Here is a closer view of my Losi Micro Desert Truck running over the plaster terrain I have made for the modular micro RC track. As you can see there are a variety of molds I have used and a few of the castings have been further worked to ensure the micro RC cars could get over them and add some interest. From the slow motion you can really see how the vehicle works over the terrain.
Here is another view of my Losi Micro Desert Truck running on a 6 module layout that was the same as the onboard video from the previous post (with some minor adjustments).
You can see the terrain elements that I made with Plaster Of Paris on the left hand side. I will show you more on those features and how I made them in a later post.
It has been a little slow going making terrain so far but I have managed to make some moldings out of Plaster Of Paris. I have shaped a few of these moldings and left some in an as molded state to use as terrain on the track. There will be a separate post with details of how I made the terrain but, for now, I have made a video using my HobbyKing Wingcam onboard my Losi Micro Desert Truck. You can see the plaster terrain flashing by on one of the straights.
As I have discussed in the last couple of posts my intent is to use magnets and dowels to pin the terrain to the modules of my micro RC race track. The initial inspiration for this system came from user ‘Healzonu’ on the Ultimate RC Forums and I have developed the concept further for use on my track. For those playing along at home, this is how you make the hole array for the first time in four easy steps.
Tools And Equipment
To do this you will need:
- Two B1 sized plots/prints of the hole pattern template (see the printables page). You can do this with only one print if you want as the B1 layout only covers half of a module. You will have to flip it around to do the second half if you only use one print.
- A drill.
- A drill bit corresponding the the size dowels/magnets you are intending to use. I actually used a 1/4″ bit for 6mm magnets to make the hole just slightly oversized.
- Tape. Masking tape is best but almost any will do.
Now I have the idea for a magnetic dowel system to position the terrain the base modules need to have holes drilled in them. This array of holes is used to pin the terrain into the plywood with the dowels.
I intend on using 6mm diameter magnets and wood dowels for the job as a starting point. It is prudent to start with small holes and make them bigger if stronger magnets are required. I am also starting with a 50mm array of holes and the module will fit a 23 rows and 11 columns with this array size making a total of 253 holes.
Rather than mark out the array on the module using a pencil and a straight edge I have decided a little more accuracy is required, so back into the CAD system and a quick layout was generated for half the hole array that can be printed to a B1 sized layout. If you want to follow along at home a PDF of the hole pattern layout will be available on the printables page. You can get this printed anywhere that does roll size plan plots. I had mine done at Officeworks here in Australia but there are many place around the world that do it such as ‘Fed-Ex Office ‘ (Kinkos).
When I first started planning my modular track for micro RC cars I was going to affix terrain to each module directly so each module was set. I really wanted to have the terrain as modular but I hadn’t come up with a way of doing that other than wood dowels which I didn’t think was robust.
In presenting the first video of the completed modules on a forum one user had a suggestion…rare earth magnets. That was the inspiration I needed. I was concerned that rare earth magnets still wouldn’t quite work through the module’s plywood unless the were very strong and a few small test magnets proved that. My ‘Design For Six Sigma’ ideation kicked in and I Pughed in my brain (in joke for my work colleagues). Hybridising dowels and magnets was the way to go.
Here is a quick sketch of the intent of the system.
The base modules that are to carry terrain will be drilled with an array of holes while the terrain will have steel inserts. The rare earth magnets can then be used as repositionable dowels attached to the terrain pieces, whatever they may be.
It’s time to approach making some terrain for my micro RC track. I have been thinking about how I want to go about this and the types of terrain modelling techniques and media that could be used. The ideas I have are:
- Paper Mache – When I was young I made my own play sets with terrain for my Micro Machines. I made paper mache using wallpaper paster to do this. There are other techniques for making paper mache glue as well such as flour and water. Paper mache will also paint quite well with water based paint but enamels will also work.
- Plaster – Using Plaster of Paris terrain could be molded, cast or sculpted. It is fairly robust once it is finished and can be painted easily with cheap water based paints.
- Epoxy Putty – Two-part, kneadable putty is common in hobby model making with brands such as Milliput and Tamiya readily available (I think I have some of both lying around the house unused). It is also available from the hardware store in various brands. It is paintable but I am assuming you need oil based paints.
- Builders Putty – This type of putty, unlike the two-part epoxy, is an oil based air curing putty used in joinery and glazing to fill gaps. I am not sure just how well it will work but it is quite cheap so it is worth trying. I think this will also require oil based paints.
- Packaging Foam – A cheap and easy foam to source is packaging foam or expanded poly styrene foam. I always seem have some lying around the house and it is easily sculpted but I will have to look in to techniques for strengthening and finishing it. It can also be used as filler for other modelling techniques.
- Modelling Foam – The other foam option is modelling foam or ‘blue foam’ which is extruded polystyrene foam (and not always blue). The extruded foam is more durable than expanded foam and used by many types of model makers. It is also considerably more expensive.
- Builders Polyurethane – Here is Australia this is most commonly known as ‘liquid nails’ and typically comes in a caulking gun pack from the hardware store. They also sell a sausage pack at the hardware store. Using this will be somewhat experimental and I am thinking of forming it into rough shapes and carving it to the final shape when cured.
- Cast Polyurethane – This is a quite intensive technique as a mold would need to be made to cast from. I would only use this if I create a piece of terrain from another method that I want to replicate many times.
- Wood – Some of my brainstorming included making jumps and a quarter pipe. Wood is a logical choice for some of these larger terrain features. Plywood techniques such as egg crating and countour building could be combined with other modelling techniques to make interesting terrain. Wood dowels on their side could also be used to make little logs to drive over.
- Cardboard – Making terrain from cardboard will not be robust in the long term but for trying out concepts before making them with wood. Cardboard can also be used to make egg crate and countour models.
There are so many other potential methods too. Let me know if you have any ideas for making terrain in the comments section below.
As I move from building base modules into making terrain for my micro RC car track I have been developing ideas for terrain on each module. There are some obvious ones such as using paper mache or building jumps out of cardboard or wood but I found an interesting product at the Australian Toy Fair that piqued my interest. It was called ‘Kinetic Sand’.
The idea of using ‘sand’ with micro RC cars that are in the form of buggies, desert trucks and rally cars seems only logical to me.
This video shows what you can do with Kinetic Sand.
So naturally what I wanted to know is can I make this myself. I researching the possibility I found that Kinetic Sand is not something that can be made easily at home, but what can be made is what is refered to as ‘Moon Sand’. There are many recipes out on the web for moon sand and they are typically a mixture of play sand, corn flour/starch and water in around a 4:2:1 ratio (there are many sites with recipes but the pictures I have seen for this one appears to be a good consistency).
There are pros and cons to using home-made moon sand vs the newer, polymer based kinetic sands.
Home Made Moon Sand
Pros – Can make at home, cheap to make, safe
Cons – Will dry out (although can be reconstituted), water based so may not be compatible with RC car electronics, can be crumbly so may get into RC car running gear, clean up may be difficult
Commercial Kinetic Sand
Pros – Won’t dry out (polymeric ingredient), safe
Cons – Not sure if polymer ingredient (Polydimethylsiloxane) will be compatible with all parts of the RC cars, expensive, sand may get into RC car running gear
With either type of moldable sand I am really not sure of the compatibility with micro RC cars and what effect it could have on them. I think I will still make a small batch of Moon Sand to see what it is like. If I don’t like the home made Moon Sand then, after a little more reasearch on the polymer ingredient, I may fork over some dollars on the Kinetic Sand. Even if I don’t use it for the Micro RC Track it still is fun to play with!