Bionics Docs

Stock & Supplies

Here are some of the supplies we attempt to keep on hand and, where we order the supplies from.


Consumables are products that get used up or consumed in the process of building the robot. Consumables are different than COTS components in that they are often modified before being incorporated into the robot.


We stock 8" and 4" zipties in black. They are stored in the black competition tool box.


We stock three types of tape:

  1. Various colors of vinyl electrical tape
  2. Red, blue, and gray duck tape
  3. Various colors of high quality, low residue gaffers tape.

The gaffers tape generally is more expensive than the other tapes. We tend to use gaffers tape for applications where we need to minimize tape residue. Gaffers tape is the only tape approved to be placed on carpets.

Wood and Cardboard

For the laser cutter, we stock 1/4" plywood. Scraps from previous projects are stored below the Velox we encourage users to make use of scraps for smaller projects.

We also stock corrugated cardboard, which is stored in the makerspace, one floor down from the robotics shop.

Some scrap acrylic is available, left over from other projects. Extruded acrylic (good for cutting) and cast acrylic (better for engraving) are available from McMaster-Carr. The acrylic sheets sold at hardware stores like Lowes are extruded.

3D Printer Filament

All of our Prusa printers use 1.75mm (nominal) filament. We stock PLA and PETG on 1kG spools, in black. We have found the quality of some of the less expensive filament vendors impacts print quality. We generally try to use Hatchbox or Prusament.


We maintain an inventory of rectangular tube and angle stock in various sizes. We generally attempt to have both 1/8" and 1/16" thickness tube available.

We have found that Online Metals has competitive prices for the aluminum stock we use, be sure to sign up for their email newsletter for monthly coupons. McMaster-Carr has better prices on 1/4" aluminum plate stock.

COTS Parts

Commercial Off The Shelf (COTS) are parts we buy that usually do not need modification before being incorporated into the robot.


We maintain an inventory of threaded fasteners. Or stock includes a wide selection #10-32 and 1/4-20 with a more limited supply of #8-32.

We are fortunate to be sponsored by Lehigh-Armstrong, who supply the team with many of our fasteners. For all other fasteners we buy from McMaster-Carr.


We have a large selection of HTD belts, many of which came in the Andymark Drivetrain Kit of Parts stored under the counter.

We have found the most economical way to buy belts is from V-Belt Guys. Their site can be challenging to navigate, the trick is to build the part number for the belt you need.

Belt part numbers are comprised of three parts separated by hyphens:

  1. Multiply the teeth times the belt pitch
  2. The belt pitch
  3. the belt width in mm For example, if you need a 5mm pitch belt with 60 teeth and the belt to be 15mm wide the part number is 300-5m-15 and the link to the belt is:

V-Belt Guys also carry 9mm wide belts, eg:

VersaPlanetary Gearboxes

We attempt to maintain a stock of VersaPlanetary parts, including:

  • 1/2" hex base kits
  • Ring Gears
  • Planetary stages:
    • 3:1
    • 5:1
    • 7:1
    • 9:1


As a subcategory of COTS parts, sensors provide inputs to the robot software to allow for precise repeatable control.

Vision Processing

We have had great success with using the Limelight v2 for retro reflective target tracking.

Similar successes using the Pixy Cam for power cell detection in the Infinite Recharge @ Home Challenges.


We prefer to use these encoders as we have a track record of success with both types:

  1. Rev Robotics Through Bore Encoder ideal for many applications. Includes support for an absolute output, quadrature and index pulse. Wiring harness comes with the sensor making connection to the RoboRio simple.
  2. For VersaPlanetary gearbox applications the Integrated Encoder Stage, the encoder stage is best used with a Talon SRX motor controller. Then the encoder cable can connect directly to the Talon SRX.


When measuring distance we’ve used a number of different sensors, including:

Limit Switches

Mechanical switches or non-contact proximity switches.