http://www.supercub.org/forum/blog.php?5982-qsmx440 SuperCub.Org Discussion Forum, Piper Super Cub, Super Cub, PA-18, Supercub, Backcountry Flying, Off Airport, supercub.org en Tue, 21 May 2013 10:15:27 GMT vBulletin 60 http://www.supercub.org/forum/images/misc/rss.jpg http://www.supercub.org/forum/blog.php?5982-qsmx440 http://www.supercub.org/forum/entry.php?166-elevator Mon, 18 Mar 2013 19:11:56 GMT In keeping with yesterdays post this picture shows the layout of my "temporary" table to build all six tail pieces. I was still at the "do I want to do this" stage and did not want to spend my time building a table like I now have. This does show you can take some scrap lumber and old plywood and make a form surface. The underside of the plywood was shimmed at various locations to achieve a flat surface between the various plywood scrap pieces.
The elevator and rudder required different bending at different locations. I rolled the whole tube to the "least" (largest radius) bent area first and then concentrated on the increasing bend areas as needed finishing with the most bent (smallest radius) areas last. Again be sure and put a clamp on the tube to keep your hand on and give a visual level indication while rolling or you will get a multiple direction bend in the tube.





Here is a tacked up all most finished tail. I did eventually get all the ribs made and installed. They are the most difficult part in as much as they taper. I found the best way to build them was to make the taper correct, make the blanks a couple of inches to long on each end and then cut out the center so as to get the length dimension I needed. I used a Harbor freight shear/brake,roll 3 in one machine that for 399 on sale is a very handy unit for building this kind of airplane. It was my brothers but it now lives in my garage for the time being.



The 6 parts of the tail is a great thing to build first since they are easy and when done you have some airplane looking parts to hang on the wall for inspiration. I don't have any more tips from my building of these since it was almost three years ago when I built these. I will say to store them inside . Mine are stored inside but still have developed a light coat of rust. I am planning on taking a TIG welding class before finish welding so I didn't want to paint them yet. ]]> qsmx440 http://www.supercub.org/forum/entry.php?166-elevator http://www.supercub.org/forum/entry.php?165-stabilizer Sun, 17 Mar 2013 20:56:13 GMT Swedging the stabilizer tube the old fashioned way. This little tool is made from a bolt with the head cut off, a couple of nuts and a stack of... Swedging the stabilizer tube the old fashioned way. This little tool is made from a bolt with the head cut off, a couple of nuts and a stack of oversized flat washers. The nuts are tightened and then the center two washers are ground/sanded on a belt sander to the "swedge" dimension you want. The outer washers on each side are ground down to the original size. The whole thing is tapered on each side of center so you can tap it in and then "hog" the hole a little by moving the handle in an arc each little ways in. Use plenty of oil in this process. I had no problems doing this and no cracking. A long rod is used in the far end to drive the swedge back out when done. I turned it several times driving it in each time to assure an even dimension.





Next the leading edge of the stabilizer needs to be formed into a semi circle. I made up the form blocks as per Piper drawings on a flat surface for the balanced stabilizer on Buggs site and then used a cheap Harbor Freight roller to form the bend. Note in the picture the clamp placed on the part. This clamp is needed to keep the pipe level or perpendicular to the roller machine. If you just start rolling back and forth without keeping the same line on the pipe you will get a double bend that is difficult to impossible to deal with. I like the roller machine since it will not kink the tube like other methods and there is no need to fill with sand or other measures. For $60 on sale it's a good deal.When your done the pipe should lay flat and true in your form blocks. Don't forget to order a couple of extra feet of tubing as the machine cannot bend all the way to the end of the tube. After you are satisfied with the bends lay the tube in your form and cut to length. I like to cross over all the parts on top of each other before cutting to make sure everything is adjusted correctly to fit the form.



And here is a picture of the parts at the beginning of the tack weld stage. I purchased the "C" channel I used in the tail pieces but made all the tapered ribs used in the tail from sheet steel and that will be a subject of a future blog. All of the curved pieces in the tail were made on the roller machine and turned out very good. Both sides of the stabilizer and elevators must match IMHO although because the prop wash is applied differently to each side the pressures will still be unequal at least in power off mode the tail should be balanced.




This work (all 6 pieces of the tail) was actually completed in 2010 and was the first parts I made to see if I really felt like taking the project on.. ]]> qsmx440 http://www.supercub.org/forum/entry.php?165-stabilizer http://www.supercub.org/forum/entry.php?42-Wing-compression-strut-parts-2 Thu, 03 Feb 2011 19:20:32 GMT Well I have finally got back to work after 3 months working :sad:? Well I mean on the plane. Actually I'm not building a Piper clone airplane. I'm building a small part of the 13 rib metal wing. Like eating an elephant. So this is the first time I attempt to post pictures and I'm not sure how it will go. As to my earlier blogs I was attempting to decide how to build a light weight wing for my attempt at building a 150 horsepower 1320# gross weight supercub clone. I finally decided on recreating the PA-18 13 rib wing as per the drawings on Christian Sturms site: supercubproject.com The parts I build for this project will follow those pages in the "drawings" section of his site (the "drawings" button is in the upper right hand corner of his home page). Once you get to the drawings page enter 10062 in the search box for the first part we will discuss. So in my first blog picture (remember you can blow it up by clicking it a couple times)


are parts in various stages of completion so that you can see my thinking. Note my favorite flyer in the cage (we have cats unfortunatly) At 14 years old she has lost her medical but still flys some (ultra light catagory only) :-P Figuring the order to make any parts is half the work usually and actually the challenging part. After you've figured out how then stamping widgets is anti climatic. In the picture you see 3 drawings from Christians site (10072) Drag strut front foot, (10062) rear drag strut foot, (10021) "N" strut gussets. Diagonally in the picture is an actual drag strut with the front foot clipped on to it. I cheated a little on this as I ordered, from Dakota Cub, 1 ea foot front and rear foot and drag strut tube, drag wire pull and nipple etc so that I would have a pattern to decide how to layout tooling and then check the quality of my work. In the second picture


you see the rear foot (10062) in various stages of completion. The triangle piece of flat aluminum is the first blank which was derived from a paper pattern. After making the first blank the rest were scribed around it to mark the rest of the aluminum blanks. I used one of those 30" shear/brake/roll that Harbor freight sells and my brother owns to cut the blanks. I did one with hand shears just to prove it could be done. It turned out fine but the shears tended to curl the blank slightly. A whack with a board brought it back into shape. Note the finished (factory) piece sitting on a blank (bottom left of second picture) to mark lines on the blank to center the bending board on. Two centering lines were scribed on each blank (flop the pattern piece over to make second mark and don't worry about width of marks just align the edges of blank and mark. You will center wood form between the marks, distance between the marks doesn't matter). In the third picture


the blank is centered under the bending board (7/8 wide piece of scrap finish wood (home depot 1" finish? measures 7/8") with the bottom edge "broke" by hand with a piece of sandpaper for the "radius" edge). The previous center scribed lines are used to eyeball the board to the center of the blank. Pressure is brought on the board by the milling quill being lowered onto the top of the board and locked. In the forth picture


a scrap of .032 4130 steel is squeezed under the edge of the aluminum and while pressing in it is tilted up a bit,presseng in again and then a second thicker piece of steel is pushed under that one and it's bent some more (repeat lifting and pushing in on the "wedges") until the side reaches about 45 degrees. At this point the blank is turned around and the other side is bent to 45* also.


In the last picture the milling vice (between the jaws) is positioned under the quill and the partially bent blank is placed between the soft jaws on top of a scrap 3/4" square tube (to keep the bottom of the part flat while you finish bending it since there is a hole in the center of the vice), the quill is lowered for top pressure on the board and the vice jaws closed to complete the two side 90* bends. Top pressure is needed while bending to keep the bottom (center of the part) from taking a curve. Some repositioning of the "X" axis of the milling table vice is needed while tightening the jaws. Note: cut your blanks so that you are bending across the grain. The blanks are 5052 aluminum from onlinemetals.com. About $20.00 for all the feet needed and the "N" strut gussets. The two certified pieces were 7 an10 dollars respectfully. Practice makes the pieces bend up perfectly on both sides so they match. For production, do several parts 1 step at a time on all parts before moving to next step. Works out to about 10 minutes a piece total/part once you've done a couple practice pieces. Finish corners on a belt sander. A slot has to be milled on the bottom like in the factory piece. I will use a ball end mill but corner holes could be used and maybe a dremmel tool or small hacksaw blade with file finish. So if you have followed so far does my description and pictures lead you to think you could build these pieces for the Piper wing?? Suggestions to improve (this works but maybe someone has a better way)? Thanks ]]> qsmx440 http://www.supercub.org/forum/entry.php?42-Wing-compression-strut-parts-2 http://www.supercub.org/forum/entry.php?24-Airplane-jokes! Thu, 06 Jan 2011 03:40:21 GMT Been sick so had all day for searching the web and ran accross these tidbits: AIRSPEED - Speed of an airplane. (Deduct 25% when listening to a ... Been sick so had all day for searching the web and ran accross these tidbits:

AIRSPEED - Speed of an airplane. (Deduct 25% when listening to a
retired fighter pilot).
BANK - The folks who hold the lien on most pilots' cars.
CARBURETOR ICING - A phenomenon reported to the FAA by pilots
immediately after they run out of gas.
CONE OF CONFUSION - An area about the size of New Jersey located
near the final approach beacon at an airport.
CRAB - A VFR Instructor's attitude on an IFR day.
DEAD RECKONING - You reckon correctly, or you are.
DESTINATION - Geographical location 30 minutes beyond the pilot's
bladder saturation point.
ENGINE FAILURE - A condition that occurs when all fuel tanks
mysteriously become filled with low-octane air.
FIREWALL - Section of the aircraft specifically designed to funnel
heat and smoke into the cockpit.
FLIGHT FOLLOWING - USAF Formation flying.
GLIDE DISTANCE - Half the distance from an airplane to the nearest
emergency landing field.
HOBBS - An instrument which creates an emergency situation should it
fail during dual instruction.
HYDROPLANE - An airplane designed to land long on a short and wet
runway.
IFR - A method of flying by needle and horoscope.
LEAN MIXTURE - Nonalcoholic beer.
MINI MAG LITE - Device designed to support the AA battery industry.
NANOSECOND - Time delay between the Low Fuel Warning light and the
onset of carburetor icing.
PARACHUTES - The two chutes in a Stearman.
PARASITIC DRAG - A pilot who bums a ride and complains about the
service.
RANGE - Usually about 3 miles short of the destination.
RICH MIXTURE - What you order at another pilot's promotion party.
ROGER - Used when you're not sure what else to say.
SECTIONAL CHART - Any chart that ends 25 nm short of your
destination.
SERVICE CEILING - Altitude at which cabin crew can serve drinks.
SPOILERS - FAA Inspectors.
STALL - Technique used to explain to the bank why your car payment
is late.
STEEP BANKS - Banks that charge pilots more than 10% interest.
TURN & BANK INDICATOR - An instrument largely ignored by pilots.
USEFUL LOAD - Volumetric capacity of the aircraft, disregarding
weight.
VOR - Radio navigation aid, named after the VORtex effect on pilots
trying to home in on it.
WAC CHART - Directions to the Army female barracks.
YANKEE - Any pilot who has to ask New Orleans tower to "Say again". ]]> qsmx440 http://www.supercub.org/forum/entry.php?24-Airplane-jokes! http://www.supercub.org/forum/entry.php?11-wing2-question-for-readers Sat, 04 Dec 2010 03:40:18 GMT I would like to get as many opinions about the tank area of the wing as I can. Piper of course runs a strut diagonally through the gas tanks and so... I would like to get as many opinions about the tank area of the wing as I can. Piper of course runs a strut diagonally through the gas tanks and so the tanks have the extra weight of a tube welded in them for passage of the strut. I have a set of D&E wing drawings and they use a bottom "shear" plate? I think it is called. I think all it is is just a thicker piece of aluminum attached to the ribs and spar caps at the bottom of the fuel tank area. I would really like to do the D&E type design in the tank area but.... Question: Is it as strong as the Piper design which hits the middle of the spar web with the strut since the strength of the shear plate is only on the bottom of the spar in a very critical area? I would expect the spars to twist easier with the plate like after you open a cardboard bx and push on the corners. ]]> qsmx440 http://www.supercub.org/forum/entry.php?11-wing2-question-for-readers http://www.supercub.org/forum/entry.php?9-Wing-1-ideas Sat, 04 Dec 2010 02:18:48 GMT Wing 1: ideas I have spent the last month or two searching wing building ideas. I have been through hundreds of posts and pictures here at SC.org... Wing 1: ideas
I have spent the last month or two searching wing building ideas. I have been through hundreds of posts and pictures here at SC.org and also else where on the web. I think I have familiarized myself with the Piper L-21A drawings fairly well.

What I think I know:

1. A 13 rib wing is adequate for a light super cub.
2. The original design is the lightest and adequate for a light build.
3. For low speed, wing tips could be left off with a 10 knot penalty in cruise.
4. Spars normally fail first by "twisting".
5. Lifting is done by rib stitching, transfered to ribs, then spars, lift struts and finally fuselage. Wing hinge bolts may experience "downward" pressure due to cantelever action of wing tips on lift struts.
6. Wings lift because of down wash (hope that is correct term) from rear of wing, ie basically a verticle force from wing rear and equivalent to the weight of the aircraft. (this was a suprise to me as I was taught differently but it makes sense)
7. Extended leading edges add 10# and not much low speed lift.
8. To take advantage of many high lift designs requires advanced piloting and is not for me this build.
9. A wing mechanism consists of: fuselage attach points, spars, lift struts, compression members and attachments to spar web, drag/anti-drag wires, ribs, stitching, covering. The fuel tank is also a major consideration when planning a wing build but not technically "structural". ]]> qsmx440 http://www.supercub.org/forum/entry.php?9-Wing-1-ideas http://www.supercub.org/forum/entry.php?5-Supercub-PA-18-150-clone Fri, 03 Dec 2010 06:31:33 GMT Well if this blog business works this will be where I document my Supercub clone build. In reality this project started about 8? months ago and has... Well if this blog business works this will be where I document my Supercub clone build. In reality this project started about 8? months ago and has been scattered over a few different sites. If this looks good then this is where I will post pictures, build notes and questions I will have to help progress.

I have had my private license since the late 70's? but I was inactive for many years. A few years back I started flying a Quicksilver Sprint ultralight. The performance was an eyeopener after the Cessnas I was used to. Other than top speed it got airborn in 50-60 feet and was at 800' agl by the end of the runway at my airport. Soon I wanted a bigger airplane with a little more speed and endurance. In all my prior flying I had never paid any attention to the Piper products considering myself a Cessna man. Another thing I had found was that I liked the owner maintenance idea of the homebuilt. I first looked at the CH-701 and considered building my own plane for the first time. But.. Something was not as I wanted. I moved to the Bearhawk but decided it wasn't quite right as a fit either. Somewhere along the way I discovered this site and also Christian Sturms supercubproject.com site and the "drawings " button. Wow! I could do this! And here I am.

I need to add here this is going to be an elsa aircraft so the gross weight will be set at 1320#. I intend to reach this goal even if the plane winds up being a single place. I plan on empty weight not exceeding 950#. Basically the mission is boring holes in the sky. Reaching this goal will mean that the A/C will be built with:
no electrical system
no interior
non adjustable seat
maybe one wing tank
maybe no wing tips (to be discussed)
small (600 or 850) tires
wood prop


At present I have :
A sheet of .020 titanium for the firewall
A box of new 1980's Schneider ribs for the main wing (no control surface parts)
A 1977 Supercub fuselage (no corrosion but some bad past repairs)
A 1957 narrow deck O-320 Lycoming w/750 smoh w accys
firewall forward cowling and nose bowl
Sensenich 74-52? prop with spinner
2 front and 1 rear lift strut
2 gear legs (no cabane v or suspension)
set of single puck Cleveland brakes
all 6 tail pieces through "tacked" (the only real building so far) completely from raw materials
new main wing spars
partially completed seat
stabilyzer jack screw assy complete (needs new screw)
engine mount with a cracked tube (upper right?)

total spent so far about 13,000

I still need:

fuel tanks
main wheels and discs
suspension
tail wheel
compression struts and drag/anti drag wires
controls and cables/pulleys
one rear lift strut
four ea jury struts and mounts
heel brakes
to build pedals, torque tube, etc etc etc..
Stewarts covering system ($3200)
boot cowl parts


I am busy for the next 4 months on a contract job that has enabled me to purchase as-I-go the above parts so no actual building now. I look to be freed up in the spring.

The main decision I am looking at now is how I will build my main wing. I have purchased d&E spars ]]> qsmx440 http://www.supercub.org/forum/entry.php?5-Supercub-PA-18-150-clone