Re: Fly Line Database
Posted: Sat Jun 08, 2019 1:31 am
I got a few comments from Bruce...
I'm back from the wilderness and will have some time to contribute to the database/line design project now. I've read about half that thread and have a few short comments.
First, calibration of both balances and micrometers will be very important. Everyone must commit to accurate measurements. That said, without cutting lines accurate weights aren't really possible so maybe balance calibration isn't necessary.
SA, and I'm sure Rio, already have most of the info. you want and I suspect both would be willing to provide. It's a LOT of data though, would take some time. And, who is going to maintain this database? The data will change annually. Initial data collection is just part of the job if the database is to remain relevant.
A couple quick line design comments. Head design - how a line carries and delivers a fly is probably the key design parameter. The mass profile of the head largely determines that. Too "delay" turnover you put more mass in the front part of the head. Think of the loop top leg only. As it gets shorter it accelerates, or tries too. As top leg mass reduces the energy is focused in a smaller mass, that's the cause. But since wind resistance is exponential any increase in velocity is met with increased resistance, the reason that it is SO important that the top leg be very straight. If the line is designed like the MED, with more mass toward the front, the mass of the top leg doesn't reduce as quickly as it shortens which delays the acceleration, slowing the top leg, allowing it to carry farther before turning over. The MED is designed with a rather long front taper for smooth turnovers, but with an oversize tip to insure it does turnover at distance.
The Wulff TT lines are just the opposite, but designed for a very different purpose. A big subject but very simple physics really...
I can help with the database if you want.