Rubber Band Catapult Gliders

[mbauer]

During 2019 I started a new way of designing some catapult Gliders. Thought small "profile" type gliders would be easy to fly.

Some did all right, most did not. Tried doing different things with the design to get good flyers using a simple rubber band launch system using a 1/4" wood dowel.

I made several gliders like this. A few were made and have survived. Below are some of the photos, taken today, to show a small sample of the designs.

For instance the F-4 Phantom has 8-different paints, only two survived sort of.

Since the original designs were completed, been thinking of ways to improve them to get better flights from them.

Most are "Lawn Darts", not real flight. The cardstock (110# Index [198.9gsm] used was too heavy.

Been using 65# [165gsm]Cover Cardstock for my big rockets. This cardstock will lower final weight of these models.

Recently, a new member: ReynoldsSlumber, has been posting about his attempts to fly scale paper models.

Since 2019 some of my thoughts have been constantly returning to these profile models that don't fly so well.

As you can see in the photos, the fuselage have warped over time. The glued back to back profile of the wings and fuselage have all warped to a degree.

The great thing about using Cover cardstock is you can find the same brightness rating for 20lb bond paper. This makes it possible to print hopefully on two types of paper and get the same look.

Underside of the wings can now be lighter weight bond paper.

The next thought was to widen the fuselage to 1/4" thick, instead of cardstock glued back to back. This should stop the warping and give a much stronger model.

One of the things I did was to make a small hook under the nose to be able to use a rubber band stick launcher. I added several layers of cardstock to strengthen this hook as well a balance weight for the models.

This semi-worked.

Today I started the re-design process to update the models to these new changes.

I have several models already complete as the Profile models, these will be updated to the thicker fuselage using the lighter weight cardstock/bond paper.

All of these "profile" type gliders are not drawn to scale, smaller rudders, increased wing span to remove weight and enlarge flying surfaces.

Here is a list of the models done so far as profile models before the new changes, each model has different "paints":


The F4 Phantom has 6-different paints for instance, two are shown in the next photo. Blue Angle and Spirit of '76.

Here are some of the models that have survived the best since first test flights:


A close up of the very small hooks added:


Close up of the layered cardstock to add balance weight and support the hooks:


Updates will soon be added as I try different things to loose weight and the thicker fuselages for strength.

Mike

[mbauer]

Updated the first of the profile Gliders: The Playboy Bunny version.

Fuselage is 1/4" wide. This might allow bond paper for the model. I printed an updated version using 90lb Index cardstock and 20lb bond paper.

The first build had several issues that have been fixed.

Here are a couple of photos of the updated profile glider. Takes 2.5 hours to cut, fold and glue:




To save time and glue weight, I combined all of the fuselage pieces into a single part. It has been printed and going to build the first version today. Here is a screen shot of the fuselage. When I print PDF files from AutoCAD they show lots of white lines-they disappear when PDF is printed:


The prototype above was done as single fuselage parts and some parts needed fixing.

I have several F4 Phantom paints that will be modified. Initial glide tests are very promising although the completed model has some issues with wing/horizontal stabilizer alignment.

Will be uploading a F4 Phantom model to the download section later today, not sure which one yet, minimum part count only two pages...

Mike

[mbauer]

3-More things found to fix. Will make make model easier to build before uploading.
1. Need Dash Fold Line on Horizontal Stabilizer/Elevator
2. Add some cut lines (dots) to Canopy
3. Need a couple of glue tab cuts to make the curve easier to glue on fuselage nose top & bottom

Photos taken during construction=Build Thread
Verifying Scale of PDF after printing: Make sure to print at 100% NO-Scaling


311-Fuselage piece is cut out


Closeup of Fuselage showing multiple cut locations, glue tabs cut lines (Dot Lines) & Fold Line (Dash Lines)


Time to do some edge coloring


1/16" wide Glue tabs, also shown edge colored fold lines, white dotted lines for the Wings, Elevator, Rudder-Don't cut these out yet, wait until the fuselage is complete


Glue tabs are scored and folded, ready for gluing


Glue applied to bottom glue tab


Bottom fuselage glued


Bottom Tail boom is next for gluing


Tail boom glued


Next will add the fuselage nose weights and super strong supports for when it hits something hard and fast!

Mike

[mbauer]

This step will add the nose weights and also supply strong support for the fuselage nose.
Bottom Front Nose is ready for gluing


Bottom Nose glue applied/Pre-shape bending completed


Bottom fuselage nose glued/also shown is the white dotted line for the rubber band hook, don't cut yet wait until final assembly steps


Scoring fold line on rudder, tool is art embosser for metal foil art work. Ball on end is 1mm in diameter, you can use wax paper or dryer fabric sheets to help it glide when scoring


Back to fuselage nose: nose lamination weights/supports need 3 for each side of fuselage


Gluing the laminates


First laminate gluing


All 3-laminates glued ready to cut out


Right side weight laminate cut out


Right side marked as is the left; Left side ready to install into fuselage-glue is ready to go


Final steps on nose weights next.

Mike

[mbauer]

Left Side nose weight is added


Check fit by folding glue tabs while glue still wet, if it won't move, you can trim any of the weight sticking up to far with a really sharp knife


Both balance weights added, glue applied for final nose assembly step


Front fuselage is completed


Fuselage aft top ready for gluing


Glue applied


While fuselage glue is drying, added some clamp weights to keep it flat


Edge coloring rudder fold line


Final parts to make


Wings are next.

Mike

[mbauer]

Cutting wings out using a quilting ruler with anti-slip mat glued to bottom. Mat is from kitchen section at store, drawer liner mat


Notice cut lines extend past part, helps insure clean cut and good separation of part from scrap cardstock


Wings cut out, time for edge coloring


Dry fit of wings to make sure fold line is correct


Gluing wings


Wings glued and drying-Note knife pointing at Center of Gravity (CG) locations. This is the spot where you balance model for flying, should hang level


Time to laminate the rubber band hook 1st gluing of both halves


Rubber band hook lamination #2 gluing


Rubber band hook ready to glue both halves and edge color too once glued together


Edge coloring complete, ready to install into fuselage


Final assembly steps next.

Mike

[mbauer]

Final steps to get the model ready for flight.

Cutting out the location for adding the rubber band hook, it is now time to cut the remaining dotted lines for the wings, rudder and horizontal stabilizer/ rudder


Rubber band hook is glued into position


Wings are inserted, glue after they are aligned in the wing opening, top and bottom of wing gluing required to make them strong


Top view of wings after gluing


photo with the first F4 made


Horizontal stabilizer aligned & then glued same as wing, top and bottom, make sure to get alignment with wing and rudder close, after drying they can be bent as needed for alignment, but accuracy now makes it easier and a better flyer


Checking alignment of flying surfaces


Model is drying


Will up load model next.

Mike

[mbauer]

Just updated the F-106 Dart to the new way of construction.

For this model I had to use a two piece fuselage width for the top front and nose. You can see where the glue butt joint is just aft of the canopy.






F106 weighs in at 8gm total.

Just realized I need to fix the flag direction. Good thing I took these photos...

New version weighs a gm less than old style.

Not sure of the next model to convert, B-47 or B-52...Possibly the ME 262, F104, ME163 or draw completely new design, F15, F16, F22 or F35...

Mike

[Don Boose]

Rubber-launched gliders are always fun. That F-4 is really classy.

Thanks for all the info and images.

Don

[mbauer]

Thank you Don. There are several paints of the F4, just need to update them.

XB-70 Mach 3

Needs some work on the structural for the fuselage. Added more strength and updated some of the graphic errors, USAF upside down, engine intakes.

Some photos of the XB-70 Mach 3 Bomber while it is drying:








Fuselage is thin and weak. This one a little difficult to build without warping.

Mike