Creel & backing tape
- The creel supplies fibre tow while routing its backing tape separately.
- Tension and routing affect how reliably material reaches the head.
Robotic
AFPAutomated fibre placement research
Programming and operating a six-axis robot while investigating the practical limits of carbon-fibre placement.
- MY ROLE
- Robot programming, operation & trials
- PLATFORM
- Motoman SK120 · YASNAC MRC
- STATUS
- Ongoing research project
- CURRENT FOCUS
- Tow adhesion & placement reliability
01 / THE PROJECT
Program the motion.
Understand the process.
Develop practical robot-based fibre placement and identify conditions that support consistent tow deposition.
- I am programming and operating a Motoman SK120 adapted for automated fibre placement.
- My work connects robot motion, placement-head operation and carbon-fibre process trials.
- Current experiments investigate adhesion and handling of the available expired thermoset tow.
6
Robot axes
12
Trials with recorded outcomes
2
Recorded layup speeds
20 and 40 mm/s
Trial counts describe the current testing record; the project is still in progress.
02 / SYSTEMS & REQUIREMENTS
One motion system.
Several coupled processes.
- Successful placement depends on motion, tow feed, cutting, heating and compaction working together.
- The available material and older control platform shaped the practical research scope.
- Requirements: Define repeatable placement and reliable tow handling on the fibreglass surface.
- Design: Develop paths using consistent user-frame and tool references.
- Implementation: Connect movement sequences with placement-head operation.
- Trials: Record torch settings, travel speed, tow batch and observed placement behaviour.
- Evaluation: Compare adhesion alongside cutting, lifting and feed interruptions.
- Iteration: Refine the experiment sequence and verify repeatability before expanding the scope.
PRACTICAL SUCCESS CRITERIA
Adhesion is only part of the outcome
- Tow should adhere early enough to remain in place during the following pass.
- The cutter should release the deposited tow without pulling it off the surface.
- Retraction and repositioning should retain enough tow for the next placement.
- Test conditions should remain traceable to material batch and handling history.
- Paths should maintain placement-head clearance and a consistent reference to the surface.
- Tow routing should preserve fibre order and stable delivery through each pass.
EARLIER PLATFORM HARDWARE
Follow the material through the system
Earlier platform development established the hardware and design choices behind the current work.
Tow guidance
- Pulleys and a swinging guide preserve tow order through robot movement.
- Twists or lateral movement can disrupt feed alignment.
Feed & cutting
- Feed, pinch and cut functions must be coordinated with robot motion.
- Tow retention at the end of a pass supports the next start.
Heating & compaction
- Hot-gas heating promotes tack at the deposition point.
- Internal head cooling limits premature sticking in the feed path.
- Roller contact presses the tow against the substrate.
03 / ROBOT PROGRAMMING
Reference the surface.
Sequence the placement.
The programming work links coordinate definitions, motion jobs and the material-placement sequence.
Keep the references consistent
- I worked with user coordinates and tool configuration to reference the placement head to the surface.
- Normal motion jobs supported taught positions and programmed movement.
- Investigating normal and concurrent jobs helped resolve position-teaching limitations.
Build paths for the layup
- Flat-panel programming covered 0°, 45°, −45° and 90° layup directions.
- Master and directional jobs organised the placement sequence.
- Cylindrical coordinate conversion was explored as a route toward curved-surface programming.
Connect motion to tow handling
- Approach, deposition, cutting, lead-out and retraction form a connected placement sequence.
- Tow snap-back and incomplete cutting exposed interactions between motion and the feed system.
- Legacy PC/controller communications required separate job-transfer troubleshooting.
EARLIER PROGRAMMING WORKFLOW
Check the job before placement
- ENVISION simulations checked reach, head clearance and wrist singularities before export.
- Part coordinates and user frames needed matching origins in the real workcell.
- Translated jobs needed checks for motion, rounding settings and feed, pinch and cut outputs.
- Pen-traced paths helped reveal differences between simulated curves and controller motion.
Approach → compression → placement → cut → lead-out → departure.
04 / WORK UNDERTAKEN
Make the platform usable.
Build experimental evidence.
- The work progressed from controller familiarisation and path programming to practical placement trials.
- Reliable deposition remains the current development objective.
OPERATION / PRACTICAL WORK
Robot and controller
- Studied the controller workflow, teach pendant, user coordinates and tool references.
- Worked through job creation and legacy communication issues.
PROGRAMMING / DEVELOPED
Flat-panel motion
- Developed master and directional flat-panel job structures.
- Connected placement motion with tow-feed and cutting behaviour.
TRIALS / RECORDED
Initial process screening
- Recorded twelve straight-line trials across six torch settings and two speeds.
- Documented adhesion, compaction, cutting and tow-retention observations.
REPEATABILITY / ONGOING
Refine the process
- Assess promising conditions with repeated tests and consistent material handling.
- Extend the speed range after reviewing the current placement failures.
05 / PROJECT EVOLUTION
From a structure
to the placement process.
The initial scope considered robotic manufacture of carbon-fibre rocket oxidiser and fuselage structures.
- Platform familiarisation and implementation constraints narrowed the immediate scope.
- Low tack in the available expired tow made reliable adhesion the first research question.
- The project shifted toward controlled placement trials on fibreglass.
- Early trials exposed feed, cutting and metal-surface sticking alongside adhesion problems.
DEVELOPMENT LESSON
Define success for the whole placement cycle
- A tow can initially stick and still be lifted off by a later cutting or retraction fault.
- Heating settings need to support both substrate adhesion and reliable head operation.
EARLIER HARDWARE EVOLUTION
Compaction shapes the steering limits
- The original single-piece roller constrained steering because every tow shared one wheel speed.
- An eight-wheel polyurethane roller allowed different rotation speeds across the tow band.
- The existing bracket and bearing cost constrained the shaft and bushing design.
- Lateral deformation and circlip retention issues led to a larger-shaft and collar concept.
Earlier platform development: the photograph shows built hardware; the section drawing records a proposed revision.
06 / RECORDED PROCESS TRIALS
Record the result.
Record the failure mode.
- Twelve recorded trials used torch settings from 130°C to 230°C and a 30° approach angle.
- Both speeds recorded full tow adhesion at 150°C and 170°C.
- Higher settings still produced cutting, lifting and sticking problems.
| Torch setting | 20 mm/s · I/J | 40 mm/s · T/U | Placement observations |
|---|---|---|---|
| 130 °C | 25% | 50% | Weak or delayed adhesion; cutting problems in the 40 mm/s run. |
| 150 °C | 100% | 100% | Full reported adhesion; the 20 mm/s run still required tow refeeding. |
| 170 °C | 100% | 100% | Full reported adhesion with favourable cutting and compaction observations. |
| 190 °C | 100% | 75% | Cutting or tow-retention issues appeared despite early adhesion. |
| 210 °C | 75% | 75% | Tow lifting and sticking near the cutter affected placement. |
| 230 °C | 50% | 75% | Tow stuck to torch-adjacent metal and interrupted cutting or layup. |
The record uses different tow batches at each speed, so it does not isolate a speed effect.
These are listed torch settings and reported adhesion observations, not measured tow temperatures or mechanical strength.
WHAT THE NOTES REVEAL
Early adhesion
is not complete reliability.
- Some trials adhered well before a cutter fault pulled the tow away.
- Other trials left tow stuck near the torch or surrounding metal surfaces.
- Material handling and repeated passes introduce additional sources of variation.
07 / ONGOING DEVELOPMENT
Build repeatability.
Then expand the range.
- Confirm promising settings through repeats with consistent tow condition and batch records.
- Investigate feed and cutting interruptions alongside the heating and travel-speed settings.
- The current plan lists 60 and 80 mm/s trials without recorded outcomes.
- Use the resulting evidence to define the next practical placement experiments.
Current status: robot programming and material trials underway; a validated process window is still being developed.
08 / REFLECTION
The lessons
I am building on.
- This ongoing project connects robot programming with the practical behaviour of a composite material.
- Troubleshooting has made the dependencies between motion, handling and heating concrete.
Interfaces shape the experiment
Frame definitions, job structure and head sequencing all affect whether a material trial is repeatable.
Observe the whole process
Adhesion alone does not capture feed interruptions, incomplete cuts or tow lifting during later movements.
Keep the scope tied to evidence
Establish a reliable deposition process before extending the work toward more complex composite structures.
JERRY SUN / ENGINEERING PORTFOLIO
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