# 342, The Burning Magnetos, 2023 Open Alliance Build Blog

ok, so its been a while since I posted. ive both had a lot of things to talk about, but had no idea what to say. we have basically had a bunch of tiny issues to work out and I just didn’t know where to start.

my struggles with the tread jig continued.
one of our other mentors put together a piece that seemed to fit better than mine, and with some help from local belt expert @Kevin_Thorp I was able to figure out the correct math for making a tread jig. turns out you have to calculate the circumference of the wheel with the thickness of the steel banding inside the tread. the one our mentor made helped to confirm all my math was correct and so we made ANOTHER new tread jig and this time it worked. we now have managed to get all the pieces of tread cut and installed. they are a little tight and difficult to put on, but thats much better than loose.

one issue that a couple others revolved around was our gripper… again.
when I designed it in cad, I used the rev rt25 belt generator featurescript. it did tell me the belt didn’t fit the center distance and pulleys I had selected, but didn’t tell me it stretched the belt model to fit anyways, so when I inserted into the assembly, it looked like it fit really well. but it didn’t. so then I had to learn how to do math, more so what math to do.
thanks to some help from @Kevin_Thorp again and some folks in this thread I was able to figure out what size pulleys I actually needed for the belts we had. figuring that out took the better part of a day.

now time to print the pulleys!
or so we thought. all of a sudden our 3d printer decided it really wanted spaghetti, which is fair. but now was not the time. we spent about 2 meetings trying to solve that, then started looking for other options. luckily one of our mentors has a printer at home, he printed some for us. and one of our students parents is a principal at one of our elementary schools, and she had someone there print some for us too.

but getting this all together took about a week. we got the original belts and pulleys last friday, went to assemble that Saturday, and then it took us till this Friday to sort all of this out.

now we finally have the gripper mounted, and its wired up, and our programmers are working on tuning PID or something on it. I still know nothing about programming lol

in our drive testing we noticed we were much more top and back heavy than we expected to be, luckily we were WAY under weight. so one of our mentors got some stainless steel cutoff scrap pieces from work. they’re basically just little pucks. we were able to drill through them, and mount them on a rod along our frame rail.

this weekend we had a shakedown with a couple teams,
4533 came to visit and did a lot of testing,
and 8137 joined us, we helped them go through the inspection process, fix some issues they had mechanically and electrically, and got their code running on their robot and the successfully drove it for the first time saturday! they will be competing week 1 in PCH Albany, and we wish them a lot of luck!
next Saturday we are hosting a scrimmage with a few local teams, 4533 will be returning, 3489 and 3490 will also be joining us.
if anyone else near Charleston SC would like to join us, let me know!

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