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Picture of Halloween 2018: Realistic Giant Spider
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For Halloween 2018 I created a large, realistic spider; I've seen a number of giant spider builds, and while all were impressive, because my father is an entomologist and taught me about insect and arachnid anatomy I was never really satisfied with their inaccuracies and strove to do better. I think I largely succeeded, although there were a number of changes from my original vision to accommodate challenges that arose during the build and time constraints due to not starting until early October and poor weather limiting the amount of time I had to work on it. The spider ended up with a legspan of over 11 feet and was over 8 feet from the end of the abdomen to the tips of the pedipalps, and over 3 feet tall.

The main parts to get spider anatomy correct are:

  • Cephalothorax (body section with the head and legs)
  • Abdomen (largest body section)
  • 8 segmented legs, not at 90 degree angles to the ground
  • 2 pedipalps, smaller appendages in front of the legs
  • Mandibles with claws/fangs
  • Minimum 4 eyes (I went with 6)

Below is the materials list, which is a rough approximation as the changes I made during the build make coming up with an accurate list difficult. I went with 3/4" PVC pipe for the majority of the build to keep pieces standard and as the pool noodles I bought had a 3/4" inside diameter.

MATERIALS

  • Skeleton/Base
    • 3/4" PVC pipe (48 feet for legs + 10 feet for cephalothorax + 10 feet for supports)
    • 1/2" PVC pipe (12 feet)
    • (8) 3/4" PVC 90 degree couplers
    • (25) 3/4" PVC 45 degree couplers
    • (8) 3/4" PVC straight couplers
    • (3) 3/4" PVC T couplers
    • (6) 3/4" PVC cross couplers
    • (4) 3/4" x 1/2" 90 degree couplers
    • (4) 1/2" 45 degree couplers
  • Body, Eyes, & Skin
    • (6) pool noodles
    • (2) 6 foot 1/2" diameter foam pipe insulation
    • (8) 6 foot 3/4" diameter foam pipe insulation
    • Hardware cloth
    • Chicken wire
    • (2) 24" latex balloons
    • (4) poster board sheets
    • (8) plastic drop cloths
    • (15) cans Great Stuff expanding foam
    • (2) large plastic ornaments
    • (4) small plastic ornaments
    • (6) cans gloss black spray paint
    • Wood board (I used a 1x6 2 foot long project board)
    • (2) pipe flanges
  • Other
    • PVC cement
    • Heat gun
    • Wire cutters
    • PVC pipe cutters
    • Zip ties
    • Masking tape
    • Duct tape
    • Plastic bags
    • Fencing tension wire

Step 1: The Base Structure

Picture of The Base Structure
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The main "spine" is a a series of PVC cross couplers with connections for the legs on each side, as seen in the first photo. I did make two major changes after that photo, however. First, the front row was shortened on each side, as these were the connections for the pedipalps and I wanted them closer to the eyes (see third photo). Second, I added two T connectors, one close to the middle and one at the back, with the 90 degree angle facing down, so I could attach hidden supports underneath to keep the body off the ground.

In keeping with accurate spider anatomy, in the first photo the four pipes off to each side act as the coxa part of a spider's legs, while the vertical pipes off them, where the separate legs will attach, act as the trochanter part of a spider's legs. The part in front with the T coupler is where the mandible supports were attached, as can be seen in the third photo.

The legs themselves are constructed as follows:

  • a 45 degree coupler for attaching to the body
  • an 18" length of 3/4" pipe for the femur section of the leg, with a pool noodle cut to length
  • another 45 degree coupler connecting the femur to the tibia
  • an approximately 15" length of 3/4" pipe for the tibia section of the leg, with foam pipe insulation cut to length
  • another 45 degree coupler connecting the tibia to the metatarsus
  • an approximately 15" length of 3/4" pipe for the metatarsus section of the leg, with foam pipe insulation cut to length
  • a straight coupler for connecting the metatarsus to the tarsus
  • a final 12" length of 3/4" pipe for the tarsus section of the leg, of course with foam pipe insulation cut to length

The pedipalps were constructed at the same time in a similar manner:

  • a 45 degree coupler for attaching to the body
  • an 18" length of 1/2" pipe for the first section of the pedipalp, with foam pipe insulation cut to length
  • another 45 degree coupler connecting the two pedipalp sections
  • a 15" length of 1/2" pipe for the section section of the pedipalp, with foam pipe insulation cut to length

The mandibles were constructed with two of the 3/4" x 1/"2 90 degree couplers, with 4" sections of 1/2" pipe leading to 45 degree couplers connecting the mandible structures.

Creepy yard decoration :)
dwspitzer (author)  Penolopy Bulnick10 months ago
Thanks!