Grinder Bit Checker
A grinder bit can't shape an inside curve tighter than the bit itself. Upload your pattern, tell the checker how big the finished piece will be and which bits you own, and it drops a colored dot on every inside curve that's too tight, sized to the bit that comes closest.
Everything happens right here in your browser — your pattern is never uploaded anywhere.
Drag a pattern here, or
PNG, JPEG or SVG. Works best with a clean digital pattern: fairly thick black lines on a light background, with the pattern's outer border drawn in.
1. Finished size
The whole image, edge to edge, including any blank margin.
Aspect ratio is unlocked: the pattern will be stretched to fit these dimensions, and curves are measured after stretching.
2. Your grinder bits
Pick every bit you have. Select at least one.
3. Download
Exports are 300 DPI at your entered size. If your device can't hold an image that big, we'll use the highest DPI that works and tell you. Spot numbers appear on screen only.