GT2 Belt Center Distance CalculatorGT2 CENTER DISTANCE

1. 1Pick or type the closed GT2 belt length (e.g. 200, 400, 610 mm).
2. 2Enter both pulley tooth counts, e.g. 20T and 20T.
3. 3Read the centre distance and check the wrap angle and teeth in mesh.
4. 4Use the links to open the GT2 pulley generator with these tooth counts and download STEP / STL.

A two-pulley belt consists of two straight spans and two wrapped arcs: L = 2√(C² − e²) + π(d1+d2)/2 + 2e·asin(e/C) with e = (d2−d1)/2. There is no closed form for C, and the usual approximations lose accuracy at large ratios, so this tool solves it by bisection to better than 0.001 mm. With equal pulleys e = 0 and the formula reduces to L = 2C + πd.

GT2 is the standard timing belt for 3D printers and small CNC machines — typically 20T pulleys with 6 mm belt. Closed loops are used for Z-axis sync or reductions such as 20T→60T (1:3). Keep the small pulley at 16T or more with at least 6 teeth in mesh, and allow for tensioning. Generate the pulleys on this site and send them to Orinovate for printing in PETG, nylon or MJF.

d = z × 2 / π
L = 2√(C² − e²) + π(d1 + d2)/2 + 2e·asin(e/C), e = (d2 − d1)/2
C solved numerically from the formula above
θ1 = 180° − 2·asin(e/C), θ2 = 180° + 2·asin(e/C)
i = z2 / z1
teeth in mesh = z_small × θ_small / 360°

Results are for design reference only; confirm against supplier catalogues and the applicable standards before manufacturing.