Hello! Welding in practice wont work as 7075 is a nonweldable alloy due to its mixture of metals. The problem is also that once the cracking starts it wont help to keep an eye on it. Fatique cracking happens in three steps (dont quote me im not a metallurgist) and the first step happens in such a way that you wont be able to see if its cracked. The visible cracks happen after more fatique and then its too late.I'm your huckleberry.
To begin with, long before you start thinking about your swingarm, you need to get to work on that crack in your garage floor.
I feel for you Pole owners. You're really getting bonedBut I'm not surprised that the company is having problems. Their machined frames caught my eye when they came out. Not because I like them, but because it seemed like a goofy idea. Everyone else is hydroforming or making carbon frames in molds. It's an economical and well established process. But Pole wanted to machine each part in a very expensive machine using a time-consuming process. I couldn't figure that one out, but just assumed that they knew more about production than I do, and wrote it off. In retrospect, we can see it's a bad idea.
But regarding your actual question, I'm not 100% certain. Maybe your idea will help mitigate potential failure. But it will be VERY time consuming. If I was in your position, I'd keep a very close eye on the swingarm. If a minute crack starts to form, I'd reinforce it and weld it up. Maybe reinforcing and welding would be a good proactive measure. I'd do that before grinding it down.
Thanks to plummets picture on the cracked swingarm. Since the cracking indeed in some cases start from the already smooth surface it would suggest that its a defect that wont be removed after sanding. The warranty thing is another story too which i wouldnt put my bets on for the future. Seems like my original plan to reverse engineer the swingarms just like earlier discussed here might be the best solution if this breaks. If mine breaks im open to share any cad/cam files i make, if someone else takes on the mission to use a coordinate measuring device to locate all the pivot points in xyz. Since you’d have to replace both sides, the location of those points would not matter that much. Im quessing a tolerance of +-0.1mm in xy-plane would be acceptable to not make noticeable difference to the kinematics. Prototyping with printed parts and machining + stocks of 7075 would probably cost around 1000€/set. Its an estimate and does not include any time/effort pricing.
Engineering is fun. Lets wait for mine to crack and we can get designing a swingarm. Anyone with marketing skills could market them in social media and even make a small batch of business there. What do you guys think?
