all items you wish to open upon starting, be sure to note the port numbers for both WiThrottle (12090) [img4] and the Web Server (12080) [img5]. These will be used later in the setup.

Next you need to setup port forwarding within your home network router. The home network router is broken up into two areas. The first is the local network, everything that you connect to it within your home. The local network has an IP address assigned to every item connected, regardless of the connection type. PC’s, Printers, TV’s and Phones. Evan the router itself has an IP address, this is normally 192.168.1.1. Every router is different when it comes to port forwarding so it’s best to read the manual. For my TP Link router, I open a web browser and enter the IP address 192.168.1.1 into the address bar. I then find my Sprog-Pi under the client list of connected devices (192.168.1.108) [img6]. Under the advanced tab, and NAT Forwarding, I setup virtual servers. Here I enter two servers [img7]. I do this to keep the port arrangement directed at only the ports I want to access from the internet.

The second area of your home router is the IP address your internet provider assigns you. This normally changes every time you reboot your home router. To find this you can do a simple google search “What’s My IP Address”[img8]. Here you see mine is 220.245.174.17, note this down as it is needed when you issue this connection address out to your operators. As most internet providers here in Australia do not supply you with a static IP, I see this as added security as after every Op session I simply restart my home router and will have a different IP address. The above setup takes around two minutes before any Op session to reconfigure.

Now you have the port forwarding setup and the external IP address for your router, you can use these to connect. First, I connect to WiThrottle using the “Engine Drive” app. In the “server address” you enter your external IP address and the WiThrottle port number and click connect (NOTE I’m only connected via my mobile 4G network, meaning a different internet connection then my Sprog-Pi) [img9]. Once connected you can see your JMRI roster under “Server Roster”, Select a loco and cycle the layout power [img10] [img11] [img12] [img13].

Now we have confirmed the connection and access is possible, you can log on to the web server using your IP address and the webserver port (220.245.174.17:12080). You can access this via a web browser on any device that is not on your local network [img14].

From here you can access any panels that are open, web throttle and your roster. The panels work as any other panel you have in JMRI. Here you can see my overall layout. This gives the user the ability to change points [img15].

So, what is next I hear you ask! At the time of writing this, I am working on video and audio for the crews. I am planning to have a few remote cameras around the layout to get an overview but not to the point the remote driver can see the operation and car spot. The audio will be via UHF radio’s here in the layout room. I plan to broadcast this along with the video over a video conference room online. After this I will look at digital switch list and operation practice that will help slow everyone down and act like the real-life railroad. My grand plan for the layout is to have two, two-person train crews out and about the layout. With another two-person train crew working the yard. Where possible the engineer for each train will be accessing via be remote login to the system, the conductor will be in the layout room with a UHF radio and digital tablet to follow switch list and throw turnouts.

Brad Anderson

Top 5 Airbrushes for Miniatures and Models

Iwata Media Eclipse HP CS

First up is the Iwata-Medea Eclipse. This is an airbrush with a 0.35mm needle and drop-in self-centering nozzle. That combination makes it excellent for applying smaller details. This is also a gravity feed gun, which makes it all the more appropriate in that capacity.

The Eclipse CS is designed specifically for spraying heavier acrylics and medea textile colors, without losing definition or clarity. Despite being gravity fed, the cup is still a decent size at 1/3oz, meaning you won’t constantly need to change paint.

The spray pattern is hairline/2” round.

Iwata is one of the best known brands of airbrush, meaning you can rely on a high quality finish and durability. It also means you can rely on great compatibility with a large range of different accessories and paints.

There’s not much negative to say about this product in fact, other than it is very much fit-for-purpose and that the chrome can occasionally become damaged.

Pros

•  This is a high quality and well made airbrush
• Perfect for fine and medium details
• Great for beginners

Cons

•  Not suitable for covering larger surface areas
• Chrome can occasionally become scratched

Badger 105 Patriot

A rather bombastic name for what is essentially just a painting tool, but the “patriot” is never-the-less a very well-made dual action, gravity fed airbrush. This time the product comes as a set, including an additional tip, instruction manual, and more.

The needle is a very middle-of-the-road .5mm, which makes it perfectly versatile for a range of different jobs. This, combined with the included extras, makes it a quite appealing option for those starting out.

Maintenance is also made easy thanks to the self-centering nozzle design. A tapered color also helps to keep the gun looking fresh for years to come.

The only issue we experienced was occasional jamming, but not to an alarming extent.

Pros

• Versatile product
• Great build quality
• Low maintenance

Cons

• Heavier

Harder and Steenbeck Infinity CR Plus

This is a brilliantly comprehensive airbrush kit that comes with additional lids, two cups, and even a nice carry case.

The big bonus in this pack though, is the cleaning brush set, as well as the additional hose!

The two self-centering nozzles provide 0.15mm and 0.4mm patterns respectively, making this another versatile option for miniature painters.

But all the freebies in the world won’t make up for a poor product. Fortunately, this is another well made airbrush that features some great quality-of-life features such as an innovative adjustable trigger mechanism, and a quick-fix end piece with a numbered dial.

This is once again a gravity fed gun.

Pros

• Interchangeable cup sizes
• Well made, well balanced, and pleasant to use
• Precise trigger control makes a big difference

Cons

• Expensive
•  Occasional sputtering

Badger Renegade Krome

This is an ultra-fine airbrush that allows spray patterns all the way down to 1/1000 of an inch! A softer trigger also allows for extremely precise control, while the gravity feed is also well chosen for the purpose. This is perfect airbrush for models and miniatures like warhammer 40k.

Also standout is the actual construction of the airbrush itself. This is a brush with a highly ergonomic design, great balancing, and a really attractive look. It also comes with a case!

That said, the airflow and precision do somewhat reflect the lower price. It’s certainly fit for purpose, but if you spend more, you will notice a more consistent experience.

Pros

• Very fine control
• Soft trigger works well
• Affordable

Cons

• Feels similar to other less-expensive products
• Case is a little flimsy

Iwata Media Revolution CR

This is another more affordable airbrush gun, this time from the major players Iwata. So what happens when a company at the top of its game attempts to offer something that can compete with more budget providers?

The answer is the Iwata-Medea Revolution CR Dual Action/Large Gravity Feed Cup. That name tells you a lot of what you need to know, including the dual action nature of the brush and the large gravity feed cup found on other Iwata products.

The needle is nice and versatile at the 0.5mm sweet spot, and this also means the brush can use heavier paints. The product has replaceable internal solvent-proof PTFE needle packing, and thanks to the well known brand, you should have no problem finding replacement parts or accessories.

Pros

• Well known brand
• Well made for the lower price
• Versatile

Cons

•  No extras

Conclusions

They say that a bad workman blames their tools. While this may be true, it’s also true that the right airbrush can make all the difference to the kind of precision and quality you’re capable of when painting your figures and models.

Any of the items on the list will serve you well, with the more expensive options of course providing a slightly higher level of precision and comfort. Choose the option that suits your budget, and think about the type of work you intend on doing. If possible, invest in a few different airbrushes and needles to handle different types of detail and scope.

And whatever you do, have fun! This is a highly relaxing, rewarding, and addictive hobby that results in beautiful figures you can display to the world.

Best Airbrush for Miniatures and Models

Are you thinking of adding an airbrush to your models and miniatures painting hobby?

Airbrushes help speed up your painting and with practice you can achieve some great results with them. With airbrush you can prime your minis indoors all year round in whatever color you want. You can use an airbrush for everything you do on your minis and models; basecoating, varnishing, priming, stencils, highlighting and many more.

Airbrushes are a bit expensive investment for your hobby. There are so many choices that may confuse you. So I have created this detailed guide along with my recommendations for absolute beginner airbrush for miniatures and model painting.

Beginner’s Guide

When choosing your airbrush, you’ll quickly realize that there are numerous different features to contend with and a number of different concepts and attributes. Some airbrushes are better suited to specific tasks, while others are just generally better.

This guide will help you find your way through the confusion.

Types of Airbrush

There are several different types of airbrush, and picking the right one is key to getting the best experience.

Single-Action vs Dual-Action

Single action airbrushes only give the user control over the airflow via a trigger or button. When you press down, both air and paint come out of the needle.

With dual action airbrush, when you press down, air will come out. Then you need to pull back trigger to release paint.

What to choose – In general, a dual-action airbrush will thereby provide a much finer control and more intuitive interaction with the brush specially for your miniatures and models.

Gravity vs Siphon Feed

This refers to the way in which the paint is actually delivered to the gun, and here both options have pros and cons.

In a gravity feed airbrush, the paint is placed in a small container at the top of the brush. This will then allow the paint to naturally “slide” into the main chamber. Gravity fed airbrushes allow you to work with a lower air pressure, which may give you slightly more control when painting detailed parts of your mini. It also helps to avoid “overspray.”

Siphon feed airbrushes meanwhile place the container underneath the main unit, and then feed the paint upward to the mixing chamber using a small amount of pressure. These allow you to store more paint at any given time, and they are advantageous when painting larger models or basecoating as they don’t require constant refilling.

Needle Size

The size of the needle is an important feature when comparing airbrushes. Smaller needles allow you to create finer lines, and when draw tiny details onto an even smaller model, this can be a Godsend. At the same time though, fine needles aren’t as useful when painting large objects. What’s more, is that fine needles are prone to clogging so you need to thin your paint.

For miniature painting it is advisable to get needle in the range of 0.2 to 0.5mm.

If you are just starting out and you can currently only afford a single airbrush, then starting with 0.3 needle may well be the better option.

The Brands

A good place to start is with the different brands. There are three particular brands that are very popular. These are Iwata, Badger, and Paasche. Other well known brands include Harder & Steenbeck, and Grex. If you choose one of these brands, then you can generally expect the product to be well made and to perform well at what it does, which is a good minimum!

Kits vs Brushes

When buying your airbrush, there is a difference between buying a brush on its own, and an airbrush kit. The latter is going to provide you with all of the different tools and accessories that you need in order to start airbrushing.

If you buy an airbrush on its own, then you will need to also invest in an airbrush compressor. This is what will power the airbrush and it is the most important piece of equipment other than the airbrush itself!

Airbrush Compressor for Miniatures and Models

Perhaps the most important piece of equipment after airbrush is the compressor. This is what will provide the airbrush with a steady air supply and help to maintain the ideal pressure and airflow.

Fluctuations in pressure can cause imperfections in your final product. You need to consider the PSI when choosing, which will tell you the maximum amount of pressure you’re able to deliver. For miniatures and models painting get one with at least 30 psi minimum.

The ideal compressor offers lots of consistent air pressure, while also being quiet to operate.

Other useful accessories to consider include:

• Airbrush cleaner – essential to keep your brush working well at all times
• Cleaning brushes
• Hoses for attaching your compressor to the airbrush
• Moisture trap
• Fittings and connectors
• Spare parts for repair – many kits will come with these

With all this in mind, let’s take a look at some of the very best airbrushes on the market right now.