Production Sequance:

Step 1 - Research and Design
Research, gather, sort, analyze information in order to plan, design. This includes searching designs of what others and have done, look at their designs and look at their advantages and disadvantages as well as ways you would improve it. List down the good and bad things you have taken away from the design as these can be used when you come to your product design. The main advice here is to make your product better than everyone else, otherwise, no one will ever buy it. After doing your research you can head on your way to designing. When designing it is always important to have an idea of what you want as your end product and how you are going to achieve it, usually, this is where concepts and brainstorms come into play. If you have no idea how to make something look good then it is recommended to look at other people’s designs and use them as inspiration for your own project, don't bother about visual elements and conventions such as the Rule of Thirds, rules are made to be broken and while they are a good base for any project, they aren't required to make a project/design good. If you are uncertain on designing or engineering a certain system that you will use in your replacement parts it is always a good idea to try out a prototype and get other people’s honest opinions on the design, they may have something to add. Also, remember not to over complicate the design process, most of the time the mechanisms you need to make something already exist and there is no point in reinventing the wheel, you are just wasting time.

Step 2 - CAD
After you have thought up your design for all the components of your arm it is time to draw it up in CAD, this allows us the flexibility to use different fabrication methods to make the design later. Some recommended programs for this include Fusion360 and TurboCad. Fusion360 can be found for free under an educational license while TurboCad is a paid program although they do offer student discounts. It's important to note that the price of a program generally doesn't depict its quality and it's recommended to get recommendations for what program to use as certain programs can be harder to use or not be practical / suitable for your application. Most CAD programs work off the idea that you will first draw in your 2D face and off that extrude parts to a 3D plane and modify them from this. Tutorials for your specific CAD program can usually be found online. At this stage you should also look into possibilities of mass production and how you plan to produce your model fast and efficiently, generally this is through the use of automated machines including injection moulding or using CNC's (Laser Cutters, 3D Printers. All use cartesian plane movement and highly accurate stepper motors to make parts precisely by using tools specific to that machine), this needs to be done at this step and not during the researching and design as without knowing our almost final design it is hard to choose the best production method.

Step 3 - Producing and Evaluating
Once we have all our components modelled up in CAD we can now produce them. When producing parts, we first produce a prototype which is generally less expensive than the final model and uses cheaper materials, this is because a majority of our parts will be changed in this stage if we didn't do our research on the materials and machines we planned to use and we didn't take into consideration the tolerances of the machine or its tool. Most of the time these tolerances also vary from machine to machine or online research that was already done on tolerances may not be suited towards the materials or methods you are using. Some information on tolerances can be found here. You may also find that certain mechanisms or systems you have made don't function as intended and these will likely have to be improved or replaced in this stage. Although not always practical in some applications, it is a good idea to test designs functionality in CAD to save resources, time and money. In programs like Fusion360’s simulation function. Simulations on stresses and safety factors can be done within the program most of the time but usually don’t take into account the tolerances when we do our prototype before our final production model or even the layer lines in things like FDM printing. Your final production model will likely be made out of the materials you originally proposed in your research. Consider using machines like CNC's, 3D Printers and Laser Cutters for your final design as you will find they make parts precisely compared to previous parts if you have been making them manually (In that case most of your tolerances wouldn't have of mattered as trial and error is an easy method in machining once you have a fairly accurate estimate of tolerances).

Parts List

Part	Guard Clip Section	Push Clip	Blade Protector	Landing Gear Type 2 - PLA Section	Landing Gear Type 2 - TPU Section	Landing Gear Type 1 - Complete Model
Materials	Hatchbox White PLA ($19/KG)	Hatchbox White PLA ($19/KG)	Hatchbox White PLA ($19/KG) & Smartsain White TPU ($31.99/KG)	Hatchbox White PLA ($19/KG)	Smartsain White TPU ($31.99/KG)	Smartsain White TPU($31.99/KG)
Tools	3D Printer, 400 Grit Sandpaper	3D Printer, Side Cutters (To remove excess material)	3D Printer, 400 Grit Sandpaper, Razer Blade	3D Printer, 400 Grit Sandpaper	3D Printer	3D Printer, 400 Grit Sandpaper
Safety Checklist	Sharp Edges? ✘ Extremely Brittle Pieces? ✘ Is it safe for children - edible? - size? - Size is small but when attached to the blade protector it's size increases and makes it somewhat suitible around children	Sharp Edges? If printed with raft, Yes. This can be removed with Sandpaper although the rafts usually come off clean and leaves no sharp edges. Extremely Brittle Pieces? - Existant due to parts having large forces exerted on them. Is it safe for children - edible? - size? NO, invidividual parts are too small and can be digested. This is fixed in the modal but can't be printed due to TPU not bonding with PLA.	Blade Exposed? ✘ Sharp Edges? ✘ (Some parts may have overextrusions due to the viscocity of the TPU but they can be fixed via use of a razer blade.) Extremely Brittle Pieces? ✘ (Flexible Material) Is it safe for children - edible? - size? As an individual part this can pose a threat to children when digested.	Sharp Edges? ✘ Extremely Brittle Pieces? ✘ Is it safe for children - edible? - size?. May be digested by children if kepty in reach, for this reason it is recommended to keep the product away from childrens reach.	Sharp Edges? ✘ Extremely Brittle Pieces? ✘ (Flexible) Is it safe for children - edible? - size? May be digested by children if kepty in reach, for this reason it is recommended to keep the product away from childrens reach	Sharp Edges? ✘ Extremely Brittle Pieces? ✘ Is it safe for children - edible? - size? May be digested by children if kepty in reach, for this reason it is recommended to keep the product away from childrens reach