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Skin-on-Frame: Yost: Establishing correct rocker
By:TheLuckyOne
Date: 8/30/2010, 9:06 pm

I've been looking over greywuuf's posts about his experiences so far building his Yost Sea Tour 15 EXP. His first post went over how to determine the correct height above the baseline for the stations/formers... and how to relate the baseline to the strongback.

I think I understand the process... using Yost's example of the Sea Ranger, the keel of stations #1 and #8 are both 2.7 cm above the baseline ( http://yostwerks.com/SeaRanger2.html ). Station #4's keel is right at the baseline, per the table of offsets.

At http://www.yostwerks.com/Frame2.html , Tom explains that he's set the baseline at 3" above the strongback. That pushes the keels of stations #1 and #8 to 4" above the strongback (~2.7 cm above the baseline). Tom goes on to explain in step #5 that he anchors the keel at the low point at 3" above the strongback (at the baseline)... 8.5' from the bow.

Where does he get the 8.5' measurement? I don't see it listed anywhere in the table of offsets, nor anywhere else on the page. I know section #4 has the keel at the 0" HAB point. If I add up the cross section spacing from the bow to section #4, I get 8.25 feet. It's not much of a difference, but I'm used to building model aircraft... small changes can make big changes in flight behavior. That's assuming the rocker is a big detail.

I do note that the distance from the bow to the first station is 36"+. I seem to remember him saying that the distance to the bow can vary depending on how the bow plate "looks"... so if he extended the slope of the plate, which pushed the bow out by 0.25'... then measured the distance to station #4 afterwards for his web site afterwards.

Messages In This Thread

Skin-on-Frame: Yost: Establishing correct rocker
TheLuckyOne -- 8/30/2010, 9:06 pm
Re: Skin-on-Frame: Yost: Establishing correct rock
Ted Milker -- 8/31/2010, 9:31 pm
Re: Skin-on-Frame: Yost: Establishing correct rock
Dave Gentry -- 8/31/2010, 10:50 pm
Re: Skin-on-Frame: Yost: Establishing correct rock
Ted Milker -- 9/1/2010, 8:13 am
Re: Skin-on-Frame: Yost: Establishing correct rock
Dave Gentry -- 9/2/2010, 7:04 am
Re: Skin-on-Frame: Yost: Establishing correct rock
Bill Hamm -- 9/1/2010, 8:24 am
Re: Skin-on-Frame: Yost: Establishing correct rock *PIC*
Dave Gentry -- 8/30/2010, 9:32 pm
Re: Skin-on-Frame: Yost: Establishing correct rock
Bill Hamm -- 8/30/2010, 9:28 pm