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        Build Log Altimus S7 Proto-type & CAD

#1 IHAVAWDY Dec 27, 2012 04:11 PM

Altimus S7 Proto-type & CAD

Hello folks, I've been designing this sailplane in my head for quite some time. It's a proto-type 4 meter woody with an eliptical wing, slight cambered airfoil that changes from root to tip. It has a camber changeable trailing edge, fullhouse, flying stab, and hopefully will finish out in the lower 70 ounce wieght class. The spar is spruce, capped with carbon fiber, inforced with +45*-45* carbon fiber & +45* -45* spar webs and feels very stiff. It's not completly finish as yet, but close. It's winter here in Montana so it will be a while before it will be flown unless I am able to get down to Az for the SWC in Feb. (not flying in contest) but hoping to go and watch and possibly maiden if time and $$ permit. I've learned the hobby of sailplanes thru the school of hard knocks. Built and crashed my share since the late 70's. This will be a record of this sailplane I've named Altimus S7. Altimus is the latin scientific name of a bull nosed shark. I hope it performs more like a shark than Bull.:rolleyes: It is also has a Greek meaning for something like ultimate, which is really what I hope for.:cool: Anyway I always like looking at everyone's build logs and usually learn something from most, hopefully you'll learn something from this mess and more importantly, teach me something before we come to the end!:D Please comment or ask questions on anything so I know I'm not typing to myself :o


* edit: this thread will enjoy some goofin off so if youd rather "Skip" (and you know I'm only joking here Ventus!) the talking, go back out and click on the paper clip on the right side of the thread page. There is a photo storybook w/ only instruction on the build and just a [I]little goofin off[/I.] We'd love to have you join in the thread though...you choose

#2 SHVentus Dec 27, 2012 05:15 PM


Goods very nice. I would love to see your build photos from start to finish with all the pertinent verbage to accompany them. :D Am anticipating your flight review. She looks like a keeper mate! Good on ya! :D

#3 IHAVAWDY Dec 27, 2012 06:02 PM

1 Attachment(s)
Alright, let's scratch out a wing...

First, pick out some straight grained spruce for the spars. these will be 1/8'' x3/8'' spruce w/ carbon on both sides of both spars. Carbon is .030 thick on the top of the spar and .014 thick on the bottom. Same for the lower spar except reversed. the .030 will be on the bottom of the wing. Carbon is bonded to spruce with G-flex epoxy. this stuff really grabs a hold of both materials nicely and gives good working time so it has time to wet out the carbon and really soak into the spruce. Like the name says, it is flexable so it doesn't crack when the spar is stressed on winch launch. I lay up all eight spars at the same time and assemble them on wax paper. I then lay a heavy piece of glass on the top of the whole mess. Add weight to the top of the glass making sure nothing shifts. Let sit for 24 hours. I build on 3/8'' glass. While the spars are curing I can continue working on cutting ribs with my hand held lazer cutter.;)

#4 IHAVAWDY Dec 27, 2012 07:13 PM

2 Attachment(s)
Break a Rib

Cutting Ribs. The best part of a build for me is the wing. It's the heart and soul of the sailplane.Everything else is just bling along for the ride.:p Unfortunately in order to build wings, ya gotta have some ribs... Those of us that are not so fortunate to have a lazer cutter in the shop gotta do it by hand. :( I've been cutting my own for a long time and there are ways to make things easier on yourself. Template stack cutting, sanding ect. This case is different. This wing has a custom airfoil. It starts at the root with a slim MH 32 airfoil blended to a Drela inspired airfoil at the mid panel, blended again to another interpolated airfoil towards the tip. That means that each rib is different. I use Profili 2 xt to print the proto-type ribs and print them out with a very fine line on the printer( only a few pixels wide) onto a high quality paper. cut them out leaving a few mm of extra space outside the rib line. Also print them with a mean cord line down the center of the rib to use as a referance to make sure the paper template is straight when glued to the 1/16'' balsa . I use a glue stick to fasten the templates to the balsa, no mess or fumes. This wing has a cambered airfoil so building tabs are used on top of the rib so that it will sit nicely on the spar and level on the glass. these will be cut off after the bottom of the wing is sheeted. You gotta be in a relaxed mood when cutting ribs, it really can't be rushed... just enjoy it and talk to your therapist for a extra hour next thursday..:p I enjoy this part of the build, really, I do. ah hem, cough, cough :censored::D
How much is a lazer cutter???

#5 SHVentus Dec 27, 2012 08:23 PM

Oh yeah baby, that's what I mean, now we're cookin. :D:popcorn:

#6 IHAVAWDY Dec 27, 2012 08:35 PM

you might be cookin in Hawaii Skip, but that white crap on the ground is snow, if you look on Wikepedia it'll explain that it has to be below freezin for it to pile up like that! Why did I move from Maui again?? humm :p:D:p

#7 Pauliwog Dec 27, 2012 09:00 PM

Now "THAT'S" Impressive!!!!!!
I like any and all build logs and scratch woodies, but this is REALLY Cool!

I used to live in Anaconda and Missoula, the background in the pictures looks like some areas I've seen around Helena or Bozeman. Still, I bet your winter-thermals in that nice dry air will be better than my winter-thermals in nice wet,wet, wet and cold Corvallis, Oregon. Gosh I miss Montana winters. I love snowshoe backpack trips.

Anyhow, that's a really cool looking plane! - Paul

#8 IHAVAWDY Dec 27, 2012 09:16 PM

4 Attachment(s)
Building panels

Ribs are cut (ya whoo!), spars are cured, lets glue'em together. Make sure the spars are straight. I use a little CA and spot glue the spar on the ends to my glass. I use a straight edge to check them and spot CA them to the glass as needed to keep them straight on the glass . My plans are under the glass of coarse. Use very little CA to do this step. I try and wipe it all off before I place it on the glass. Next, I place one rib down on the spar and spot glue it, making sure it's perpendicular to the spar. I then epoxy a 45* cut shear web on the spar and butt the next rib to that. This way there is no gap of any kind between shear webs. continue all the way down the panel in this fashion. Epoxy the upper spar onto the ribs making sure of a perfect fit. Once cured, I spin kevlar thread (tow) tightly around the spar.

Next, I glue the 1/4'' trailing spar onto the ribs. use this step to insure that ribs are correctly spaced and 90* to carbon spar. Finally I glue false leading edge to front of ribs insuring again 90* and proper spacing. Now do it again for the other panel. :D

#9 IHAVAWDY Dec 27, 2012 09:18 PM

Thanks Paul, and welcome to the build...

#10 Pilatuspc12 Dec 27, 2012 09:34 PM

Neat bird. Outstanding design.Will it have plans published?

#11 IHAVAWDY Dec 27, 2012 09:38 PM


#12 IHAVAWDY Dec 27, 2012 09:43 PM

Very possible, it's got a ways to go before that. gotta perform. Polars, graphs and looks mean nothing if it doesn't perform. proto-type will tell the story, but if all goes as planned... and if there is any interest, possibly. Thanks for lookin in

#13 SHVentus Dec 28, 2012 12:04 AM


You sure that white stuff isn't sand? Hey, we get below 32* temps here on Mauna Kea along with that stuff called snow. We just don't live in it. :)

Hey, I've lived in, driven in, & shoveled my share of that shave ice, but I now prefer my shave ice in a cone with rainbow flavorings. :D

#14 SHVentus Dec 28, 2012 12:08 AM

PS: Do you like your "snow" with or without azuki beans? :D

Just joshin ya. Hope that bird of yours is all that you hoped for, the polars prove wonderful, and she flies better than the glass slippers out there. All the best!

#15 IHAVAWDY Dec 28, 2012 12:17 AM

LOL Sometimes i pretend it's a white sand beach but then my wife tells my to put some clothes back on cuz the neighbors are staring again. I remember one day driving my Maui cruzer down Front st in Lahina and WHOP! something hits my car... look over and a truck full of "Locals" had been up to Haleakala and loaded the back of the truck with snow, Brought it to town to throw at cars going by... took a while to register what had just happened to me as it was about 80* outside. Reminded me of my childhood,I got in plenty trouble doing the same thing growing up in Montana

Thanks for the well wishes... It will be worth it just to get the thing out of my head :p:D:eek:

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