Crane Toy

For this project you will need :

Material :

• plywood 5mm thick
• plywood/cardboard/oak... 18mm thick
• M5-12mm screws, quantity 7
• M6-40mm, quantity 4
• M6-50mm, quantity 1
• cord string

Tools :

• A cnc router or a laser cutter (think to the fablabs network if you don't have this at home)
• A 3D printer with PLA
• hex keys for M5 & M6

Step 1: Cut the Wood

Tips :

• For the plywood I've used a downcut bit (2mm diameter).
• I have a STEPCRAFT D600 with a M800 spindle : I've cut with a speed of 260 mm/min, spindle speed 3.
• For the circle foot I've cut a 18mm oak plate to a 250mm circle. But I recommend cardboard because oak is expansive.

I give you here the DXF file with the profile.

Step 2: 3D Print

There is 6 items type to print :

• 7 spacers, they will be used to assemble and maintain the 2 plywood profiles
• 2 return pulleys
• 1 main pulley (to wrap the string)
• 1 crank
• 1 bracket to fix the bottom crane
• 1 hook

Materiel : PLA, 0.4mm nozzle, 0.2mm layers

TIP : print the crank a little bit larger, scale 100.5 or 101%. This will help further to insert it on his axe.

Step 3: Prepare the 3D Printed Items

Tap the spacers with M5. The thread must pass through the all length.

Step 4: Assemble the Crane

• Screw the spacers on one profile.
• Insert the pulleys.
• Place the second profile and screw it.
• Insert the crank : push it on the axe of the rollup pulley, it is normally tight enough to hold itself. If not reprint it changing the scale.
• Insert the bottom bracket and tight the M6 screws in diagonal. You will notice the different sizes of the holes : some are 5.5 mm, the M6 screw will tap itself when inserting.
• Tap the bottom bracket with M6.
• Drill through the bottom plate to let pass the M6 screw, then drill to mid-point with a larger bit to let pass the head of the screw.
• Screw the bottom bracket, not to tight to let the crane turn.
  • you can add a washer between the plate and the bracket to have a smoother move.
• Attach a string to the hook and to the main pulley.
  • I've used a Flex filament for 3D printing. But anything kind of string can do the job.

Step 5: Conclusion

My 3 yo son is happy :-)

As an extra, it is possible to decorate the crane with colored pencils, markers, paint ..

If you want to make this project and don't have a CNC router and/or 3D printer, contact me to provide you the parts you need. I am happy to help.