Archives for August 2013

Model Design, Top Flite DC-3

 

I added two items to the website this week.

Electric powered Top Flite DC-3

Electric powered Top Flite DC-3

The first is a page on design procedures to draw up an RC model plane. This will be the start of several pages and postings that will provide specific information on what size model to build, setting fuselage length and determining the proper wing span.

As you gain design skills you will learn that there are exceptions to every rule. But these guides are a starting point.

I do mention (and use) the TLAR method for model airplane design. TLAR stands for That Looks About Right. As a general rule, if an airplane “looks right” there is a good chance it will fly right. Sometimes you just have to take a look at a finished design and make changes based on inspection.

Retro RC electric powered model airplane

Retro RC electric powered model airplane

Thus a good design approach is to use the dimension rules in the article on model airplane design and see it the finished product looks right.

I had this situation happen to me during the design of my Yard Ace. The prototype’s wing was just a bit too short. The model flew well, but had to be flown at a high airspeed to prevent a stall. On the final version I added two inches to each wing. The result was a much smoother flight at a lower airspeed, all due to the increase in wing area.

The second item added is a video from the Rock Valley RC Flyers All Electric model airplane meet held on August 18, 2013. This was a fun gathering of RC flyers featuring kit built and ready to fly electric models.

Of note was a very nicely done Top Flite DC-3. Darryl finished his DC-3 in American Airlines colors. This is a most appropriate choice as Darryl is a Captain flying for American Airlines out of Chicago. Darryl installed retracts made for the Top Flite kit and follows a flight profile just like the full scale bird.

 

TurboCAD, ParkZone and Fond du Lac

 

I made three new additions to the website over the past week.

The first item is an updated video on using TurboCAD to draw radio control model airplane plans. TurboCAD is a sound computer aided design (CAD) program choice for the RC hobbyist who wants to prepare a set of model aircraft construction plans.

ParkZone combination receiver, two servos and electronic speed control

ParkZone combination receiver, two servos and electronic speed control

TurboCAD is affordable at around $130 for the deluxe version (includes 2D and 3D drawing tools). TurboCAD is easy to learn once you understand some of the fundamental tasks that any CAD program employs, such as trim, snap and mirror.

The video gives an introduction to the TurboCAD user interface. You will see a demonstration of the thought out and flexible user interface, such as floating tool bars. You will also understand that you need to learn just a few basic commands (lines, circles and curves) to draw a set of plans. There is no need to study every nuance of this mature CAD program.

I added a page on the ParkZone line of ultra-micro radio control electronics. The ParkZone RC gear is installed in their popular Bind-N-Fly line of ready to fly foam micro RC models.

Albatross WW-I fighter at Fond du Lac RC Airshow

Albatross WW-I fighter at Fond du Lac RC Airshow

The ParkZone combo has a “brick” that contains a radio receiver, electronic speed control and two linear servos matched with a tiny geared electric motor. This unit makes a compact power and control solution for models weighing less than about three ounces and having a wingspan of under about 30 inches. You really cannot go wrong using the ParkZone electronics unit in your next indoor flyer.

Although this website is focused on electric radio controlled model aircraft, I do like to cover other interesting RC models and events. On Aug 16th I had the chance to visit the Fond du Lac “Warbirds and Classics Over the Midwest” model airplane meet at Wellnitz Field. This superb flying facility is located about a 2.5 hour drive north of Chicago.

The four day fun fly, held in August each year, was well run. Lots of pilots flew an interesting mix of large scale military aircraft. The craftsmanship and flying were exceptional. Jet turbine, gas engine and electric powered models were airborne at all times. Below is a video of my tour of the flight line and pit area.

 

Update on Werner’s Blackburn RC Model

 

Following is some additional information from Werner on his build of the 1912 Blackburn Type D Monoplane RC model. Plans for the Blackburn are available here.

Werner enlarged the CAD Blackburn plans 125%. The RC model uses three channels of control. No ailerons are installed as the rudder is used for turns. This approach works well for the model’s slow and close in flights.

Werner's Demoiselle, Bleriot and Blackburn radio control model planes

Werner’s Demoiselle, Bleriot and Blackburn radio control model planes

Werner reports his Blackburn tips the scales at 0.585 kilograms or about 20.6 ounces. This is an ideal weight and wing loading for this larger modification. You can see the results in Werner’s flight video.

Werner installed a 2S 1300 mAh lipo battery to power a Roxxy Bl Outrunner 2220/12 electric motor. Flight times are around 12 minutes.

Spoke wheel on Werner's 1912 Blackburn Monoplane

Spoke wheel on Werner’s 1912 Blackburn Monoplane

Enlarging a plan is a great technique if you want to adjust the size of your finished aircraft. You may have to substitute some wood sizes from the original plan. This is not hard to do. Always ensure you have adequate strength while not getting too heavy with excess structure.

Werner constructed one of his models from the Sig “Pioneers of Flight” series of kits. This includes the Demoiselle with my build here. By enlarging the CAD plans of the Blackburn, Werner’s rendition is around the same size as his other two models.

Pilot figure in the cockpit of Werner's Blackburn RC model airplane

Carved pilot figure in the cockpit of Werner’s Blackburn RC model airplane

Adding a pilot figure to any model plane is a good idea. Having a pilot in the cockpit makes the model look “right” in the air.

Werner did a nice job hand carving a pilot out of lightweight balsa and foam. The addition of some paint makes the final figure come alive.

The large cockpit control wheel is a nice touch as well.

Spoke wheels help with the appearance of these antique flyers. Spoke wheels were used by just about all of the early aircraft. A spoke wheel offers a lot of strength at a very light weight. This was an ideal approach for the under powered aircraft of that era.

Control wheel installed in Werner's Blackburn

Control wheel installed in Werner’s Blackburn

Dummy balsa engine detail in 1912 Blackburn RC model plane

Dummy balsa engine detail in 1912 Blackburn RC model plane

Aircraft in those days typically spent little time moving at high speeds on their wheels. The aircraft of that era had short takeoff and landing runs.

Pilots rarely conducted extended ground operations. Under these operating conditions the relatively fragile spoke wheels were a good solution.

A small amount of attention to an RC model’s dummy engine adds a lot to the visual appeal. As with the addition of a balsa “engine” to my Fokker Spin, Werner added balsa cylinders to replicate the Blackburn’s engine. Low vibration electric motors make these modifications a snap.

Werner’s Blackburn

 

Engine and nose detail of Werner's 1912 Blackburn Type D Monoplane

Engine and nose detail of Werner’s 1912 Blackburn Type D Monoplane

It’s always nice when someone builds a radio control model from plans you drew up,  and then thoughtfully shares pictures of their finished aircraft.

Werner did this today with his build of my 1912 Blackburn Type D Monoplane plan.  Werner did an exceptional job with the construction.  Werner enlarged the plans 125% to make a slightly larger model.  This is a common technique, and allows anyone to make yet another variation of an existing design.

Front view of Werner's Blackburn RC model plane - 125% of plan size

Front view of Werner’s Blackburn – 125% of plan size

The Blackburn makes for a pleasant flying three channel RC model.  Aircraft of that era needed plenty of wing area to fly with the low powered engine available.  For a radio control model this abundance of wing area, usually combined with a light weight structure, makes for a low wing loading and leisurely flights.  In other words a flight profile just like the original full scale machine.

I might add that Werner not only shared two  photos but also added a YouTube video – see below!

Werner demonstrates exception control, close in slow flight, touch and goes and a beautiful landing with minimal roll out.  The spoke wheels add a lot to the visual appeal.  Job well done!

 

Fokker Spin Plan and Pictures

 

1911 Fokker Spin top view

1911 Fokker Spin top view

I added a new page this weekend describing the final version of my RC model of the Fokker Spin plan and scale detailing. The Spin was a remarkable aircraft, designed by the famed World War I fighter aircraft designer Anthony Fokker in 1911. Fokker was just 21 years old at the time and he used the Spin to teach himself how to fly.

Anthony Fokker’s trainer was a well-designed aircraft for that period. The Spin would be a challenge for today’s pilot to fly given the exposed cockpit and rudimentary controls. Fokker’s ability to take the Spin safely aloft and somehow learn how to fly is a testament to the skill and daring of these early aviation pioneers.

The Spin makes for a pleasing sport scale radio control model plane. I designed the Spin with a 28 inch wingspan, which works well for the ParkZone line of ultra-micro radio control electronics. The ParkZone electronics can be purchased at Stevens AeroModel.

I first built and flew a Spin prototype to see how the model handled with its unique swept wings and all-moving rudder. Note that I located the radio control electronics on top of the prototype’s fuselage for ease of installation.

On the final version of the Spin I relocated the RC electronics to the fuselage underside. This did a good job of keeping the ESC brick out of view, yet keeping the same control rod runs to the tail surfaces.

Dummy engine and rigging wire details

Dummy engine and rigging wire details

The Spin’s final version also allowed for some fun with decorating the model. The exposed engine can be detailed with balsa blocks, heat shrink sleeves and metal tubes to simulate exhaust stacks. The original Spin had numerous cabane struts that added to the model’s visual appeal. Thread is used for simulated rigging and flying wires.

The final item is the landing gear. The secret here is the easy to bend 0.032 inch music wire. Take your time studying the pictures and plans to install the gear. Axles are held in place with thread and glue. The skids are made from bamboo skewers purchased at the local grocery store.

CAD Spin plans are available for $6.95. I’ll e-mail the plans to you on three sheets in a PDF format, which can be printed on any home computer. Print the sheets out and enlarge at a nearby FedEx Office or other graphics store to full size. Good luck with your Spin build. Send me photos of your finished model and I’ll post to the website.

Full scale Fokker Spin getting ready for takeoff

Full scale Fokker Spin getting ready for takeoff

I also added a page with a fifth picture gallery to the site, this one of the final version of the Spin. In these pictures you can view details of the installation of the ParkZone microelectronics to the fuselage underside, as well as the unique landing gear arrangement. As discussed earlier the landing gear is simple to fabricate from the lightweight music wire, offers plenty of strength and adds a lot to the visual appeal of the model.

1911 Fokker Spin radio control model airplane in flight

1911 Fokker Spin in flight

The Spin relied on extensive flying wire rigging to hold the entire structure together. Note that the fuselage is nothing more than a flat, open wood frame. Fokker included a unique arrangement of fore and aft cabane struts on the full scale version. These music wire struts are easy to install on the radio control model. Sewing thread is used to simulate the flying and rigging wires. This is a simple task and adds a lot to the final appearance of this historical aircraft.

Chickadee Gallery Added

Chickadee RC model plane front view

Chickadee RC model plane front view

I added a fourth picture gallery to the site today, this one on the Chickadee three channel RC plane.

I designed the Chickadee in 2009 to experiment with the construction techniques I learned while building the Sig Demoiselle.  The Chickadee has a similar wingspan at 44 inches, and refined the design concept of using fuselage mounted metal tubes for the wing dowels.

The Chickadee flew fine and gave me further insight at how much wing positive incidence to set for these slow flyers.  The general outline and proportions of the Chickadee were replicated in my Blackburn plan.

The Chickadee to Blackburn is a great example of incremental design steps.  The Chickadee is a simple build with its open fuselage framework.  CAD plans are available when you purchase the Blackburn plans.

Blackburn Monoplane Plans

I added another item to the Store today, the $7.00 plan set for the 1912 Blackburn Type D monoplane.

Blackburn nose section detail RC model plane

Blackburn nose section detail

The Blackburn uses three channels of control and has a 46 inch wingspan.  The Blackburn uses normal building materials of balsa and plywood.  The large wing area and light weight of under 14 ounces makes for a slow and relaxing flyer, much like the original.

A full article on the development of the Blackburn model will follow.  The CAD plans provide all the information needed to build this historic aircraft.  I also include a full construction article when you purchase the plans.

As an added bonus, when you purchase the Blackburn plans I’ll include the Chickadee.  The Chickadee was a test platform as I worked out construction techniques for the Blackburn.  The Chickadee is fun airplane to build and fly on its own, and uses a simple balsa frame for the fuselage.

Fokker Spin plans

Guillow Lancer - free flight kit converted to radio control

Guillow Lancer – free flight kit converted to radio control

I made several additions to the website this weekend. Hope you like them!

I added a new page on what size model airplane to design to. It might seem obvious, but you need to think ahead as to what size model you wish to create. This could be governed by the size of your workshop, amount of budget or type of flying you wish to do.

In my case I enjoy making smaller models for indoor flight. I have access to a great indoor flight facility at the Field House of a local education center.

ParkZone electronic speed control, dual servo and receiver brick

ParkZone electronic speed control, dual servo and receiver brick

The ParkZone line of ultra-micro electronics is ideal for these sorts of indoor flyers. I use the three channel set up originally used in the ParkZone foam ready to fly P-51 Mustang.

The electronic speed control, two linear servos and a receiver are all in one compact unit. The geared electric motor and 160 milliamp lipo battery all work together well. Based on experience, this combo will work fine is a model with a wingspan of under 30 inches and a weight less than three ounces

Once you figure out these sorts of parameters you have a great starting point for future designs.

This is just the approach I took with my design of the 1911 Fokker Spin. CAD plans for the Spin are now for sale under the “Store” menu tab. The plans are available for $6.95. I’ll e-mail the plans is a PDF format. You will need to print them out and enlarge 279% for create a full size print out. Plan enlargement is easy using scanners at a service such as FedEx Office.

1911 Fokker Spin front view showing dummy balsa engine cover

1911 Fokker Spin front view showing dummy balsa engine cover

The Spin is designed around the ParkZone electronics and motor. The aircraft has a 28 inch wingspan and weighs just under three ounces. The Spin is easy to build, looks great and is a smooth flyer. See the video of the prototype Spin design here.

The final addition to the website is the use of a WordPress plug in for optimizing the site’s appearance on a smaller mobile device such as an iPhone. The site’s appearance work is all done in the background.

When viewing the website on something like an iPhone, the program automatically senses the smaller device and creates an entirely new presentation of the menus and browsing function to optimize the smaller screen at the best user advantage.

As so many folks are using mobile devices these days, this is yet another demonstration of the benefits of using WordPress to host a website.

Author:  Gordon McKay

TurboCAD Precision

 

TurboCAD rendering of a gas motor

TurboCAD rendering of a gas motor

I added information today under the TurboCAD menu button on using TurboCAD for preparing model aircraft plans.  TurboCAD is an affordable drafting program that is ideal for the home hobbyist to use for preparing a set of model aircraft plans.

Illustration vs. CAD programs

Most of us have used some sort of computer illustration program, whether it be a “paint” genre program, PowerPoint for presentations, PhotoShop, etc.

While it is possible to prepare a set of model aircraft plans with a free form computer illustration program, you really need a dedicated CAD program to properly draw a set of plans.

The key advantage of a CAD program as compared to an illustration program is precision. A CAD programs “knows” the size of what you are drawing and can very accurately draw and connect various objects (circles, curves, lines, squares, etc.) to complete the drawing.

This drawing precision concept becomes more evident as you gain proficiency with a CAD program. For example, if you draw a wing that is 40 inches in span, no matter what size the view is on your computer, the CAD program “knows” the wing is 40 inches in span.

All other objects you add to the drawing, such as a fuselage or tail section are drawn in the correct size in relation to the wing. This is an amazingly powerful design concept that is central to any CAD program and is not resident in an illustration program.

Learning CAD

TurboCAD Floating Toolbars

TurboCAD Floating Toolbars

The trick with any CAD program is learning it. The discussion of the precision tools and techniques, such as snap, trim or vertex are new to anyone working to understand the program. Learning CAD can be a difficult challenge for the first time user.

The good news is that once you understand “how the CAD program thinks” your ability to be productive with CAD increases rapidly and dramatically. Actions and procedures that you need to follow to prepare a set of plans quickly fall into place.

The other bit of good news is that CAD programs have been around for a while and have a rich set of design features that are standard on a 2D drawing interface.

The 20% rule

When using a program like TurboCAD you only need to know about 20% of these commands to be completely proficient. There is no need to study and understand every feature of the program. This insight can save a lot of training time.

Purchase TurboCAD training CDs at Store tab

Purchase TurboCAD training CDs at Store tab!

Check back from time to time as I add notes on this blog regarding using TurboCAD to draw model aircraft plans. I’ve used a wide range of CAD programs since 1998 and TurboCAD’s precision and ease of use is the answer for me. My last five model plane designs were all drawn with TurboCAD.

I offer a set of TurboCAD video training CDs here for $16.95. Over two hours and 50 minutes of narrated instruction I take you from a clean sheet of paper to a finished model aircraft plan. Seeing how a CAD program is actually used will save you lots of time as opposed to reading the manual.