Disc Diameter Variation

At Oklahoma City we experienced some persistent disc magazine jamming that we had never seen before. After getting access to a couple of field discs, we found them to be slightly larger in diameter (around .050"-.060") than our own discs, or any that we had ever handled before at other events. After finally understanding the problem we were able to resolve it with a modification, but I thought I would try to gauge how common this variation may be by asking if any other teams have observed the same thing.

At Inland Empire (Week 5) we experienced magazine jamming that was non-existent at San Diego (Week 2). We determined the main cause to be worn discs and burrs on discs. We also experienced much more aggressive defense at IE which disrupted the disc stack in our magazine and caused some jamming.

Of course we are familiar with wear, rubber build-up, flatness, burrs, out-of-round, etc. These discs appeared to be genuinely larger in diameter.

Sorry, I wish we had thought to measure the discs.

At Inland Empire we experienced jamming that we did not at Long Beach, but it may have been due to an issue with our machine rather than the discs. I can’t be certain.

Actually we did had measured the discs but then one of us checked the manual and told us they changed the size of the discs so that they were larger.
We made our shooter adjustable for this difference because the discs we received from the KoP were of the small size and we needed to practice.
All of those minor changes are always in the manual I suggest you to check it regularly in case they make a chenge. I know it’s hard to read it all again but just check the important things such as sizes or the fouls.

Can you say where in the manual this is?

He may be referring to [Team Update 01-08](http://frc-manual.usfirst.org/Updates/0#term 24), the very first one:

The DISCS are Wham-O part number 53214 (custom colored Red, White, or Blue) and have a nominal diameter of -10- 5/8 11 in., a nominal height of -1 1/4- 1.4 in., and a weight of 180 ± 5 grams.

-'s are strikethroughs.

I remember you guys talking about that with us while we were down there, but we didn’t have a an issue with that. However, back home on the practice bot, our KOP discs have room to slide around and stack weird, thus jamming our shooter from time to time.

I’d say the solution for both of us is to maintain adjustability in our buckets.

This is interesting, as we also experienced jamming on Thursday and Friday of South Florida (Wk. 5) that we did not experience in Orlando (Wk. 2). We were absolutely unable to reproduce it on the practice field (and beleive me, we tried really hard to cause a jam!). On Saturday morning, the problem vanished… This is an interesting observation. Thank you.