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Bill of Materials (BOM)

This BOM is divided into three sections:

  1. Housing Parts - The laser-cut acrylic and styrene parts from which the CrowBox housing is built.
  2. Electronics Parts - The parts required to construct the electronic 'guts' of the CrowBox.
  3. Tools & Supplies - Tools and shop/household supplies needed to complete the build.

Total cost will depend on where you buy your parts plus shipping, but we worked hard to keep it as low as possible - likely between $200-300 USD.

Housing Parts

Acrylic Housing Parts

Parts laser cut from acrylic sheets which are 1/8 inch (or 3mm, depending on the provider) thick. You may download the ready-to-cut geometry files for the CrowBox housing parts for free, right here. If you have access to a laser cutter, you may cut these yourselves. Otherwise, you may be able to have the parts cut at a local MakerSpace. You can also buy fabricated CrowBox parts online, directly from a provider like Ponoko.

The CrowBox is built using three different colors of acrylic: A light color, a dark color, and transparent. The transparent parts must be transparent so that birds can see the rewards that are on offer. You may choose whichever light and dark colors please you, but you should make sure to pick colors which result in a neutral, natural color scheme in your intended environment.

Click on any image in this section to view a larger version.

Transparent Acrylic Parts

Quantity/Pieces Part Name Part Image Notes
1 Basket Front Window
1 Rotor housing_rotor.jpg
1 Rotor Hub
2 Rotor Push Pin
1 Sled
2 Sled Shelves
2 Sled Shelf Supports
1 Servo Spine
1 Sliding Lid
2 Coin Fence
2 Shoulders
2 Basket Alignment Tool

Light Color Acrylic Parts

Quantity/Pieces Part Name Part Image Notes
1 Perch Platform
1 Access Door
1 Front Panel
1 Base Panel
2 Rail Uppers
2 Coin Magazine Side Panels Note the Coin Magazine parts are designed for
U.S. Quarters and may need to be
adjusted for coins of different sizes / thicknesses
2 Coin Magazine Feet
2 Coin Pushers

Dark Color Acrylic Parts

Quantity/Pieces Part Name Part Image Notes
1 Rear Panel
1 Side Panel
1 Side Access Panel
2 Ribs
2 Rail Frames
2 Rail Lowers
4 Ramp Support Stringers
2 Basket Perches
1 Perch Hook
1 Basket Spine
1 Base Reinforcing Ring
1 Coin Magazine Front Panel Note the Coin Magazine parts are designed for
U.S. Quarters and may need to be
adjusted for coins of different sizes / thicknesses
1 Coin Magazine Rear Panel
1 Coin Magazine Cap
1 Perch Tensioner
1 Coin Sensor
1 Coin Sensor Stand
1 Perch Fulcrum
1 Coin Intake Ramp

Styrene Housing Parts

Laser or hand-cut from .5mm thick sheet styrene. Sheet styrene is flat and flexible. White or other light color is recommended.

Quantity Part Name Part Photo Notes
2 Upper Ramp Panels
2 Lower Ramp Panels
1 Basket Food Liner
1 Rotor Pin Wrap This part is no longer used but still appears
on the sheet of styrene parts

Other Housing Parts

Miscellaneous off-the-shelf parts that are used to build the housing.

Quantity Part Name Part Photo Notes
1 Two-inch silicone rubber band Ordinary office-supply rubber bands are made of latex and will deteriorate very quickly in outdoor conditions. The silicone (chef's type) rubber bands are highly recommended for their durability and consistent performance
9 sq. in. Conductive Copper Tape Used in building the coin sensor. Sometimes called “copper shielding tape” or “emi shielding tape”. A 1 inch wide roll is recommended.

NOTE: A suitable item can be found at home and hardware stores, often labeled as 'slug and snail barrier tape', if electrical shielding tape is difficult to find.
24 Grip/Traction Tape Used to provide non-skid surfaces for birds to stand.

NOTE: Duct tape may be used in a pinch if you are unable to source traction tape.
asstd. M2 and M3 machine screws with nuts 2mm and 3mm machine screws. 3mm screws in 8mm and 10mm lengths, 2mm screws in 12mm length. Pan head or socket cap recommended.

NOTE: Avoid 'countersink' style heads
NOTE: It's easiest to buy a machine screw assortment that contains assorted 3mm and 2mm screws, but these can also be bought individually and in small packets at Home Depot or other home building supply stores. Unless you're supplying a home shop for multiple projects this is probably a better solution than buying a large quantity online.
2 1/8“ Hitch pins Used to secure the perch platform while allowing for easy removal.

NOTE: These are optional- You can use small plastic cable ties instead, as the perch platform rarely needs to be removed.

Electronics Parts

The CrowBox requires a few common electronic components, listed here. We are not affiliated with any online vendors, but we do provide some recommendations for where you can find the required items:

Probably the least expensive way to get everything you need. The parts needed for a CrowBox are very common and there are usually multiple sellers offering each part, many offering free shipping. (prime)
Perhaps the fastest and most convenient way to buy parts if you are a prime member. As of July 2018, all parts are available for free delivery via amazon prime. The parts are usually more expensive than eBay counterparts and you may have to buy larger quantities of some parts than you might on eBay.

The notes section of the following table will provide some search terms which will help you find each of the parts if you're shopping online.

Quantity Part Name Part Photo Notes
1 Arduino UNO Revision 3 hardware required! Also sometimes called 'REV3' or 'R3'

We recommend Genuino, but the following UNO clones have been tested by us and performed as expected:


Online shopping search term: arduino uno r3
1 USB A (male) to B (male) cable This cable is only needed to plug the Arduino into a desktop or laptop computer so that it can be programmed. Often this cable will come with a new Arduino Uno board. If you have to buy this cable, buy a short one. NOTE: Be sure to avoid MICRO type B connectors!

Online shopping search term: USB A male to B male cable -micro
1 170 Point Micro Breadboard
Online shopping search term: 170 breadboard
2 Micro limit switch w/roller
Be sure to buy the black-and-white switch pictured here.

Online shopping search term: ultra mini micro limit switch roller
1 PCB mount pushbutton
6x6mm size recommended

Online shopping search term: pcb mount dip tactile switch 6mm
1 MG995, Futaba 3003 or 3004 180 degree Servo NOTE: These servos are manufactured by several different companies and are sometimes sold with different assortments of accessories. Ensure that the servo you buy is a 180 degree servo and that it comes with a six star horn accessory, shown here:
Online shopping search term: “MG995 servo”, “Futaba 3003 servo”, or “Futaba 3004 servo”
asstd Dupont jumper wires Select 10cm length, one set of male-to-male and one set of male-to-female.

Online shopping search term: 10cm dupont m-m f-m
1 set Dupont male with alligator clip Dupont male on one end, alligator clip on the other.

NOTE: only two alligator clip wires are required. You can make your own by soldering alligator clips to ordinary dupont wires, if you already have the gator clips.

Online shopping search term: dupont alligator clip
1 5mm terminal block
Color may be green or blue- it does not matter which you buy, just be sure to get 5mm pitch.

Online shopping search term: 5mm terminal block 2p
asstd. 3mm standoffs Nylon is recommended but brass is fine. Only three standoffs are required, recommended height is 8mm.

NOTE: It's possible to cobble together standoffs using M3 screws and multiple nuts.

Online shopping search term: 3mm standoff kit
1 2.1 x 5.5mm female DC power pigtail Only one is required but almost always sold in lots of 10 or more. Be sure to get the FEMALE type

Online shopping search term: 2.1 x 5.5mm female power pigtail
1 5 volt 2 amp (5V2A) power supply These are inexpensive and widely-available. The appearance of the wall socket plug may vary from what you see here.

NOTE: Be sure that you buy an adapter with 5.5mm plug!
NOTE: Be sure to buy a 2 amp adapter!

Online shopping search term: 5v2a 5.5×2.1mm DC power supply

Tools & Supplies

Many of these things are probably already lying around a typical home.

Quantity Part Name Part Photo Notes
1 Small screwdriver set Select a small tool set that includes drivers of the type required for your M2 and M3 machine screws. Also make sure there's a small phillips driver for adjusting the screws on the 5mm terminals.
1 Wire Strippers Any type will do. If you strip wire with your teeth, don't tell your dentist!
5oz SciGrip/Weld-On #16 acrylic cement This is the primary adhesive for the acrylic parts of the CrowBox. This product is sold in multiple sizes. The small size (5 oz) is plenty of cement to build a single CrowBox.

NOTE: Be sure to get the #16 formulation. May also be called 'syrup' or labelled 'syrupy consistency'

NOTE: An applicator tip is essential for proper, precise application of the cement. If your cement doesn't come with one (most don't) you'll need to buy it separately or you're going to be cursing and screaming when you go to build.
1 Hot glue gun Used mainly for creating weathertight seals at critical joints. A high-temperature model is best, but any hot melt glue gun will do.
1 Hot Glue Sticks The right size and spec for your hot glue gun. Use the type labeled “acrylic” if you can find them.
1 Soldering Iron A small amount of basic soldering is required to complete the electronics.
If you need to buy a soldering iron, a basic 30 watt iron should be inexpensive and will do everything you need for this project. It's usually easy to find an inexpensive soldering iron that comes bundled with a small bit of solder. So, two birds and all that.
1 roll or tube Rosin core solder Use the solder you like for your other electronics work. If unsure, select a 60/40 rosin core solder with a max diameter of 1mm. A diameter of 0.6mm is good.
1 small square Medium grit sandpaper Useful for making minor adjustments to acrylic parts during the build. We suggest ~300 grit, or type labelled “medium grit”
1 or 2 Ordinary rubber bands Helps hold some smaller parts together during cement application.

NOTE: contact with acrylic cement may damage or destroy ordinary rubber bands.
1 Cotton rag, cloth or old t-shirt Keep on hand to clean up minor cement mistakes.

Avoid paper towels- paper towels may deposit paper dust and small torn paper fragments on acrylic if used to blot up cement.
1 Small set square, machinist's block, or small handful of Lego bricks Used to ensure proper alignment between critical housing parts.

NOTE: A perfectly fine set square can be made from a few Lego bricks, so no need to buy a proper set square if you have Lego toys around. (see housing assembly video)
kit/crowbox2_v20_bom.txt · Last modified: 2023/02/06 02:24 by admin