Answer: Head gap means the distance between “Highest point of media” and “Head surface”.
A smaller head gap will provide high quality print results because ink will be fired straight. The Head gap should be 1.5mm maximum for optimum print results.
1. Set up the head gap with following procedure.
If the media surface is not flat, or is a convex-concave surface, the distance between concave point (lowest point) and head surface is farther than the distance between convex point (highest point) and head surface. The head gap from the lowest point and the head surface equals “Head gap value you set up” + “the difference between convex and concave”.
Make sure the convex-concave distance is less than 2.0mm. (0.078inch).
If the print surface has more than 2.0mm (0.078inch) convex-concave surface, there will be some serious print issues such as ink misting and nozzles dropping out during the print.
With the “Gap check” function, the printer senses the highest point of the table, and adjusts the head gap automatically to the head gap value you set at the “HEAD GAP” function.
However, if the media or jig has significant height variations, the actual head gap will be much higher than then the value in the SETUP menu. This will cause “Ink mist”, “Nozzles deflection” or “Nozzle out” issues.
Please be sure to check below conditions to avoid the issues.
① No dust or tape fragments left on the printing bed.
② The media should be flat with no deformations or large height variations
③ There are no height differences between multiple media types on the same table or print job.
④ If you use a jig to print on the media, please make sure the media sits on the jig correctly. All pieces must be a consistent height and set into the jig evenly with respect to the print head.
⑤ Never use printing jigs which are damaged, bent, or do not sit flat on the print bed