On this side you will find various tips
How to start
Collect as much information as possible. I spent more than 100 hours in order to find all the plans that were needed to complete my R2D2, to solve all problems, to get all the answers and to get all the parts together. The first port of call should be the R2-Builders` Club. At present this club consists of more than 6,000 members of many different nationalities. The language used is English but you nevertheless can find some R2 Builders, who can answer questions in German.
In the club you can also find the necessary blueprints as pdf or DXF files. However all measurements must be converted into the metric system.
Carry out preliminary tests before working with new materials. For example Silicon doesn't get along with most screeding compounds, therefore, if a master model is cast, which was finished with the wrong screeding compound, the silicon will not harden correctly.
The same applies to adhesives. Make bonding attempts and test the results, before your R2D2 falls in pieces in the end. I personally prefer thickened epoxy resin. Sometimes I also glue in combination, namely two parts are joined simultaneously in some places with resin, and in other places with power-glue.
Machines and tool
The following machines and tools are among the other things that are absolutely essential for the building of a R2-D2:
a drilling machine
a “Dremel” tool with a flexible shaft
a pair of digital scales weighing up to 500g in 0.1g measurements
a pad saw
a fret saw
a high performance vacuum pump - only needed for silicon mould production
a dehydrator – also only needed for silicon mould production
These do not always need to be the best professional tools, normally tools from a DIY outlet are perfectly good enough.
Storage of silicon moulds
I normally leave the last cast part or laminate in the silicon mould. This prevents deformation due to the weight/shape of empty moulds over long periods.
If a R2D2 is built only as a static model, the ground clearance isn't critical. However, if it is mobile, I recommend a minimum ground clearance of 2 cm. My first R2-D2 had only a 1.2 cm clearance and is therefore only suitable for smooth surfaces. If you check the apparently insignificant height of a carpet, a door stop or a small stone, then you may believe to start with that a 1 cm clearance is sufficient. But if however, the R2-D2 moves with its middle foot on a carpet, then the rear edges of the two main feet already touch the ground.
A remote control for a R2-D2 should be able to handle a minimum of 8 channels. I bought a MX 16 and the 8 channels were just sufficient.
Driving motors and wheels
Most gear motors have plastic gear wheels. These are able to move a R2-D2 but not to carry the whole weight of the droid. That means that the wheels must be mounted in such a way that they can carry the weight of the robot without creating an excessive load on the drive shaft of the gear motor.
I couldn't find bronze-painted hoses needed for the connection between the battery box and outer foot in Germany, and so I decided to paint normal silver-painted hoses bronze. The colour should be applied only thinly, as thicker colour tends to splinter off if the hoses are moved or bent later.