DGR Homework: parting line height and relative stabilities

[marmoset]

I have this theory. I am hoping the DGR community could prove or disprove it. The people who have been reading the overstable Roadrunners thread are now rolling their eyes

My theory is that the height of the parting line is an easy way to tell which disc will be more overstable.

Homework Assignment:
Take 2 newish discs of the same mold and place them both on a flat surface so their noses are kissing. I say newish because the parting lines are much easier to see when they are newish. The higher the parting line the more overstable they are. Throw these discs and see if my theory is right. There is more visible variation between parting lines on the faster drivers so that might be the easiest thing to try this on.

So far it has worked for the few molds that I've tried it with. Tell me I'm right, tell me I'm wrong, or tell me to shutupanddropitalready!

[marmoset]

Since when has homework been this fun?!?
Maybe I can convince my wife to buy me more discs if it is for research!

[tigel]

You know you're addicted to disc golf when you imagine two discs kissing and say, "HOT".

[Mason65]

Just proven factual for my 11x vs 12x Firebirds, 1.1 vs. 1.2 SOLFs, pro vs Champ Boss (biggest difference!) and X vs ESP Cyclone.

[marmoset]

Just proven factual

This is good news... I think this could be a valuable tool if you get the opportunity to fondle before you buy. It would have saved me some money for sure! I have a bunch of discs that turned out to be mutants and I was not happy with them...

pro vs Champ Boss

My Bosses (145g R-Pro vs. 175 g Champ) were more than a 1/8th inch difference. That's HUGE!

You know you're addicted to disc golf when you imagine two discs kissing and say, "HOT".

Where do you think minis come from? Do we need to have "The Talk"?

[chainbanger]

im interested in this but what do you mean by parting line? if i set 2 of the same disc next to each other touching, am i measuring from the bottom to the top of the disc?

[chainbanger]

nevermind i got it now, read another post where you explained this. so its that little line of extra plastic on the nose of the disc right?

[DiscZombie]

You know you're addicted to disc golf when you imagine two discs kissing and say, "HOT".

Where do you think minis come from? Do we need to have "The Talk"?[/quote]

[marmoset]

This is a picture that Anakha posted a while back. It clearly shows the parting line on each disc. The parting line is the little thin piece of flashing halfway up the nose of the disc.

To describe it a different way, if you set the disc on a countertop and then slide the disc over to a wall, the parting line would touch the wall first.

I realize these are 2 different discs but if they were the same mold then the one on the right should be more overstable.

[RS39]

Early clear blue Striker is 1/16 lower (1/2 nose thickness) then newer deep blue, both 168, and newer is more stable.

Champ and Pro Katanas, exact line up, not thrown yet, Pro is mo' dome/less dia.

Mix of 5 PDs, 1st S, Freak S, and Pro Freak, exact line up, S a bit more stable flight, domes 'darn close'.

[TheTyrant]

Whoa. I have a freakishly overstable 12x teebird that I just compared to my other teebirds and its parting line is significantly higher than the rest. Your ideas are intriguing to me and I wish to subscribe to your newsletter.

[Spike]

Gateway has an interesting article about the parting line of the Magic compared to a Wizard....

http://www.gdstour.com/gateway_magic_specifications.php

[JackMontana]

This seems to be a consequence of wing height, which is why tuning discs work. The parting line should be in the same place wrt lip on identical molds. Therefore, the only way to get variation in parting line height would be through wing height differences which could result from the cooling process and/or storage pressures. When you tune one less stable you flex the top of the disc so that the wing is lower wrt the bottom edge, thus lowering the parting line. Visa versa for tuning more overstable. So, to me the parting line correlating to stability is a consequence/symptom of wing height variation and is not itself responsible for the effect.

What did I get wrong?

J

[marmoset]

No no no, I completely agree with you.
The parting line height is just a convenient mark that should be the same height on every Teebird (or whatever disc) but will change as the wing angle affects it.

There are several factors at work but the parting line height is the indicator of those forces and the amount they affected the particular disc.

[Jeronimo]

This is precisely the phenoma I am seeing with my newest Latitude 64 Visions. The parting line is WAY higher than its ever been on the disc and these things are HELLA stable now.