Nixal delta 4040

• Deltabot calculator
• Configuring Marlin 1.1

G28 disables bed leveling, but leaves previous leveling data intact.
G29 automatically or manually probes the bed at various points, measures the bed height, calculates a correction grid or matrix, and turns on leveling 
compensation. Specific behavior depends on configuration and type of bed leveling.

Conclusion: don't send G28 after G29