Disc Weights

[Frank Delicious]

I had as similar situation with a 175, it weighed 178.8 and it's technically illegal. It's been thrown 10 times or so and I don't use it anymore.

There are a lot of discs marked as max weight for that disc that will come up as more than the max weight but that is a whole other can of dumb worms that has been talked about a ton.

 

[ERicJ]

What's your source for that?

It seems pretty unlikely given the consistency of measurements I've seen on hundreds of discs so far.

I looked for the some quotes on DGR but couldn't find them because our search feature is crapping itself server side but I remember a couple of guys who worked in factories (wanna say Mill or Gateway) saying that is how they did it. Plus I think it's been mentioned in this thread by someone besides me.

also you might be the only one who says there is consistency in weight in this thread.

(note: I agree, most discs I have are spot on or very close)

If discs were weighed in stacks and averaged I would think that there would be a significant number of discs that weigh in at more than a few grams off.

If you had a stack of ten discs and nine were 175 and one was 165, you'd average them all to 174 and one would be marked 9g off.

My experience is pretty close to sidewinding's in that there aren't a lot of discs off by more than a few grams.

 

[disc-o maniac]

yea when i get several molds of the same disc and same weight and every flight pattern is different it gets very annoying to find that some discs are up to 5g's off the marked weight

 

[John Rock]

If discs were weighed in stacks and averaged I would think that there would be a significant number of discs that weigh in at more than a few grams off.

If you had a stack of ten discs and nine were 175 and one was 165, you'd average them all to 174 and one would be marked 9g off.

My experience is pretty close to sidewinding's in that there aren't a lot of discs off by more than a few grams.

I've also read many times that discs are weighed in stacks and averaged. I can believe it, they've been doing this stuff for a long time and I'm sure by now they've got lot's of experience in what works and what doesn't when it comes to producing a certain weight disc.

 

[Frank Delicious]

If discs were weighed in stacks and averaged I would think that there would be a significant number of discs that weigh in at more than a few grams off.

If you had a stack of ten discs and nine were 175 and one was 165, you'd average them all to 174 and one would be marked 9g off.

My experience is pretty close to sidewinding's in that there aren't a lot of discs off by more than a few grams.

They can make a run of discs at or around a specific weight. It's not like they just inject the mold and hope for the best. A good example of this is when Innova was trying to run lighter star bosses, they had to come up with the starlite mix to get them to mold up at 167-169.

 

[John Rock]

I would bet that the head honchos at WHAMO back in the day (not Ed H. or Stork) didn't know or care crap about injection molding of plastic discs. They were just suit & tie guys. The guys who are heading today's disc golf companies can probably explain every step in minute detail. And they play with the products. Full scale research & development.

 

[sidewinding]

Starlite Starbright,
This Boss I chose is light,
I wish I may I wish I might,
hit the chains at end of flight

 

[crawdad62]

They can make a run of discs at or around a specific weight. It's not like they just inject the mold and hope for the best. A good example of this is when Innova was trying to run lighter star bosses, they had to come up with the starlite mix to get them to mold up at 167-169.

That's my contention. The mold is set specific (I'm assuming) and the injector will lay out the required amount of plastic. I'm sure there are variances but it wouldn't be too much. While stacking a bunch of disc together and averaging them out might not be the most accurate it wouldn't vary too much. I'm sure it might complicate matters if some of the discs were from different runs of the same disc/weight (ie 4 discs made on Monday and 6 made on Thursday weighed together) made at completely different times though.

 

[LewisFlameworks]

Wow.... I did not realize just how much moisture a disc can absorb or retain after production.....

Anyone have any real numbers on the amount of water a disc can absorb without being submerged?

 

[Marmoset]

Wow.... I did not realize just how much moisture a disc can absorb or retain after production.....

Anyone have any real numbers on the amount of water a disc can absorb without being submerged?

It is dependant on the blend of plastic. I think the Champ/ Z urethanes will absorb and hold less than DX/ Pro D.

 

[LewisFlameworks]

It is dependant on the blend of plastic. I think the Champ/ Z urethanes will absorb and hold less than DX/ Pro D.

That is kinda what I thought and everything I throw is Champion,Star,Z or Evolution with the exception of a pro line Ryhno and Supreme JuJu.

I guess I just plan on bringing in my own scale to the store. I have been using an OHAUS triple beam, but it looks like I gotta get a nice digi to travel with.

Still seems ridiculous that they can't just put the correct weight on the disc.

 

[valkyrie]

Seems like they could just use a scale while they are marking them.

 

[ERicJ]

From what I have read the discs are weighed in groups of 10 and then the average weight is what is written on the bottom of that group.

they weigh them in stacks and then divide the weight by the # of discs weighed and that is what they write on the discs.

Just traded e-mails with a top guy at Millennium and he confirmed that both Millennium and Innova weigh/mark each disc individually.

 

[RHINESEL]

Wow, great info.

So, now that that is taken off the table... what are we left with for the reason, water absorption?

 

[ERicJ]

Wow, great info.

So, now that that is taken off the table... what are we left with for the reason, water absorption?

As well as:
Poorly calibrated scale.
Inaccurate scale.
Human error, just writing the wrong value.


One of these days I'm going to run an experiment on water absorption.

 

[garublador]

As well as:
Poorly calibrated scale.
Inaccurate scale.
Human error, just writing the wrong value.


One of these days I'm going to run an experiment on water absorption.

Are you saying the manufacturer's scales aren't calibrated or inaccurate or the $20 scales customers are using aren't calibrated or inaccurate?

 

[toothyfish]

I just weighed a bunch of Voodoo's. All were either on target (+/- .5 gram from labeled weight) I think two were off by 1.5. I used a lab-quality scale that is extremely accurate.

Not bad.

 

[ERicJ]

Are you saying the manufacturer's scales aren't calibrated or inaccurate or the $20 scales customers are using aren't calibrated or inaccurate?

Could be either one... hopefully the factory scales are accurate and precise. Generally speaking there's no telling on home scales.

 

[kpc2004]

i have a very accurate scale (max 400g d=.01g) and i went through and weighed out all my discs and found that if you consider .01-.49 rounding down and .50-.99 rounding up, over half my discs were off. a few by over a gram. i had multiple "175's" weighing in at over 177. one boss weighed in at 177.7, almost 178, and it was marked 174 :\ ....ive always wondered why this happens so often

 

[Vegan Ray]

Why do you think? If a 177g Boss is unsellable & would need to be reground, remelted, & remolded (all procedures that cost $$) to be able to be sold, doesn't it make financial sense for the disc company to fudge the weight a little to a legal, sellable number?