Building week 2 - more mistakes and problem solving

Second week of building was a slow start, as on monday morning I was still travelling back from the Netherlands. I thought then that it could be a good idea to use photoshop to draw some accurate measurements for cutting and drilling the plates, but then I rejected the idea as my lack of experience with photoshop made that it would take me longer just figuring out how to do that effectively that I thought I could as well spend that time drawing it by hand. Tuesday after visual culture I started my first effort at making a hinge joint (for the 'elbow' of the wing). I brazed the parts together but then found out that probably I had heated up the metal too much and softened it. I couldn't get it all as nice and straight lined up as I wanted. I learned that I would have to find better methods of keeping everything in place while brazing. The principle of the joint worked, which is simple enough of course, but clearly it could still be improved a lot... Also I found that I should have left the gap in between the two sandwiching plates longer, so the moving joint part can move in entirely, allowing the wing to fully fold in at this part. The joint was also already getting quite heavy on its own, and remembering the advice about limiting the weight I decided I didn't need the joint to be as wide as this one and made the next effort a bit narrower. This next time I thought it would be good to go for silver soldering instead of brazing, but the stores at the university did not sell the white flux to go with the silver solder so I still had to order this (only later I would find out that it was actually available in the metal centre itself. I thought they only had the blue brazing flux. Anyway...).
More mistakes and learning on wednesday... I had researched on annealing the type of steel of the stainless teel ball bearings and found that I would have to heat it up to 1100 degrees Celsius. I tried this with the enamel ovens in the casting department. The display went black just before reaching the temperature... probably had gone too hot (luckily later it worked again and I hadn't ruined the oven...). I talked with Paul and he could tell me more about annealing and why the methods tried so far didn't work... The process has to be a bit more technical and the metal has to go through a specific cycle of heating up, holding temperature and cooling down in order for it to work right. I hadn't been able to find very specific temperature requirements for the annealing for this specific type of metal so we only had approximate heating and cooling down temperatures. This time used an oven in ceramics which could set a timer overnight. Also, the ball bearings would have to be buried in sand for the heat to be spread equally. So next step was to make a box for the ball bearings to put the sand in to put them in the oven, so I could soften them, to drill them in my tool, to... I can understand why many people rather try to find pre-drilled ball bearings. The only ones I could find were rather expensive. Well, maybe if I can develop a succesful method I should just make loads of them and sell them myself, not such a bad idea...
Anyway, another silly mistake: I accidentally picked up a scrap piece of aluminium instead of steel to drill nice rounds for the bottom and lid of the box. Ok, now I have two nice but useless circles of aluminium... In the end Paul helped with making the box and I continued trying to measure, cut and drill some parts for the wing joints. Still struggling to find a way of doing it accurately. Either needing better tools or just more practice?

Trying to measure things accurately...

More problems to be solved. Keeping plates clamped together that have to be drilled through together, getting strips of metal that have bend while cutting or while separating during drilling (by mistake) straight again... Hopefully at some point more problems will be solved then new ones created so I can actually produce something that functions. At least I'm learning.
Thursday were presentations of the work done so far, which took all day. Friday I could finally get the ball bearings out of their box and see how they'd done. They were still pretty hard to drill through, so could have been better. But at least it was possible now. Just takes some patience.
I made a new attempt measuring up the plates and lining up the holes more precise then in my previous attempt. I made my first attempt at tapping a threaded hole and tapped some more holes over the weekend.

 Drilling

Work so far, drilling tools, not so successful attempts...

And the - not so successful yet - first attempt at making a hinge joint.