How to troubleshoot vision dispensing machine missed and skipped dots? Check the six links one by one

in a batch, a few glue dots are consistently missing, or on the same board some dots have adhesive while others are empty—this is called missed dots or skipped dots on the line. It is not the same as a broken glue line:stringing-off is when the glue line breaks partway but can still reconnect; a missed dot is one where no dispensing happened at all. The direction of checking is also different; following the glue path all the way down, you can mostly converge to a certain link.

first distinguish whether the miss is at a fixed position or at a random machine position

use a marker to circle the empty dots on defective parts, line up several pieces horizontally, or bring up the path diagram to compare. If every piece misses at the same coordinate, the problem is inprogram, needle, or fixturing; if the position differs every time, then towardVision, signal, air pressure and adhesivedirection. This step takes only a few minutes and saves a long session of random disassembly.

for points that fail recognition, the program skips them directly

vision dispensing machine干活是capture image to locate first, then run the path. When the contour or positioning mark cannot be recognized, the program treats it as skipped; some only log an entry without alarming. The operator sees the machine running continuously, but dots are already being missed.reflection, dark surfaces absorbing light, positioning marks blocked by the material tape, light source aging, all reduce recognition accuracy. First check the recognition results and logs to distinguish whether it failed to recognize or recognized with offset; use Bolli's self-developed light source for supplementary lighting, whose angle is adjustable—do not start by changing program parameters.

array and point positioning errors—once a miss occurs, it is an entire row

when copying an array, the row/column spacing is entered wrong, or one fewer point is set—the result isentire row or column left empty, ora missing dot at regular intervals. Count the dots in the path preview and compare against the drawing and the actual part; you can spot it in a few minutes. After editing, save a new version—do not overwrite the original program, you will need to refer back to it later.

valve-open delay compensation to insufficient; once speed picks up, the starting dispensing point is lost

the valve takes time from receiving the signal to actually dispensing; the faster the movement, the more the dispensing point lags. The compensation value is too small, so the moment of starting dispensing is left empty. The typical symptom is normal sample testing at low speed, but missing begins once speed is increased; or the first dot of each path is missed while the middle stays continuous. Give lead time to based on the actual speed, and after changing, test at the same speed—do not use low-speed results to verify high-speed work.

when air pressure drops to the lower limit, the high-speed section misses first

Bolli equipment uses air at 600-1200 hPa; on-site it is generally kept in the middle of the range, to leaving margin for fluctuation. When air pressure approaches the lower limit, the vision dispensing machine dispensing response slows, and the high-speed section fails first. The pressure gauge must be read while running—static readings reveal nothing; an air-source pipe that is too thin, a clogged filter regulator valve, or a leaking quick-connect fitting will all drag the dynamic pressure down.

bubbles in the adhesive—when they reach the valve port, they become an empty dot

The source of bubbles is not complicated: introduced during filling, sucked back by setting the suck-back too high, or not degassed before loading the syringe. The symptom is typical: a single empty dot, at a different position each time, while the glue lines on both sides are normal. Let the adhesive sit or vacuum-degas it, load the syringe vertically and vent after loading; do not open the suck-back amount too high—enough to stop the adhesive is sufficient.

needle height and half-clog are the kind of miss that works sometimes and fails other times

needle too far from workpiece, the glue droplets fall intermittently during descent;too close will smear adhesive and hit parts;needle bore half-clogged, the dispensing volume is insufficient, and it also looks like a missed dot.check Z-height consistency: workpiece flatness, fixture clamping, and incoming material thickness from batch changes all alter the actual gap. Removing the needle to clean it and checking the inner wall for cured residual adhesive is often faster than searching through parameters for a long time.

fix the sequence so next time you do not have to start from scratch

the troubleshooting sequence for missed dots, by recordpattern, Vision, program, signal, air line, adhesive, needlegoing all the way down, most sites can converge to the specific link within half an hour. Vision-based automatic dispensing equipment is not mysterious, and problems often hide in these inconspicuous details. If you really encounter one that cannot be found after repeated checks, keep the defective parts, parameters and recognition logs safe,Bolli Automation Co., Ltd.13352947677, we can review it together remotely.