TachCraft: Optical Tachometer

TachCraft turns your phone into an optical tachometer for the workshop. Stick a strip of tape on anything that spins, point the camera at it and read the speed in RPM.

HOW IT READS FAST PARTS
A phone camera takes about 30 pictures a second, so most camera tach apps get confused by anything faster and show a false, slow speed (the wagon wheel effect). On most phones TachCraft staggers the timing of its pictures and keeps the shutter short. The false speeds stop fitting and only the true speed lines up. With good light it reads well past 10,000 RPM, and it tells you the fastest speed the current shutter can follow.

CAMERA TACH (FREE)
• Finds the mark by itself; tap the picture to choose the spot yourself
• Steady reading with a plus or minus figure and a "sure" bar
• Shows the mark's brightness over one turn, so you can see the reading fits
• Torch stays on steadily to light the tape
• Marks setting for parts with several identical marks or blades
• Hold a reading on screen
• Honest about phones that only allow a fixed frame rate, with speed bands for faster parts

TORCH STROBE (FREE)
• Flashes the torch so a mark seems to stand still
• Fine steps, half and double rate, turns per flash for fast parts
• Short flashes timed on their own high priority thread
• Measures how steady your phone's torch is and says when it cannot keep up
• Check with strobe: set the strobe from any reading in one tap

TACHCRAFT PRO (ONE PAYMENT, NO SUBSCRIPTION)
• Sound tach: reads a fan, motor or drill from its steady hum. Set the number of blades. No mark needed.
• Vibration tach: rest the phone on a running machine and read its shake
• Run stats: min, max and average, plus a pass or fail band around your target speed
• Saved readings with names and notes, shared as a CSV file
• Workshop tools: surface speed for lathes, routers and drills, wheel speed, pulley and gear ratios

GOOD FOR
Lathes, drill presses, bench grinders, fans, RC motors and props, bike wheels, potter's wheels, model engines, washing machine drums and more.

PRIVATE BY DESIGN
Camera pictures, sound and motion are analysed on the phone as they arrive. Nothing is recorded, uploaded or shared, and there is no account.

SAFETY
The strobe flashes light and shows a warning before first use. Keep hands, hair and the phone clear of spinning parts. Readings are estimates for workshop use.

Questions or ideas: support@zarkon.co.uk

Recent changes:
Fixes the Pro unlock store connection.