Classical warfare enters the present!
Welcome back! The Gladius build has progressed significantly since the last update, during which I mentioned that the decoration and soldering were the two main stages left. Both of these are now completed, and end the result is a thoroughly Roman looking machine! Amazing the difference some stickers and paint can make! In the following section I'm going to cover how the decorative parts were made and how they take inspiration from classical warfare.
Most of the robot is wrapped with adhesive wood-textured vinyl for an authentic and distinctive look - The ancient Romans certainly didn't have HDPE kicking about 2000 years ago! For the shield design, I painted directly onto the vinyl with red spraypaint, and the golden insignia on top was just drawn on my PC, printed out and covered with transparent book covering film.
At the front of the robot are three wedges, which are hinged and made out of bare aluminium in order to mimic the flexible, segmented armour of Roman soldiers. The wedges scrape the ground when Gladius is right side up or inverted.
Meanwhile, the shape of the side spikes resemble the spike of a Pilum, a type of javelin used by Roman soldiers for long ranged attacks and for warning off short ranged weaponry. In the case of Gladius, they serve a similar purpose, and should prevent opponents from getting in close to the chassis to deliver big impacts from the side. They are made from aluminium angle, with an aluminium spiked rod running through them to protect the wheels.
At the rear of the robot, a metal grating covers the polycarbonate panel. Hiding the removable link is three leather strips. The historians reading this may recognise these strips as being similar to the those hung from the belt of a Roman soldier to protect his "unmentionable area". I suppose you could say that in both the case of the robot and the ancient warrior, these strips protect the most vulnerable zone!
Finally to top off the look, is the standard, which would accompany the Roman army into every single battle. In my case, it's made out of a drinking straw and more leather, in the hope that it will collapse when the machine is flipped over. Not exactly high-tech, I know, but it should do the job well.
With the exterior completed I only had the electronics to sort out. Some major issues with this arose however, and they were the main culprits behind the long delay since my last blog post. I unfortunately found out the hard way that 25mm gearmotors really don't like being disassembled and put back together again. I cannot stress this enough for other builders: do not take these gearboxes apart. An unforeseen consequence of dissembling them, was gears that consistently became misaligned upon reassembly. I spent literal hours trying to put them back together but for whatever reason, they weren't happy, and so a whole new set of gearmotors had to be ordered. Mysteriously, after being left alone for several weeks, the old gearboxes appear to be working again, but I dare not put them in the robot in case they break once more. Another slight annoyance is the significant amount of electrical noise these 25mm motors produce, which is likely another symptom of their cheap nature. I was advised to solder 100nf capacitors across the motor leads to reduce this interference, which I have also done. So all in all, while these motors are cheap, I wouldn't exactly call them cheerful. They do perform adequately, but if I ever build a more competitive beetleweight I'll definitely look into other options.
Now, with all that moaning out of the way, I am delighted to finally present Gladius' first ever test drive around my kitchen floor! Check it out!
After 5 months, Gladius is finally completed and fully mobile! I am very proud of the final result, which I think really fits the bill of a combat robot designed by the ancient Romans! What started out as a simple introductory beetleweight, quickly evolved into a much more complicated build than I had expected. I have nonetheless learnt a lot about material properties, manufacturing small parts and beetle weight building during this process, and I hope to take this knowledge into future projects. I think my only real concern is the durability of the front. The plan was to upgrade the wedges from aluminium to titanium, but with only around 50g remaining until Gladius hits the 1.5kg weight limit, I doubt that will happen. A compromise may be to source some higher grade aluminium, as the current wedge is just cheap stuff I had leftover in the shed.
Other than that though, I couldn't be happier. I'm just dead excited to take this design to an event. It's not really meant to be a winning bot, but it should be awesome fun to drive in the arena, and enjoyable for the audience to watch as well.
As always thanks for reading and take care. Hopefully Gladius will enter the arena soon!