Introduction: Motorized Spider Halloween Candy Delivery System
Anyone can send candy down a tube.... The challenge is sending it on the outside of the tube...that and working with tricky spiders and magnets.
What better way to deliver Halloween candy safely than with socially distancing spider couriers.
After trying for weeks to train real spiders to walk down a log to deliver candy and failing... I turned to a mechanical conveyor system to keep the squiggly guys on track.
Used this last weekend at a campground Halloween weekend event. The kids loved it as they tried to catch the candy from the spiders. The candy was supposed to land in the bucket but occasionally the spiders flung it too far or it bounced out. (especially at higher speeds.) The system had no problem keeping up with the mob of costumed kids and they were happy to wait their turn to get candy from a spider.
Also note the large spider web in front of the tube seen in the campsite photos (made from tent poles creating a 10 ft arch and dental floss webbing.) It was effective at keeping the kids from interfering with the spiders at work.
6" Dia. PVC schedule 40 pipe (6ft long)
Spreadable Mastic (1 gallon "Liquid Nails")
1"x4" board (8ft long) conveyor structure
1/8" steel cable and ferrule to join ends (xx long)
Magnets (6 large qty) 1" Dia. fender washers (qty 6)
Felt - (Peel & stick chair leg feet)
DC motor 60 RPM (2 qty)
2"x4" board 8" long to make 3" Dia pulley wheels (qty 2) or 3D printed pulleys optional construction
Mending brackets and various other bits and bobs I have forgotten but you will be able to identify in the pictures/videos
Rubber Spiders (6 qty)
Magnets (6 small qty)
3D printed plastic body
4x8 sheet of 3/4" plywood
Step 1: Spiders
Shameless Begging * for your Vote in the Instructables 2020 Halloween contest. (* My grandmother from the old country used to call trick or treating...Begging hmmm)
INSECTS!...Once responsible for a prior pestilence in the form of Bubonic plague carrying fleas of the 1300's, insects are here to redeem themselves. Spiders (I know technically arachnids not insects..but the bottom of my shoe can't tell the difference) have come to help prevent the spread of 2020's pandemic.
The spiders are in your control...and on the straight and narrow you could say...in their creepy crawly sort of way, to keep Halloween safe (and a bit scary).
With this Instructable an endless troop of spiders has been sent forth to spread their candy goodness, without spreading their germs. Be safe little trick or treaters, and distance... like the spiders.
Create 6 Spider candy carriers so that multiple spiders can be on the conveyor line with some off line being reloaded with candy.
A file of a spider body (abdomen candy cup) and a front tab with a magnet pocket was created and 3D printed (6 qty)
Use the smaller magnet (12mm dia) in the depression in the 3D printed spider body tab and glue in place
Cut the rear end (abdomen) off of 6 rubber spiders
Glue the front end of the rubber spiders (head & legs) to the 3D printed spider Bodies (super glue works well)
Paint the bodies as desired (Testers paint works well)
Note: the rubber spiders used here were pre painted, as manufactured, and trying to add additional paint to the stretchy rubber front parts did not hold well.
Step 2: Log
6" Diameter PVC Pipe 6 feet long
Grind a flat spot along the length of the pipe this will be the top runway for the spiders.
The thinner wall stock of the pipe increases the magnetic force
Slide the conveyor board with the pulley features and cable into the pipe. Place just under the flattened run way and secure with screws drilled through the outside of the pipe into the board
Coat pipe in heavy layer of Mastic. apply with gloved hands. Create lines and groove and features to look like bark
The mastic shrinks as it dries so error on a thicker coating. However larger blobs for knot holes may sag before setting up (and the thicker portions remain soft for a few days)
When cured paint with acrylic paint. (brush on and wipe off to create color variations)
Step 3: Conveyor System
1x4 board 8 feet long. Cut notches in the ends to accommodate the pulleys. The top of the pulley (and cable are just slightly above the top surface of the conveyor board.
(2) pulleys 3" Diameter Cut out of 2x4 with a hole saw. Mount on a shaft in a drill and file a "V" groove for the cable to run in. Or 3D print a pulley (I made one of each. The drive wheel was easier to mount to the motor using a hex shaped pivot hole to fit 1/4" threaded rod couplers.)
For the drive wheel either epoxy the motor "D" shaft in the pulley hole or use the 3D printed version with the hex hole.
For the hex hole. Drill out the threads from 1/4" threaded rod couplers to fit on the 6mm motor shaft. Drill and tap a hole for a 10 32 set screw for the flat on the motor "D" shaft. Do this for both motors.
Use (2) 60 RPM 12v motors (Amazon) wired to a PWM (Pulse width module) speed controller. Be sure to wire the motors opposite to each other so they turn the pulley in the same direction.
(I tried with one motor but it did not have enough torque so I added the second.)
Cut slots into 2 angle brackets and use springs, mending brkts, 1/4" threaded rod & nuts and springs to make a tensioner to keep the cable taut. Keep the nuts loose on the threaded rod; the whole motor assembly needs to move freely in the bracket slots. (the cable washers going over the pulley causes the pulley to need to slide in and out)
the first few photos show the installed motors, pulley & tensiononer mechanism in place. It is located on the under side of the conveyor board. The next photos show it disengaged to make some of the details visible. Also the motor is removed from the hex coupler to show the set screw and interface to the pulley.
Two angle brackets are need at the other end of the board for the stationary pulley. Use a 1/4" bolt and nut as an axle for this pully.
Step 4: Conveyor Cable
1/8" steel cable is used for the conveyor. Cut to xx feet
1. Modify 1.25" fender washers to be magnet carriers attached to the cable
2. Add opposing "dimple trenchs" to the washer so the washer will lay flat against the cable.
3. Bend the "wings" of the washer up to create a slight "V" this will allow the magnet to sit flat on the cable and not rock on top of it. (Also, the "V" shape better conforms to the "V" in the pulleys as the washer is pulled around
4. Slide the washers on the cable and space evenly along the cable loop
At each washer location. Use two vice pliers to grip the cable. Rotate the pliers 1/2 turn in opposite directions to open the strands in the cable
Feed a short length of small gauge wire through the open cable strands. Release the pliers. The cable strands will close and trap the wire in the cable)
5. Use this smaller wire to "tie" the washer to the cable. (wrap the wire a few times through the washer hole and around the cable and twist the ends to secure the washer in place)
6. Cut a furniture leg peel and stick felt pad into a circle slightly larger diameter than the washer. Cut a hole in the center. (a 1/4" compression brass fitting with its sharp edges makes a nice punch to cut the hole)
7. Place the larger 18mm magnet on each washer and adhere the peel and stick felt donut to the washer around the magnet.
The felt keeps the magnet from sliding off the washer and it holds the magnet in place and because it is proud of the magnet it reduces the magnets "clamp" force on the PVC and provides a better friction surface so the washer will slide along the underside of the PVC pipe.
8. After the washers are secured to the cable, join the cable ends with a crimped ferrule.
Step 5: Base & Bucket
Cut the following interlocking tree shapes from a single 4x8 sheet of 3/4 inch plywood
The cross piece at the front holds the catch bucket and the table at the rear holds the battery and spiders when not in use.
Runner Up in the