Progress on Nuenen House #3

This is the first house from my Band of Brothers Nuenen project, but I've called it House #3 based on its map location. I realise that this is nowhere near as exciting for anyone other than me - it's just another MDF kit building - but for me it has grown from an idea into something that is almost ready to place on the wargaming table.

Progress is being made! The roofers need to fit the tiles :-) but all the walls are up and in the process of being finished off. Once I have added the mortar to the bricks on the chimney, I will then affix the pre-cut tiles. Here is one elevation with the base colour painted on and mortar added to the brickwork.

It has taken several weeks to get to this point and I have learned many more lessons on the way, so the next building will inevitably be better and take less time to complete. This was the first piece off the laser cutter, about a week ago; I painted the edges of the internal window frames prior to assembling it just to make it a bit easier.

Here is the interior view of the same piece with the "glazing" added.

And the same piece from the outside.

This shot shows the window cills; it also shows where I forgot to switch on the air assist for the laser cutter when it was engraving the brick courses: it has left a burnt residue!

One lesson: I didn't account for the extra 2mm required for the base, so there are some small gaps where the walls are supposed to slot into place.

Starting to take shape; this is the four internal walls glued to the base.

The first of the exterior walls glued onto the interior face.

And another external wall in place.

Once all the walls had dried, I attached the gable ends and started to paint the base colour. It is quite a bright yellow ("Chueca" from B&Q) when it first goes on, but it does dull down once the "mortar" is applied.

Really starting to look like a house now, with the roof, chimneys, dormer window and decorative brickwork added, plus the base colour painted all over. I've also affixed thin card, again cut to near perfection by the laser, to the bottom of the house beneath the line of the windows. I need to allow for an extra millimetre when cutting due to the thickness of the "kerf".

A close-up shot of one wall. Note that the base colour is not uniformly applied, which is by design because it makes the final brickwork look more natural and weathered.

Once the "mortar" has been applied, it looks a lot more faded ,weathered and irregular.

The last bit of laser cutting I have done for this house was to cut (and then paint) some brick arches to fit above the windows and doors. The mortar needs to be applied to these too, which will lighten the brick colour.

The end is in sight for this building, so I've ordered up some Artizan US paratroopers from Great Escape Games, so that I can take some photos with Easy Company in the foreground.

Lessons from the Laser Cutter

I have been experimenting further with the capabilities of my new laser cutter, which has involved methodically testing a number of variables:

• Height of the laser (which determines the focus)
• Materials (different sheets of MDF)
• Number of passes
• Output power
• Speed

I started off performing a ramp test, which showed me where the ideal height for the laser to be positioned above the material should be. However, the "hobby" laser cutter I have purchased (the Neje Laser Master 2S Plus), does not allow the laser to be accurately moved up and down on the Z axis.  To move the height of the laser, you need an allen key to unscrew a bolt, which then allows the laser module to be moved. This is not conducive to very fine levels of control because I cannot guarantee that I am moving the laser module by hand a millimetre at a time. So...the ramp test got in me positioned in the right ballpark.

Height/Focusing of the Laser

I performed some cutting tests with it positioned according to the ramp test results and settled on some other variables (5mm/sec and 75% power) for the testing. Because the laser I have is at the low/cheaper end of the output scale, I need to maximise every watt of output to get the best cut, so accurate focusing is important. Rather than moving the laser module any more, it is now screwed firmly into place, but I performed another four height tests by raising and lowering the height of the cutting bed by -1mm, -2mm, +1mm and +2mm to find out whether the focusing could be improved to get better cutting power. I performed cutting tests using 4, 5 and 6 passes at each height too.

As it turned out, the height of the cutting bed in relation to the position of the laser module was spot on, but the test proved that the laser was focused correctly.

Materials

Something else that I discovered whilst testing is the variability in materials. I want to use my laser cutter primarily for cutting sheets of MDF to make buildings for my Band of Brothers Nuenen project, so that is what I have been using for all the tests so far. I had read on various forums that MDF is not consistent in its composition, but even two sheets, which were delivered to me in the same batch from the same manufacturer performed differently. The difference wasn't great (5 passes versus 6 passes to get a really clean cut), but it was different nevertheless, so needs to be accounted for.

Another difference that I was expecting, though not in the way that it turned out, was between 2mm and 3mm MDF. I expected the cutter to require more passes for the 3mm sheets, but it actually required less (4 to 5 passes) than the 2mm. The density of the 3mm is probably lower.

I purchased the 2mm from a supplier in the UK - they are the only place that I have found so far that sells 2mm sheets, though it is excellent value and great service. The 3mm came from a Chinese supplier on Amazon. The 3mm is the lighter sheet on the left; lightness being an indicator of density perhaps?

You can see some of the other tests that I have been performing, trying out different line thicknesses for engraving the detail of the brickwork. The house I am currently designing is "House 3", which looks like this in Band of Brothers:

The bricks are a base yellow colour, but have a lot of variability in them. This is what I achieved on my first attempt at engraving and then painting:

The mortar between the bricks was produced by scraping some wall filler (spackle for our American cousins) across the engraved lines, then wiping off the excess before it dried too much. The variability in brick colour is created using some Agrax Earthshade for the darker bricks and a wash of brick red paint for the reddish hues, plus the original yellow base colour (a colour tester pot called "Chueca" from B&Q) to bring out some of the yellow. I think it is going to look awesome on a whole building. The colouring isn't exactly the same as the screen grab from BoB, but the TV producers desaturated the colouring of the film to create visual "atmosphere". I heard that this was a technique pioneered by Steven Spielberg in Saving Private Ryan, so I don't think the colour is ever going to be an exact match for what we see on the screen, but what I have created does look like the brickwork that I have seen in real life in England. The Vincent Van Gogh museum in Nuenen also has a number of bricks (plus red ones) that are similar.

Passes, speed and power

After several tests, only changing one variable at a time, I have settled on 75% power and 5mm per second for cutting. The number of passes depends on the material I am cutting: 6 passes guarantees a clean cut for my 2mm MDF and 5 passes for the lower density 3mm MDF.   It is possible to go with one less pass for each material, but the cut sometimes leaves a few tiny bits of MDF that need trimming with a sharp knife.

Progress on House 3

I have been busy all week (2-3 hours every night) designing all the various aspects of House 3. It has been a real challenge figuring out the millimetre perfect detail for each external and internal wall, the positioning of windows and doors, and especially the roof and brickwork. I think that I have almost finished, other than to work on the dormer window and chimneys. Once I have done that, I am going to take the plunge and start cutting everything out. I am reasonably confident that it will all fit together perfectly on the first attempt, but...we'll see!

First lessons from using a laser cutter

As part of my latest project (recreating Nuenen from episode of Band of Brothers), I had been considering whether to buy a laser cutter or not, for the purpose of being able to custom make the buildings with some precision. The kits which are available from the main MDF terrain manufacturers (4Ground, Sarissa and Warbases) are not similar enough to the houses in that episode of Band of Brothers to suit the project.

Anyway, I took the plunge and bought a laser cutter/engraver after several days of intensive research on forums, Youtube and manufacturers' web sites. What did I learn?.. that it is really confusing and complicated and that there are very few clear answers to the questions that I had! My main requirement for a laser cutter was that it could cut 2mm (or possible 3mm) MDF into the shapes I wanted, plus undertake a little bit of engraving to add some detail to the building fascias. Another requirement was that I did not want to spend a fortune on the device; obviously the more that you spend the more certainty there is about the cutting power.  It seems as though you can spend several thousand on a "pro" device, which would make cutting 2mm MDF a breeze, but I don't have thousands of pounds spare, so I had to go to the budget end of the scale.

If you are prepared to pay upwards of £500, then you can move away from the "diode" type of laser to the big brother (CO2) devices. Given all the other bits that I needed to buy to complete my setup, I steered away from the low end CO2 lasers.

The Laser Cutter/Engraver

With some degree of uncertainty, I took the plunge and ordered a Neje Laser Master 2S Plus with the N40630 (30 watt) laser module. There is a web site called Banggood, which appears to be based in China, which had a lower price, but having ordered from Amazon plenty of times before, I thought that I would pay a bit more and have the peace of mind that if something went wrong, then I could easily return the item back to Amazon for a refund. I paid £280 for the last one that Amazon UK had in stock.

Neje's naming convention takes a little bit of figuring out.  The "frame" of the device comes in three sizes, but there are several laser modules which can be selected.  The bit that you attach the laser too, which moves, is called the Neje Laser Master 2S...all of them. The supplementary part of the name Max is the largest device, the Plus is the middle option and the Mini is the smallest. The "hobby" lasers, which seem to be the smallest available which are capable of cutting MDF, are the N40630 (30w input, 5.5w output) and the N40640 (40w input, 7.5w output). It is the output wattage which seems to be most important - this is the level of power that the laser diode emits and enables it to cut and/or engrave.  Various wattages are claimed by all the manufacturers and this was one of the really difficult things to wade through in various forums, videos and claims made by manufacturers.

The Software

This decision was actually quite easy because there are two choices (or three if you count the native Neje software, though I had discounted that as an option prior to my purchase). Laser GRBL is free, but seems like it requires a bit more time learning how to use it. The option I went for, largely because they provide a really good support forum, is Lightburn. It is free for the first 30 days, then costs $46 to buy a licence. There are loads of features in Lightburn, though I have only skimmed the surface so far.

Lightburn is used to send instructions to the laser cutter to perform the cutting and engraving i.e. it controls what the laser does.

I use some other software packages to work on the designs (shapes and measurements etc). These are Powerpoint for creating rough sketches like the one below, and Visio, which I am already very familiar with, for creating the accurate "architectural" drawings. Visio allows you to export images in SVG format, which can then be imported into Lightburn.  I have not found it easy in Lightburn to exert the same level of control over the shapes and dimensions that I can in Visio, which is why I will continue with Visio.  If you are familiar with the Adobe suite, such as Illustrator, then files from that can also be imported into Lightburn.

Safety

There is plenty of safety advice about the use of laser cutters in the various forums, but it is probably worth repeating.  The Neje package I bought came with some safety goggles, which cut out the glare of the laser, so I have been wearing those whilst my laser device is switched on.

The other health and safety consideration is around the effect of cutting.  The laser generates a lot of heat, so being aware of the fire risk when cutting combustible material such as MDF is worth mentioning.  

Cutting also generates a lot of smoke - essentially the laser burns its way through the MDF, so some decent ventilation is required.  Therefore, another Amazon purchase was an extractor fan.  I bought a Black Orchid 100mm silent fan, which cost £34; it is actually fairly quiet and does shift enough air so that my garage room does not stink of burning MDF.

I bought some 100mm aluminium ducting to attach to the back of extractor fan and vent the fumes through a hole in the wall.  That cost another £7.60.  To ensure that the ducting was securely attached to the fan, I bought some 100mm pipe clamps (again from Amazon) at £3.25 for two.  Unfortunately, the outlet pipe from the extractor fan is really smooth so the ducting and clamps don't really have anything to grip onto. I might drill a couple of holes in the outlet pipe and then securely attach a ring of something around the pipe so that the fan outlet has something to prevent the ducting from sliding off.

Something else that I intend to do, once I have got the configuration dialled in, is to create an enclosure for the whole shebang. That way, I can catch all the fumes inside the enclosure and expel them via the exhaust system.

Software and Cutting

OK, so I have the laser cutter and the software to control it, but it is nowhere near as straightforward as that!  You cannot just jump straight into cutting. ;-(

I decided that I would make a decent baseboard and screw the Neje onto it, mostly so that it was stable and not subject to the risk of being knocked or nudged whilst it was cutting (when the object is to achieve millimetre perfect accuracy). I screwed and glued two lengths of wood along the edge and then affixed the Neje to these rails. This had the effect of raising the Neje higher than it would normally be positioned, but the extra height allowed space for a cutting bed. Apparently, this makes cutting easier due to air being able to flow underneath whatever you are cutting. I bought one from Amazon which was large enough to sit underneath A4 sheets, though I had not accounted for the thick solid metal edges, so I now wish that I had spent a little more on a larger model than the £65 it cost for this one.

To aid with airflow, I have put some small wooden slats underneath the honeycomb cutting bed.

Focusing the Laser

One of the most, if not the most, important aspects of using a laser diode for cutting is to ensure that it is correctly focused. This sounds straightforward and the various Youtube videos showing how to perform a "ramp test" also make it look simple...my experience has been that this is actually quite difficult. Before undertaking a ramp test, you need to ensure that your laser is positioned at roughly the right height and is focused to somewhere near where it is going to end up being positioned (on the Z axis).

Once I had figured that out, I re-read a bunch of forum posts on the Lightburn forum and re-watched a bunch of Youtube videos about performing ramp tests and tried it out. The purpose of the ramp test is to find the sweet spot where the "waist" of the laser beam narrows to its thinnest point: that's the height where the laser should be positioned to maximise its cutting power. I think that I am almost there, but can probably do a little bit more fine-tuning.

Cutting Tests

I am pleased to report that I have managed to get my 30w Neje to cut through 2mm of MDF, though I think that I still need to perform some more tests and calibration before possibly getting better results.

Apparently, it is not a good idea to run your laser at 100% power all the time because it drastically shortens its lifespan, so I started off testing at 100%, then have dropped it down to 75% as I got a feel for the impact of making adjustments elsewhere. For example, focusing and height of the laser; whether to use air-assist or not; the speed at which the laser head moves.

I can cut through 2mm MDF using the following settings:

• 75% power
• 5mm / second
• 6 passes
• Air assist on/off doesn't seem to make any difference.

I have read that it should be possible to cut this thickness of MDF within 2 passes, hence why I've got a bit more experimentation to do.  Even if it remains at 6 passes, then it's not a big deal.  I'm not going into commercial production, so if it takes an hour to cut out a house, then there are plenty of other things that I can be getting on with whilst the Neje does its job.

"Air assist" is supposed to help with cutting, though it has not made a significant difference in the tests I have performed so far, so I am thinking that I perhaps don't have it set up correctly yet. I bought a nozzle from a chap on Ebay (£15) and connected it up to the air compressor that I already owned with a bit of plastic tubing donated from my Dad's fish tank. When the air is switched on, I can see it blowing the smoke and tiny particles of burning MDF (the whole purpose of having air assist) away from the cutting area, so it seems to be working, though the number of passes has been the same irrespective of whether it is on or off.

Conclusion

Would I recommend the Neje?  It's probably too early to tell and I don't have experience of any of the competitor machine that I looked at in this price bracket, such as:

• Atomstack A5 Pro
• Ortur Laser Master Pro 2
• Neje Master 2S Plus with A40640
• Scuplfun S6 Pro
• Sculpfun S9

A bit more experimentation and cutting is required. Watch this space!

Band of Brothers - Nuenen House #3

For my Band of Brothers Nuenen project, I now have made a decent start on drawing each building. I've completed an elevation view and an "architectural" drawing (with measurements) for each side of three buildings so far. 

Building #1 was the first on the map, so I started with that, but in retrospect, I should have probably started with an easier building first. The challenge with building #1 is that it adjoins building #2 and several aspects of it were not particularly clear, or even visible from watching the episode, even watching it frame-by frame. Building #1 (and #2) is in the background when the British tanks move into the village and stop prior to being shot up by the Tiger. Another reason for perhaps not choosing to start with buildings #1 and 2 was the complexity of some of the features. Anyway, it is done now and I learnt some lessons along the way, which meant that I managed to complete all the drawings for house #3 in about 2 hours. Building #1 and #2 probably took about 12 hours of work!

Here is what the eastern facing elevation (aspect J) of building #1 and the northern-facing side of building #2 (aspect H) looks like. Aspect H was a complete fabrication on my part because it does not feature in any of the shots in Band of Brothers. I think that aspect J is a reasonable representation of what is in BoB; more surface detailing will be added when I make the actual model though.

And here is the more accurately proportioned architectural drawing, which shows the major features.

The process I followed for getting to that point above was to watch the battle scene from episode 4 in slow motion, even going so far as to slow it down and viewing a frame at a time, so that I could capture some screen shots. I then created a "mood board" of all the various views of each building, like these two for building #3.

Putting all these screen shots together next to each other also allowed me to piece together the route of each squad through the town and thus create the map. That process was probably 8-10 hours work of watching, noting down, re-watching, correcting etc!

Here are the four graphical representation and architectural drawings for House #3.

The next thing I will do, probably before I have finished drawing all the buildings, is to start making some of them. I've started researching whether it will be worth it to buy a laser cutting machine and creating my own MDF buildings. 

There are three companies which already manufacture some excellent buildings in MDF: 4Ground, Sarissa and Warbases, all of which look good. The problem is that none of their buildings are similar enough to the BoB Nuenen set to be useful. I'm sure that I will end up buying several of their buildings though to flesh out the town; the BoB set only contains nine buildings, which isn't much of a town, so it might look better with a few more in the periphery of my "film set" buildings.

My other option is to scratch build each one, but I quite like the idea, now that I have gone to the effort of visualising and drafting plans for each building, to be able to make several of each. I quite enjoy scratch building (check out my cereal packet Mediterranean shepherd's hut or my Cretan church, for example), but making the buildings using a laser cutter would be a new challenge. The model I have been looking at is the Atomstack A5 Pro. There are some other challenges which come with using a laser cutter, such as getting the design software, building a fume extraction hood and learning how to design the buildings.  Sounds like it's going to be lots of fun!

Vehicle storage

It's been really wet and windy today, so I've had a day of sorting stuff out, which included getting around to gathering together various cardboard boxes that I have been storing my collection of 1/56th scale WWII vehicles in and putting them into a more permanent storage solution.

I purchased a couple of hard plastic storage boxes from the Really Useful Box company. The ones I bought were the 7 litre boxes which measure:

• External Dimensions: L 400 x W 350 x D 85mm
• Internal Dimensions: L 340 x W 307 x D 70mm

They're great because they are the perfect height for storing vehicles in, come with locking lids and are intended to neatly stack upon one another. Here is a case of German vehicles for North Africa (or possibly Italy).

I put some paper in the base, so that I could mark which vehicle went into which slot. Each slot was created using the foam that comes out of the spaces cut into a figure tray and trimmed to size. It's the pieces of the figure tray that you would normally throw away so that you have slots to store your figures, but I knew it would come in useful one day.

Once the edges of the box were lined, I then started playing Tetris with the vehicles to maximise the number that I could fit in and once happy with the places, started trimming more of the foam pieces (which have an adhesive bottom) and sticking them to the paper around where each vehicle would fit. Here is the start of my British vehicles for the Mediterranean.

I ended up filling six boxes with vehicles and storing them away neatly, which means I now have a bit of space on my shelves, so that I can start the next phase of cleaning and tidying! The missus will be so chuffed!

Ambushed supply wagon, part #3

Progress on this terrain piece has been a little slow this week due to work and family stuff, but I've now finished.  However, I might add some dust effects to the bottom of the wagon to make it look a little bit more weathered.

Here are a few of the in-progress shots picking up from where I left off in the last post. After sticking everything to the base and adding sand and fine grit, I then primed the whole thing with grey car primer from Halfords.

The next step was painting the base colour using some Dulux tester pots. Whilst the brown base colour was still wet, I dripped some diluted grey paint onto the brown to create a patchy, non-uniform effect. Once the base colour had fully dried, I dry-brushed a lighter brown over the top to highlight the texture.

Next, I painted the base colours, then the highlights onto each of the models, including the wagon.

The final step was to paint on some PVA glue and scatter a mix of various flock, static grass and clump that I had pre-prepared in a tub, then leave it to dry.

Whilst I was flocking, I also went and grabbed a couple of other pieces that I have worked on recently, but not yet flocked. One of them was the destroyed Panzer III, which I have written several posts about.

The other piece that I finished basing today was a Pak36 gun and crew.