StuntRibX - progress?

Hey, Larry... I just downloaded StuntRib from the new PAMPA website yesterday, and I've now spent an obscene number of hours playing with it. First of all, here is (I'm sure) the "standard" reaction - Wow, am I impressed! (I bet you get that all the time). Not only have I read all three parts of the articles posted (well, okay, my eyes glazed over a few times, so I need to read them a few more times), but I've also read the Readme file and as much as I can find here on the forum.

So far, I'm delighted with it. I now regret that it's taken me this long to get around to trying it, but frankly, I don't think I was ready before - the discussions I'd read here referring to it left me cold before, but now my interest will undoubtedly perk up!

The one thing I've discovered it can't (yet) do (or at least I haven't learned how) is to move the high-point of the airfoil forward from its 30% position. I understand you're working on that, Larry. How's it going? Any idea when there'll be an extended version available? Can I be a beta tester?

The first thing I've tried to do with it is generate root and tip airfoils for cutting new wings for my Ukey 40. Yes, I know, that's a pretty ambitious thing to attempt when you haven't even cut any foam yet at all, but I've got lots of foam, so I thought I'd give it a try. Anyway, I can come pretty close to the same airfoil, but can't quite nail it. The leading edge seems a little less blunt than the Ukey leading edge - I think the high point is farther back than it "should be". I do think it'll be a very acceptable airfoil, though, so if a new version is not forthcoming for a while, don't worry, I'll make do. Just askin'...

Tim,

You should see the prototype spread sheet with StuntRib function Larry is working on. Yikes!! It's awesome. I couldn't have built my new elliptical wing plane without it.

I'd be happy to have you as a beta tester, Tim.

Unfortunately, my regular job has had me covered for the last couple of months and I haven't been working on the spreadsheet Stuntrib-X version. I need to get off my duff and work on it again.

The mod to move the high point of the airfoil is simple, I suppose I should make some preliminary versions of pieces of the new program, as soon as I have, I'll let you play with them.

Apologies!

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"It rubs the lotion on its skin,
it does this whenever it's told.."
-Buffalo Bill, in "Silence of the Lambs"

Thanks, Larry. Keep in mind I'm not a real power-designer, and so far my needs are pretty simple. I don't even need geodetic ribs. I found the interface for your program to be poetically simple - not clunky at all! Very easy to use. Looking forward to the "new and improved"...

Larry,

I can't wait to see more. I did most of the design work on Tango Red II on the partial version you sent me. It's how I got the elliptical taper and the very tricky ribs past the flap ends to work. It is very cool.

T & R,

Something crude comes your way.. Check your email.

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"No comment is a splendid expression. I am using it again and again." -Charles De Gaulle

Larry,

Crude is great! I love crude.

Randy Powell

Edit: checked the mail and I got it. Now I get to play! Already planing a Tango III.

Edit 2: No joy. It crashes when I try to load it. I do get one of the fun and useless MS error report dialogs.

Randy, not so useless - you have to click to see the details. I got a crash also (which is, believe it or not, good news!) - it's an Invalid Page Fault in one of the DLL files. I've already emailed Larry, so hopefully he'll be able to sort it out. If not, well, back to the proverbial drawing board...

Sorry, guys.. My problem is that I don't have Excel 97 on my computer, and I'm using Excel 2000, telling it to emit a 97 compatible .XLS file.

It probably has something to do with that JPG I inserted. This is the sort of problem you get when you get "cute" and/or blindingly trust Microsoftware to actually be downward compatible.

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musta been because I got "cute"..

I've been religiously updating my Windows 2KPE trying to stay ahead of security issues, perhaps that induced the problem. I sent Randy a fairly complex Excel spreadsheet some time ago, which did not have this sort of problem.

It looks like the problem is fairly common, a Google on the phrase "invalid page fault in VBA332.dll" finds many references, and it looks like the Windows update site has Office 97 updates. Perhaps somewhere out there a wizard is reading this, and saying, "Oh yeah.. you need to .. blah, blah, blah.."

Please chime in, if you know how to fix it.

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"If builders built buildings the way programmers write programs, then the first woodpecker to come along would destroy civilization." -Weinberg's Second Law

I think I just need to get a newer version of Excel, or perhaps ANY Office product (this sounds like the kind of DLL file that is included in many Microsoft products). My problem at the moment is a tale of 2 computers. My "main" computer is a 2-year-old Pentium 4 machine running at 2.4 GHz with 512Mb of ram and Windows XP Home, but I don't have Office installed on this machine. It came with Microsoft Works, so I only have the Works spreadsheet, which does not work with THIS spreadsheet at ALL. My "other" computer is a 1999 Pentium-II running Win98SE. IT has Office 97 on it. However, I haven't really kept it up to date.

The problem here, I think, is that Larry is using a much more recent version of Excel, which doesn't match with my older, out-of-date version. I did download Office SR-2b this evening, but that didn't improve matters. Larry, the DLL you sent me is older than the one I have, so no good.

This is a REALLY common problem among those distributing software, whether free or for fee. I sure don't envy those who make their living doing it. Larry, I'll see if I can get a newer version of Office on my "main" computer - maybe even an evaluation version, just to see this thing work. Don't get discouraged! People like me just have to stop keeping dinosaurs around (although one of the reasons I don't upgrade that machine is that I have TurboCad2D Freeware on it, which won't run under XP).

Well.... scratch that theory. It also crashes on Excel 2002. Sorry, Larr...

Larry,,

I have Excel from Office 2000. The latest sheet works fine. Very cool. In combination with the previous sheet you sent (setting up the elliptical planform), you can pretty much lay out anything.

Thanks!

I, too, have received the latest spreadsheet, and IT WORKS! I haven't had time to do more than confirm that, so after work this evening I do plan to play with it. I expect to be delighted. Great work, Larry!

if you look on Selig's airfoil site at Indiana U there are a couple of programs that do airfoils, similar to stunt rib, that are a little dressier and easier to use.

Or, most CAD programs can do a true offset polyline or shape to allow for sheeting.

http://www.aae.uiuc.edu/m-selig/ads/register/AIRFOIL1.EXE

http://www.geocities.com/CapeCanaveral/Hangar/2524/nvfoilen.html

http://www.rc-soar.com look for plotfoil. you also need VBRUN300.dll

In 1996 when I wrote the original Stuntrib program, I got the NACA airfoil generator equation and other information from the public domain C source and documentation for Plotfoil..

I simplified the equation for a symmetrical airfoil and added a feature to chop of the trailing edge and rescale it to provide a non-zero trailing edge height.

There are wonderful things on the internet, many freely shared, if you look around a bit.

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"Columbus did not seek a new route to the Indies in response to a majority directive." -Milton Friedman