Stringman Hardware Kit

Build it Yourself

This bundle includes everything in the Stringman BOM

The anchors feature four powerful and silent Damiao hub motors. They can position a 4 kg payload anywhere in a room up to 7 meters from ceiling corner to opposite floor corner. Two anchors are mounted in opposing corners and in the other two corners ceramic eyelets are mounted. Three tethers are composed of 40 lb test braided fishing line, with one being a FEP-jacketed wire to supply power to the gripper, or whatever end effector you come up with.

The gripper features a Raspberry Pi Zero 2W streaming video from a wide angle camera, a custom PCB for power distribution and inertial sensing, a pressure sensor in the finger, laser rangefinder, ST3215 servos to control the grip and wrist, and ABS tube rigidly linking it to the display box above.

What's Included

Anchors

• 4 Damiao DM-H6215 Motors
• 5A 2-wire slip ring
• 50m of braided fishing line
• 7m FEP power tether line
• 2 Raspberry Pi Zero 2W
• 2 aluminum heatsinks
• 2 Raspberry Pi Camera Module 3
• 2 4cm ribbon cables
• 2 Neufangled Anchor Hats (PCBs)
• bearing kit for powerline spool
• bearings for support spools
• 4 small carabiners
• 2 ceramic rings
• 1 JST-ZH connector male
• 2 JST-ZH connector female
• solder seal connectors
• heat shrink tubing
• All necessary screws and washers
• 2 DC barrel jack extension cables
• 2 5A power supplies (north american plugs)

Gripper

• 2 Feetech ST3215 Smart Servos
• Self-adhesive grip foam tape
• Pressure sensing pad
• PCTG drive gear
• 15 dBm cooling fan
• Laser rangefinder
• 32 GB MicroSD card
• Heat sink
• Raspberry Pi Zero 2W
• Stringman Gripper Hat (PCB)
• 8 cm camera ribbon cable
• RPi Camera Module 3 Wide
• 2 washers
• 10x15x4 wrist bearing
• 2× 25 cm by 1 cm ABS tube
• Screw package

What You Need to Provide

You will need to download and print the STLs from our downloads page. All parts but one can be printed in PLA of any color you like.

The finger drive gear needs exceptional layer adhesion and must be printed in PCTG at 265°C, so it's included in the kit. You do not need to print this part.

The anchors will use two outlets.

In order to avoid shipping a much larger box, the gripper's ABS tube is supplied in two 25 cm sections. These must be joined with a printed coupler and cyanoacrylate glue (white suggested). Though there's no harm in sourcing your own 50 cm by 1 cm tube.

How To Build

Anchors Build Guide Gripper Build Guide

Assembly takes roughly 2–4 hours total. Please refer to the online build guides for detailed information on the required tools and steps.

Soldering is necessary only to solder 2.54-pitch headers onto the Pi and rangefinder for the gripper. The anchors do not require soldering, but you do need to use a heat gun to splice wires with solder seal connectors.

Hands on support for the whole build process is available in our discord channel.

Pricing

The price of this kit is determined by the amortized landed cost of parts in bulk to the USA (roughly $630), plus a profit margin. In the USA, sourcing all these parts yourself will probably cost you about the same price. However, if you are anywhere in asia, you can probably buy the whole BOM for signifigantly less.

If you want to source the common parts yourself, you can purchase only the custom PCBs and wires from us.