RoboticsDesign complete on paper (stages 1-6) for Guide; Drive at block level; not built

SmartLine Kit

RTK guidance and auto-valve for the field striper you already own

Bolts RTK GPS, a handlebar screen and an automatic paint valve onto a walk-behind striper so one person marks a field without strings; an optional drive module makes it drive the lines itself.

Who buys it: Athletic director or grounds lead at a school, small college, youth league or parks crew.
Why it pays: Guide is $2,490 + $29/month against $6,000-16,500 a year for a Turf Tank subscription; a new field first-mark drops from 2 people x 3 h to 1 person x about 1.5 h (est.).
Target price: Guide $2,490 + $29/month; Drive +$3,490 or $249/month seasonal rental (target)
First-minute wow: Pick 'U12 soccer', tap two corners, walk the bar graph, and the paint switches itself on and off at every line end and arc.

See the CAD design Concept page

SmartLine Kit concept: the idea and where each part goes — The concept. The CAD design is below, under Printable CAD.

What the research found

And how this design answers it

A $9,900 robot against Turf Tank and TinyMobileRobots → a $2,490 retrofit for the striper the buyer already owns
Capital-heavy → about $1,020 of parts including a base station, no custom PCB in phase 1
Needs field service → Guide has one swappable valve; Drive is rented per season and serviced in the off-season
±1 cm marketing claim → specs stated as measured 95th-percentile error: ±3 cm Guide, ±2 cm Drive
Robot safety near children → operator-attended only, dead-man fob, hardware E-stop, 1.2 m/s limit

Use case

First-mark of a new U12 soccer field

Grounds leadSmartLine GuideBase station

01Trigger: the league adds a U12 field on open grass
02Setup: the base goes on the monument nail and the operator taps two corners to fit the template
03Guidance: the handlebar bar graph keeps the walk within ±3 cm while the valve paints only the line segments
04Action: the field is saved so every re-line follows the same lines

Outcome: One person in about 1.5 h, saving about 4.5 labour-hours ($110) per first-mark (est.)

How it works

Architecture

01
Sense: u-blox ZED-F9P RTK rover on a mast, BNO086 IMU, own ZED-F9P base over 915 MHz radio
02
Decide: ESP32-S3 maps position to the field template, computes cross-track error and valve timing
03
Act: 12 V normally-closed paint valve; Drive adds 2 ODrive S1 controllers and hub motors
04
Tell: 4.3 inch handlebar screen, run quality logs and a field library in the cloud

Hardware

Real parts, buyable today

Bill of materials: about $1,020 for the Guide kit including the base station; Drive adds about $1,100 (est.).

Block	Part	Why this part
RTK GNSS	u-blox ZED-F9P (SparkFun GPS-RTK2) + ANN-MB-00	Multi-band RTK, 10 mm + 1 ppm CEP, moving-base heading for Drive
Corrections	SparkFun SiK Telemetry Radio V3 915 MHz pair	Licence-free, over 1 km across a field, own base needs no NTRIP subscription
Controller + display	Waveshare ESP32-S3-Touch-LCD-4.3B	One board runs the UI, template engine and valve logic
Valve	12 V normally-closed solenoid valve + IRLZ44N	No power means no paint
Drive (phase 2)	2x ODrive S1 + 36 V hub motors	Swappable modules; no Jetson needed for GNSS path following

Mechanical

Printable CAD

8 parts, generated from code and checked as closed solids. Pick a part to inspect it, or download the STL files to print.

See the CAD parts render

SmartLine Kit printable parts, rendered from the CAD — Render of the printable parts from the actual CAD. Not yet printed or photographed.

Loading the CAD…

Real CAD · drag to rotate · scroll to zoomReal CAD · swipe sideways

Open risks we are working on

Buyers may see a guided walk-behind as still manual and wait for a robot subscription
Walking to ±3 cm by bar graph is unproven until the field test
ESP32 firmware needs a compiler toolchain on CI; the lab is Node-only
Drive needs product-liability cover before any rental

Design stage only: nothing on this page is for sale. Specifications and prices are targets.