Flapping family transporter with 4 ocupants

This monster was created to celebrate the coming of an additional family member. A mere 12 months earlier we didn't even have a family. I've never claimed to be a quick developer, and marriage definitely proved that. What has not been shown yet is the monster to celebrate the 3 person family which happened a year earlier. This is mainly as a result of the wheels being non-standard and I haven't figured out how to turn them for a video.

4 Occupants in a flapping monster

The monster is modelled slightly on the Challenger aircraft which featured earlier. In this case the wings have a cranked motion instead of a simple flapping motion. This adds to the general movement in many directions, and is more interesting. I cannot prove it, but it just feels that for a heavier air craft the cranked motion would work better. Seems more efficient for big loads (maybe it is because the wing tips don't travel as far). Guess that's why birds tend to flap with a cranked motion and small ornithopters generally don't.

The construction is in between the woven wire grid used in earlier models, and the geodesic inspired but not quite copied open frame structure of later monsters. In this case the tail of the aircraft shows the triangular structures (for strength) which have been filled with copper wire (to look fuller).

The wings also made use of a new construction technique, with the edges of the wing no longer supported by a frame. Not the most successful experiment. I quickly went back to the more boring, but satisfying, covered frame type wing. Don't like the flappy material bits on the edges of the wing.

The wheels were made of family not friendly lead (old wine bottle tops). This was done to reduce the overall lead in circulation in the world to make it a safer place. All family members have been warned not to suck the wheels or lick their fingers after giving the monster a spin.

Old looking picture of some of the family which I would not have had if I hadn't moved out of my comfort zone.

The photo above was added as it has a classical feel about it. It was taken with expired photo sensitive film in a big Mamiya TLR (no digits were involved). It feels really old, but illustrates the joy of family and in-laws and dogs and wine etc. Below is the immediate family in the lengthened cockpit of the monster. The necks and shoulders have been constructed of recycled tin cans and allowed to corrode for ambience. The heads are once again made possible by the sacrifice of the local crabs in the Rhebok region. I don't know if any crabs were harmed before the making of this monster or whether they declawed themselves. I having only collected already empty claws from the beach.

Close up of the father, mother, big daughter and little one.

Well this is the last blog of the first year of blogging. I have decided to break it into years which coincide with my birthday. Maybe I'll find the inspiration to start year 2 soon?

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Counter Rotating Flapping Helicopter

This was created some time after Frojo the flapping helicopter. It was inspired by the helicopters which don't require a tail rotor. This is done by having counter rotating blades which cancel out each others torque. Generally there are two configurations for this ie. having the blades stacked above each other or offsetting the rotors (either in line or abreast)  to prevent the platform from growing too large. In this case the rotors abreast style was chosen. The rotors need to be synchronised with each other to avoid them interfering with each other. This resulted in a frog like aircraft with rounded body. The flapping rotor bit was added to keep to the general monster theme. The body is built using similar methods to the older monsters, where a sturdy brazed or silver soldered wire frame holds most of the mechanical bits and a woven thin wire structure adds shape. Following previous themes is the sealed sewn silk covering with painted patterns. The patterns made up of simple geometric shapes and bright colours. A silk covered vertical fin is added to make the model more interesting (a bit of a frog crossed with a fish - something one may expect to find in a rock pool at the coast?)

Fat little frog body and rounded curves evident in full body shot above

Details of painted silk patterns on a rotor

The biggest challenge in building this monster was making the gears to drive the rotors. This was done by silver soldering brass teeth to a bent wire frame. The rotors are mounted at a relatively shallow angle to the main drive so commercial gears were not freely available. The final drive looked interesting but did not perform well. When making the video it was a challenge to get the monster to operate without jamming the gears. The main problem was located to the teeth of the rotors  interfering with the main drive axle. This was solved by lifting the rotors a few millimetres with a spacer bent out of wire placed between a stop soldered to the main rotor shaft and the wire bearing through which the shaft was mounted. The movement was also limited by the flapping mechanism only acting on one surface of the swash plate. This was fixed and the monster worked without jamming for the rest of the video session. 

Brass and wire gears for the synchronous counter rotating mechanism

Mechanism to act on the swash plate when going up or down

This was the first monster to introduce decorative glass beads into the wire work. This was inspired by typical African art, of which there were abundant examples around locally (especially in Boom Street in front of the National Zoological Gardens in Pretoria). In this case the neck of the monster is decorated with glass beads (the head still being the common crab claw). The main wire wheels, by adding some extra loops, have also got a slightly different design to the older models. Suspect this was supposed to make it easier to get the wheels to approximate a circle and run a little truer. Guess it is time to try a new helicopter configuration....sometime?

Monster crab claw head and glass beads

The Tricyclist

This is one of the oldest wire monsters. It was created at the same stage as the dragon on a 3-wheel penny farthing monsters were created.  This one is not a typical dragon though as there are no spines on her back (although it would be difficult to achieve as the back is left open).

For this monster there are no external cranks or levers. The pedals/cranks are formed from the axle between the wheels. Her feet are placed on the pedals, and drive her legs. Her one thigh is extended to form the lever which drives her wings and neck via suitable push rods. There is not an excessive amount of movement, largely due to trying to keep the mechanism within her body space, and partly due to not planning it as well as I could have. Anyway there should be a place for subtle in kinetic models.

Detail of pedals driving the legs

 The back of the monster carries the push-rods for the neck and wings. They are all driven from a single point, so the mechanism is simple. The back of the monster is painted red, to show that it is the inside of the body. In this monster the coloured bits are canvas, which are sewn onto a wire frame, and then painted in bright primary (mostly) colours. To add texture to the body and wings the canvas has been covered with texture paste and slightly modelled. This was the only time that I tried this. I prefer the thin silk covering with a few patterns these days.

Back view of monster showing the moving mechanisms

The overall shape of the model, with ample thighs and tapered top, was not as popular in the 80's as it is now. It suited the model well, as there is ample space for the moving bits, and it also gives the monster a very stable rounded feel.  

The frame of the monster was made of thick copper wire. This wire was sourced next to the road on the way to Elands Bay, where new power lines were being installed. This definitely dates the model as these days copper is stolen off the poles, and no one waits for off-cuts. Also power lines now favor aluminium in stead of the heavier more expensive (and desirable) copper wires.

The rear wheel was moulded out of modeling clay with a copper pipe for a bearing. This was a once-off and has not appeared in later models. 

Side view of monster showing strange rear wheel

Bi-Wing Ornithopter

If a biplane was an ornithopter, would the wings flap together or out of sync? In this one the out of sync option is followed.

This monster was conceived during a sea-side holiday. During the morning beach comb, interesting sun-bleached bones presented themselves. I assume the body bones were originally the vertebra of a large fish but as they were found in isolation this is just a conjecture. The shape and size of the bones begged to be included in a monster. The rear body shape  is similar to that of a coelacanth , a very primitive large fish (Coelacanth - wiki). The body shape was defined by the 2 rear bones. The additional bone at the front of the monster was just for effect and I don't know what it represents. A hood ornament?  To enhance the primitive feel I have added a photo recently taken with expired Kodak Plus X (from 1988) in a Mamiya C330 and processed by a novice using old chemicals. I actually like the effect.

Analog black and white image of a bi-wing ornithopter

For this monster a variation on the woven grid  covering was implemented. In the cockpit area the covering is done with a finer black wire and a random pattern instead of approximate squares.  The end result is a more delicate finish, but I have not used it in subsequent models, yet. The ever-present crab claw face does make it's appearance. This makes it a creature instead of a device.

Example of fine wire random woven covering.

The movement of this monster is relatively simple. The wings are driven from cranks which are 180° apart. To try and get a symmetrical flapping motion there are 3 cranks. A central crank driving 2 push rods. Either side of this there are two cranks which are 180° opposed driving a single push rod each. These are connected to the wings and cause the upper and lower wing pairs to flap out of sync. The upper wing has an additional forward/backward motion. This is as a result of the shaft, around which the upper wing bearings rotate, being too long. I feel that the motion adds an element of interest, and have therefore not constrained it. This is one of those unintentional elements that come when using wire and not precisely machine mechanisms. If the wayward motion were stopped, then the relative movement between the pairs of wings would be more symmetrical, as initially intended by using the 3 cranks, but then again not all progress is as a result of intention. The nodding creatures head is driven from the central crank. Overall this is a fairly well balanced mechanism (compared with most of my other attempts). The whole lot is driven from a pair of lead cast wheels (do not feed this monster to kids), with a nose wheel added for balance. Generally I prefer a conventional undercarriage, but for this tail heavy monster this balances it out quite well.

View of motivating mechanism and monster 

The wing and tail surface covering is once again sourced from an old silk parachute. This is stretched, doped, and then a vein like pattern in black, yellow and red paint added. 

I have tried to create a relatively delicate monster this time (relative to the others).  These monsters only happen by chance (finding bones and dreaming, or a faulty mechanism which stays), and are more a result of seeing what bits from that beach walk present themselves as, rather than forcing your design on the material.  Initially chance should guide you, but sometime you have to take over so that you don't seem to lack direction.

Challenger

This Challenger is based on the Quad City Challenger, a kit built ultralight aircraft. The original was a collection of aluminium tubes, nuts, bolts & pop rivets and fittings delivered in a very large plywood box. Add some fibre glass, a Rotax engine and gearbox, some dope and fabric and you have a toy you can fly in.

ZU-CPH near the Vaal, before my carrier type landing

Basic description of the Challenger.
The Challenger 3D sketch follows the same basic shape as the real deal, with 2 crew to add to the effect. The only big discrepancy is that the wings flap (something that is avoided at all cost on the big one, therefore the struts).

The frame of this monster is made up of relatively thin wire with a structure of triangular geometric shapes to add strength. This is a departure from the brazed thick wire frame structure used in earlier models. The individual wire triangles are filled with a grid of copper wire. The copper wire is a slight variation on the standard theme, and is much softer to bend. Didn't take off though as it is also comes loose easier (ie. does not hold tension as well).  In the original Challenger I covered the wings the traditional way with Superflite fabric and a large variety of dopes (nitrate, clear butrate, silver for UV and colours). For this monster silk, clear butrate and pretty paint trim in geometric patterns did the job. Oh, the original wing was glued to the frame, this one sewn. 

The wire monster has an electric motor driven from 2 batteries to spin a hand carved wooden propeller.  The electric motor happened to have a diameter which was the same as an AA dry cell, therefore the handy tubular construction. The original also had a custom made wooden propeller with red tips. The model propeller was made by laminating a number of thin plywood strips together and then carving the shape.

Details of the hand carved wooden propeller and motor.

The switch mechanism for the motor is also a custom design. The one pole of the battery connects with the electric motor. The other pole of the second battery is connected to the metal battery and motor housing, and the other side of the motor via a brass contact attached to stranded wire. The brass contact is pulled against the battery pole when the stranded wire is clipped under the "switch". 

Custom motor switch above the aircrew

The aircrew are the now familiar crab claw heads mounted to wire and tin plate necks. The mechanism to flap the wings and move the heads is a fairly straight forward crank and lever arrangement, with the pilots moving together. Thought that in this case it would work better if they pulled together as a team.

A variation in this monster from the previous monsters documented in this blog is that the wheels are cast from lead. Not recommended in this day and age, but the origins of collecting and casting lead come from my childhood in the late '60s. We used to go to the Swartkop Country Club which was close to my best friends home. Behind the clubhouse there was a large pile of old wine bottles which still had a lead foil around the neck (apparently to protect the cork from being gnawed away by rodents or infested with cork weevels - I'm sure that having a toxic foil really chased the pests away). We collected the lead from the bottles, melted it and cast sinkers or other lead weights. Well the wheels are an extension of this. The molds were hand carved from a soft engineering plastic. This only lasted long enough to get two or so wheels molded before the heat destroyed the mold. So these are fairly unique, never to be exactly repeated wheels. The lead this time was sourced at tire merchants who discarded the old weights used to balance the wheels. My only advice is that if you ever lay your hands on one of these monsters - don't suck the wheels! The axle is soldered to the wheels - another advantage of the lead is relatively easy soldering. The end result is that these wheels are centered a lot better than the wire only versions. I suppose these are similar to mag wheels on cars, where the engineer missed the brief about reducing the unsprung mass.

One last picture which, without the aid of photoshop, to show that ZU-CPH actually flew (not so the Challenger sketch --- but it is only a sketch after all)

Flutterbee

This is the next one in the numbered series that I still have (no. 3 was "borrowed" and never returned). Firstly I have to apologize for mixing languages in the you tube video (the hazard/benefit  of living in a multilingual environment). This is inspired by butterflies (wings) and bees (body). Actually if I have to be honest the "Flutterby" name came from a sketch that I did some years ago to document the elements which make up the movement of the monster, but on reflection is should be Flutterbee.

This monster uses a similar construction technique as developed for the previous examples. There is a wire frame which is covered by a weaved wire cover or painted material. In keeping with the sketch theme not everything is filled in, and the holes in the wire grid helps to display the internal mechanism. A little character is added with the crab claw head.

This monster experimented with the use of copper and silver solder to construct the abdomen of the flying insect. The shape is inspired by bee bodies. The external form is generated with brass wires threaded through the copper ribs of the body. The ribs are attached to the former using an egg-box technique, which I learnt from my father when building model aircraft. This makes it easy to keep in position while silver soldering the components (self-jigging).

This is similar to the technique used by the 3D wooden puzzles built by slotting various pieces into each other. The following image shows an example of a wooden bee which inspired the monsters abdomen's . The paint work is strongly influenced by Ndebele art patterns. A very relaxing way to spend some evenings and a good way to test patience.

The final image shows the shape and colour scheme of the wings. It is definitely more butterfly than bee, therefore the flutterbee. The movement (in the video) of the monster could be smoother, but it is only a sketch. Maybe in the future I will get around to refining the movement, but it is always a good idea to have some unplanned features.

No.2 : FROJO

Why can't you have a flapping helicopter? This is not done on purpose in real life. Apparently helicopters have hinge pins to allow some flapping due to lift differences between advancing and retreating blades, but they do not actively flap the blades. FROJO (FRed* Or JOe) actively flaps its rotors.

The construction is similar to No.1. A silver soldered wire frame holds the moving bits in relation to each other. A painted cotton covering adds some detail to the model. All the sewing is done using cotton and not wire sometimes. The rotors are covered with parachute silk which was done as a restoration job. Later monsters all make use of parachute silk. There is a beaten copper nose panel for effect, as well as two aluminium side panels with fake rivets. The body is shaped with meshed wire. The wheels are formed from wire with binding to help hold the shape. For the fun of it Fred and Joe have different necks, but both make use of crab claw heads. 

Fred and Joe ended up being desert fighters (maybe South West Africa - yes, pre-Namibia). In their adventures they have sorted out a camel, a sea gull (or maybe pelican), a pair of WWII German aircraft and a pair of AWB mounted combatants. The livestock and bird were accidental. The WWII German aircraft go back to my favourite childhood literature of war comic books, in which a small number of British aircraft sort out many superior German aircraft wanting to overrun their small island. The AWB mounted combatants just added a South African flavour to it as their symbol was 3/4 of a German tail marking and they didn't have aircraft, only horses.

Back to the monster. The fun bit was figgering out how to get the flapping mechanism to work. I knew that it had to have a swash plate, because all helicopter had one. Once this was decided the rest fell into place. A long lever moves the swash plate up and down. By hinging the blade along its edge instead of fixing one side of it, the blade flaps instead of changing pitch (ie. the hinge is rotated 90 degrees to that of a standard helicopter). From the videos reference later you can see that I may have a little too much movement, but that is how I did it then and I don't want to change it now.  The rotor blades are driven by hand cut copper gears which work better than those of No. 1 because they are at right angles to each other. 

To add a bit of visual interest Fred and Joe move in opposite directions and by different amounts. This seems to make them work against each other, which is a common South African trait. A tail rotor driven by a chain was added also for visual effect. This chain came from old photo processing equipment and had to be used. The gears which form part of the chain drive were hand cut from copper (see a theme developing?). The original idea for the monster was to push it along the ground, which would mean that the main rotor and tail rotor would be driven at the same time. For the video I however added a separate motor to the monster mount to drive the tail wheel. This allowed me to get a realistic tail rotor speed, which would not have happened when pushed. (For the video :Youtube Frojo Video)

Sketch showing some principles of the kinetic bits

*FRED : Flapping Rotating Entertaining Device?

This is No. 1

After doing the dragon on a cycle 3D sketches, the next phase involved monsters that could have been derived from aircraft or insects. At this stage I thought it would be a good idea to number them, and this was the first. 

No. 1 approaching?

The numbered monsters have a few characteristics in common. They have wings which flap, are driven by wire wheels, have brazed wire frames and critical moving bits. The wings are covered by cotton cloth and a little painted decoration. The frames are covered with a meshed wire pattern. They all have one or more nodding crab claw "heads", which could be called the pilot(s). I'm not sure though whether it is the pilot or the monsters head. I like the head idea with the flapping structure forming the body. This also works better for the insect derived monsters.

Number 1 is strongly based on a school boys idea of an round engined fighter (https://en.wikipedia.org/wiki/Brewster_F2A_Buffalo) maybe crossed with a Gee Bee Sportster (https://en.wikipedia.org/wiki/Gee_Bee_Model_R). Like all real aircraft it  has round engine  (courtesy of Coca Cola).

This monster retains a little of it's origin in the dragon era by having spines along its back and a scaly paint job on the covered tail surfaces. 

Details showing the scaly tail surfaces paint job

The wings have been made with wire ribs, similar to ultralight aircraft construction. Additional details, such as the covering on the side of the aircraft sewn with fine wire, are to create the impression of a cloth covered aircraft. Details around the cockpit include aluminium panels with false rivets, brass chain mail inserts as well as a copper plate on the nose. These are all for effect and serve no mechanical purpose. The black Eisernes Kreuz (derived from the Cross Pattée) was used on German WWI aircraft before 1918 (and the death of the Red Baron), with this one being closer to the one used between 1916 and 1918. The cross is painted on the wings to create the retro-feeling of an aircraft of 100 years ago (only 70 or so years ago when it was made). The coke bottle cowling was painted red in front with an aluminium plate with bumps representing the bolts on the engine. The aircraft ambiance is rounded off with a copper spinner for the two bladed propeller. 

The mechanical parts of the monster were more challenging. Bearings for the wheel axles, cranks and gear shafts are created by bending wire into a circle. The propeller is driven by hand cut copper gears driven from the wheel axle, and turned through 120 degrees with a bent wire universal joint. The wings and head move via couplings to a crank on the wheel axle. Not everything turns smoothly all the time, but this is why it is a sketch and not a mechanical mechanism (which would imply refinement through iterative designs).

Some mechanical details

The following link is to a longer video which is easier to view than using the bloggers video app : Video of No. 1.

The Starting Blog

This is the first of the actual KR3DS blogs. The purpose of these sketches are to demonstrate some form of movement. This particular one hasn't got a name or originated from any great inspiration, but was purely born out of a "what if ?" moment. 

The basic movement of most of these rotary kinetic sketches is the wheel driving a crank and the crank flapping wings (via one or more push rods). After this there follows many variations of the theme. This particular one has an additional hinge on the end of each wing and an offset fixed point coupled with a push rod. This allows the tips of the wings to swivel and add a little complexity to the basic flapping motion.

Image to give the impression of flapping wings.

The basic movement of the 3D sketch is demonstrated in the following video.

This video shows the sketch (or monster) mounted on stand with a motorized drive for the wheels. The motorized drive is battery powered and drives a large reduction gearbox to provide the necessary torque to turn the mechanism. Originally the intention was to push the monsters on the ground to provide rotary motion via the wheels. Unfortunately the wings generally provide a very unbalanced load, and the wire wheels do not have sufficient grip for smooth motion over the full flap cycle. If you push with enough downward force for a convincing demonstration you end up deforming the monster (wire bends after all). Anyway the motorized drive means that one can have a video without the pusher getting face (or hand) time. There is also the added benefit of not having to be behind the camera as well as in front of the camera at the same time. I prefer it this way.

This monster shows most of the construction techniques employed in the series. 

The frame is constructed using thick wire which is brazed or silver soldered. The overall shape of the sketch is formed with thinner wire, generally woven to create a sturdy structure. Wings are covered with silk in this and the later models. This is stretched and stitched keep it taut. The silk is coated with clear coats of dope, and usually has a pattern painted on the surface.

This particular monster has a cover made of aluminium printers tray with false rivets, for an aeronautical effect. It is attached with brass plates and small pop rivets.  The surface of the wing is painted with red veins to mimic a bats wing with back-lighting from the sun. I don't know why I decided on this paint scheme, but I guess it does fit in with the general theme of "things that could possibly fly".

Here is a link to a longer video showing the basic movement of the 3D Sketch as well as a close up of the mechanism in motion (the crank bits which flap as well as the forward flung hinged wing tips). Youtube video of the starting monster