Thread: Team Death - New Heavyweight

Sundaaaay!

This week we tried something a little different, a skid! Colin had preprepared this during the so its week, and the only thing left for today was to weld it in place, which we dutifully did. We used polycarb for the base of the skid, as it was the item of least friction there was to hand around the workshop.
After welding, we got straight off to the testing area. The skid correcfted the steering issues, and the bot drove in a straight line. However, the motors were notably making much more effort and current draw, and whilst it worked OK in forward and reverse, it struggled to turn corners due to the added friction. When checking on the bot, the connectors were noticably hot from the battery, where they are usually nothing more than lukewarm, so the motors must have been trying considerably harder to make the machine move, if there is enough current to make them hot. In the end, we removed the skid, but we still have it if we decide to use that later on. We're going to reconfigure the castor layout instead, and try to get the same straight drive, without the extra friction the skid was causing. Unfortunately we can only test on concrete, so the friction may have been OK in arenas, whose to know.
The skid;
IMG_20180520_140449.jpg
Next week, we'll be doing the castor change, and going out to the test area again - we may revisit the skid perhaps with some nylon instead of polycarb.

I had also acquired some bike tyres over the week, and one of the plans is to cover some tyres to try increasing friction. We tried this, however decided to try other things, as it was taking way too long to even do one piece. We may revisit this if we decide this is still the best couse of action later on.
Here is an image of that, this is a pneumatic (air filled) tyre, with the internal air hose removed, and the donor tyre riveted on. We went with rivets, as it's the method that we hope will leave the least amount of debris inside the tyre for the air tube to burst upon. It also looks rather industrial from the outside, which fits in withthe overall theme. There was also a layer of glue/cement suitable for rubber underneath, although we later found this had not stuck at all, and was only being held on by the four rivets.
IMG_20180520_130024.jpgIMG_20180520_140726.jpg

This is a very time consuming thing, especially as the rivets take a lot of might to pull together, and each piece takes 4 rivets, and the tyre will take 9 pieces of tyre. However, I think next week we'll go straight to the castors and see if we can make that work before revisiting any of the above.