Not by the machine. By decisions made on the drawing months earlier, usually for reasons that had nothing to do with tape.
A part arrives for quoting with a tape line that runs into a corner, changes direction twice, passes under a rib with a few millimetres of clearance, and ends against a boss. Taped by hand, it works because an operator adapts continuously without noticing. A machine follows a defined route with a physical applicator that occupies space, and every constraint the operator absorbed becomes a geometric requirement.
The same design-for-automation issue appears anywhere pressure-sensitive tape or gasket material must follow a controlled path. The earlier the application surface, radii, datums and access conditions are reviewed, the more options remain available to simplify tooling and cycle time.
None of that means the part cannot be automated. It means the cost was set before anyone quoted it. Here is what determines it while the part is still changeable.
The application surface
The surface decides more of the outcome than the tape does.
It should be flat or consistently curved along the path, continuous, and clear of features the tape has to bridge. Ribs, gates, ejector marks, parting lines and texture changes crossing the path create local variation in contact, and contact is what produces bond performance.
Width matters too. A surface wider than the tape gives placement tolerance. A surface the same width as the tape means any positional variation puts adhesive partly off the intended area, and that tolerance has to be recovered in the fixture instead.
Draft angle is easy to overlook. A surface with draft is not parallel to the datum plane, so a head approaching perpendicular to the datum will not meet it squarely.
Access and clearance
The applicator is a physical object with a footprint, an approach direction and a retract path. All three need room.
Clearance depends on head configuration and application rather than being one number. What holds generally is that features standing proud of the surface reduce the envelope, features on both sides of a path are more restrictive than on one side, and a recessed surface is substantially harder to reach than an exposed face.
Approach direction constrains the robot as well as the head. We check reach and orientation in simulation before committing a concept, which is where an access problem should surface rather than at debug.
The tape path
Corners and radii are the most common constraint. Tape has a minimum radius it will follow without lifting, wrinkling or tenting on the inside of a curve, and that minimum depends on the tape construction, thickness and backing. Inside and outside corners behave differently, and a sharp direction change with no radius is a different problem again.
Direction changes require the head to reorient, and each reorientation is a motion. A path with four square corners can be entirely feasible and still cost noticeably more cycle time than the same length with generous radii.
Path continuity is worth designing for. A continuous loop with a defined start and end is straightforward. A path interrupted by features forces the head to lift and re-establish, and starts and stops are where placement accuracy and adhesion consistency are most at risk.
Tolerances, datums and variation
Placement is only as repeatable as part location, and location depends on the datum scheme.
Tolerance the application surface relative to the features the fixture will use to locate the part. If tape position is specified from one datum and the part is located from another, the stack between them lands directly on placement accuracy.
Population variation matters as much as any single tolerance. A path with comfortable margin on a nominal part may run close to a feature on a part from another cavity. Large or flexible parts may not hold nominal shape unsupported, which means the fixture has to support the part in the taping condition, not merely hold it.
Designing for repeatability
Parts that locate positively and identically every cycle, present a consistent surface, offer an unobstructed path with generous radii, and vary predictably will produce consistent results. Parts meeting most of those can usually be automated with additional engineering. Parts meeting few can often still be automated, but the cost moves into fixturing and cycle time.
RoboTape was developed by Innovative Automation, which designs the fixture, the tooling and the cell rather than supplying a head into someone else’s line. That is why a design review with us tends to be about your part rather than about our applicator.
What the machine can absorb, and what stays in the drawing
Some geometry problems are solved in configuration rather than on the drawing, and it is worth knowing which before you revise a part.
RoboTape is a configurable platform rather than a single fixed head. The RoboTape XL data sheet gives a working range for wide-format tapes and gasket materials up to approximately 30 mm by 30 mm, subject to the material and application, with optional larger spool capacity for longer run times, and a modular design intended for complex geometries, curved paths and constrained application areas in new and existing cells.
For lower-volume or space-limited applications, the RoboTape Lite Cell pairs the system with an ABB GoFa cobot on a mobile base and, according to the current sell sheet, can operate from a standard wall receptacle.
Path curvature, tape width and access may be addressed through system configuration, but the final feasibility depends on the tape, part geometry and validated application requirements. Tolerance stack between the tape path and locating features, along with interruptions in the application surface, still need to be controlled in the part and fixture design.
Because we design the fixture, the tooling and the cell rather than supplying a head into someone else’s line, a design review here is about your part, not about our applicator. Applications develop the concept, and the mechanical design lead who would build the fixture is part of that conversation, which is why a geometry question usually comes back with a fixturing answer attached rather than a request to change the drawing.
Design review checklist
- Application surface flat or consistently curved along the full path
- Free of ribs, gates, ejector marks and texture changes crossing the path
- Wider than the tape where placement tolerance is needed
- Draft angle considered in the approach geometry
- Adjacent features clear of the applicator envelope and approach direction
- Radii appropriate for the specified tape
- Path continuous where possible, with starts and stops in acceptable locations
- Surface toleranced from the features used to locate the part
- Margin sufficient for cavity-to-cavity and tool-life variation
- Part shape stable when supported in the taping condition
- Assembly sequence checked for access
Frequently asked questions
What part features prevent automated tape application?
Features standing proud adjacent to the path, deep recesses limiting approach, components already installed at the taping stage, and ribs or gates crossing the path. Many are resolved by changing the assembly sequence rather than the part.
How much clearance does a robotic tape applicator need?
It depends on head configuration and approach direction rather than being a single figure. Confirm the envelope for your configuration.
What radius can tape follow without lifting?
Minimum radius is a function of tape construction, thickness and backing, so it belongs to the tape manufacturer’s data for the specific product.
Does part variation affect placement?
Yes. Tolerance the application surface relative to the locating features, and check that the path has margin across the whole population.
Send the part for a design review
A drawing showing the tape path, the surrounding features and the locating datums is enough to start.
Our applications engineers will tell you whether the path is workable as drawn, what would need to change if not, and which constraints are cheap to fix now versus expensive to fix in fixturing later. That review is worth most while the part can still be revised.