Mechanical 3D Printed Orca

In this instructable I will show you how I went about creating a Kinetic 3D Printed Killer Whale or Orca as they are more commonly known.

I have seen one of these type of mechanical whales before but the Orca appeals to me, probably because of the striking coal black and brilliant white colours, which makes it ideal for this project.

In order to progress this project I would have to find a 3D Printed Orca STL online, I don't know how to use Software like Blender etc.

My aim is to make the Orca movement as close as I can get to the real thing, the movement of the Orca seems to be very tail oriented, the head is more or less still with slight tilt motion and the middle part of the whale generates the momentum for the Tail action, the tail being a big part of the Orca's armoury, the mechanical movements I have seen have all been from a bottom crank with offsets at different degrees, I would like to suspend from the top with something like fishing line to each segment and some sort of pulley system.

To the first chapter which is finding an STL file and then Importing into Fusion 360

3D Printer..

Orca STL Free file

1.75 PLA Black.

Fishing line/monofilament.

Hot Glue.

6 x SG90 Servos

Pololu Mini Maestro Servo Controller.

DuPont cables

9v Battery

A simple search online see's me finding the perfect candidate for my project, this free to download Orca STL has got the perfect shape as I want the whale to be in 6 sections for a more fluid movement.

On importing the file into Fusion 360 as a Mesh I now convert it to a solid using the convert mesh tool in Mesh, the STL has a lot of Triangles so it takes a while to compute, my Lap Top is old and not that fast, so I just sit tight and let it do it's thing.

Once converted, I checked the dimensions, it's way too small for my project so I need to scale it up, I scaled it up by 2 and again left it to compute, for some reason the original Converted mesh solid was still there within the scaled up version so I deleted both the original mesh and Solid as to avoid any confusion, the outcome is it looked too big to fit on the bed of my 3D printer but that doesn't matter as it's going to be in 6 segments, it will be just right.

The next job is to create an offset plane, this is the front facing plane and is moved out 50mm to the side of the whale, I create sketch on that plane and sketch in 6 vertical lines where I want the segments to be, I convert the body into a component and Using the Split Body tool I can now split the whale into 6 Segments using the vertical lines as the splitting tool, at this stage we are ready for 3D Printing.

I have 2 3D printers and placed 3 segments on each printer, they took approx 5 hours on each Printer to Print, I used support for the fins, and printed with Low Quality as the parts will be sanded and Painted

Please check out the screen shots for the process for more clarity as some of these things are hard to explain, choosing the correct words etc.

The next section is creating the joints.

This part had me scratching my head a bit, it needs to be some sort of hinged affair for this to work correctly, I have a box with some brass hinges in, what I had forgotten about is that I also have some tiny round hinges, using 2 of these per segment would be just perfect, I still had to match everything up which is a challenge in itself.

As a starting point I started with the head section and the next segment along, I marked a horizontal centre lines and the marked 12mm inboard from the outer edge of the section, The hinge dimension came out at 4mm and I had a 4mm star point drill, I drilled the first 2 holes and finding a couple of the hinges which were a bit more stiffer, I used these as my guides for the next section, I put a small dab of yellow paint on each one and gently placed the next segment on top, the paint marked where the holes on the next segment wanted to be and I drilled these holes, then used some CA Glue to secure them in the correct position, had I had any I would of used epoxy to secure the hinges but CA seems to be ok on this occasion, I repeated the process with all the segments, it's not perfect but not too bad considering I had no clue on how to do it initially.

With all the Segments glued up and moving freely its time to sand and then apply some Acrylic paint, the pla I had was black, so I applied a quick coat of Black board paint this dried quickly, then I applied the white paint for the markings I looked at a couple of images to guide me on where to paint the white bits but they were all different anyway so there is no set way to do this, and the final part is to apply a coat of lacquer for a shiny finish.

On to the next part, this is building a framework for the Orca to suspend from the Top and create movement, I have an idea on how I want to do this, there will be a bit of trial and error with it as always.

My idea for creating movement is to use small servos connected to the Orca with fishing monofilament, the Orca will be suspended from the top creating a more fluid movement.

I used a piece of the Walnut veneer flooring I had as a base, I had 4 lengths of 5mm threaded bar with nuts and washers off a previous project, these will suspend the top part of the frame and already pre drilling a piece of plywood for the top part, with 6 holes for the monofilament to pass through plus the 4 holes to secure this onto the threaded bar.

The Orca is in 6 segments and I used 6 Servos which I didn't need to, the Orca's head hardly moves, these were secured with hot glue with the first hole of the horn placed over each hole in the plywood.

I fixed the head of the Orca to the base to stop forward and backward movement, this was done with some polished chrome bar and one of the brass round hinges.

I placed some objects underneath the Orca to keep it off the base and connected the monofilament to the Servo horns.

I used 4lb fishing line to suspend the Orca and a bigger diameter monofilament to make some sliding knots, thread the line through the Servo horn and then make a sliding knot it makes the task of suspending the Orca and any adjustments a lot easier.

The Servo controller is a Pololu 6 channel and a script can be creating controlling individual speeds and acceleration to mimic the Orca's movement using the Pololu Maestro control centre.

Once happy with the Servo/Orca movements the script can then be saved so it runs on battery power alone.

I boxed the top part of the project with 3mm ply this was cut and glued into position, the lid needed to be removeable to change the battery when needed, to facilitate this I cut 4 short lengths of 12mm dowel and glued these into each corner then I drilled the lid in each corner and used 4 small screws to secure, with this completed I could paint both the top part, the base and the threaded rod with Blackboard paint.

To finalise the project I made a sea scape back drop out of 3mm ply, this was painted with some blue pre mixed paint I had left over from a previous project, I sketched in 2 Orcas and for the black I used a black sharpie, and for the white a white paint pen, the board is then secured to the back part of the framework with hot glue and then finally some blue LED's are added to create some effect.

I drilled 4x 4.9mm holes in the top and pushed the LED's in I then took power from the Pololu board then into a buck converter and wired the 4no LED's in series and adjusted the voltage to 3.2 volts, the effect looks pretty good

That completes this project, suspending the Orca and getting the movement something like was a challenge but I enjoyed messing with it, using the sliding knot made it a lot easier to get the height and posture correct then connecting to the Servos, any tweaks could be made with the sliding knot.