Racing Cyclist Whirligig

Being an avid cyclist it was only a matter of time before I made a wind driven cyclist Whirligig, building upon a couple of earlier projects (Wind Vane & Against the Clock), to provide the building blocks.

This is a custom designed 12 blade sun ray pattern; self orientating, wind vane complete with pedalling cyclist.

A mainly 3D printed project primarily in yellow in homage to the Tour de France although other colour combinations could be employed as suits personal preference.

Size: 187(W) x 240(H) x 460(L) mm

Weight: 290g

3D printing filament PLA (Yellow and White), although other colours may be used as suits personal taste.

M2 x 6mm machine screws - Qty 2 (crank/pedals)

M2 x 8mm machine screws - Qty 4 (propeller)

M2 x 10mm self tapping screws - Qty 2 (cyclist)

M2 X 10mm machine screw (drive stop)

M2 x 15mm machine screws - Qty 3 (optional main bearing fixing)

M3 x 6mm machine screws - Qty 8 (bearing, pivot and drive supports)

M3 x 8mm machine screws (handle bar)

M3 x 10mm machine screws - Qty 4 (legs)

M3 x 12mm machine screw - Qty 4 (pedals and shoulders)

M3 x 20mm machine screw (handle bar)

M3 x 25mm machine screw (torso)

M3 x 10mm threaded hex standoff - Qty 4 (hips and handle bar, optionally cylindrical standoffs can be used).

M3 locking nuts - Qty 4 (legs)

M3 plain flat washers - Qty 14 (legs)

Technic worm gear 5T

Technic double bevel gear 20T* (crank/pedal gear)

Technic Axle 8L*(~63mm) (drive shaft)

Technic Axle 6L *(~39mm) (crank/pedal)

*Metal technic parts exist as alternatives for added strength and durability

Brass tubing 6.5(dia) mm with 0.2 mm wall thickness (cyclist axle)

Brass tubing 3.5(dia) mm with 0.2 mm wall thickness (legs)

Metal tube 6mm (dia) x 21.5(L) mm (Stainless Steel Drinking Straw) - Qty 4

Flange Ball Bearing: 13.5 (OD) x 12 (ID) x 4(H) x 6(Bore) mm (main bearing)

Ball bearing: 7/32inch (5.56mm) diameter (pivot)

May prove more cost effective to buy a range of values rather than individual values unless you already have them available. Some components may also have a MOL greater than the quantity specified in the component list.

No affiliation to any of the suppliers feel free to use your preferred supplier that suits the requirements. Cannot guarantee the availability of specifically listed parts due to supply or obselecence requiring alternatives to be sourced that may vary from those listed. 

Links valid at the time of publication.

Tools

3D Printer

Pliers

Vice

Saw

Needle files

Sanding paper

Craft knife

Screwdriver

Marker

Adjustable spanner

Drill

Drill bit 2mm

Drill bit 3mm

Drill bit 3.5mm

Drill bit 5mm

Drill bit 6mm

Drill bit 6.5mm

Plastic Adhesive

Varnish/thread lock

Silicone Lubricant

Know your tools and follow the recommended operational procedures and be sure to wear the appropriate PPE.

The 3D printed elements were designed using BlocksCAD, sliced using Cura 4.5.0 and printed on a Labists ET4.

1: Cycle and cyclist upper body. Size:197(L) x 139.5(D) x 15(H) mm, Weight: 47g

2: Cyclist torso. Size: 59.1(L) x 33.4(D) x 5(H) mm, Weight: 7g - Qty 4

3: Cyclist arms. Size: 39(L) x 30(D) x 5(H) mm,Weight: 3g - Qty 2

4: Cyclist thighs. Size: 36.3(L) x 48.4(D) x 5(H) mm, Weight: 3g - Qty 2

5: Cyclist lower legs. Size: 25.7(L) x 46.7(D) x 5(H) mm, Weight: 2g - Qty 2

6: Pedals/Crank. Size: 28(L) x 12(D) x 6.5(H) mm, Weight: 1g - Qty 2

7: Hip spacers. Size: 20(dia) x 6.5(H) mm, Weight: 2g - Qty 2

8: Chainring spacer. Size: 20(dia) x 2(H) mm, Weight: 1g

9: Propeller. Size: 186.7(dia) x 10.9(H) mm, Weight: 56g

10: Propeller back. Size: 20(dia) x 24.5(H) mm, Weight: 6g

11: Rod cap. Size: 10(dia) x 18.5(H) mm, Weight: 1g

12: Pivot. Size: 31(L) x 24(D) x 33(H) mm, Weight: 12g

13: Main Bearing. Size: 24(W) x 51(H) x 20(D) mm, Weight: 16g

14: Worm bearing. Size: 24(W) x 45(L) x 45(H) mm, Weight: 23g

15: Vane clamp: Size: 16(dia) x 47.4(H) mm, Weight: 9g

16: Vane Tail: Size: 128.6(L) x 113.1(W) x 3(H) mm, Weight: 25g

17: Drive Shaft stop. Size: 20(dia) x 8H) mm, Weight: 3g

18: Balancing foot. Size: 20(dia) x 20H) mm, Weight: 2g

Weight and size may vary from those provided if the material or printing differs from the details specified.

Layer Height: 0.15mm

Infill: 100%

Wall Thickness: 2mm

Bed Adhesion: Skirt

No supports

All parts are correctly orientated within the files for printing directly.

A combination of individual and multiple elements are required which subject to size can be printed individually or in groups on the print bed.

From experience PLA will last several seasons subject to thickness, infill, physical and environmental (temperature/moisture), stresses. 

An epoxy overcoat will aid environmental robustness sealing gaps to reduce moisture ingress.

Situated out of direct sunlight will reduce UV degradation (brittleness and colour fading). 

However, you may wish to use PETg or ASA as these may prove more robust in the longer term.

It's been designed to use screws and push fit for the assembly as far as possible this is to enable easy replacement of any part which may suffer the effects of the environment or even allow for storage.

Some post processing may be required to remove aberrations in the cavities and around the edges with sanding paper and needle files in addition to opening and smoothing the holes with a drill bit.

Use a needle file and/or sanding paper to smooth the parts in areas were they come together.

Prepare the Drive Support

The worm gear is supported on an axle that is supported by two 5.5mm bushings.

These are fitted in a similar manner to the bushing on the thighs.

Prepare the Thighs

The rotating parts of the thigh occur at the hips and the knees for which some type of bearing is required to enable smooth movement. For simplicity this would be a plain bearing (bushing), press fitted into the hole as the load is light with a small degree of movement and low rotating speeds.

The bushing will be made of brass due to the following properties; self lubricating, corrosive resistance and resistance to bonding to steel (hip and knee shafts).

With a 6.5mm drill bit clear out the hole for the hip.

Cut a level length of 6.5mm brass tube greater than 5mm in length and ensure the end to be inserted is burr free and smooth.

Place the thigh on a level firm surface and using a piece of wood or plastic to protect your fingers apply firm level and even pressure to position the brass tube into the hole at this point it needs to be free standing and level. If it is not level press it out from the other side with a length of 6.5mm tubing and reseat.

Once confirmed level use a smooth face vice or parallel pliers to press the tube fully into the thigh.

Using a file remove the protruding tubing flush with the surface of the thigh.

Clear out any burr from within the tube with a round needle file/ roll of fine sanding paper and check for smoothness with the shaft of a cotton bud which should not catch/drag.

Repeat the process at the knee with 3.5mm drill and tubing.

Prepare the Legs

The rotating parts of the leg occur at the knees and the feet which will be using bushings as with the thighs.

Repeat the process as applied to the thigh at the leg with a 3.5mm drill and tubing appliying this both to the knee and foot.

Prepare the Cycle

The chainset axle hole requires a 5.5mm bushing fitting.

This are fitted in a similar manner to the bushings on the lower limbs.

Prepare the vane tail.

Apply a little adhesive to the edges of the vane tail to which the vane clamp will be attached.

Push the vane clamp onto the vane tail, if necessary insert the metal tube unto the hole in the tail clamp to retain alignment. Be aware of applying too much adhesive if you wish to remove the tube at a later time.

Set the vane tail assembly aside until the adhesive has cured.

Press the flange bearing into the bearing support with a vice or parrallel pliers

In the event that it can be pushed in with fingers or is loose subject to tolerance variation with the printing material or the bearings. The bearing can be held in place with 3 x M2 x 15mm machine screws.

Fit 2 x M3 x 6mm machine screws in the holes coincident with the tube retaining holes.

The pivot is on which the whirligig sits and rotates in the wind.

Check the fit with a 6mm pipe and if too tight open up with a 6mm drill bit, if too loose wrap a layer of thin tape around the pipe to fill the gap.

Fit 2 x M3 x 6mm machine screws in the holes coincident with the tube retaining holes.

The drive support holds the worm gear and axle which are connected to the drive shaft.

The worm gear is aligned with the crank/pedal gear which drives the legs.

Additionally, there are required 4 x M3 x 6mm machine screws, two for the support tubes, one for the vane tail and one for the counter balance.

Cut a length of 6mm diameter tube to ~48mm (such that it is slightly longer than the width of the hips to prevent the thighs binding when the screws are tightened), and deburr and smooth the interior and external ends.

Subject to the tolerance of the standoff and the tube it may be necessary with a reamer or 5mm drill bit to open out the ends on the tube to accept the standoff.

Apply a suitable adhesive or epoxy putty into the end of the tube and push in the standoffs until its flush with the ends and set aside to cure.

Alternatively by tapping in the standoff with a mallet or press fit between a vice. Be sure to protect the open tube end with a wooden block or other soft material to prevent damage. Reducing the circumference at one end of the standoff with a file will help with insertion.

Clear the hip hole in the main cyclist body with a 6mm drill bit and Insert the rod to half its length.

Clear out the 6mm holes at the hip of each of the 4 torso elements and slide 2 on each side of the main cyclist body ensuring they are all aligned with the central 3mm hole aligned. Clear out the 3mm hole with a 3mm drill bit and pass through a M3 x 25mm machine screw then fit a M3 nut and tighten.

Fit a 6.5mm spacer over each end of the pelvic rod.

Feed a M3 X 25mm machine screw through the hand hole on one of the arms and thread a 10mm spacer onto the screw. Hex spacers were used but cylindrical spacers are equally suitable.

Feed the free end of the screw through the hole in the handle bar and screw a 10mm spacer on the other end.

Align the remaining arm with the open end of the spacer and attach with an M3 x 8mm machine screw.

Align the holes of the shoulders for the arms and the torso and fix in place with M3 X 12mm machine screws.

The lower limbs consist of the thigh and the leg which are attached together at the knee.

Thread a plain washer onto a M3 x 10mm machine screw and pass the screw through the thigh at the knee then place another plain washer over the screw.

Pass the screw through the knee of the leg and place a plane washer over the screw and fix in place with a self locking nut.

Tighten the nut to reduce side to side play to a minimum but still allowing the leg and thigh to rotate about the knee with low friction.

Hold the top of the thigh between thumb and finger letting the leg hang down and swing the leg in line with its plane of movement. The leg should swing freely.

If leg does not swing freely, check for over tightening of the nut, missing central washer.

Open the hole in the pedal with a 3mm drill bit to allow a M3 screw to spin freely.

The pedal is orientated such that the recess faces into the centre of the cycle and is attached on the inside of the foot.

Thread a plain washer onto a M3 x 12mm machine screw and pass the screw through the pedal and then place another plain washer over the screw.

Pass the screw through the foot of the leg and place a plane washer over the screw and fix in place with a self locking nut.

Tighten the nut to reduce side to side play to a minimum but still allowing the foot and leg to rotate about the pedal with low friction.

Hold the top of the thigh between thumb and finger letting the leg hang down and swing the leg in line with its plane of movement. The crank/pedal should swing freely.

If leg does not swing freely, check for over tightening of the nut, missing central washer.

Attaching the drive gear to the left leg.

Note: The drive is applied on the left side whereas a conventional cycle is on the right.

Cut the 6L axle to a length of ~38mm.

On the drive side feed the axle through the crank then feed on the 2mm washer and then the double bevel gear on to the axle.

Feed the hole in the thigh over the pelvic rod and the axle through the hole in the vertical frame support.

Push the non drive side crank/pedal onto the axle.

Ensure that the cranks are aligned in opposing directions (180 degrees apart).

In the event that the crank/pedal does not sit snugly on the axle provision is made to fix this using 2 x M2 x 6mm machine screws.

Feed the hole in the thigh over the pelvic rod.

Check the movement of the lower limbs and drive assembly by rotating the gear by hand resolve any binding that may occur.

Secure the legs to the pelvic rod with a 2 x M3 x 10mm machine screws and plain washers.

The leg should rotate freely about the hip with ~1mm side to side play, without this play the hips can bind when the hip screws are tightened.

If not rotating freely and assuming the internal surfaces of the plain bearing are burr free and likewise with the exterior surface of the pelvic rod a tolerance or alignment issue may exist.

Rotating the thigh about the hip a number of times from left to right will likely smooth out the issue.

Attach the cyclist to the drive support with 2 x M2 X 10mm self tapping screws.

Slide 2 x 6(dia) x 215(L) mm pipes in to the ends of the drive support and fix in place with 2 x M3 x 6mm machine screws.

Fit the pivot on to the ends of the 2 x 6(dia) x 215(L) mm tubes (support tubes), and position ~31mm from the drive support lighlty fix in place with 2 x M3 x 6mm machine screws.

Fit the main bearing onto the ends of the support tubes and fix in place with 2 x M3 x 6mm machine screws.

Push the free end of a 6(dia) X 21.5(L) tube (drive shaft), through the back of the main bearing.

Although, the bore and rod are 6mm, manufacturing tolerance may affect the fit.

The fit for the rod in the bearing should be tight to prevent it spinning loose

For example a single layer of thin (0.05mm), metal (copper/aluminium), tape around the rod may be sufficient to fill the void.

Press fit the rod cap on the free end of the drive shaft.

Cut the 8L axle to a length of ~58mm.

Feed the axle through one side of the drive support and the worm gear and out the otherside and into the rod cap.

Attach the propeller back to the propeller with 4 x M2 x 8mm self tapping screws.

Push fit the propeller assembly onto the free end of the drive shaft.

If the propeller back sits loosely on the pipe provision is provided to fit a M2 x 10mm machine screw to hold it in place.

Check for free rotation of the drive assembly by blowing on the propeller.

If it fails to rotate or requires a lot of effort to rotate check for tight spots or rubbing of surfaces.

In the unlikey event that the shaft should come free from the bearing at speed the drive stop prevents the drive shaft spinning free.

Cut a length of 6mm diameter pipe to 95mm deburr the ends and push into the vane clamp

Fit the Vane tail in the central hole at the back of the drive support align vertically and secure with a M3 x 6mm machine screw.

Into the base of the pivot insert a 7/32inch (5.56mm) ball bearing and push in a ~100mm length of 6mm hollow pipe.

On the end on the pivot pipe push on the pivot foot on which the wind vane will sit whilst balancing.

The wind vane will balance with the pivot foot on a flat level surface when balanced.

The pivot foot can be removed once the wind vane has been balanced.

Position the pivot on the 2 support pipes to find the balance point and secure with 2 x M2 x 6mm machine screws.

As the cyclist sits slightly off horizontal centre it may be necessary to include a counter balance.

The counter balance added is a length of 6mm pipe in the side hole in the drive support the length of the pipe adjusted to achieve balance. Alternatively, a shorter pipe with added weight.

All that remains is to mount the wind vane on a suitable vertical cylindrical rod (plain or threaded).

This could be on a pole in the ground or fixed to a right angle bracket on a post, wall or fence.

Hope you found it of interest.