Tuesday, November 29, 2011

Weight Notes, Thanks to Johnnie


I did the following and have been mining the combined Affordaplane sights and seeing what CAN be done. Check this out and some that know might respond.

Affordaplane Materials Cost & Weights;
Per Aircraft Spruce & Specialty pdf catalog and internet search.

Actually priced the AN3 & 4 bolts. Then multiplied that amount by 2.5 (to simulate bolt, washer and nut combo), that came to $257.50. By adding each bolts lengths, a total rod length was determined, so a (kind of) bolt weight could be derived. That total was doubled to allow for a (kind of combo weight) bolt length plus the bolt head and nut. This came out to nearly 8 pounds. This doesn't include cable, cable tangs, hinges, rivets, or gussets and things.

Next was the tubing: size & weight per ft TTL WT TTL COST
46 ft of Sq tube. 2"X2".125 1.120 51.52 lbs 211.60
48 ft of rnd tube ½"X.058 0.0962 4.62 lbs 204.70
10 ft 1"X.035 0.1275 1.28 19.90
3 ft 5/16"X.049 0.0423 0.1269 6.75
132 ft 1"X.058 0.2060 27.19 382.80
64 ft 1 1/8"X.058 0.2321 14.85 185.60
24 ft 1 ½"X.058 0.3137 7.53 126.00
24 ft 2"X.058 0.4225 10.14 141.60
6 ft 1 3/8"X.058 0.2865 1.72 29.82
6 ft 1 7/8"X.058 0.3954 2.37 39.00
4 ft Al Rod 1" 1.2 4.8 46.12
14 ft 7/8"X.058 0.1777 2.5 35.00
3 ft Al Angle 2"X2" 0.125 1.5 4.50
130.15 lbs 1433.39
Above hardware 8.0 257.50
138.15 lbs 1690.89

We haven't gotten to the motor or re-drive / gearbox … so let's take a glimmer. Engine Choices (excerpt from plans) The Affordaplane was originally designed with a Rotax 277. With the weight of the test pilot being 240 pounds, and carrying a ballistic, it was not enough power. I recommend an engine with at least 35 horsepower, and weighing not over 80 pounds. You can choose from a rotax 377, 447, 1/2 vw (watch the weight and hp on these) a 2SI 35 hp, or a Kawasaki 440. The plans show an engine mount for the Rotax 447.

Rotax 447 engine specifications.
DESCRIPTION: Two-cycle, two-cylinder engine, oil in fuel lubrication
BORE: 67.5 mm (2.657 in.)
STROKE: 61 mm (2.40 in.)
DISPLACEMENT: 436.5 cc (26.635 cu. in.)
COMPRESSION RATIO: Theoretical 9.6, effective 6.3
POWER OUTPUT: 29.5 kw (40 HP) at 6000 rpm
TORQUE MAX.: 44.0 NM (32.5 ft. lbs.) at 6000 rpm
DIRECTION OF ROTATION: Counter-clockwise, viewed towards PTO
CYLINDER: 2 light alloy cylinders w/ cast iron sleeves
PISTON: Aluminum cast piston with 2 rings
PISTON/CYLINDER CLEARANCE: 0.08- 0.09mm (.00315-.00354 in.)
IGNITION SYSTEM: Breakerless Ducati capacitor discharge ignition with magneto
RECTIFIER-REGULATOR: (optional) a.) #9103 requires minimum load 12 W (1 amp.)
b.) #9251 requires no minimum load
IGNITION TIMING: 2.09 mm = .086" BTDC
CONTACT POINT GAP: 0.4 mm = .015"
CARBURETOR: 1 X BING 36mm, with hand lever choke
FUEL PUMP: pneumatic fuel pump #6903
FUEL: Regular gasoline, octane not below 90 unleaded
LUBRICATION OF ENGINE: Super two stroke oil (AV-2)
MIXING RATIO: 50 TO 1 (2%)
STARTER: Rewind starter
optional: electric mag side without recoil option
REDUCTION GEARBOX "B": Reduction gear-box with Torsional shock absorber
RATIOS: 2.00 to 1, 2.238 to 1, 2.58 to 1
DIRECTION OF PROP ROTATION: Clockwise, viewed toward prop flange
COOLING: Air cooled by axial fan
WEIGHTS: Engine without carburetor, intake silencer, fuel pump, Exhaust System......................
Carb With Rubber Socket.......... 2.0 lbs.......( 0.9 kg.)
Exhaust System (approx.)........ 10.8 lbs.......( 4.9 kg.)
Electric Start Kit (Optional).... 7.70 lbs......( 3.5 kg.)
Reduction Box "B" - Dry...........9.9 lbs.......( 4.5 kg.)

You still need gusset material, wheels for your landing gear, the plastic ends to mount your wing ribs to the spars (or foam to make the ribs). You'll need various wire rope cableing for your guys, rivets, seat material… etc, you'll just have to get the plans and READ them. One fellow told me a completed wing weighed 39 lbs (but he had a aluminum fuel tank in each.

You can lighten it up in several areas by leaving out the false spars, ribs, and nose ribs. No, it won't be quite as smooth looking but it would be functional. I too, will be doing further research to find ways to lighten her up and would appreciate any suggestions be emailed to me.

This is just something, I spent today putting together, as "FOR YOUR INFO" as a set of condensed ball park figuires. THANKS John

Video: Tim W's affordaplane.

On Turkey day I went and saw Tim W's plane. I also took a little video. I was at the wrong end of the field, but he did get the plane airborne a couple times. It was a little windy, so I don't blame him for not flying the pattern. Enjoy!

Click here: Tim's Affordaplane

Sunday, November 27, 2011

Wing Building: Roger is at it again - How he makes aluminum ribs.

Well Roger did it again. He went ahead and detailed how he built the aluminum ribs for his plane. The process seems very similar to how the hummelbird people do it, and given the success of that plane, that's nothing but a compliment.

I'll annotate the pictures he posted, but here's his letter to the group:

"I'm back by request of one or two interested people on how I made my wing ribs. I posted a few photos again on cheapaircraft2 - Rogers (Kenneth formally Jims)photos.

It really is easy to make them this way. They are attached with rivits. That part goes fast. I put a wide cap strip on either end. To cut them out, You lock the piece up between the forms with bolts, The thin one on top to hold it down tight and the thick one on the bottom to guide the router. You need to make sure the bolt head on the top is flush or below the surface of the jig so the router can pass over it without dragging. I used toilet flange bolts because they have a flat head.

For the holes, you simply plunge the bit through the middle of the hole some where and cut it out fast and easy. Then cut around the outside. In less than a minute it is done. It takes more time to put it in the form than to cut it by far.

Next you lock it in the bending form and tap it over with a mallet. remember to make half each direction. The outside ribs do not have the lighting holes cut out. When you take them out of the form they will bend because of the curve of the air foil. You will have to flute them about every 2 inches to straighten them. I made a fluting tool out of a pair of vice gripes with a rod welded in the middle of one jaw and two on the outsides of the other by passing outside of the other to bend the aluminum to a controlled amount by adjusting the vice gripe closing screw. You then have to flange the holes to stiffen them. that is also quick with the home made flangers. With that you are finished. If your bit is sharp and cutting well which is normally not a problem, you will not even need to deburr the edges.

I made the aileron ribs the same way. It was quick and easy also. If this doesn't make sense shoot me a message and I will try to explain it better.

Warning, do not try to cut more that one at a time or you will have that many pieces welded together. I speak from experience.
Good luck and keep building. Roger."

How about lets follow along in pictures. First, he made his ribs from aluminum flashing from the hardware store. It typically comes in a 2' by 50' roll.

Step one is to make some cutting guides. You should make four without holes in them for the end ribs.
You can see the bolt holes in them, that you use for locking the aluminum in between the cutting guides. After you cut out each rib, you'll then need to fold the edges over. This provides a wide attachment point for the fabric, and prevents a sharp aluminum edge from slicing open your wing from the inside. These forms get banged on quite heavily, so they're made of much thicker material than the cutting guides. You'll want to make sure you make "left" and "right" sided ones. Which you decide is which doesn't matter, so long as you mirror the left and right sides.
Now the bit you folded over is longer than the outer surface of the airfoil. Which means you now have a pleasantly pringle shaped rib. On some planes they have cuts in the flange to do this, But seeing how those lead to more sharp edges I think the following method is better.

To straighten them out, you'll need to crimp, or flute, the flange you folded over. The flutes will take up the excess metal, without leaving sharp edges. An easy way to make a fluting tool, is to weld two pieces of welding wire to the top jaw of a pair of vice grips, then weld a single wire to the bottom jaw. It will take you a few attempts, but you should be able to figure out a pattern which leaves you with a very, very straight rib.

Also to improve the stiffness of the ribs, the cutout holes should also be flanged. That's best done using some blocks of wood that have been routed out. These are then pressed together over the opening in the ribs. Here's a couple pictures of the tooling that Roger made:

And here's a grandkid using the tooling:
Isn't it nice to call it tooling? It sounds so professional.

He also used the same techniques to build his ailerons.

Not bad eh?

Thursday, November 24, 2011

Tim W's Affordaplane.

Hey everyone, this morning I visited Tim W at the airfield. The weather concerned me on the way out. It was a little windy, a bit hazy, and the clouds were quite low. When I got to the airfield, he took me on a tour of his plane, and the build decisions he made.

Welcome to my first impression of the airfield... :-) Poor plane.

My first impression of Tim's plane however, was very good, and it stayed that way. His modification list is quite extensive. The winds were a bit high, so Tim kept his flying to a couple of quick runs down the runway.

Performance wise, with his MZ201 powered Affordaplane, is a mixed bag. The planes level maximum airspeed is in the 65mph range. However the climb performance is disappointing.
Hi Tims plane.

So, what all did tim do? He tried to make the plane easily disassembled. He did something similar to Gent's tail, where the horizontal stablizer can fold. ... except the control horns interfere with the rudder. On the bright side, having a hinge means you can use the pins as a quick removal tool. The main and TE spar are also held on with pins.
The tail originally just had single bracing wires, but Tim saw the leading edge dancing during flight, and he decided they needed some more bracing. While we're on the subject of flying surfaces, he also sealed the elevator and alerion gaps.

I really liked the landing gear. It's fiberglass rod, and beyond providing some shock absorption they are lighter than the per plans landing gear. They also fail progressively on a hard landing. (Tim's turning out to be a good test pilot.) Due to the way they are attached, they are easily replaced.
While we're looking at Tim's planes legs, I'll note that he did not use the solid aluminum round bar to transfer strut load from one side of the plane to the other. He used some flat 2024 plate. You can also see he doubled up the bottom tube. The stock gear were hard enough on the frame to bend it.

The MZ201 he's running is the planes second engine. It was originally on a Kawasaki with a reduction drive. His engine mount is 2" longer than per plans. Despite that, he has 20oz of lead on the tailskid.

I like the prop.

He also ran all cables for the control surfaces. I'm not sure I'd make the same choice, but I have the whole r/c plane thing going for me. But look at those beautiful belcranks. The cables also facilitated the folding tail.

Thank you Tim for letting me look at, and show off your plane.

Tuesday, November 22, 2011

Rogers Affordaplane

Roger completed his plane in the last few days. He built a fiberglass fuel tank, that fits in place of the wing seal. He also made his using aluminum ribs.

He tells the story best, Roger wrote:
"I made quite a few changes to the plane and did not
want to talk about them until the thing flew. It will now be until spring
because of the cold weather. Some of the things I changed are; gap seal fuel
tank, droop tip wings, wing ribs made from sheat aluminum, US 35b wing foil. I
uses a 400cc polaris snowmobile engine which should put out about 40 hp as
arranged. I also made my own prop with ptips. It pulls very well. It weighed in
an 72 lbs. Many of the changes I made did reduce the weight. The finished wings
without droop tips weighted 27.5 lbs the tips were about 4.5 lbs each. The gap
seal tank serves two purposes of tank and most of the gap seal. I also went with
Y struts to make it easier to get in and out. I will try to post pictures when I
can figure out how to do that. There are some pictures on cheapaircraft 2 under
kenneths and under Rogers. They were posted by my son. I put it in our county
fair in Aug. and won a sweepstakes with it. I also took it to our local flyin
and did a bit of taxi work. It handled better than I had expected on the ground.
I also got a little experience in a two seater but it was a trike gear. I need
tail dragger experience and that a a bit harder to come up with here. I do not
know the final weight but I believe it will be under 300. I learned a few things
along the way like fiberglass tanks do not hold up to ethanol fuel. I had to
coat the inside of the tank. I would like to find plain gas but can't find any
here locally. I spent less than $2,500 out of pocket but I am a really good
scrounger. If you want any more information please contact me direct and I can
give you more info. Keep building. Roger"

"I was very careful to check out weights of all the changes I made
and everyone except putting very large tires on were under or at the weight that
the plans would have been. and the wheels were lighter than wheel borrow so that
would have been close to a wash. I wanted large tires to make up for no
suppension. The sheet aluminum ribs were almost half the weight of doing the
foam ones. I made one out of foam to compare. It took me about 20 minutes per
rib to make them but the time is in making the jigs. once set up they are almost
fun to make and turn out exactly the same every time"

That's a darned good looking plane. I can't wait till spring when we can get some flight reports about it!

Some new information from the horses mouth:
"I do not know the weight of everyone elses wing, but mine did come in with fabric and paint at 27.5 and 27.8. One wing was a bit heavier because I ran out of 1.8 ounce fabric and finished that wing with a bit of 2.7 ounce cloth which I had on hand. I did install droop tips which weighed about 4.5 lbs each The material is siding coil which comes in 2' x 50' rolls."

Not part 103? Well we can fix that.

So, the affordaplane really isn't a part 103 legal airplane.

At least as per the plans. However, there is some hope. The idea is good. The concept is solid. So lets make it legal.

Dan L suggested we swap to .75" tubing on the tailplane. We'll need to do the math to determine if it will support the aerodynamic loads. He suggests there's an 8lb savings to be found there.

I recommended the replacement of the tail tubing, windshield post tubing, and lower motor mount tubing with 2"x.0.0625 wall tubing. I think there's 19lbs to be saved using that technique. Math will need to be done to determine if the tail will have sufficient torsional rigidity.

The cross bracing on the tail should be .75diameter and you can go with much thinner wall tubing.  There's 1.6lbs to be saved there, if you retain the same wall thickness.

I suggested that by going to V wing support struts, you can eliminate one 1" aluminum bar, and save two pounds. and the front strut, if bolted in properly, could have it's center 1' removed. Saving three pounds total.

The landing gear as designed leaves a lot to be desired. We'll need to discuss the replacemnet options. Gent has a 30lb bent aluminum plate as his.  The texas parasol landing gear are lighter, and provide suspension as well.

Monday, November 21, 2011

tlwalkeril61's Affordaplane

45 hp

200-400fpm climb.

level flight ~65mph

Landing approach at 50mph, touchdown at 35

Gross Weight 540lbs with half a tank of fuel.

Thursday, November 17, 2011

Performance Statistics.

Our depth of data on the performance of the affordaplane is fairly shallow. What I do have is:

Gents Big silver bird-
Stall: 29kts
Cruise: 50+kts

Wednesday, November 9, 2011

Built and flying Affordaplanes

So, here's an incomplete list of who's flying Affordaplanes.

1. The original.

2. Gents big silver affordaplane

Gent's big silver affordaplane.

Straight from Gent.

"Some specifics on my plane, it still doesn't have a name, N840XP
Empty weight: 425 lb
Fuel capacity: 5 gal total in wing tanks on the CG
Engine: 4A084 military, 40+ hp
Prop: modified from a 60x24 to 56x22ish Cloudcars wood hoerner tips
Airfoil: true ClarkY as replotted by Dan to fit the Chord
Wingspan: clipped from the plans to 26' 8" with Hoerner tips
Dihedral: 2 degrees
Spars: front, 2"x.058 sleaved full length with 1 7/8"x.058
rear, 1 1/2"x.058 also sleaved full length 1 3/8"x.058
Ailerons: 7ish inch chord 1 1/4x.058 LE spar Mike Robbins inspired
"easy ailerons" with the piper TE
Struts: Carlson streamlined, large front and small rear with
Carlson streamlined jurys in a Y configuration
Strut attach/carry thru: 1" square 2024 t3
If you want more detail ask specific questions LOL!"

And how about a picture or two?

And here's a link to his youtube videos.
Gent's youtube videos.

Affordaplane weights.

The plans state that an affordaplane weighs 254lbs. That's the "rule" weight. Something seems rather fishy about that. Turns out.. it's as fishy as it sounds. Here's a list of completed Affordaplane weights:

Original Prototype: 265lbs
With Rotax 277

Gents A-Plane: 425lbs
His is 084 powered. That alone is a 125lb powerplant.

Mike R's A-Plane: 310lbs
With Rotax 447

Todds A-Plane: 426lbs
With Rotax 503

Todd B A-plane: 324lbs

aplanebuilder A-plane: 320lbs
With efforts to lighten it.

danl239: over 456lbs
Not built to plans.
356lbs without engine.

Please, if you have built one, tell me what yours weighs. Lets get you in as part of the database!

The word is, that with some work, and lots of work, the plane can be built under part 103 weight. That will be discussed in some of the modification posts.

Mailing list refrence: http://groups.yahoo.com/group/Cheapaircraft/messages/390

Ongoing build projects:

Here's a list of ongoing build projects. If you want to see yours listed, send me a message. The more, the merrier!

outofthebox50 is building an enclosed Affordaplane. He's using C channel on the tail to save 6 pounds. Perhaps that will make up for the weight of covering! He has laid down metal, so it is not just talk.

So what about the Affordaplane?

So if you build an Affordaplane, what can you expect?

Who is building one? Well here's who is building them.

How many have been completed?

Do we have proof of them flying? Yes! Lots! In various configurations.

What will it weigh? This is what an affordaplane weighs.

What is the planes glide ratio, at what weight, and at what speed? Good questions!

What engine should I chose? Here's your options, and what they weigh, and how much power they make.

What defines the VNe?

What is the expected takeoff run?

What are the power on, and power off stall speeds?

Will the plane spin? How easily will it recover from a spin?

What sort of performance should one expect from a given power level?

Questions the plans left open to interpretation.

I'll happily add anyone else's questions to this. The answers will be covered in later posts.

The plans never mention the weight of the prototype: What do these things really weigh?

The plans indicate the prototype used a Rotax 277 and that it was underpowered: What defines underpowered?

The plans indicate the Rotax 447 is the recommended motor, it weighs 82lbs. The plans state the motor weight budget is 80lbs: What is the real engine weight budget?

The plans don't have any indication of what the target weights are for components: What should each part weigh?

Getting the plans.

I ordered my plans from www.affordaplane.com.

They were delivered within minutes via e-mail. You have 48 hours to download the plans, and only three attempts. So... make sure your internet is working, and plan on where you're going to save the files.

Sure the going rate for the plans is $8 a set, but having to spend that money again to get another copy because your hard drive crashed is going to make you cranky.

it all begins here.

Really it all begins in the same place for all of us. That passion for flying. But that's not something I can help you with. We'll assume you know you want a small plane that looks like it could take a beating, or whatever else you might throw at it. That would very handily describe the subject of this database. The Affordaplane.

My involvement started where I found several mentions of it on a few forums, and a few clever videos of one on youtube. That was enough to convince me to buy plans.

From there.. I found a few snags. We'll cover one in each post. Along with individual planes, buld tips, statistics, crash reports, and hopefully a healthy dose of humor.