Why Your Dispensing Robot Leaves Too Much Material at Corners

The symptom

The straight sections look fine. The bead is consistent, the right width, the right height. But at every corner — where the robot changes direction — there's a blob. Too much material. On the exit from the corner, the bead might be wavy or thin for a short distance before it settles back to normal.

You've tried adjusting the dispense rate at corners, but the timing is hard to get right. Slowing the whole path down helps, but the cycle time penalty is significant when the part has a lot of corners. And every new part geometry means re-tuning.

What's happening

The dispensing system is doing its job — delivering a consistent flow of material. The problem is the robot. It has to slow down to change direction at corners, and even with the best trajectory settings, the TCP speed drops. Meanwhile, the material keeps flowing at the same rate. Slower robot + same flow = too much material.

After the corner, the robot's arm vibrates briefly as it accelerates back to speed. The dispense nozzle oscillates, leaving a wavy bead until the vibration decays.

These are fundamental physics of how robot arms move — they apply to every brand and model. The question is how to manage them.

How to fix it

Software-based motion compensation works on the robot side of the problem. Instead of trying to match the dispensing system to the robot's imperfect motion, it improves the robot's motion to be closer to what the dispensing system expects:

• The arm navigates corners with less speed variation

• After corners, the arm settles faster with less vibration

• The TCP follows the programmed path more closely throughout

The software works through the robot's existing controller. No changes to the dispensing system, no new sensors, no mechanical modifications. Calibration is a one-time setup per arm.

Results

• More than 80% vibration reduction — significantly less post-corner bead waviness

• Better speed consistency through corners — reduced material excess

• Higher throughput on complex contours — less need to slow down for corner quality

• No dispensing system changes — the improvement is all in the robot's motion

Example

A sealant application on an automotive component with 24 corners per part, running 400 parts per shift. Each corner produces a slight excess of sealant that must be manually inspected and occasionally reworked. Software-based motion compensation reduces corner excess to within spec, eliminating the per-corner inspection step and reducing sealant waste on corner-heavy geometries.