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Jun 11, 2004, 06:10 PM
Demon-Leather's Avatar
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"Pseudo Pa-Nee" the "No-Plans" Cropduster!

Hi there!, Bob here... Welcome to the "Pseudo Pa-Nee" building thread! The construction will be all-sheet type,drawn on 1/16" X 4" X 36" LIGHT balsa sheets, with no actual "hard-copy" plan. The plane is a "Pseudo-scale" of the Piper PA-25 Pawnee low-wing crop dusting aircraft.
This aircraft's construction is based on it's predesessor, The "Pseudo-Pa".. another Piper-Type PA That was basically designed to look like a "Piper-Something" ( the whole story is here, in case you'd like to read it
That I decided to build on a "lark" one day... by an old "fossle-fuel Dinosaur" like Me, who thought designing an electric after so many small glow-engined planes, would be a "walk in the park".... I can say it was a truely eye-opening experience for me
So... with all the hardships,mistakes, and knowlege gained from it.. I set about yet again in a noble mission.....

The Mission:
Design: I wanted to design a plane that is simple enough for a person fairly new to electrics, perhaps (with the help of other Ezoners chiming in from time to time with their experience) even someone who has never before attempted to build anything, but might have ARF foam experiece,or other ARF's, or perhaps a lazered kit, etc.
Trying to cover everything: This thread will hit on EVERYTHING I can possibly think of To make the model a sucsess for the "never-built-anything" guy (or gal) Covering selections of the mundane to the experienced builder, such as building-boards, Tool selection, Wood selection, etc., etc. With that said, I'm afraid The experienced builder will be bored to death with the first section of this post,... I hope I don't lose You being anal about things You already know about.
Expence: Let Me say this now.. I am CHeeeEEEEEEeep! Another goal of this project is to build an actual flying aircraft, as cheaply as possible,.. including tools, building boards etc. One of the things that scares new people away is having to buy a TON of stuff to make a 9 oz aircraft! So... if You're looking for a brushless-powered Li-poly's not here... If You have it, You will have to design it in... (which I sincerly hope someone will do! ) This one will be built using a inexpensive GWS geared IPS and micro-r/c gear, with old surplus Qualcomm Li-Ions for power... sorry, all I can afford, and I have a LOT of them to use.) The aircraft in this thread SHOULD be large enough, and strong enough to take anything from My system to geared 280-300, or perhaps DD 400 or geared 400 (might take a "bit of bracing here & there for the "big-stuff", but I don't see a problem.)
Ok,... I wanted to wait on this thread, to complete the plane and do flight tests, However.. My P/C hard drive is too old & too small to hold the photos & I'm afraid if I try, it will crash and I will lose everything. I nearly embarrassed Myself & almost shot Myself in the foot posting the Pseudo-Pa before completion. Luckilly, it actually flew, though extemely under-powered at 10 oz and only a 35.5" span... it proved the concept worked.
With that, I feel semi-safe in saying this one should fly too, and with a lot more wing area, and hopefully a couple oz's lighter,fly slow enough for a beginner, or at least someone who has a few previous flights under his belt.
However.. if You build-along with me istead of waiting till the end, You will build-in any"goofs" I do, and have to deal with them as I do....
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Jun 11, 2004, 06:21 PM
Demon-Leather's Avatar
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The "PLAN"......

The "Plan" is based on an old Walt Mooney (I guess you'd call it "walnut-scale") plan with a 16" or so span. I blew it up a looong time ago to around a 40" span for the "then new" Thunder-Tiger" 07 glow.. never built it.... I used the basic outline for "scale", and changed pretty much everything else....

Approx. Stats:

Length: Approx28" tip of Spinner to tail
Span: Approx 40"
width: (at largest point 4" LOT's Of Room! )
Weight: Approx 9 oz (with IPS & Qualcomms.. Li-Poly approx 1 oz lighter )
Power: IPS A , 280 geared,300 geared,to DD or geared 400 (pretty much anything You want.. Plenty of room for about anything! Don't know ANYTHING about "brushless"..too expensive for Me, so You are on your own there.)
Raidio Function(S) 3-4-5 channel (3-ch beginners,4 with strip ailerons for bigger motors.5 for a "duster using talc powder & a pager motor w/ vibrator, something like the old Sterling stearman crop-duster.."too ambitious" you think? )
Last edited by Demon-Leather; Jun 11, 2004 at 06:23 PM.
Jun 11, 2004, 06:36 PM
Demon-Leather's Avatar
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Building Board...

To build a straight model with no warps, You need a straight board. If You'll look at the photo, You will see My chouce. It's a piece of Georgia Pacific fiberboard insulation(available at Lowes, Home Depot, etc..). You get it in a 4' x 8' sheet,and can cut it to fit your entire modeling table (my table is an old school desk from the 50's or 60's.. price 20 bucks, weight about 300lbs..whats that less than 15 cents a lb,.. not bad! ) One sheet will cover your table, and then some,.. and leave you with smaller, "portable" boards(by portable, I mean if the Mrs. isn't home, and You have a "quick-project" in mind,and your building table's full, You can plop it down on the dining room table, and do a "quick-emergency-move" if she comes home early! ) If You have a small apartment, & can't have a big desk, You can buy a modile home "Door Blank",and a couple of those folding saw-horse brackets to make saw-horses out of boards.. after your build, fold up the horses,lean th door in the corner, or closet. You can use duct tape to affix yor board right to the door. Door blanks run about 14-22 dollars depending on place of purchase.. still cheap, AND can be out of the way!(if You are single, You can just plop the board down on the kitchen table..NOTE: DO NOT TRY THIS AT HOME WITH A SPOUSE! )
Price on all these building boards will be about 8 bucks.. if You just like building small... Lowes or home depot carry accoustic-type cieling tiles( I think they are over 4'X 2') price on those, are about 5 bucks ea,.. AND will fit in a car, if You don't have a truck for the "big" sheet....
Jun 11, 2004, 06:50 PM
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Now,.. here's where it CAN get expensive..I've emassed My tools over the last 30 years... drill presses, belt sanders jig saws, Die grinder,grinders,etc, etc.. but.. I made My living with a lot of them. As a new modeller. I will try to keep the tools to a "minimum" to keep expenses down....Here's what I believe You really HAVE to have
Exacto Knife Set:...A MUST.. Non-name brand ok,. I think WalMart has them for $14.95 with nice wooden case,extra blades & all the handles. That way get the large razor saw blade(pictured with the red handle on it) Another must-have, cuts plastic, balsa,foam,anything..."clean" If You don't have a Jig or scroll saw, You might also consider getting some Exacto "keyhole saw blades for cutting inside of the ply formers & such,.. though a drill will suffice.

Balsa-Stripper:.. make ANY size balsa sticks from sheet.. about 8-11 bucks,.. but after 2 models or so, will pay for itself... Go ahead.. price those sticks.

Screwdriver set:.. most guys have these.. but in case you dont Stanley makes a 10-in-1 set That I love.. even has a pick and a teeny "crowbar"plus a "power-handle" that the small drivers fit in(this was my wifes!,..but I liked it so much, I stole it!.. shhh!)

Plyers: gotta have for holding,tightening,& most importantly bending gear & other wire-stuff.. Needle-nose, regular, adjustable, and a "leatherman's tool gomes in pretty handy too!

Measuring devices: ...Rulers (6"-12"-36", protractor, triangles,compass, tape measure(flexable tape-type) get em at WalMart.. School supply section

Sanding blocks:... You can buy them(like the small Great Planes pictured, or go to Lowes & buy a 1 X 2" piece of pine and cut custom lengths. You can use the Great Planes self adhesive rolls of Fine & coarse on these to Any length, but they will not "stick" well to the board inlesss it is painted7 smooth. Regular sand paper,any grit, in sheets can also be used, and the paper held in place with thumbtacks pressed in the wood (with the paper wrapped tight,use the tacks on the side)

Marking pens & pencils:..... Your choice.. a thousand makes out there
Small files: You can get them in a set.. cheeaap & fle Markets or Harbor Frieght
Drill & bits:.....You need a drill.. can be cheap..Big Lots has on for 14 dollars..
cheap drill bit set 1/16" to 3/8" Don't need expensive ones, Harbor frieght has cheapies..were not drilling titanium, just balsa & ply..

Dremel Tool:...Worth thier weight in GOLD!.. But, "pricey" WalMart has them w/attachments/case for around $39.95 .. I saw one at BIG LOTS this very week.. A cheapy, runs on battery or AC adaptor(supplied) all attachments/bits like a Dremel.. $9.95!!! (I'm getting one for JUST the attachments!... might be nice to hve one without a cord in the way once in a while too!)

Digital-Postal scale:... Sorry,.. NOT cheap,.. but if you're going to do electrics.. it's a VERY must-have!..You just cant "feel" that "extra1'4 oz in that wood when You buy it..I take mine to the hobby store & weigh-before-I-Buy! I bought mine at Staples about 2 or so years ago.. $34.95.. not "too-bad"

Scissors:.. cutting paper, letters, 1/64th ply, covering (more on that later) Be advised.. Get Your OWN scissors,.. DON'T use Your WIFES!

Clamps: .. "Clamps are your frinds!".. they give your fingers a break! I bought the ones in the pictures at a flea market $.25 cents ea. But the REAL heros are spring clothes pins... and thier wee friends the mini-spring clothespins.(cute, huh? ). Walmart... a couple bucks.. do the job the larger clamps would crush. Another great clamp are #64 & regular rubber bands. You can put them around sheeting, and wind them like a tourniquet with a popcicle or balsa stick..twist in the tension,and tuck one end of the stick under the rubber band.. it will hold itself...
That about covors the tools...
Last edited by Demon-Leather; Jun 11, 2004 at 06:55 PM.
Jun 11, 2004, 07:12 PM
Demon-Leather's Avatar
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Selecting Wood.....

Most of the wood will be 1/16" X 4" X 36" sheet ( if You have a 48" sheet handy, You can get both sides from one sheet,with lots to spare.. almost got 2 from a 36" sheet.."almost" ) 4 sheets SHOULD suffice the entire aircraft...You will also need 0ne sheet of 3/32" X 4" x36" sheet for yout rudder & horizontal stabilizer & elevator. Other woods will be 6" X 12" X 1/32" Aircraft ply(1/16 lite-ply might do,.. but its kind of "splintery" for me, so I'll use the 1/32 birch ply) and a bit of 1/16th birch ply.... and1/8th" sheet to strip some 1/8 x 1/8" sq sticks. If You don't have a stripper, You'll have to buy 1/8 X 1/8" X 36" sticks..probably 8- 10,
and some .014 carbon fiber laminate 1/4" thick.
About the wood.. BE VERY CAREFUL choosing it! LIGHT IS RIGHT! heavy/firm stuff almost did-in the Pseudo-Pa.... Light now, means less (or maybe NO) lightening holes later!
Here is an example of the various weights of wood in My personal supply.. The Pa was made of the "firm" stuff at the heavy end (I didn't weigh it before building ) If You are using a larger powerplant, weight will not be so "criticle,.. but ANY wieght saved in an electric plane equates to better flying! Take Your new digital scale to the Hobby store with You,.. It will amaze You in the difference You just can't "feel"!
Last edited by Demon-Leather; Jun 11, 2004 at 07:23 PM.
Jun 11, 2004, 09:52 PM
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Let's Make Some Sides!

Ok first thing Is make sure your sheet is square, If it's not, it will throw everything else off. If it off (and a LOT of "factory-sheets are) sand it till it checks with your square, or 90 degree triangle.(pictur#1)

Carefully measure from the end 21" on the money,(this will become your tail post) and make a line using your triangle down the sheet at that mark, then measure 3 5/8" from the TOP (the top is your side top). (Picture #2)

Go back measure down & mark 3 5/8" in the front, and with a straight-edge(such as a yardstick) draw a straight line from front to rear at both 3 5/8" marks... You have just made the baseline to the fuselage sides...(Picture #3)

Now,.. from the rear tailpost,meaure 12 13/16" back towards the front,and at the top (Picture#4)
Last edited by Demon-Leather; Jun 12, 2004 at 04:18 AM.
Jun 12, 2004, 02:40 AM
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Keep Going.....

At the 12 13/16" mark(from the top) use your triangle to make a square line down to the baseline. (picture# 5)
**NOTE** That is 12 13/16".. (NOT 13" like it says in the Photo..Sorry)

From that line, measure 6" more towards the front, and do the same.. (picture # 6)

Now, go back to the tailpost and measure 1 5/8" down & mark it.. (picture # 7)

With a your straight edge, align the 1 5/8"mark at the tailpost to where the bottom base line intersects the 12 13/16" mark as in Picture # 8
** AGAIN NOTE ** It is 12 13/16" NOT 13" *********************

Ok,..Now we go to the 12 13/16" mark, and measure 1/16th of an inch up on it,from the base line and mark it.
go to the mark 6 inches in front of that, and measure up 1/4" and mark that. Now, take your straight edge & draw a line to connect both marks.. You have just set your approximate 2 degrees incidence! (picture # 9)
Last edited by Demon-Leather; Jun 12, 2004 at 04:29 AM.
Jun 12, 2004, 02:54 AM
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Almost Done....

Now go to the front (firewall) and measure 1 1/8" UP from the Baseline towards the fuselage top,.. and make a mark (picture # 11)

Connect it to the leading-edge incidence line at the 1/4"mark with your straight ege and mark it (picture #12) Your fuselage outline now is basically complete! (wasn't that hard now, was it? )

Now, go to the top/front(firewall) and measure down 3/8" & make a mark, go to the tail post and make the same 3/8" mark. line your straight edge up and make a light dashed-line down the length of your fuselage... this will be your thrust-line (picture # 13)

When You are done with that,.. You SHOULD have someyhing that looks like this.. Picture # 14)(well,.. except for the double line in the front & the incidence,it was dropped a bit more before I had the final figures I just gave You...
Jun 12, 2004, 03:58 AM
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Ready to Cut!

But,... before we do... let's make sure we're on the same sheet of music.
Lets do some measuring,.. from the front (firewall,to the leading edge incidence line.. it should be 2 3/16" From the leading edge line to the trailing edge is 6" and from the trailing edge to the tailpost is 12 13/16".. That is a grand-total of 21"...If that is what You have,.. the rest is probably correct. If so we can start cutting. If You are wondering why it says 13" in the photo, it's because I was tired, and marked it wrong. It does come out to 13" .. diagonally from the bottom of the tailpost to the bottom of the trailing edge line... I had to go edit-out the 13" I had stated in the post as well,.. I apologize for the oversite.
It would be nice to know if I am making sense explaining all this.. I'f I'm not, I can change tactics before going further. My wife says I "explain too-much" and lose people. Your opinion, building or not, would be helpful & appreciated at this point. Meanwhile, I'll get My required 4 hrs sleep... that's all for today! Bob
Last edited by Demon-Leather; Jun 12, 2004 at 04:40 AM.
Jun 12, 2004, 07:24 AM
toddhudgel's Avatar
Originally Posted by Demon-Leather
Digital-Postal scale:... Sorry,.. NOT cheap,.. but if you're going to do electrics.. it's a VERY must-have!..You just cant "feel" that "extra1'4 oz in that wood when You buy it..I take mine to the hobby store & weigh-before-I-Buy! I bought mine at Staples about 2 or so years ago.. $34.95.. not "too-bad"
I got a food scale at Wal-Mart for $20. Works well. Food (pun intended) for thought...
Jun 12, 2004, 02:30 PM
So far so good! I think you are providing many good tips and tricks especially about the wood not being square and straightwhen it is "new".

Keep it up!
Jun 12, 2004, 03:03 PM
victim of the system
TooTall's Avatar
Alright Bob....looking good so far ,, I have my 2 sides .....Thanks....Tom
Jun 12, 2004, 06:51 PM
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Thanks Guys!....

Thanks on the tip for the scale toddhudgel! that's the kind of things that are needed here!
Thanks for the encouragement Willin,.. You are the type that keep Me going!
You hung-out on the origional thread since the beginning of it, and supplied a LOT of help!
Tom.. Slow-down!... You're going to beat ME building!! hehe I'll have something you'll need for the fuselage-build, and a wing rib template for You in a few minutes... I need to touch some bases on cutting first....
Jun 12, 2004, 07:09 PM
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Tips for "New" cutters......

Before We start cutting, a word about cutting-boards...I don't use the, I use cardboard to cut on.. It's FREE, You can rip pieces off to mix epoxy on, and when it's cut to ribbons... Chuck it in the trash! Yes cardboard is another great friend in Many ways!

Ok everyone,.. pick up your Exacto knife,.. big or small, which ever is more comfortable.
First,.. let Me say.. "The pointy-side goes down" And.. if you look on the other end You will notice that there is no "eraser" on that end so anything You do with this tool is perminent. In other words.. "careful cutting saves money!" on wood, and trips to the emergency room for stiches.
With that said, lets begin!
I always begin with against the grain cuts, because if You don't, chances are cutting them after the with-the-grain cuts ususually ends up in a split,and a missing piece that must be glued back, or thrown out. I start with th smallest cross-grain cut, then go to the next etc. I cut more diagonal angles first, then Lesser angles,then straight with-grain cuts last. Just follow the order of the photos, and You'll see what I mean........
Last edited by Demon-Leather; Jun 21, 2004 at 12:46 AM.
Jun 12, 2004, 07:26 PM
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Dang-it! now,.. where did I put the thin CA?? Just kidding! Hopefully You have something that looks like the second picture,..(not the first! ) If You are unsteady-handed, You can use a metal straightedge to aid in cutting,and if You think you are not going to be able to cut completely straight, ALWAYS "err" to the outside of the part line.. a sanding block will straighten it up in a hurry.
Last edited by Demon-Leather; Aug 17, 2006 at 12:19 AM.

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