Season is almost upon us and we (1989) have a pretty good idea how is it going to go. The experiments with FiberGlassing worked pretty well. On everything Standard marine resin works best and we are using 6 oz glass in multiple layers Where necessary. On ABS you can use ABS slurry as a resin, On Hardboard, Wood, Cardboard Elmers Glue-all works pretty well and on foam Polycrylic is a Hit - that if you don’t want to use standard 2 part resins. It all is pretty tough and definitely helps the print. On multiple layers and some cases even on hips and PETG you can get away with the original gorilla glue on the first layer and then use one of the aforementioned ones if you don’t want to go into a 2 part solution. So based on what we have looks like we are going to go non-metal for the most part this year. You can follow us here and on grabcad and the code like every year is public on github as its written (This year all newbs so thats going to be interesting) Due to cost/benefit factor our main materials are going to be HIPS and 6oz FG. And the parts lying around from past seasons, Toughbox minis, (Mini)Cims, Gearmotors and whatever comes in the kit. Some of the parts - mostly the frame - will be reinforced with 1/2in square 16 gauge al tubing where necessary. Some with probably something heavier as we now know we can do a robot of last years at about 80 lb and depending on whatever this years challenge is set to be it might not make sense having an 80lb robot so some of the 1/2 in tubing in the frame might wind up to be solid iron or steel to add the 40 lbs to get closer to the 120 lb. But then maybe this year is a challenge where light weight rules and we loose some more weight by replacing the aluminum square tubing with something else.
Well I hope so - its definitely a goal. A challenge especially for a small team. But then 3DP is what we hope to be the equalizer.
We had a discussion about that last week and one serious concern was voiced by a member:
If we are really successful evryone is going to go that route. It takes 20-30kg of filament to do a complete robot and if there are 2000-3000 active teams that is more than 40 tons of plastic and as none of that can be reused (based on rules) next season that is 40 tons of plastic garbage in the environment. So right now the plan for the off season is to find a financial feasible way of turning that scrap (wole robot) at the end of the season back into filament. Another option would be a rule change but i would not hold my breath on that as FIRST historically seems to put more weight on its contributer (NI,Andymark, CTRE etc) making money than being environmentally friendly and recycle and reuse.
As much as I would advocate for re-use of 3DP parts, re-using an entire robot is never going to be in the cards. You could make the same argument about waste for a metal robot, but they are not going to change the rules to allow teams to completely re-use an entire robot, drivebase or even a frame or bellypan.
With the introduction of the rule about re-using modified COTS parts where the work done constitutes less than 30 minutes of work with hand tools, I see that there could be a light at the end of the 3DP tunnel. It would be fairly easy to allow re-use of 3DP parts that were less than x amount of material (say 1.0 kg) and where the CAD was publicly released and where those parts were made in-season. This would certainly cover items like camera holders, RasPi cases and other simple items, but would exclude re-use of large structural bits. I’m not sure if it would allow re-use of swerve module or other larger assemblies, but it probably would allow the re-use of the individual parts of a swerve drive (such that you would need to disassemble and re-assemble the swerve drive to be able to re-use it). This feels like about the right level of re-use to me. Let’s see where things go with this.
I don’t think a whole robot should be reused - but its parts? Hence our drive towards reusable parts. Creating a system that allows the creation of a finite number of parts that can be reconfigured in different concepts. So for example as you mentioned drive train. The current toughbox mini- 6in wheel mounts (we only have 6 in wheels in stock and 3 8 inch mechanums ) can be used in (assuming 120in circumference rules as they were in- well forever) anything from a 30x30 to a 12x48 in frame (rectangular) and different hexagonal and octagonal configurations. So in theory I could take the robot and change its base dimensions quickly (I know would cause a challenge with bumpers and what mounts to it) but certainly I could use almost all parts of this years robot in next years robot granted I might have to replace a 14 inch piece with a 12 in etc in some places but as everything complies to a form factor and the goal is to comply all components like shooters, winches, elevators etc to that form factor everything could be easily reused. The goal of getting away from custom making a robot and moving towards reuseability as a design feature has been a goal for the past 18 months or so and its not always easy and a challenge. But the current belief is that it makes for better designing and a better more sustainable philosophy towards engineering by channeling creativity into reuseability and recyclability. And yes we are not even close in a lot of areas yet and yes I am the driving force behind it as I am a strong believer in that design philosophy. And it came to me looking at nature. Just look at all those creatures with for extremities and how a basically identical build plan (upper limb, lower limb heel, foot, toes) can make anything from a wing (bat), to running legs (horse etc) to bipedal foot and hands (humans) and climbing and even flippers for swimming. Just trying to bring that to robotics and through additive manufacturing as that too is closer to nature. Nature does not start with a lump of biomass and cuts pieces away to make a human or other organism (ending up with a lot of shavings/waste) but just grows it out of just the right amount of resources needed to achieve the goal. So I would like to incorporate that too. (And all in a budget we can afford)