The nice thing about being "a little off" is that it is as likely to help you as hurt you!
Ray
--- In Indoor_Construction_at_yahoogroups.com, "joemargbartek" <j.bartek@...> wrote:
>
> Ray
>
> Thanks. I take your response as support for using a calculator with chord as a parameter. The Excel one I found would need one more cell to make rib height apparent at the start, a simple calculation of chord X %chamber/100. If you wanted a direct calculation of % camber from rib height, it would be simple to do that,too.
>
> Coincidentally, I've got an A-6 on the board. It's a Gary Hodson "Wart" with a 2 inch 4% airfoil. I'd chopped the ribs out using an aluminum template cut to match the plan. I've just plotted the airfoil from its Excel Table, and I'm a little off. Got to save the plot for next time.
>
> Joe
>
> --- In Indoor_Construction_at_yahoogroups.com, "ray_harlan" <rbharlan@> wrote:
> >
> > Joe,
> >
> > Actually, I haven't ever used a Simplex calculator, or a Simplex airfoil, for that matter. However, The idea is that a Simplex curve will give you a fixed percentage camber for any chord you make with the chosen template. Whatever calculator you use, it needs either camber percentage or rib height and chord. The latter would be easier to use, since you only need to do one calculation, your rib height.
> >
> > Ray
> >
> > --- In Indoor_Construction_at_yahoogroups.com, "joemargbartek" <j.bartek@> wrote:
> > >
> > >
> > > Gary
> > >
> > > Thanks. I've just run Fred's program for a 5% airfoil and it works.
> > > However, as far as I can see, chord is not an accessible parameter. I
> > > haven't tried running it with the different calculated percentages to
> > > get the same height for the mixed rib wing that Ray found, and then
> > > using a ruler to cut across to the right chord for each % thickness to
> > > see if the heights are the same, as they should be. Maybe an addition
> > > to the ReadMe file indicating the way to get matching rib heights of
> > > different chords is in order.
> > >
> > > The Excel file I mentioned has both chord and % as parameters. I had no
> > > trouble plotting the ribs to the exact chord using Excel's graphing
> > > function. The X/Y table it generates has 25 steps.
> > >
> > > Joe
> > >
> > >
> > >
> > >
> > >
> > >
> > > --- In Indoor_Construction_at_yahoogroups.com, Warthodson@ wrote:
> > > >
> > > >
> > > > Joe,
> > > > I am not Ray, but I use Fred Rash's Simplex plotter in the files
> > > section of this group (Indoor Construction):
> > > http://groups.yahoo.com/group/Indoor_Construction/
> > > > Gary Hodson
> > > >
> > > > -----Original Message-----
> > > > From: joemargbartek j.bartek_at_
> > > > To: Indoor_Construction Indoor_Construction_at_yahoogroups.com
> > > > Sent: Tue, Dec 4, 2012 9:20 am
> > > > Subject: [Indoor_Construction] Re: simplex airfoil
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > Ray
> > > > Thanks for the clarification. What do you use for the Simplex airfoil
> > > calculator/plotter? Have you tried the one I referenced?
> > > >
> > > > I know tastes differ on whether to use EXE or EXCEL on math problems
> > > like this. I've used both, but have stuck with EXCEL lately because of
> > > the easy housekeeping and built in plotting. I've pulled the method out
> > > of the table in the one I tried, and will share it if anyone wishes.
> > > >
> > > > Joe
> > > >
> > >
> >
>
Received on Wed Dec 05 2012 - 09:56:31 CET