Trying to get MPS Finished...
Posted Oct 20, 2008 by Matt | Tags: news
So much for more consistency in the updates. It has been an aggravating last several weeks. The weekend of October 4th, originally slated for getting our first shots off with Medieval Postal Service, did not go as planned. We did get the frame set-up finished, and it looks terrific. Finishing that took up most of Saturday. Sunday did not go as smoothly. The main axle hole in the arm was barely large enough, but slightly misaligned to the bearing holes, and so while we were able to get it together with the axle, the axle was totally incapable of rotating. Track mounting went slow, though we did eventually get them up. Jason also had to make a trip to Buffalo Friday the 3rd to fix some other holes that we had found to be too small (and a couple just weren't drilled, they got missed somehow the week before). Things took time, and the next thing we knew, it was time to pack up for the weekend and tarp M.P.S.
During the following week, Chris went to Buffalo to get the holes in the arm drilled out to a larger size so as to allow us to assemble the arm. This problem was now fixed. He also got the holes drilled in the carriages that had been missed earlier. Matt had a prior commitment Saturday, but Jason and Chris headed down and began preparing for what was intended to be a day of firing on Sunday. Again, small problems cropped up that slowed us down Sunday. We still fought through it and were getting set for our first shots mid-afternoon when another problem with the arm popped up, where a clearance between the end of the arm was too tight. That was the final nail in the coffin for this weekend.
Now for Saturday, October 18. Roughly 1.5 weeks before we leave for Delaware. M.P.S. has still not fired. We are up against it now. Chris and Matt went down Friday evening so as to get an earlier start Saturday, which turned out to be a VERY COLD morning. There was ice collected in the tarp on M.P.S. from the rain earlier in the week. We first had to jack up one side of the frame 3/4" as we had discovered the week before that the two frames were not level across the top. This actually took only about 10 minutes with the two of us, and things were nearly perfectly level. Jason showed up around noon, at which point the frame had been re-set, and the tracks were about to get mounted (we take them down every week as they are still raw steel and we want to reduce the rust they collect. They stay indoors during the week.) We got the arm clearance issue fixed, and tried getting the hanger on. Holes were not lining up AGAIN. After quite a bit of hand filing on things, we got it all together. As the light disappeared, Medieval Postal Service took its first ever shot. We shot a 1 pound, 3.5 ounce gourd with no counterweight loaded. We just wanted to ensure the motion of this new design would work properly. For the most part they did, but a too shallow pin angle coupled with a very long sling resulted in a backwards shot. Still, nothing seemed to have broken. And the gist of the motion worked! Overall, it was deemed a successful launch, and things were left for the morning where we hoped to start adding counterweight after a few more low power tests.
The morning brought even colder temperatures, and we took a while to get going as a result. But we got ready for a repeat of the previous night's shot, this time with a 1 pound, 7.5 ounce gourd. But like the previous shot, it went backwards. It turned out that we were hitting part of our triggering system when the sling began swinging around. Initially we thought this was a result of the arm not traveling as far down the track as anticipated, possibly as a result of no counterweight, thus a low counterweight-to-arm ratio. We added a little counterweight. The arm traveled much further down the track, about to where was expected, but the gourd still hit the same things. Then we figured out a way to fix the problem. No details are going to be provided right now, but suffice to say it is a rather simple, though inelegant solution that will work for this year, but will be changed for next year. The bottom line is that we started firing forwards. We added more counterweight, all the way up to a third of our intended amount, and launched the 4 pound medicine ball. It was a low line drive, just about horizontal, but it still traveled a decent distance. That was it for the weekend. Next weekend is our last, and most of Sunday will be spent tearing down and packing up for Delaware in 1.5 weeks.
