Yard Ace Construction Begins

Yard Ace three channel RC plane front view

Original size Yard Ace three channel RC plane 

I have started construction on a smaller version of my Yard Ace model airplane design. This variant is sized to accommodate the ParkZone line of electric motor and an electronics brick that contains two linear servos, a receiver and and electronic speed control.

Initial fit of ParkZone motor and electronic control brick

Initial fit of ParkZone motor and electronic control brick

From experience I know that a final model weight of around three ounces works well for the ParkZone motor. As discussed in an earlier post, I enlarged a set of plans to a smaller size from the original Yard Ace to be a better fit for the ParkZone set up.

Fit check of paper wing rib template

Fit check of paper wing rib template

As you build a smaller variant of a model there is an aspect of “designing while you build”. The original wood sizes will no longer be accurate for the new model and must be adjusted accordingly. You will have to consider the need for a strong wing and fuselage structure yet at the same time working constantly to keep weight at a minimum.

Front view of completed Guillow Lancer

Guillow Lancer offers useful insights to wood size needed for smaller Yard Ace variant

In addition the use of lightweight iron-on plastic covering has shown to add a lot of overall strength to the covered structure.

As the target model weight will be under three ounces, the model does not require the robust structure typically used in a larger aircraft. Gaining experience building other examples of indoor models such as the Stevens Aero or Guillow line can give useful insights as to just what size of balsa wood is needed for a successful variant.

More to follow as i complete the wing and next tackle the fuselage!

Brian’s Chickadee

I always enjoy hearing back from modelers who have built planes from plans offered on this website, and better yet from those who have experimented and made improvements.

Top view of Brian's Blackburn showing rigging and ample wing and tail areas

Top view of Brian’s Blackburn showing rigging and ample wing and tail areas

Brian earlier successfully built and blew a Blackburn Monoplane. He then tackled the Chickadee. Note how Brian used the Blackburn wings for the Chickadee, a smart move that saves building time.

Quiet and Electric Flight International magazine published the Chickadee plan in their Sept 2009 issue

Quiet and Electric Flight International magazine published the Chickadee plan in their Sept 2009 issue

The Chickadee was an experiment in design for me regarding wing and tail surfaces moments, areas and incidence settings. These parameters were adapted from the Sig Demoiselle kit. The Chickadee allowed for a quick built and the open layout of the wing mount allowed for easy adjustments on critical items such as the wing incidence.

My Chickadee prototype flew just fine. With the magic of TurboCAD I kept the rough wing area and incidence settings, easily grafting them onto the side view of my Blackburn plan. The result is a nice flying semi-scale model of an historic British aircraft.

Brian’s note follows:

Hi Gordon,

First, I want to tell you how enjoyable it has been to cruise lazily around the sky with my Blackburn on some calm summer evenings. A very realistic looking “days gone by” scenario.

I decided to take advantage of the Chickadee plans that came with the Blackburn but thought I would use the Blackburn wings instead of making a new, dedicated pair for the Chickadee. The Blackburn wings were a little heavier than the Chickadee plans called for of course, and I altered the wing mounting locations to suit the Blackburn wings. I did keep the wing location as shown on the Chickadee plans.

All went well. The weight before battery was 10.0 oz. However, the assembled fuse and wings was quite tail heavy and I had to add 3 oz of lead up front in a little “baggage compartment” under the nose and a 2s 800mah battery close behind the firewall to bring things in line.

I have not flown it yet. The all up weight is 15 oz., quite a bit more than the 9.5 stated on the plan. I know it will fly, just a bit faster than a lighter one. The motor is a Twisted Hobbies Crack Series 2203 – 1750kv with an 8 x 3.8 s.f. prop. I get 67 W @ 9.5A which works out to about 70W/lb. I won’t need all of that I’m sure.

I had another rare moment of genius as I wondered how I could carry it around without breaking it. I decided to modify the transport rig that I made for the Blackburn so that it could accommodate both planes (2 fuselages and one pair of wings). It works great.

I look forward to trying out the Chickadee soon. I’m sure I will love it. Thanks again, Gordon, for creating both of these aircraft.

Take care, Brian

Brian had an inspiration with his unique design of a lightweight foam carrying case.

We all know that the larger, lightweight electric models can be a challenge to transport with any amount of wind present. Brian took advantage of a common wing set for his build of the Chickadee and Blackburn, plus the fact that the wing panels are removable due to the fixed metal friction-fit mounting tubes. Note that the carrying case has the Blackburn fuselage (lower one), both wing panels and the Chickadee fuselage all in one unit. Brilliant!

Brian, thanks once again for a great recap and pictures, as well as sharing an original and innovative model transport scheme. Best of luck with your Chickadee test flights!

Close up of Chickadee nose section

Close up of Chickadee nose section

 

Chickadee fuselage under construction

Chickadee fuselage under construction

 

Detail of Chickadee fuselage, motor mount and wing tubes

Detail of Chickadee fuselage, motor mount and wing tubes

 

Innovative use of foam to make a lightweight model carrying case

Innovative use of foam to make a lightweight model carrying case

 

Ron’s Foam Yard Ace

Yard Ace electric powered RC model airplane on a fly by

Yard Ace electric powered RC model airplane on a fly by

 

The Yard Ace is one of my earlier model aircraft designs. The Yard Ace uses a simple layout with a high mounted wing and straight lines for the tail surfaces.  In short, an ideal set of plans for a first time builder as well as someone who would like to make some simple modifications to the existing design.

Yard Ace three channel RC plane front view

Yard Ace three channel RC plane front view

Ron just sent in some pictures of his version of the Yard Ace and the results speak for themselves. Ron had the neat idea to use foam as the building material for his variant of the aircraft.

Ron reports that his version came out a bit tail heavy, but he was careful to add sufficient nose weight to ensure the model balances at the correct center of gravity location. Proving his knowledge of aerodynamics and aircraft design, Ron plans on building a second Yard Ace later this summer using a slightly longer nose moment to compensate for the tail heavy condition.

In addition to the nose modification Ron will install the pushrods inside the fuselage as well as moving the servos to an interior location for a tidier appearance.

Ron, great job and I look forward to pictures of your second version of the Yard Ace!

Plans for the Yard Ace are located here. You likely have sufficient wood and other building materials in your parts bin.  Order a set of plans and create your version today!

Side top view of Ron's foam Yard Ace

Side top view of Ron’s foam Yard Ace

 

Rear view of Ron's foam Yard Ace

Rear view of Ron’s foam Yard Ace

 

Side view of Ron's foam Yard Ace under construction

Side view of Ron’s foam Yard Ace under construction

Brian’s Blackburn

Side view of Brian's completed Blackburn

Side view of Brian’s completed Blackburn

Brian recently purchased a set of Blackburn CAD plans, completed his model and was kind enough to share the results. Executive summary:  Brian’s Blackburn looks great!

Detail of Blackburn cockpit and after servo installation

Detail of Blackburn cockpit and after servo installation

The 1912 Blackburn Type D Monoplane was one of the first aircraft designed and built by an Englishman and then flown in the United Kingdom. With its front mounted engine and aft tail surfaces, the Blackburn has a surprisingly modern layout for an aircraft conceived just nine years after the Wright brothers’ first flight.  The generous wing and control surface areas as well as the substantial nose and tail moments make for an ideal radio control model aircraft.

Front view of the Blackburn, ready for takeoff

Front view of the Blackburn, ready for takeoff

Brian’s reports that his model finished out a bit tail heavy. Brian wisely added the correct amount of nose weight to bring the model with the proper center of gravity range.  It is absolutely critical that any aircraft balance within the correct center of gravity range prior to any test flights.  A model will be uncontrollable if flown with a CG out of limits as there is simply not enough control authority to override the resulting uncommanded pitch changes.

Top view of Brian's Blackburn showing rigging and ample wing and tail areas

Top view of Brian’s Blackburn showing rigging and ample wing and tail areas

As to why the model came out tail heavy, there is no certain answer. What I do is to always attempt to “build in lightness” as I construct the model.  I try to employ the lightest weight balsa for any fuselage structure aft of the cockpit, to include the tail surfaces, to minimize the possibility of a tail heavy aircraft.

Nice job with simulated spoke wheels and landing gear arrangement

Nice job with simulated spoke wheels and landing gear arrangement

Sometimes, despite your best efforts, a model will come out slightly tail heavy. One of the reasons I selected the Blackburn is the generous nose moment (distance of the propeller to the center of gravity) to make the most use of any weight added to the nose to move the center of gravity into the correct place.

Custom built foam carry case

Custom built foam carry case

The slight added weight for Brian’s model (about five ounces) should have no appreciable impact to the Blackburn flight characteristics. The full scale Blackburn had ample wing area, as the aircraft of those initial days were woefully underpowered due to the early state of aviation engine technology.  In a sense many of these early flyers were powered gliders.

This plentiful wing area makes the addition of some extra weight essentially not noticeable. The added mass will likely make for a smoother flying aircraft in the end.

Detail of custom built foam carrying case for the Blackburn Monoplane

Detail of custom built foam carrying case for the Blackburn Monoplane

Brian also took the extra step of constructing a custom designed foam carrying case for his Blackburn. As per the plans, the Blackburn’s wings friction fit into metal tubes mounted to the fuselage.  This makes it a snap to disassemble the model for ease of transport.

Brian did a superb job of tailoring his foam carrying case for the Blackburn. This is a great idea I had not thought of, and I will for sure employ this approach for future model aircraft designs.

Brian, thanks again for sharing the photos of your finished aircraft and carrying case.  Good luck with the test flights!

 

 

Build a Rough Prototype

ParkZone electronics installed in the Spin prototype

ParkZone electronics installed in the Spin prototype

I added a page today discussing the concept of a “rough prototype” for model aircraft design.

Aviation has always embraced the idea of a prototype with any new aircraft design, power system, construction method, etc. Perhaps one of the most interesting examples of this is the first Boeing 707 jet airliner.

There were so many new techniques and procedures with constructing and flying the world’s first swept-wing jet powered airliner that Boeing elected to not certify the initial B-707 aircraft with the FAA. Boeing kept it as an “Experimental” aircraft with no FAA issued “N” registration number (and of course no ability to carry any passengers), just so Boeing could figure out if this type of design was worthy of a full production variant.

This historic B-707 is on display at the Smithsonian Museum Udvar-Hazy Center aircraft collection outside of Washington Dulles Airport. Worth a visit.

The idea of using a prototype for model aircraft design makes full sense. I advocate the approach of using a “rough prototype” to work out aircraft sizing, incidence settings, surface areas, etc. before taking the time and effort for a fully finished product. See further details here!

Chickadee Prototype Design

Quiet and Electric Flight International magazine published the Chickadee plan in their Sept 2009 issue

Quiet and Electric Flight International magazine published the Chickadee plan in their Sept 2009 issue

Front view of the completed Chickadee park flyer

Front view of the completed Chickadee park flyer

I added a new page to the website, under Design, that discusses my approach to laying out the plans for the Chickadee. This method to come up with an original aircraft design can be of use to any new RC model plane designer.

With the Chickadee I adapted some construction and sizing techniques from an earlier kit-built model (Sig’s Demoiselle) and employed them with the Chickadee. The Chickadee uses a straightforward and uncomplicated structure to permit quick modifications. Once the design parameters are confirmed during test flights, follow on model plans can be drawn using these aircraft constraints.

 

Chickadee in flight

Chickadee in flight

For example one item that needed adjustment on the Chickadee was the wing’s incidence. The prototype had plenty of power from its brushless electric motor, but would not lift off during the takeoff run.

The solution was easy with an increase wing incidence by raising the wing’s leading edge. As the construction was open frame this modification entailed lengthening the two forward wing mounting posts. The result was a smooth takeoff and a pleasant flying model.

These dimensions and settings were transferred directly to my Blackburn design, to include the same motor and battery arrangement. Interestingly, the handling and flight characteristics of both models are remarkably similar.

The idea of using a rough prototype that can be readily modified, to iron out the proper aircraft parameters, is a sound way to design RC model aircraft and can be used for a variety of model airplane designs. I will expand on this concept in a later update to this blog at the end of December and show how I used this same approach with the Fokker Spin.

 

Detail of the Chickadee nose section and control system layout

Detail of the Chickadee nose section and control system layout

Yard Ace Build

Yard Ace electric powered RC model airplane on a fly by

Yard Ace electric powered RC model airplane on a fly by

The Yard Ace is one of my favorite designs. The airplane’s layout is simple and construction employs normal building techniques and materials. The Yard Ace is a great first choice for a plans-built model.

Yard Ace wing under construction, note addition of aileron servos

Yard Ace wing under construction, note addition of aileron servos

Russell recently sent in some photos of his Yard Ace. Russell is working on a third version with students as part of a classroom project. Note the addition of ailerons and wing mounted servos, an indication of just how straight forward “kit/plan bashing” modifications are to this flyer. Russell, many thanks for sharing your Yard Ace building experiences!

Russell has given me a great idea, and that is to make a smaller indoor version of the Yard Ace designed around using the ParkZone microelectronics. It will be easy to produce the reduced size plans printing with TurboCAD, or employing the tile feature contained in the print box of a PDF file.

Yard Ace fuselage under construction

Yard Ace fuselage under construction

Based on experience, I think about a 25 inch wingspan variant of the Yard Ace will be about right for the motor and prop used by the ParkZone equipment, looking towards a finished weight of under three ounces. Note that I used this empirical sizing technique designing the Fokker Spin, which came in at a 28 inch wing span and a three ounce flight weight.

As my December Mesa flying schedule with United Express permits I look forward to sharing progress with you on this construction process!

 

Yard Ace after a slight landing accident, with motor mount needing a replacement

Yard Ace after a slight landing accident, with motor mount needing a replacement

Front view of Russel's Yard Ace

Front view of Russel’s Yard Ace

Enlarge Model Plans for Free!

Prototype of the Yankee Mike, my first model airplane design

Prototype of the Yankee Mike, my first model airplane design

One of the many nice things about radio control modeling and the internet these days is the abundance of model aircraft plans that can be purchased and downloaded on-line.

My site is a great example of this. I designed my first model airplane, the Yankee Mike, in 1998. RC Modeler magazine published the full size plan and construction article. Offering full size blue prints of various model aircraft construction plans was all part of the business model of RC magazines in those days. It was not uncommon to see three construction articles in a single issue.

As a side note I had to draw out, by hand, the full size Yankee Mike plan. Practical home use computer CAD programs just did not exist at that time. I mailed these depictions to RC Modeler magazine. A professional draftsman traced over my drawings to prepare the finished full size plan. Sadly, RC Modeler magazine went out of business several years ago.

On a happier note, you can still purchase many of these classic RC Modeler construction plans today.  A Google search will show several sources. RCM had some wonderful and original designs that would make ideal flyers today.

"Yankee Mike" construction article in 1998 RC Modeler magazine

“Yankee Mike” construction article in 1998 RC Modeler magazine

Since then I have had five additional model aircraft plans published in the modeling press and available for purchase on this site. For further details please see the Plans pull down menu on the home page.

But back to the subject of this post, how to enlarge a smaller aircraft plan drawing to full size. Any plan that you obtain from the internet typically will be a smaller size drawing that will need to be enlarged.

See my detailed page here on the subject of enlarging a model aircraft plan. The good news is that the free Adobe PDF reader has a built in function that easily allows you to set an enlargement ratio and print out 8.5” by 11” paper “tiles” on your home printer.

When all the tiles are printed out you tape them together for the full size construction plan. I’ve included Sheet One of the three Fokker “Spin” plan sheets for the demonstration that you can download and experiment with.

Following this method you can make any size plan you wish from a smaller PDF drawing. Recall that if a plan is downloaded in another format (say, a Word document) most programs have a “Save As” feature that allows you to save the file as a PDF document. Once you have the file in a PDF format you can use the enlarge (“Poster”) feature in the PDF Print dialogue screen to create the full size plan.

For those of you who have TurboCAD or some other CAD (Computer Aided Design) program installed on your computer I always include the full TurboCAD file when you purchase one of my model aircraft plans. TurboCAD has a built in feature that allows an enlargement of any plan with a tiling feature for the finished print out.

 

Spin Sheet 1 on a single page (left) and 150% enlargement (four tiles) at right

Spin Sheet 1 on a single page (left) and 150% enlargement (four tiles) at right

Finch Build Page and Flight Video

Front view of the Finch covered with silkspan

Front view of the Finch covered with silkspan

I added a full description and build page on my Finch plan, used to build a three channel indoor radio control flyer . Check it out here. The Finch goes together quickly with modeling supplies you likely already have in your work shop. The airplane uses a flat frame for the fuselage and employs a top mounted wing.

The Finch uses the popular ParkZone line of radio control electronics and electric motor, thus there are few concerns over obtaining the correct micro-electronics for successful flight. Full ordering details for the electronics are covered.

Finch showing 1/32" balsa cowling

Finch showing 1/32″ balsa cowling

The Finch’s full size CAD (computer aided design) plans are absolutely free and can be downloaded on the page. And best of all is the fact that I have taken the computer drawn plans created with TurboCAD and pasted them into a Microsoft Word document.

While any CAD plan can be easily offered you will need some sort of CAD program on your computer to open, view and print the plan. Not every modeler has one of these programs installed. By making the plan available in Word format, just about anyone with a computer can download and print out the plan.

Do take a look at the Finch. By building one for yourself, you will have a fun indoor flyer as well as something different from the other ready to fly models at your local indoor flying venue. Check out the video below of one builder’s Finch.  Give it a try and good luck!

 

Build the Finch – Free CAD Plans!

Spektrum transmitter and completed Finch

Spektrum transmitter and completed Finch

The Finch is a three channel indoor micro radio control model that I designed a few years ago. The Finch is easy to build and flies very well . . . and best of all the plans are free!

Finch showing 1/32" balsa cowling

Finch showing 1/32″ balsa cowling

Click here for a set of Finch Full Size Plans.  The Finch plans were created in TurboCAD and then pasted into a Word file. Thus there is no need to have a CAD program to print out a set of full size plans.

Everyone can get access to Microsoft Word. Just print out the nine pages, tape then together per the instructions on Sheet 1 and start your build!

The Finch has a 20 inch wingspan and is a bit over 15 inches long. I used the popular ParkZone line of RC electronics and matched electric motor. This setup weighs next to nothing and provides plenty of power. Any other light weight set of electronic controls and motor will work just fine.

Three channel radio control Finch in a fly by

Three channel radio control Finch in a fly by

The Finch is easy to modify with different cowling arrangements, an increase in wing span or maybe changes in the tail surface outlines, just use your imagination. When working with a small model like this it is easy and affordable to make a few mods here and there, see how they work, and have a chance to experiment a bit. “Plans bashing” is the first step towards designing your own model airplane some day!

Mike recently built his version of the Finch and it came out great. See below!

 

Nose section of the Finch showing landing gear, motor and RC electronic arrangement

Nose section of the Finch showing landing gear, motor and RC electronic arrangement

 

Mike's Finch with clear yellow heat shrink covering

Mike’s Finch with clear yellow heat shrink covering