FDM Printing

What is FDM Printing ?

FDM printing is very simply a spool of plastic filament being feed into a heated nozzle and laid down in thin lines over multiple layers in all 3 axis of movement. The size of the nozzle and the printer settings define the quality of a print, and the overall printer software package determines ease of use. The software takes a STL file and slices the file to create a 3d model that can be printed. STL files are widely available on the net, either to purchase or for free and if you have the ability you can also create your own. This does require a 3d program such as CAD or Blender and a learning curve. I taught myself 3d modelling some 20 years ago and so can make very simple models, or amend existing files.

I purchased a Bambu A1 mini last July for about £170 including an extra nozzle and some filament. Since that time I have purchased roughly half a dozen spools of filament and a new 0.2mm nozzle (the smallest size available).

I have 1807 hours logged on the printer and using simple maths ( I like simple maths and you will see it a lot in this blog) that works out not far off 10p per hour amortised cost. 

My printer normally sits on a wooden block under my game table and churns out prints on demand. There are no toxic chemicals used in the process, but every now and then a little bit of molten plastic on the nozzle will overheat and smoke a little, but in truth the most invasive thing about the printer is it makes a small amount of noise on occasion. Shut the door and that stops being a problem. This is a small printer with a print bed 18cm x 18cm and so a model that is larger than that needs to be cut into smaller parts. Even with buildings I have not yet found a model I needed to cut more than I would wish to get it to fit. 

STL files

I have over 500 vehicle STL files all downloaded from the net. Some are duplicates of the same vehicle type by different designers but this is a massive pool into which to dip. To date I have only purchased two vehicle files (one was actually for a Pak40 which was £3 or so, but in the event I subsequently found a better file for free).  So all the others are legitimately available, for free, from generous model makers who share their work.

Marco Bergman is one such 3d model maker and I think this is his full catalogue, with all models made at 1:100 scale (15mm). As can be seen he alone offers an extensive range of models. These are good quality and comparable with the available 15mm white metal or plastic kits.

This is the other vehicle STL file I purchased - the Hotchkiss Geschutzwagen 39H - as I have not been able to find anyone else offering this oddity. 

I will do a future post covering the process of printing this model in detail but on slicing the file  the software advises this will use 8.71g of filament. Filament comes in 1kg spools, and I paid £8.50 for this spool. Print time will be 3 hours 43 minutes, and the cost for the print will be 7p. 

Yep - just seven of those shiny British pennies. 

I can therefore afford a few failed prints while I seek the best set up for this particular print and still be way ahead of the game. A quick check on ebay for a single AFV plastic sprue shows I would be paying somewhere between £4-10 for an injection moulded kit if one was available.

I will happily argue that printing vehicles and AFVs at 15mm (1:100 scale) is the sweet spot for the FDM printing process, particularly when the model was made with printing at that size in mind. I have reduced the size of 28mm models and printed them, but the level of detail becomes harder for the printer to cope with. There is no doubt a resin printer will produce a better model than a FDM printer. However at this scale the FDM printer is more than capable of producing good quality prints suitable for the table and at 7p a pop you can't go wrong. No messy or toxic chemicals to have to deal with either.

Everything but the tarps are FDM printed, including the commander

15mm

 

Rather than being a scale 15mm (or 20/28mm for that matter) is a measurement of a figures height. In the past this seems to have been the height between the ground and the top of the head of a standing figure, but now is typical measured to the figures eyes. Regardless of this figures described as 15mm are likely to vary in height by a couple of millimeters. This will have no effect on game play but may affect the aesthetic on the table if noticeable. 

Peter Pig are my 15mm figures of choice. They are metal rather than plastic or resin and so have that nice heft and are also robust. The level of detail sculpted into the figures is impressive and not always noticeable on their website, and their WW2 range is extensive, particularly for British and German troops.

Not perfect measurements but enough to get a good feel for the size of their late war figures. (The earlier sculpts seem to be a little smaller)   

                     

     

15mm is generally considered to be 1:100 scale. Simple maths confirms this. A standing man that is 5'11" (1.8m) tall will be 18mm high - very close to the figure above.

Model vehicles and buildings are typically quoted at their scale, and for 1:100 the maths is very easy if working with metric numbers - just divide actual size by 100 - very handy when printing STL files to ensure they are the correct size.

Chain of Command

The quoted ground scale for CoC is 12" equals 40 yards (1"=10ft). That is a scale of 1:120 and so given the variance of 15mm figure heights is pretty close to matching the 15mm ground scale. Interestingly when scaling a 6'x4' table we get a battle area 220m x 146m (240 x 160 yards) which is a surprisingly small area. This shrinks to 102m x 68m (112 x 75 yards) if 28mm figures are being used which are generally considered to be at 1:56 scale. Therefore there is a degree of abstraction creeping to the game at that scale, whereas  when playing with 15mm what you see is what you get in terms of weapon ranges and the like.

This weeks reinforcements

 

Elements of an Aufklärungsabteilung arrive.

I printed the Sd.Kfz 234/3 soon after getting the printer, but had never got around to painting it, in part because the print quality was not as good as I would like. The layer lines are quite visible and there is a line across all the wheels at the lower hull level. But this week I thought I would have a go at painting it to see if I could freehand a half decent camouflage scheme with the airbrush. I threw the 251/1 into to the pot as well, gave the airbrush a strip down and deep clean and the results are better than I was expecting. So much so I consider it good enough for the table.

Figures added, both from the Command Decision range, along with a little foliage for the halftrack.

From a CoC perspective, the Sd.Kfz 251/1 costs 3 support points, and while the 234/3 is not listed in the German support list it can probably be said to cost 4 points - equal to the 250/8 and 251/9 Stummels and one point less than the 234/2 Puma.

Both STL files from TigerAce1945 and free. 

The Game Changes part two...

 

In the previous post I detailed the three game changers that led directly to where I find myself today.  

So where is that ?

At the start of May last year I had no 15mm figures, vehicles nor terrain - Zero, Zilch, Nada !

Today I have 

• Four complete CoC platoons, plus the ability to make a couple more by adding or subtracting figures as required.
• 12 fully painted and table ready British vehicles
• 8 fully painted and table ready German vehicles
• a small village of French styled farm buildings and barns
• a small forest of trees, hedges and table scatter.
• and sufficient road elements to create a realistic road network. 

In addition I have a dozen or so partially or unpainted vehicles, more trees in construction and over 500 STL files covering vehicles, buildings and other terrain features that I can print as required.

All of this has been driven by the move to 15mm, which really hits a sweet spot. The vehicles and figures can be more quickly painted when compared to their larger brethren, and yet retain a good level of detail so they also look good on the table.

 

 

The Game Changes...

 

The Kitchen Table

Chain of Command v2 are "rules for WWII combat at platoon level" which is very much the level at which I enjoy gaming - one figure represents on man. The rules are designed to be scale agnostic, but 28mm, 20mm or 15mm seem to be scales at which the majority of games are played with a table 6' x 4' or larger recommended. 

But what if your table is not that big?

Following a kitchen refurb in 2024 we ended up with the old kitchen table being spare, and much to my delight, my wife suggested it go into a spare bedroom in case it came in handy. At that moment it was no longer a spare kitchen table - it was a wargaming table, it was battlefield. 

Only issue was it measured 5' x 3' and so a little smaller than the recommended (and de facto wargaming standard) 4' x 6'. Still I was not going to look a gift horse in the mouth. Thinking through the options the obvious solution to having a slightly smaller table than ideal on which to play CoC was to reduce the figure size.  

If you could play with 28mm figures on a 6'x4' table then surely 15mm figures on a 5'x3' would work. There was the added bonus that the Chain of Command rules mention that the rules use a ground scale of 12" = 40 yards being 1:120 scale. Close enough to the 1:100 that 15mm is often also classified as. 

Peter Pig

Having not previously thought about 15mm figures I did not really know what my options were. A quick Google search threw up the Battlefront Flames of War range, the Forged in Battle range and company called Peter Pig. The first two sell platoon and company sized forces, but have limited, and in some cases unusual poses. Peter Pig on the other hand offer a wide range of figures in packs of eight figures which allows you to build bespoke platoons matching CoC's platoon lists.

The FDM Printer

At the same time as I was purchasing my first Peter Pig figures, I started to read about a 3D filament printer that even an idiot could use (I'm paraphrasing here). I had been considering getting a resin printer for a while, but had discarded the idea due to the cost, complexity of use and the toxic nature of the chemicals required for printing and cleaning. A FDM printer, which uses a spool of filament and requires no aftercare or cleaning once printed seemed a good way to get into printing and an easy way to print terrain elements and buildings. It also looked cost effective. I purchased a Bambu A1 mini for £160 and within minutes of receipt it was printing armoured vehicles. While there was a bit of a learning curve I was able to print vehicles to a more than acceptable standard using STL files that are available for free on the net. So not only was I going to be able to print buildings as planned but also vehicles and AFV's. 

Welcome to 1st Section.

 

Following retirement a year or so ago I find my self with too much time on my hands to not only paint and wargame, but also to now put pen to paper and write a little about my journey and enjoyment in playing the excellent Chain of Command Rules using 15mm figures.

Chain of Command v2 are "rules for WWII combat at platoon level" which is very much the level at which I enjoy gaming - one figure represents on man. The rules are designed to be scale agnostic, but 28mm, 20mm or 15mm seem to be scales at which the majority of games are played with a table 6' x 4' or larger recommended. 

But what if your table is not that big? - I'll come back to this in a later post

A few years ago when I started getting back into wargaming I was very keen to use 28mm figures as I am also a keen figure painter. (That had been my primary hobby for a good while). I had only painted a few figures when I thought that I would be better off dropping down to 20mm, as this would reduce painting time and figure costs. Having painted a platoon or so of figures I started to consider terrain elements and scratch built a couple of buildings. But again at this stage I started to wonder how much storage space I would need for 20mm. And so last year I again stepped down a scale to 15mm and it was a game changer.