Sig Rascal 110 #1 Construction

Sig Rascal 110 #1 – UMN UAV Project


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Project started March, 2005.

I am involved with the University of Minnesota Aero Dept. on a UAV project. My part of the project involves assembling the airframe as well as being the chief test pilot.

November 3, 2004.

It appears that our small UAV project got funded here at the U of MN. Hooray! I get to be paid (for a short time) to build and fly R/C airplanes. We plan to purchase our first hardware in early February ’05 and immediately work on assembling and test flying the airframe .

February 24, 2005.

U of MN UAV project update: We have done the initial airframe, engine, and R/C gear order. A couple items were backordered so we don’t have any fun toys to play with quite yet. The airframe will be a Sig Rascal 110 running an OS 1.6 2-stroke engine. Initially we will hand fly it (perhaps using an onboard camera rather than direct line of sight?) but eventually we will develop autonomous capabilities as well.

April 4, 2005.

Installed ailerons, aileron servos, linkages, and routed servo leads. The wings are essentially complete. Here are some pictures of the different pieces:


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April 6, 2005.

Here are a few pictures of some of the toys hanging around the Aero work shop:


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May 2, 2005.

Installed OS 1.60 engine into the Rascal with special ordered beefier engine mount.

May 4, 2005.

U of MN UAV project update: I cut, fit, and installed the cowl today. I found an 18×10 prop (in the recommended range) floating around the lab and slapped it on temporarily. Yikes … it is big! I will have to make one more opening for the mixture adjustment. It looks like we will need to special order a spinner for this beast. I also took a heat gun to the wings and fuselage and shrunk out most of the wrinkles.


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May 6, 2005.

Today I bought a larger tank (24oz) than stock and fit it. I haven’t locked it in place yet, but that’s [hopefully] a quick thing. I also glued in the fairings which provide a bit of extra support for the horizontal stabalizer where it attaches to the fuselage. Next up is installing the elevator and rudder servos in the tail. Here are a couple pictures from inside the cabin.


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May 9, 2005.

Today I installed the rudder and elevator servos in the tail of the Rascal. This minimizes the length of the linkage used (thus reducing slop and the risk of flutter.) I then attached the horizontal and vertical stabalizers and the additional two fairings on the top side of the horizontal stab. Then I attached the elevator, tail wheel, and finally attached the rudder. Next up is the rudder and elevator linkages.


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May 10, 2005.

Today I fabricated and installed the rudder and elevator linkages. I also installed the springs that attach the rudder to the steerable tail wheel. After that I turned my attention to the inside of the aircraft and installed the onboard radio on/off switch and the throttle servo and linkage.


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img_2529 Then I assembled and installed the main gear. The Rascal wheel pants come completely finished, even with blind nuts already installed. It’s about a 10 minute job to assemble and attach the main gear, wheels, and wheel pants, including taking them out of the baggies.


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img_2530 With the main gear installed, the Rascal can now stand on her own, so it was time to pose for some pictures.


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img_2519 Now I add the wing.


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img_2523 I almost forgot about the cowl.


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img_2525 And I might as well put on a prop while I’m at it.


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May 11, 2005.

Items completed today:
Installed the side windows.
Installed a new prop (appropriately drilled out for our shaft diameter.)
Secured fuel tank.
Installed an extension to the receiver on/off switch.
Initial balance tests indicate that we might come out pretty close with no added weight.

May 12, 2005.

Items completed today:
Pad and secure battery and receiver.
Route the receiver antenna.
Touch up and shrink covering in a few areas.

May 13, 2005.

Today I checked the control surface throws to verify they matched the manufacturer’s recomendations. I also moved the battery as far forward as possible to put the aircraft in balance. I think we are now balanced with no need to add additional dead weight. With the exception of final checks, this plane is ready to fly.

May 19, 2005.

Today we fired up the brand new OS 1.60 FX 2-stroke engine and ran 24oz of fuel through it. The engine behaved well and pulls *very* strong. The next big step is the maiden flight. I will be gone most of next week so we will likely shoot for a day the week after next weather permitting.

May 30, 2005.

Fit and installed new spinner. We still need to get all the right tools so I can properly tighten everything up. Right now a couple pieces are only finger tight, but they look good.

June 6, 2005.

New pictures … all ready for her maiden flight tomorrow (weather permitting.)


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Stabilization

Roll/Pitch Stabilization System

Pictures of the FMA Direct Co-Pilot installation …


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The FMA Co-Pilot has some complexity to it, so it’s important to read through the manual carefully to get it setup properly, and to get it calibrated properly at the field before flight. The manual explains quite a bit about how it works, and what it can and can’t do. It’s important to understand these things so you know the devices limits and what you can expect. I mounted my sensor on the centerline of the fuselage immediately behind the trailing edge of the wing. This gives me good visibility left/right and makes for a very clean installation. Exhaust comes out the bottom-left of cowl so it’s fairly protected from residue. I pick up more bugs there than anything else.

I discovered that you have to be very careful and precise with the field calibration procedure, otherwise it will try to drive the aircraft into a bank and the plane will be constantly turning. Conveniently, my transmitter trim still works with the Co-Pilot device activated, but one caution, if your aircraft is trimmed for normal manual flight and you activate the co-pilot and it is not perfectly calibrated, you need to retrim. That can lead to (possibly substantial) trim changes with the device on versus off … it’s workable, but you have to be aware of it.

I setup the Co-Pilot so I could turn it on/off and adjust the gain with my “flap” channel. That worked well, and I found that with my big, slow Kadet Sr. I could fly with the gains dialed to full max just fine. Initially I only activated it altitude, but eventually I tried flying lower, and even landing with it activated. It worked so well that I eventually did takeoffs and touch and goes as well as landings. I observed no ill tendencies and it seemed to help make my landing smoother because it can compensate for gusts more quickly than I can (and I was able to practice this because the winds were getting gustier as my test progressed.) With the co-pilot activated, it wants to drive the wings level and sort of tries to hold pitch. But it still passes through your manual inputs “additively” so you are able to fly fairly normally and override the stabalization controls.

Ok, so the big question after playing with the co-pilot for a few flights is “how will it work as a UAV stabalization system?” My answer at this point is, yes very well for many applications and airframes. However, it’s not perfect and it’s not magic. The Kadet is big and slow, so even with the gains dialed up to max, it can’t keep the plane perfectly level all the time. It is highly sensitive to the field calibration procedure, so you need to perform that carefully, then ensure that you are well trimmed before cutting it loose to do anything on it’s own. It does do the job though and keeps the plane reasaonably stable. With the system activated, it is very safe. You can input full rudder deflections and while I do observe some banking, the system holds it’s own and limits the bank to 10-20 degrees and keeps everything under control. Note that this is a “simple” proportional controller so it can’t cancel out all errors or biases, but it produces a “stable” system. That’s why it can’t hold the wings level against rudder input, but with neutral rudder it does just fine.

I think I’m happy enough with the co-pilot to move forward and start looking at getting my flight computer running.

 

Overview

EGN Project Overview

My first goal is to have fun and use this as an outlet for a few ideas that have been bouncing around in my head. I have a life long love of aviation, airplane models, and computers so I would like to mix these together a bit.  I have an FMA Direct CoPilot IR stabilization system that I plan to use to keep the aircraft self stable. Notice that this is instead of any type of gyro/accelerometer/IMU unit. An IMU typically reports orientation as input to a flight computer which then does mathemagic to calculate servo positions to keep the plane level. This IR unit does all that itself in a$100 unit. The downside is it can only hold the wings level, the upside is that is usually exactly what we want to do.

I also have a small flight computer, a First Robotics Minicontroller. This has a CPU and can drive servos directly. I hope to attach a GPS, do a small amount of crunching and then drive the rudder servo to steer the aircraft to a waypoint (such as home.)

I also hope to use this to do some sort of aerial photography … either wireless video, or digital stills, or both.

Beyond that it would be fun to add a radio modem to pass telemtery information to a ground station and perhaps pass commands back to the onboard computer system. I could envision some integration with FlightGear to use that as synthetic vision or overlay the live camera view on top of the synthetic view.

I am funding this project on a hobby budget. So I plan to scrimp and save, reuse existing equipment, buy off of ebay, etc. and only move as fast as my spare funds will allow. My goal is to build a self stable, self navigating R/C aircraft for under $1000 total cost.

Safety

Let me just say a brief word about safety and politics. I understand the AMA is concerned about UAV projects. They don’t want irresponsible behavior ruining the hobby for everyone else. I plan to always operate this aircraft under the constraints of the AMA safety code. (i.e. always in visual and radio range, always within the R/C model altitude limits, always with a human pilot able to assume manual control at any instant.) I also understand the FAA doesn’t really know what to do with UAV’s yet and has no immediate plan for fitting them into the USA airspace. Again, I plan to operate this aircraft entirely as a R/C model aircraft which the FAA is not interested in regulating.

Throughout this project I plan to pay keen attention to safety issues, fault tolerance for the onboard systems, safety for the pilot, safety for the aircraft, and safety for everyone else. I know I can’t control every aspect of every circumstance, but I wish to be very thoughtful, and very considerate of a wide range of safety issue so that (1) the aircraft itself is fault tolerant as much as possible, (2) the on board intelligence will be able to detect some problems before the pilot on the ground and take steps to minimize or avoid damage to the aircraft, and (3) I will operate the aircraft so that if something does happen, it will happen as far away from any person or property as possible.

I believe this approach is essentially restating the spirit of the AMA safety code with fewer specifics.

Construction

EGN Construction Log


img_2376 Please note: these entries are arranged in reverse chronological order with the newest entries at the top.

Maintanence Tasks

 

  • Engine installation.
    • Need to enlarge the cowl openings a bit for better engine access.
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  • Radio installation.
    • Need to fashion better strain relief for the antenna where it exits the fuselage.
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  • Apply decals.

May 13, 2005.

This project is officially moved over to active flight status!

May 11, 2005.

Today I threw on about 10.5 oz of lead up front to balance the airplane. I think we are just about ready to top off the batteries and go fly!

May 9, 2005.

Sealed gap (on one side) between horizontal stabalizer and fuselage. Balancing: now that pretty much everything is in place, I have done some initial test balancing. I have 4 3/4 oz of stick on lead in my inventory, but I think I will need a bit more than that in the nose for it to balance right. I always hate adding dead weight, but what can you do. I think the remote servo in the tail + the tail wheel is what did it to me. That said, the Kadet starts out with such a light wing loading that a few extra ounces should be unnoticable.

May 8, 2005.

Today I installed a remote fuel valve, as well as a 12×6 prop and the spinner. I screwed on the cowl, and tighted up the muffler. I then bolted on the wing and set it outside for some pictures …


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May 7, 2005.

Today I finished off the main gear installation. The aluminum main gear was special ordered from TNT landing gear. I wonder if I should have ordered two so I could install floats someday? 🙂


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img_2478 I also padded the receiver and battery, and routed the antenna out the bottom of the airplane and to the rear. Finally I cut out and installed the side windows. It looks like she may come out a tad tail heavy, but I haven’t put the prop and spinner on yet. We are getting close to being ready for the maiden flight. It’s down to a few details now.

May 2, 2005.

I had previously mounted the tail wheel and tail wheel servo, but I needed to rig up the pull/pull spring/wire system. Today I bought some thin piano wire and did just that. It’s not perfect, but looks fine from 10′ away and is solid structurally so I guess it will do.

April 23, 2005.

Maisy expressed interest in being chief test pilot …


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April 23, 2005.

Last week I glued on the tail surfaces. Yesterday and today I installed the cabin servos. I then constructed the elevator and rudder pushrods, and installed them. The provided hardware/wire for one end of the pushrods broke when trying to make an “L” bend. Fortunately I had some replacement wire pushrods laying around that worked out just fine, probably better.


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img_2436 I also fabricated and installed the throttle pushrod and connected it to the engine.

April 10, 2005.

Today I glued in the elevator and rudder hinges and then test fit the tail surfaces.


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img_2429 The tail surfaces are glued on with epoxy and care must be taken that the horizontal stabilizer is aligned with the wing (when viewed from behind), and also that it is perpendicular to the fuselage (when viewed from above). It should only require a small amount of balancing and leveling to achieve this, but 5-min epoxy means I have to work quickly. I also purchased a micro servo and tail wheel assembly for my tail-dragger conversion. I plan to plug a “Y” harness into the rudder port of my receiver and run two servos. A standard servo will control the rudder surface, and a second micro servo mounted in the tail will control the tail wheel steering. The servo will be linked to the tail wheel with springs so it won’t need to generate (or endure) a lot of torque.

March 6, 2005.

Today I drilled a new throttle pushrod hole. I filled all the extraneous left over fire wall holes (I moved the engine mount up, The throttle push rod had to move, and I am not using a nose wheel.) I also left two holes/routes (temporarily sealed) back to the main cabin if I ever want to install a larger tank. Finally, I sanded the cowl cutout so it is nice and smooth.

February 27, 2005.

For this project I have chosen a 4-stroke engine. This has caused me a fair amount of grief. With the default upright mounting scheme, the throttle arm is dead center with the tank; not exactly ideal. My final solution is to mount the engine upside down to the bottom of the motor mount arms, and move the mount up by the height of the arms so the thrust centerline stays the same. This keeps the motor mounts from needing to extend above the top of the firewall. This also puts a lot more of the engine inside the cowl and lets me use the original nose wheel push rod for the throttle. I need to be a bit careful about tank height vs. carb height, but we’ll see. I might want to add a pressurized fuel system to avoid this problem and allow me to install more fuel capacity.


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September 18, 2004

I’m a little hung up on an engine mounting problem. This kit is setup to mount a 2-stroke engine upright, and everything is laid out perfectly for that. I’m trying to install a 4-stroke engine, and *everything* is in exactly the wrong spot for that … no matter what I come up with. Here’s a page I setup to describe my problem. Kadet Senior ARF 4-stroke mounting problem.

September 9, 2004.

Today I took a few minutes from the daily grind and finished installing the aileron servos and linkages into the wings. For all practical purposes the wings are now finished and flyable. Here are some various pictures of the wing:


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IMG_1955 Just to reference the size of this model, I’m about 5′ 9.5″ tall (1.77m for people outside the USA.) The wingspan is about 6′ 8″ (2.03m).


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IMG_1957 And finally, here I am testing the fit of the wing with the fuselage:


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July 14, 2004.

My engine arrived today. I purchased it off of ebay … a Magnum 61 four stroke, but was sent an ASP 61 four stroke. As best as I can tell they are the exact same engine from the same manufacturer, but the instructions are in Chinese. You get what you pay for I guess. Here are online Magnum 61 instructions. Just Engines sells ASP engines and parts.

July 12, 2004.

Today the flight pack arrived. I purchased it new from Tower Hobbies to match my existing transmitter brand and frequency. I also purchased an extra servo (one servo per aileron) and the necessary 24″ extension cables and a “Y” harness. I needed the aileron servos and extension cables to start construction so now I’m ready to begin.

July 1, 2004.

I purchased the airframe from rcuniverse.com “new in box” for about $50 less then I could get it from any hobby shop. It arrived today. Yikes! It’s huge! Much bigger than I expected!


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Super Sportster Mk I ARF

Super Sportster 40 Mk-I (ARF)

April 6, 2003

I bought this aircraft used off of Ebay, mostly on a whim. I threw in a last minute bid, and to my horror I won. Now what do I tell my wife?!? 🙂 I fixed up a number of things such as adding a tail wheel, putting checkerboard on the bottom of the wing, fixing some shipping damage, replacing a missing carburetor screw on the engine, etc. It is a very nice aircraft, a wonderful flyer, and looks very cool from every angle in the air and on the ground. I really like the Super Sportster lines.

April 22, 2003


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SS40-2 My wife and daughter came out to witness the maiden (for me) flights. Hoping for the thrill of victory, but expecting the agony of defeat. 🙂


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SS40-4 I flew the aircraft for the first time on Tuesday, April 22, 2003. I was somewhat apprehensive because this would be my first tail dragger, and first low wing aircraft. But I figured how hard could it be, right? But I brought along my bushel basket just in case.

It turns out my nervousness was completely unjustified. This is a wonderful flying aircraft. The take off run tracked straighter than any tricycle gear aircraft I’ve ever flown. Just hit full throttle and don’t mess with anything. It tracks along the ground like it’s on rails. With a little up trim, it will gently rise off the ground on it’s own and head skyward … it’s about as easy to take as a trainer. (You can mess with the rudder on take off if you want to make it look like it’s a handful, but that is optional.)


SS40-5 She’s also a beauty in the air … very stable and she “flies like she’s on rails.” She’s not as fast as I was dreading (which was kind of welcome.) Full throttle, she flies at a manageable speed.

I was worried about stall behavior though, so I tried a few stalls with plenty of altitude. Look out, this thing drops altitude fast when you stall it and if you hold a lot of elevator you can hold the stall longer than you have altitude. But center the elevator and she flies right out of danger. I’ve heard of people stalling these sorts of planes on final approach and that’s something you definitely want to avoid… especially on that last low slow turn.

So for my landings I trimmed back (nose-up) a little on the elevator to slow the aircraft down and tried to resist the urge to pull back on the stick. I added some throttle through the turn to base and final to make sure I kept the speed up (I am getting a lot of nose drop in turns … maybe nose heavy with fuel?) and then coasted in. Update: I found I have much better luck if I push my down wind leg out further from myself so I can make a much wider/gentler turn to base and final. With my sweet stick and with a trainer you can really wind up a tight 180 and be all lined up for the final approach. However with this higher performance aircraft things work a lot better if you make wider gentler turns on final … less nose drop, less risk of a stall, and everything works out a lot smoother. Today the sun was in exactly the wrong place for my first landing approaches so I had to duck “under” it and fly my approach much lower and flatter than I would have liked to, and remember to keep my speed up, etc. etc. This resulted in some bouncing and long roll outs, but nothing major. The successful completion of my landing was never in doubt (at least not by me.) 🙂

All in all this is a very sweet aircraft. I’m not sure I’d recommend it for a 2nd aircraft — but definitely a 3rd for after you’ve mastered something along the lines of a “stik”. Some people insist that all R/C modelers should have at least one stik. I think I will now insist that all R/C modelers have at least one Super Sportster. AWESOME AIRPLANE!!!! I definitely would recommend this to anyone looking for a fun, great flying airplane.

June 30, 2003

The glue seal around the canopy began to peel away so I had to rip that off and reattach it.

The main landing gear also needs to be addressed. The stock main gear is in two pieces with each wheel mounted individual under it’s respective wing, but this aircraft has a more generic one-piece aluminum main gear mounted just forward of the wing. Unfortunately it doesn’t appear that the person who made this modification, took any extra steps to beef up that area of the fuselage, so the mounting screws are just going into weak balsa. I need to beef that up a bit before my next flight because the main gear has gone all wobbly.

The other remaining issue is that I’m not getting full aileron throw. I think the aileron linkage is hitting the fuselage inside and limiting the travel. I may need to hack out a bit more of the wing mounting plate inside to give better clearance … that’s something I definitely need to address before the next flight.

Finally, the engine get’s a little dodgy when I pull inverted g’s (i.e. in an outside loop.) I’m not sure what’s going on there, but the clunk in the tank seems to be free to move and doesn’t seem to be getting hung up on anything. There’s something a little dodgy with the engine anyway … it has a small leak in the carburetor or needle valve assembly some place and seeps fuel or draws air depending on the context. Otherwise the engine runs good, so I need to keep my eyes open for a cheap OS 40 FP carburetor.

August 16, 2003

Ok, just for fun, I have converted my “Super Sportster” into a “Super Splashter,” or should I say “Super Floatster”, or maybe “Super Sploatster”? Hopefully not a “Super Splatster.” 🙂


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August 27, 2003

Pictures from my failed attempt to get airborne off floats. But we still had a lot of fun. 🙂


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March 18, 2005

Having flown this aircraft about all I wanted to fly it, and needing space for new projects, I opted to give it away to a good home. Hopefully the next owner can have as much fun with it as I did.

Ace High Mk-II

Ace High Mk-II

Built Spring 1987 – Sold July 2004.

This is a powered glider. It’s not the greatest flyer … it doesn’t glide all that well and really mushes around the sky, but can be fun diversion when I’m tired of punching holes in the sky with my Sweet Stik. I built it as a cheap project in college when funding was especially tight.


This is a picture I found on the web … I think this is from the original box art.


Posing in front of our Jewel St. house.


Posing with Hannah (about Age 3).

Mariner Construction

Lanier Mariner 40 ARF (Orange)

Construction log.


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June 13, 2003

I bought this aircraft NIB off of Ebay. It arrived today, Friday the 13th. I haven’t had a chance to begin assembly. I think I’ll need to get a flight pack + 1 servo first.

 

October 17, 2003

I was pretty fed up with all the stuff I was supposed to be doing so I pulled this out of the box to see if I could make any headway on it. Here are some pictures as it comes from the box.

 


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I am really impressed with this ARF. Generally it seems like pretty good quality wood, pretty good quality craftsmanship, solid, nice looking, and everything seems to fit together quite nicely so far.

October 18, 2003

This aircraft uses one servo per aileron. That simplifies the linkage tremendously at the expense of an extra servo.

 


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My only complaint so far has been with figuring out which hardware (screws, etc.) to use in certain places. Occasionally the manual is very brief, or omits specific details about which bit to use where. The parts bags aren’t packed the way the instructions say they are supposed to be laid out which makes the situation even worse. I’ve been left scratching my head in a couple places and making my best guess. I may have to go back and switch things around possibly later on. I hope not, but I’m not entirely confident in all my hardware choices.

Here is the detail of the wing floats and the completed wing halves. The floats go on really nicely, they are very sturdy, and look very nice (especially compared to some of the goofy wing tip floats on other seaplanes I’ve seen.)

 


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Here is a picture of the wing halves joined together.

 


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Here are a couple pictures of things setting in their relative places. I like to get an idea of how things are shaping up once in a while so I pose all the parts as best I can. 🙂

 


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May 8, 2004

I’ve been chipping away at this little by little and haven’t taken any pictures of my progress, so here I am nearly finished. The engine pod assembly has been completed, the engine mounted, tank installed, throttle servo installed, and cowl fitted and installed.

I bought a Magnum Pro 45 off Ebay for about $35 to power this project. My goal was to get something that ran well, but was a bit on the inexpensive side in case it ends up sucking in water. The engine looks like it is in great shape with no stains or rust. It has seen fuel, but has been well taken care of.

 


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May 18, 2004

There are always a million little details to finish and I’ve been slowly knocking them off, one by one. Here are a few comments looking back on the assembly process.

 

  • I’m still not happy that the hardware was not bagged like the instructions said. This made identifying screws and other bits quite difficult. I understand that things change in the kitting process and it’s hard to fix all the references in the manual, but this made the assembly process slower and more frustrating than it needed to be – at least for someone who puts one of these together at best once a year.
  • The instructions showed trimming the canopy with an xacto knife. I could have saved myself an hour of frustration if I would have gone after it with a decent pair of scissors.
  • The parts bags include 4 small mysterious wood blocks and 2 other pieces that look like push-rod supports. These came from an earlier version of the kit, but were never removed from production so they can be ignored.
  • The wing hold down bolts screw into raw balsa. I’m told that works ok, but I made some reinforcements out of scrap plywood from another kit, painted them white, epoxied them in place, and now I feel much better.
  • The covering came out of the box a little “loose” in places, especially the tail surfaces and wing. I figured no biggy, I’d just shrink it down myself at the end. But I found that some of the wrinkles are too big to get out … not a huge deal, just one of the very few things I can find to complain about.
  • Overall though, despite a few minor nits, this is a really spectacular model. It has wonderful lines, has a sharp color scheme, and looks like it will fly great. The kit quality is very good, and in most cases the instructions are good or at least sufficient.

This evening I decided to take the airplane out to test the engine and see how my Ebay special runs. I also wanted to take a few pictures before I attempt to fly it. 🙂

I have no instructions for the engine so I had to guess at an initial carburetor adjustment. It took me a few tries to get in the right ball park, but once the engine fired up it ran beautifully. Very smooth, very solid, very strong. This engine should pull this aircraft right out of the water with no trouble at all.

My daughter is all set to go to the lake and fly … it’s a perfect day, but it’s getting too late to drive anywhere.

 


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Here are some pictures of just the airplane.

 


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Ultra Sport 40 Assembly

Great Planes Ultra Sport 40 ARF (Red)

Initial Comments

This was my b-day present for May, 2002. My super sportster 60 construction project has been mostly stalled so I thought I’d see how things fared with an ARF. By the time my Super Sportster is ready to fly, I’ll have a large time/emotional investment in it so I would like to have some low wing tail dragger time in the log books before I actually try to fly the Super Sportster 60.

The skin of this aircraft is interesting. Typically, kit construction has you building up some sort of frame and then sheeting over the top of some or all of the structure with thin balsa sheets and finally covering with a thin plastic heat shrink film. This ARF takes a different approach. Instead of balsa sheeting they have a thicker layer of covering that is made of some dense foam laminated with a thin plastic external layer. This plastic/foam sheet wraps around the underlying structure (which can be rough cut because it doesn’t show through the foam layer) and has “cool” designs printed directly on it, so there is no need for painting or decals. All in all it’s about 1/8″ to 3/32″ thick or so and structurally significant. The wing for instance is built up with standard wing ribs and stringers, but then wrapped with this foam/plastic composite instead of sheeting with balsa. The advantages I see are that it is light, probably cheap, and you can directly print your cool color scheme to it. The disadvatage is that if you ever ding it up significantly, I’m not sure how it could be repaired. There are a lot of plastic pieces on this plane in addition to the plastic/foam sheet covering. If you crashed and did any kind of substantial damage to this airplane, I think you’d have to toss the whole thing. Especially since it is discontinued so you probably can’t find replacement parts for it.

Assembly

I’ve just begun construction so I’ll share some thoughts and photos as I go. I don’t have a separate work shop so my work area is very tiny and shared with the rest of the family. My apologies for the clutter in these pictures. 🙂

This is my first ARF. Generally construction is straightforward. Things always take longer than you hope/plan/expect, but the sorts of things you need to do with an arf, you would have to do anyway with a kit, and the arf saves you building up the major structures.

Things don’t always fit together perfectly, so expect to shave a bit off here and there and do a good amount of sanding. The box says sanding is not needed, but the instruction manaul correctly says otherwise. I have a power sander I bought for a house project which actually works very well for the various sanding chores. Even with ample sanding, it’s hard to get everything to go together just perfect. Oh well, hopefully it will be good enough, and I’ll just slop a little extra epoxy in the cracks. My assumption is that with no extra sanding (as per the claims on the box) I would get a functional and safe plane, and any tiny discrepancies may affect looks and perhaps subtly affect tracking through the sky, but I don’t think it should be a safety issue.

Wing

05/20/2002 – Here are pictures of the wings. The two halves are joined and the landing gear is installed. I’m sure this hotrod will fly as fast as I need it to go, so I opted for the simpler, fixed gear installation.


wing1


wing2 05/20/2002 – Just for fun I placed the fuselage on top of the wing to see how things are shaping up:


test-fit1


test-fit2 05/22/2002 – I glued in the wheel well covers and the top and bottom wing fairings, as well as the front dowl (for securing the front of the wing) and some foam to seal the exhaust residue out. The wing is almost done with the exception of installing the aileron servo and lincages.

05/23/2002 – Doh!!! First major setback. Once the wing is assembled, you need to mount it to the fuselage. This ARF uses a single dowl in the front of the wing and two nylon bolts in the back. The dowl is installed in the front, center of the wing during wing assembly and the corresponding hole comes predrilled in the fuselage. The problem is that it doesn’t fit right. (Or at least my resulting wing didn’t fit right.) The wing chord is too long, or the dowl mounting hole is too high, or a combination of both. The fuselage has major structural bulkheads on the wing front and back, so the fuselage opening can’t easily be made bigger. So I carefully sliced open the plastic wing fairing in the back of the wing and started hacking away balsa and plywood from the trailing edge. I also got out my knife and worked on lowering the front dowl hole a bit. I probably need to close off the top of the hole with some sort of filler so there isn’t any opportunity for movement of the dowl. However, the wing is already so tight against the saddle in the fuselage that I doubt that could ever happen. I don’t know what this is going to do to the wing incidence, but I suppose I should check/measure before I fly the thing. (Update: I never got back to checking the wing incidence, but she flies pretty great as constructed.)

05/24/2002 – I finished installing the aileron servo and lincages and did a bit more carving to get the wing to fit better. I think the wing is pretty much done. The powerplant hasen’t arrived yet, so I’ll just skip working on that end of the fuselage until it comes. Next up is the wing mount.


aileron-servo 05/25/2002 – Finished the wing mounting. I was a little nervous about the two main wing mounting bolts. I tend to have a hard time drilling holes that line up when I’m done, but in this case I followed the technique outlined in the manual and everything worked great. Next up are the horizontal and vertical stabalizers.


ruth1


boss


wing-mounted

Tail

05/27/2002 – Working on mounting the horizontal and vertical stabs. I followed the instructions and things seem to be progressing in a straightforward manner. The structure is pretty chinsey/weak back there though. I can see why they add two aluminum brackets to reinforce the horizontal stablizer. And then the plastic fairing around the base of the vertical stab also is a significant structural component. It makes me a little nervous, especially compared to other kit’s I’ve built, but I’m proceeding with faith in the instructions. This will be a very sharp looking aircraft, but not one you want to bang up. It has very light weight construction. (Update: after putting the tail together completely, it came out very sturdy. The braces make a big difference. All in all, this is as solid as any other kit I’ve built.)


horiz-stab1


horiz-stab2


vertical-stab In this next image I have the rudder and the vertical stab fairing positioned, but not glued. Next up is the tail wheel.


tail 05/28/2002 – Except for the control lincages, I finished up the tail. This involved gluing on the fairing for the vertical stabalizer. This fairing is a major structural component so it needs to fit and be glued securely. However the instructions were careful to point out that the horizontal and vertical stabs needed to be slid back far enough so that the rudder line is flush from the back of the fuselage to the back of the vertical stab. This unfortunately meant that the vertical stab fairing wouldn’t fit correctly. I hacked on it and chopped off a bit from the back until it would fit flush along the sides and the front. This means it isn’t quite as pretty, but it should serve it’s structural duties just fine. (Update: once everything is together, this blemish is almost impossible to notice.)

I then proceeded to install the tail wheel and rudder.


tail-wheel Then I proceeded to install the horizontal stabalizer braces. These actually add a lot of support and structure.


tail-brace

Finishing up …

04/30/2003 – Ok, finally, I made some time to do a bit more work. I’m so close, I just need to push through and get it done. Recently I’ve installed the control lincages, installed the fuel tank, and installed the engine. The two major remaining items are to install the cowl and the canopy. I might do the initial flights with the cowl off? That OS .46 Max sure swings a big looking prop … 🙂


almost-1


almost-2


almost-3

Midwest Sweet Stik

Midwest Sweet Stik Pictures

Built: 1984
Engine: K/B 40 (1981)
Pilot: Curtis Olson
Mechanic: Curtis Olson
Photographer: Bob Hain
Camera: Sony Mavica

This plane has seen on and off action through the years. I did very little with R/C through college, and for a few years thereafter. I flew this airplane once or twice about 8 years ago and had a slight mishap due to radio interference. It turned out that it only needed minor repairs (whew) and I got it back in the air about two weeks later and dinged up the aileron due to a gust of wind on the landing (it certainly couldn’t have been pilot error!) It then sat in my garage for a few years when I decided to take it out, fixed the aileron, charged up my batteries, bought some fresh fuel and got her up in the air again. What a blast. 4 flights and everything in one piece at the end of the day. Couldn’t have been better. 🙂 That got me motivated and I ran a whole gallon and a half of fuel through this plane 2 summers ago.

Still Shots

These pictures were taken November 27, 1999.


Head on.


Engine Detail.


Me and my toy (1)


Me and my toy (2)


Me and my toy (3)


Me and my toy (4)

Action Shots


Flying (1)


Flying (2)


Flying (3)


Flying (4)

Video Clips

Fairchild F-24

Guillow’s Fairchild F-24 Project

When I was in Jr. high in Peru I built the Guillow’s Fairchild F-24. It was myfirst rubber band model that I actually got to fly for more that 10 feet.It was great, I would wind up the engine, stand on top some low bleachers, andsend the plane skyward across our local the soccer field. It would fly straight and true, climbing steadily and solidly until the rubber band engine unwound. Then it would lazily circle back down to the ground. We moved back to the USA after I finished Jr. high, but alas, all my models had tostay behind.

I picked up an identical kit about a year ago and built up the frame in acouple evenings. It’s sat for a while, but I decided it was time to finishit. I completed the model right at the end of 1999. Here are a couple pictures and one bonus story.

May 12, 2005

A while back I bought a new rubber band for the motor, but must have gottensome old rubber from the LHS. 🙁 After a moderate number of winds, therubber exploded inside doing some significant structual damage. It doesn’tlook to bad from the outside but as of today, this model is being officiallyretired from active flight status and now is on static display status only.

July 20, 2004

I replaced the old cracking motor, but haven’t test flown it with the newrubber yet.

The real thing


A real Fairchild F-24.


An image of a Fairchild F-24.

Click here for more information on the Fairchild F-24

The model


The frame is finished and I’ve just begun covering the tail.


Another view of the frame.


The bottom of the wings are covered.


Another angle.


The tops of the wings (sans wing tips) are now covered.


Another angle.


Fuselage is covered. The assembly process begins.


Another angle …


The horizontal and vertical stabalizers have been installed and everythinghas been given a coat of thined out dope to seal it a bit.


The wings have been glued on and the windshield installed.


Another angle …


Pretty much complete except for the decals.


Another angle …


That’s me. 🙂


Decals have been added.


Pretty spiffy, almost ready to leave the nest. 🙂

Other related information

      Gene Lehman

gene@vintagewings.com

      writes:The F24 was first produced in 1938. There were others before it but it was the first designated the 24. They were continued through 1947.

Benton Holzwarth bcgh@teleport.com has an F-24 story to share:

I had a chance one night a couple years ago to attend a local EAA chapter meeting where one of the local ‘old farts’ was speaking, filling in for another guy who had to drop out at the last moment. Dave Lewis of Lewis Aviation was a spry, old guy, and stood at the little podium and talked, recounting stories of his lifetime of flying adventures, for about 90 minutes before breaking to take questions.

One job, before the war, had been test flying airplanes off the production line at Fairchild. From the log books for that era (he brought a pile of ’em with him to show, or check dates I suppose) I looked in after the talk, he was flying about two of every three F-23s and F-24s (I think I’m remembering the models right — if F-24s came after the war don’t shoot me!) as they came off the line – according to the serial numbers logged. The deadpan remarks column was great —

Std test, OK
Std test, OK
Std test, oil temp high
Std test, OK
Std test, engine quit, deadstick landing
Std test, OK

and then the ones there’d been a squawk on would be flown again a day or two later, with the ‘Std test, OK’ remark. And it just went on for pages and pages. Later, he left there to fly P-51s off the production line at NorthAmerican. He was great, just a walking encyclopedia of flight from the 30s on. Still pretty sharp, the last time I saw him, back in the summer.

Benton 23dec99