Skip to content

2026‐06

Jump to bottom
Vector edited this page Jun 18, 2026 · 7 revisions

June 1, 2026

Spearhead Call — Recording · HearHear transcript

Attendees: alperenag, errrks.eth, zeynepb5793, kbmollysuh

  • STORK FPV / Flight-Test Prep

    • Alperen ordered a replacement servo for STORK and a new GPS antenna so the F9P antenna can be removed from the nose area and space can be opened for an FPV camera.
    • Alperen researched low-cost FPV options and found that many inexpensive systems assume goggles, while receiver-to-computer paths often require analog video conversion and may add too much latency.
    • Latency target discussed: anything above roughly 200 ms is likely problematic for flight use.
    • Zeynep will research FPV camera/goggle/receiver options as well. Alperen can share the camera he found; rough acceptable budget is up to about $300 for a useful full system.
    • STORK does not need to wait for FPV before the next tests. After replacing the servo/GPS setup, Alperen will re-check CG because removing the F9P antenna may require nose ballast.

  • Spearhead Wing / Manufacturing Prep

    • Alperen has the main wing ribs and control-surface ribs modeled, but the full wing design is not finalized yet.
    • The blocking detail is the control-surface hinge design: one tested plywood-based idea did not carry the load, so Alperen is redesigning that part.
    • Alperen plans to assemble the laser cutter and source 4 mm plywood from the industrial zone. Once the wing structure is ready, he can start cutting ribs and gradually assembling wing parts.
    • Structural design remains Alperen’s top priority.

  • Flight Dynamics Model / Stability Analysis

    • Zeynep opened a PR with the first version of the flight dynamics model, including full code plus trim and linearization routines.
    • She plans to add a graphical/user-facing layer so other contributors can more easily run simulations.
    • Initial runs using Alperen’s aerodynamic database look logical and expected. Zeynep said the aero database is producing similar/credible behavior compared with earlier estimated values.
    • Full stability analysis still needs more data, but initial results look stable and not alarming.

  • Electrical Layout / PT1 Architecture

    • Erick has been updating the Spearhead electrical planning document and layout diagram with decisions made so far.
    • Current PT1 direction is to stay off-the-shelf as much as possible rather than design/order a custom PCB immediately.
    • A candidate off-the-shelf PDB may power ESCs and provide regulated outputs for simpler PT1 needs; signals can mostly be wired directly to the flight controller.
    • The main blocker remains servo power: main-wing and tail servo torque/current/voltage requirements determine whether the team needs extra voltage regulators.
    • Zeynep shared a likely servo option available in Turkey with a 6–8.4 V operating range. Alperen also raised the possibility of 5 V servos for PT1 if the first prototype only needs hover/control-surface motion rather than loaded cruise flight.
    • Using 5 V test servos could simplify PT1 wiring, but would not represent the final loaded servo choice.
    • Tail electronics still need careful treatment because long low-voltage runs may have voltage-drop/noise issues. Erick will revisit whether tail 5 V can come from the flight-controller/CAN path or needs local regulation.

  • Wiring / EMI / Cable Routing

    • Alperen asked whether main-wing servo PWM wires running near ESC DC power cables for roughly 1 m could cause interference.
    • Erick will check common separation/shielding practice. Initial guidance discussed: keep signal and power separated where practical, cross at right angles if needed, and consider shielded cable.
    • Erick explained that Quiver avoids similar PCB noise issues largely through multi-layer routing and ground/power-plane separation; Spearhead’s discrete wiring will need equivalent attention.

  • High-Voltage / Low-Voltage Disconnects

    • The earlier high-voltage and low-voltage switch requirements came from Quiver/final-product style assumptions.
    • Alperen wants safety disconnects eventually, but PT1 can skip or simplify some final-product requirements if they add too much mass/complexity.
    • Contactors are considered heavy/bulky. SSRs may be lighter, but add low-voltage activation complexity.
    • Current simple PT1 power idea: split battery power to PDB and flight-controller regulator paths, likely using or adapting XT150 / AS150U-style connectors. Erick will look for splitter options; custom soldered splitters remain possible.

  • Documentation / Task Planning

    • Erick expects the electrical planning task to be finished around Wednesday, then will make a BOM/connectors list and update the wiring diagram.
    • Alperen asked Erick to write a short decision/information note summarizing what was considered and what PT1 will use. Erick has an open PR for the electrical planning and can add this there.
    • Zeynep has a README for the Flight Dynamics Model v1. Alperen asked for an initial stability-analysis information note.
    • Next FDM task: update the code to operate on control-surface deflections and add minor upgrades. Alperen set a target of June 12 for Flight Dynamics Model v2, pending control-surface deflection aero data.
    • Zeynep also expects FPV option research to take about two days.
    • Alperen will add a “Review Needed” column to the GitHub project board so completed tasks can move there and become his responsibility to review.

  • Open Items

    • Alperen: replace/install the new STORK servo and GPS antenna, then re-check CG after removing the F9P antenna.
    • Alperen: share the candidate FPV camera/system with Zeynep.
    • Zeynep: research FPV camera/goggle/receiver options for STORK/Spearhead, aiming for a practical low-latency setup under roughly $300 if possible — target Wednesday.
    • Alperen: finalize Spearhead wing/control-surface hinge design.
    • Alperen: assemble the laser cutter and source 4 mm plywood for initial wing manufacturing.
    • Zeynep: publish/complete the initial stability-analysis note for Flight Dynamics Model v1.
    • Alperen: review Zeynep’s Flight Dynamics Model v1 after it moves to “Review Needed.”
    • Erick: finish Spearhead PT1 electrical planning by Wednesday.
    • Erick: write a short decision/information note for PT1 electrical architecture: what was considered and what the team will use.
    • Erick: create/update BOM, connector list, and wiring diagram after planning is complete.
    • Erick: determine servo/regulator path for main wing and tail, including whether PT1 can use 5 V servos or needs 6–8.4 V regulation.
    • Erick: check wiring/EMI guidance for servo PWM lines running near ESC power cables, including separation and shielding recommendations.
    • Erick: investigate XT150 / AS150U splitter or custom splitter approach for PT1 battery power distribution.
    • Alperen: provide/control-surface deflection aero database inputs when available.
    • Zeynep: update Flight Dynamics Model v2 to consume control-surface deflection data and add minor upgrades — target June 12.
    • Alperen: add a “Review Needed” column to the Project Spearhead GitHub project board.

June 5, 2026

Spearhead Chat — Recording

Attendees: alperenag, errrks.eth, kbmollysuh, zeynepb5793

  • Stability / Flight Dynamics Model

    • Zeynep found a late issue while preparing the stability report: the pusher motor location in her model was slightly wrong.
    • After correcting it, the aircraft became unstable. The previous modeling mistake had likely masked the stability problem.
    • Alperen and Zeynep discussed whether this is a real design issue or a tool/data issue.
    • Suspects include reference frame, reference point, non-dimensionalization, CFD-data post-processing, or the design tool.
    • Alperen initially still suspected a reference/post-processing problem, but also said the neutral point / CG envelope behavior may point to a design issue.
    • Working design fixes discussed: shift CG forward, increase tail incidence, or make the tail larger.
    • Increasing tail chord is more likely than span, but would reduce tail aspect ratio and increase drag.
    • Alperen and Zeynep planned a separate Turkish call after the meeting to debug the problem more deeply.

  • Main Wing Structure / Manufacturing Prep

    • Alperen showed the main wing structural design and said it is close to ready for manufacturing.
    • The wing uses a 30 × 30 mm square carbon-fiber tube, plywood rear spar/ribs, balsa ribs in some locations, and interlocking slots between ribs and spar.
    • The servo bay will use a 3D-printed box with threaded inserts once the servo choice is locked.
    • Alperen designed a removable hinge/control-surface scheme using off-the-shelf hinges plus custom mating hinge inserts and a ~1.5 mm steel wire/pushrod as a removable hinge pin.
    • This should help with Oratex covering, manufacturing, and future maintenance.
    • The inner/transition section of the wing will likely use 3D-printed skin, probably PLA Aero or ASA Aero, instead of Oratex.
    • This printed skin direction is only for the inward/transition area, not the whole wing, and is meant to help harnessing, maintenance, and assembly.
    • The laser cutter is working, so structural/manufacturing changes should be quick to iterate.

  • Fuselage / Tail / Assembly Logistics

    • Fuselage structure is expected to be more straightforward: four longitudinal carbon-fiber longerons plus 2 mm and 4 mm plywood sections/ribs.
    • Upper fuselage sections will likely be covered by three separate parts; lower section likely Oratex.
    • Tail work remains after the stability/design question is resolved.
    • Assembly and transport are becoming real constraints: the wing may fit in Alperen’s study room, but the fuselage is around 1.1 m wide and likely needs workshop assembly.
    • The current trailer will not fit Spearhead without modification; Alperen plans to take it to an industrial zone for modifications.
    • Heat inside the black trailer is also a concern for Oratex/ASA Aero during summer transport.
    • Repainting the trailer white, adding ventilation, or using a cooling/fridge trailer were discussed.

  • Electrical Planning

    • Erick had no major electrical update since Monday because of work and illness.
    • He had started updating the electrical document with Monday’s decisions and preparing the information note.
    • He has not yet finished the final BOM or updated wiring diagram, and plans to work on those over the weekend.

  • Harness Routing / Carbon-Fiber Tube Risk

    • Alperen is considering routing main ESC power cables through the carbon-fiber tubes rather than outside them.
    • This may be cleaner and avoid awkward external holes in Oratex/printed wing skin, but would require drilling/cutting access holes in loaded carbon-fiber members.
    • Alperen thinks reinforced sections near aluminum plates may be safer candidates, while the center section is structurally more concerning.
    • Erick flagged that this sounds challenging and likely needs analysis/FEA.
    • A custom aerodynamic cable tray remains a possible alternative, though it adds weight and would need a very specific shape.

  • GitHub PR Signing

    • Alperen approved Zeynep’s PR, but GitHub blocked merge because commits need verified signatures.
    • Zeynep said command-line pushes caused the same issue before.
    • Alperen suggested using VS Code/Codex to configure signing, and also told her to avoid letting the AI tool add itself as a co-author.

  • Decisions / Direction

    • Tail design should wait for the stability root-cause check; the tail is still easy to change because it is not yet structurally designed.
    • Main wing structure is close to manufacturable; the laser cutter should allow fast tolerance/design iteration.
    • Inner wing/transition area is leaning toward 3D-printed skin rather than Oratex for access and harnessing.
    • Trailer modification is needed before Spearhead can be transported safely; thermal management inside the trailer is an explicit concern.
    • Routing cables through structural carbon tubes is a candidate path, but it requires structural validation before committing.

  • Open Items

    • Zeynep/Alperen: debug Spearhead instability after the corrected pusher-motor location; check reference frame/reference point, non-dimensionalization, CFD post-processing, and design-tool assumptions.
    • Zeynep: run additional stability cases / alpha sweeps and test alternate CG locations and tail incidence values.
    • Alperen: evaluate likely design fixes if instability is real: forward CG shift, larger tail, and/or tail incidence changes.
    • Alperen: continue wing manufacturing prep from the current structure; copy/add remaining ribs for the inner section as needed.
    • Alperen: lock servo choice, then finish the 3D-printed servo box/cover with threaded inserts.
    • Alperen: continue fuselage structure design after main wing; tail design waits on stability results.
    • Alperen: modify/enlarge the trailer for Spearhead transport and decide on thermal mitigation: white paint, ventilation, or cooling.
    • Erick: finish Spearhead electrical information note, final BOM, and updated wiring diagram over the weekend.
    • Alperen: investigate routing main ESC power cables through carbon-fiber tubes, including hole locations and reinforcement strategy.
    • Alperen/Erick: validate tube-drilling/harness-routing approach structurally, likely with FEA or equivalent analysis, before committing.
    • Zeynep: fix verified-signature issue on the PR commits so the approved PR can merge.

June 11, 2026

Spearhead Chat — Recording · HearHear transcript

Attendees: alperenag, errrks.eth, far1no, kbmollysuh

  • Electrical Layout / Procurement

    • Alperen said PT1 will most likely use a Pixhawk 6C or 6X, whichever is easier to source, because Zeynep said either is acceptable.
    • The team already has GPS antennas and many Pixhawk/JST-compatible cables, but still needs a concrete electrical parts list.
    • Alperen specifically called out voltage regulators and the tail CAN-to-PWM board as parts that may need ordering soon if lead times are long.
    • Erick acknowledged he owes the list and said he will make Spearhead his focus for the rest of the day and the next morning, aiming to have the list ready before the next call.
    • Alperen asked for the general electrical layout as well: which cable goes where, wire types, regulators, CAN-to-PWM, and related connection details.

  • Fuselage / Avionics Layout

    • Alperen modified the fuselage shape and zoning, including a longer/thinner nose and a forward battery position to help CG.
    • Avionics no longer need to use the nose; he plans a large, top-accessible shelf above the battery.
    • The shelf should be easier for PT1 wiring and later provides a rectangular space for any custom PCB or integrated avionics board.
    • Alperen asked Erick to become familiar with the current layout so electrical planning matches the new geometry.

  • Engine / Motor Order Logistics

    • Alperen changed the current engine model to a DLE55cc-class gasoline engine for near-term layout work.
    • During the call, MAD Motor Poland sent him a purchaser/customs document for the motor/ESC order that must be printed, signed, and returned.
    • The document includes his address, so he did not post it publicly.
    • Alperen needs to print/sign it without delaying shipment; his printer cartridge is out, so he may need to print elsewhere and order a replacement cartridge.

  • Starter-Generator / Future Hybrid Research

    • Alperen contacted three companies that claim to build starter-generator systems for internal-combustion engines; all three replied.
    • One is connected to a Czech four-stroke engine company already using its starter-generator; the other companies are in Germany and the US.
    • The US company asked for a call, which Alperen and Erick may schedule next week.
    • Alperen is interested in a four-stroke twin-cylinder option for later prototypes because it may be more efficient and vibrate less.
    • Rough trade discussed: candidate four-stroke is about 1.2 kg heavier than the current two-stroke, but could burn roughly 600 ml/hour at cruise versus about 950 ml/hour. Over six hours, that could save about 2.4 L / 1.8 kg of fuel, potentially offsetting the heavier engine if vendor claims hold.
    • The candidate also appears to make more power than the current 55cc two-stroke, potentially useful for climb or faster battery charging.
    • Julius said he is too busy over the next month with PCB and Quiver battery work, but may have more capacity once those move to assembly.
    • Alperen suggested starter-generator work could become a future Spearhead sub-project/grant, probably for PT3/end-of-year rather than PT1 or PT2. PT1 will not use a gasoline engine, and PT2 may simply fly with a gasoline engine rather than a starter-generator system.

  • Aero Teaching / Background

    • The latter part of the call became an impromptu aerodynamics lesson from Alperen for Erick, covering climb, angle of attack, drag increase, stall, separation, and Kármán vortex shedding.
    • This was useful background but did not create direct project decisions.

  • Decisions / Direction

    • PT1 flight controller remains flexible between Pixhawk 6C and 6X, based on sourcing convenience.
    • Near-term electrical procurement should focus on voltage regulators, the tail CAN-to-PWM board, and layout/BOM details.
    • The fuselage/avionics layout is moving toward a top-accessible avionics shelf above the forward battery compartment.
    • The current near-term engine model is a DLE55cc-class gasoline engine, while four-stroke / starter-generator options are future-prototype research.
    • Starter-generator work is not expected for PT1 and is more likely a PT3/end-of-year subsystem candidate.

  • Open Items

    • Erick: produce the Spearhead electrical parts list before the next call, focusing on voltage regulators, CAN-to-PWM tail board, wiring/connectors, and lead-time items.
    • Erick: continue/finish the general Spearhead electrical layout: which cables connect where, wire types, regulators, and tail electronics details.
    • Alperen: continue finalizing Spearhead structural design and target starting manufacturing next week if possible.
    • Alperen: update/share the latest fuselage layout so Erick can design around the new forward battery compartment and top-accessible avionics shelf.
    • Alperen: print, sign, and return the MAD Motor Poland purchaser/customs document for the motor/ESC order.
    • Alperen: order/replace printer cartridge to avoid future document-signing delays.
    • Alperen/Erick: review the starter-generator vendor responses and clarify the electrical details Alperen did not fully understand.
    • Alperen/Erick: schedule a call next week with the US starter-generator vendor if timing works.
    • Alperen: evaluate the four-stroke engine tradeoff more formally after Spearhead weight budgets are clearer.
    • Julius: optionally consider a future starter-generator subsystem/grant after current PCB and Quiver battery workload eases.

June 12, 2026

Spearhead Chat — Recording · HearHear transcript

Attendees: errrks.eth, alperenag, zeynepb5793, sleety.eth, kbmollysuh, thomasg

  • STORK / Near-Term Priority

    • Alperen had no new STORK flight work. STORK can be made ready again, but likely waits until after Spearhead flies, maybe early July.
    • He designed a stronger PA6-CF landing gear / nose-support reinforcement after the STORK nose broke again near an earlier field repair.

  • Fuselage Structure / Manufacturing Prep

    • Alperen said the Spearhead PT1 fuselage structural design is effectively finalized.
    • Current structure uses 4 mm plywood, longerons/bulkheads, and a 30 mm square carbon-fiber tube through the fuselage with a 3D-printed support/adapter and locating pin.
    • Erick’s electronics area is roughly a 9 cm tall, ~180 × 250 mm compartment between longerons.
    • A removable plywood shelf should preserve flexibility if the battery compartment needs modification.
    • PT1 leaves space for future fuel tank / gasoline-engine hardware, but those parts are absent for PT1, so CG will shift forward and likely require aft dummy mass.
    • Alperen added strap/cutout locations for CG ballast and expects CG balancing to be a real test-prep task.
    • 4 mm plywood is back in stock locally; Alperen plans to buy it and test-cut longerons/bulkheads.
    • The CAD currently does not add extra slot tolerance because laser kerf may provide enough clearance; test cuts will verify.
    • Alperen dislikes the current fuselage shape/maintainability and expects PT2 fuselage improvements, but schedule pressure means PT1 should build the current rectangular design.

  • 3D-Printed Skin Blocker

    • Alperen wants PT1 fuselage and inner wing skins to be 3D printed.
    • ASA Aero/ASA IRO print quality is still unresolved: parts hold shape, but loose/broken gyroid infill rattles inside the print.
    • PLA Aero prints more easily, but is not acceptable because the aircraft could soften/melt in the sun.
    • Full printing may take roughly 1–10 days, so Alperen needs test prints/settings work before committing the full cycle.

  • Flight Controller / Sensors

    • Zeynep said Pixhawk 6X is overkill and expensive; Pixhawk 6C is sufficient but may be hard to source in Turkey.
    • Pixhawk 6C Mini has the same processor/sensors/IMU with fewer ports, and Zeynep’s port estimate suggests it should be enough.
    • Current direction: likely Pixhawk 6C Mini, pending sourcing and port verification.
    • Sensor baseline is Here4 plus F9P. The F9P they have is UART, so it likely belongs in the nose rather than the tail.
    • Pitot tube can come later and is not required for first flight.
    • LiDAR is optional; Alperen may have an old Feather unit, and Zeynep can search for a cheap LiDAR if needed.

  • Electrical Layout / Battery Telemetry

    • Erick walked through the updated electrical diagram, which still needs to be converted from Pixhawk 6X assumptions to the likely 6C Mini architecture.
    • Baseline architecture: battery to Metaxis-style PDB; XT150/AS150U-class main connectors with anti-spark preferred; PM02D/power-module path for the flight controller; PDB current sensing if possible; CAN ESCs; rear power module / CAN-to-PWM for tail electronics.
    • Because 6C Mini may expose only one power port, Erick and Alperen discussed using the PDB’s analog current output through AD/IO or a custom cable rather than relying on Power 2.
    • The team wants usable battery/current data for PT1 because Spearhead will have much shorter battery margin than Quiver.
    • Erick thinks PDB analog sensing and/or ESC telemetry should provide the needed data, but must verify wiring and ArduPilot parameter assumptions.

  • Servo Power / PWM / CAN

    • Erick removed the main-wing CAN-to-PWM converter from the plan because direct PWM should work and saves weight, as long as signal wiring is separated/shielded from high-voltage lines.
    • Tail servos still use CAN-to-PWM plus rear/local regulated power.
    • The original 6X drawing used CAN1 for ESCs and CAN2 for rear/tail devices; final bus plan depends on 6C Mini ports and device interfaces.
    • Servo power remains a blocker: main/front servos available to Alperen are 6–8.4 V, not 5 V.
    • The candidate PDB provides 5 V and 12 V by default; the rear module can be configured around 5.2/6/8 V.
    • Erick will check whether the PDB can provide suitable servo voltage; otherwise PT1 needs a separate regulator/UBEC, alternate PDB, or similar solution.

  • Safety / Harness / Procurement

    • Hardware kill switch remains simplified for PT1. Erick does not see a clean contactor placement without more components.
    • Current PT1 direction is likely a software ArduPilot motor kill plus anti-spark connectors such as AS150U/QS10 for inrush management.
    • Cable gauge working plan: 8 AWG battery to PDB, 12 AWG PDB to ESCs, 16 AWG to the flight-controller power module, and likely 18 AWG low-power taps/regulator lines.
    • Alperen thinks 12 AWG should fit inside the carbon-fiber tube and plans to order cables/connectors/supplies after reviewing the list.

  • Battery Tradeoff

    • Alperen wants the newer high-energy Tattu semi-solid packs eventually, but availability/import to Turkey is difficult.
    • Early PT1 may use older-style LiPos.
    • 16 Ah may give roughly 12 minutes and be more reusable for PT2; 22 Ah adds about 1.1 kg but could give roughly 17–20 minutes and make PT1 field testing easier.
    • Charging in the field may take 1.5–2 hours for one battery, so one pack may limit test-day productivity.
    • Current direction is to start with one battery and buy a second only if initial tests justify it.
    • Alperen may check whether Feather PT2 batteries/cells can be salvaged or reused temporarily.

  • Future Modular PDB / Regulator Idea

    • KBM suggested Arrow may need a reusable modular power-converter/PDB family for future projects and attachments.
    • Alperen and Erick agreed it is interesting, especially for attachments, but should not block Spearhead PT1.
    • Alperen sketched a possible stackable bus + voltage-regulator/output module concept.
    • Erick suggested KBM study existing Quiver/Caribou regulator designs and datasheets first, focusing on clean voltage levels, capacitors, dividers, current capacity, and tradeoffs.

  • Decisions / Direction

    • Spearhead PT1 should proceed with the current fuselage design despite known PT2 maintainability/aesthetic improvements.
    • Pixhawk 6C Mini is the likely PT1 flight controller if port/sourcing checks pass.
    • Pitot tube is deferred for first flight; LiDAR is optional.
    • PT1 should still have meaningful current/voltage telemetry because battery margin is limited.
    • Main-wing servos can likely be direct PWM; tail servos remain CAN-to-PWM.
    • PT1 likely uses software motor kill plus anti-spark connectors rather than a hardware contactor architecture.
    • Battery selection remains unresolved between 16 Ah reuse and 22 Ah field-test endurance.
    • Modular PDB/regulator work is a future/attachment concept, not a PT1 dependency.

  • Open Items

    • Alperen: buy 4 mm plywood and make test cuts for longerons/bulkheads to validate laser kerf/tolerance assumptions.
    • Alperen: debug ASA Aero/ASA IRO print settings with small test prints before committing to full PT1 skin printing.
    • Alperen: proceed with PT1 fuselage manufacturing using the current rectangular/less-maintainable design, while noting PT2 fuselage improvements separately.
    • Alperen: confirm electronics/battery/fuel-tank/dummy-mass mounting provisions and CG-balancing strategy before assembly.
    • Alperen: find/check the possible existing Feather LiDAR unit and identify whether it is CAN or UART.
    • Zeynep: if Alperen cannot find a suitable LiDAR, look for a cheap first-flight LiDAR option.
    • Zeynep/Erick: verify Pixhawk 6C Mini port availability for power/current sensing, CAN buses, PWM breakout, UART F9P, Here4, and optional LiDAR/pitot sensors.
    • Erick: update the Spearhead electrical layout from Pixhawk 6X assumptions to the likely Pixhawk 6C Mini architecture.
    • Erick: verify how to feed PDB current/voltage sensing into ArduPilot with 6C Mini, including AD/IO or custom cable options and parameter mapping.
    • Erick: evaluate servo-power options for 6–8.4 V main-wing/front servos: PDB capability, separate buck regulator/UBEC, alternate PDB, current capacity, heat, and wiring.
    • Erick: verify CAN bus plan for ESCs, rear CAN-to-PWM, Here4, and F9P/UART constraints on the likely 6C Mini.
    • Erick: update and upload the electrical documents, information note, BOM/parts list, and wiring diagram to GitHub.
    • Alperen: order cable/connectors/supplies after reviewing Erick’s gauge/connector list; confirm 12 AWG fit inside the carbon-fiber tube.
    • Alperen/Zeynep: choose initial PT1 battery size after weighing 16 Ah reuse vs 22 Ah field-test time and cost.
    • Alperen: check any usable Feather PT2 batteries/cells as a possible temporary/salvage option.
    • KBM: if pursuing the modular PDB/regulator idea, study existing Arrow Quiver/Caribou regulator designs and regulator datasheets before proposing a concrete board.

June 15, 2026

Spearhead Chat — Recording · HearHear transcript

Attendees: errrks.eth, alperenag, zeynepb5793, thomasg, kbmollysuh

  • ASA IRO Printing / Manufacturing

    • ASA Aero / ASA IRO printing is still the main Spearhead PT1 manufacturing frustration.
    • Alperen repeatedly printed a small wing section and eventually found settings that worked for the small part.
    • A larger nose-cone print failed in the final few hours because of broken/stringy infill inside the walls, leaving unsupported shell areas that flex or rattle.
    • Thomas had seen similar shaking/rattling and finish issues on STORK parts.
    • Manufacturing has technically started, but slowly; once ASA IRO settings are reliable, Alperen expects to print remaining parts and cut ribs/spars.
    • Alperen set a task to complete the tail design by the end of the week, then write a larger structural-design information note.

  • Battery Direction

    • Alperen found a Tattu/Profuse-style semi-solid battery option around 290–300 Wh/kg.
    • The 12S 22 Ah pack would be about 3.7 kg, lighter than the earlier conventional-pack estimates and much lighter than the previous 22 Ah estimate.
    • Continuous discharge is listed around 15C, which Erick/Alperen thought should be sufficient; Zeynep had also checked Quiver flight data and thought it could work.
    • Alperen also found a 14S option, but Erick’s current electrical/PDB plan is 12S and the existing charger is likely 12S.
    • The team stayed with 12S to avoid unnecessary PDB/charger changes and cost before test results.
    • The candidate battery uses a QS8 anti-spark connector; Erick said QS-style connectors are acceptable and similar to the QS10 used on PT1 Feather.

  • Ankara Flight Restrictions / Test Timing

    • Alperen flagged major NATO-summit security restrictions in Ankara in early July.
    • Non-commercial/charter flights may be banned until roughly mid-July; even paragliding far from central Ankara was already restricted.
    • Alperen expects a likely two-week delay to Spearhead flight/ground-test plans and does not want to risk legal/security issues.
    • Ground runs might be possible, but serious flight/testing likely moves toward mid-July.
    • The team discussed moving the next meetup/test window to mid-July if Thomas and Erick can attend.

  • PT1.5 Electric-Pusher Option

    • Alperen raised a likely PT1.5 path after PT1 is built and weighed: convert it to an electric-pusher version while building PT2 from scratch.
    • The concept would add a pusher prop and pusher-only batteries in the fuel-tank compartment.
    • With the semi-solid battery option, Alperen’s rough estimate suggests PT1.5 could fly for 1–1.5 hours.
    • This remains dependent on real PT1 weight and test results.

  • Electrical Planning / BOM Handoff

    • Erick said Spearhead electrical planning is mostly done.
    • Remaining work is updating the information note and diagrams with the Friday decisions: Pixhawk 6C Mini, extra voltage-regulator assumptions, front GPS likely on telemetry/UART rather than CAN, and power/current wiring details.
    • Alperen treated the previous planning task as effectively done and split follow-up into two clearer tasks: updated planning information note/BOM by Wednesday, then electrical layout / wiring diagram around June 24.
    • Erick wants component choices finalized before detailed CAD wiring so he can build a useful wiring table with source/destination, connector type, cable type, and approximate lengths.

  • Pixhawk 6C Mini / Bench Integration

    • Wire/electrical planning should now assume Pixhawk 6C Mini unless new evidence forces a change.
    • Zeynep said the standard 6C was low stock in Turkey, while the Mini was available.
    • If the Mini does not work, the team could potentially swap in the 6C from STORK because STORK does not need such an overkill controller.
    • Alperen proposed that Zeynep buy/receive the Pixhawk 6C Mini, CAN-to-PWM converter, wiring/connectors, jumper leads, and related bench hardware so she can test the system herself.
    • Zeynep has a DC power supply and some workshop supplies, so this is more useful than Alperen keeping all hardware in Ankara.
    • The team decided to wait for Erick’s Wednesday BOM before ordering the rest.
    • Zeynep ordered the Pixhawk 6C Mini during/after the call, expected arrival Wednesday, and will send photos of the included cable set.
    • Erick will research direct wiring from the PDB to the Pixhawk power port if the kit does not include a suitable power module.
    • Zeynep will review whether she has concerns about powering through the regulator/PDB path.

  • Flight Dynamics Model / FPV

    • Zeynep’s Flight Dynamics Model v2 remains partly blocked because Alperen has not delivered control-surface deflection aero data.
    • Alperen deprioritized that input because PT1 does not need control-surface deflection work immediately compared with structure/manufacturing.
    • Zeynep is still improving the Python model, adding UI and simulation capabilities similar to MATLAB/Simulink workflows.
    • Zeynep’s FPV research found Walksnail Avatar as the likely best option already used on STORK.
    • A receiver/transmitter plus separate display may avoid forcing goggles if the team wants screen-based flying/monitoring.
    • Because STORK and FPV work are no longer immediate PT1 blockers, exact purchase links can wait.

  • Quiver Material Side Note

    • Alperen raised a cross-project Quiver idea: if ASA IRO printing can be solved, Quiver enclosures/caps might switch from PETG-CF to ASA IRO.
    • Possible benefit is roughly 300–400 g weight savings and more payload capacity.
    • Thomas and Erick thought it is worth testing, but durability needs validation and KBM/Julius should be involved before treating it as a real Quiver change.

  • Decisions / Direction

    • Spearhead remains 12S for PT1; 14S would require PDB/charger changes and is not worth the added cost before test results.
    • The 12S 22 Ah semi-solid battery option is now the preferred planning direction if the claimed specs and sourcing work out.
    • Ankara/NATO restrictions likely push flight or serious ground-test activity to mid-July; do not risk restricted operations.
    • Mid-July is the tentative meetup/test window if Thomas/Erick can attend.
    • PT1.5 electric-pusher conversion is a plausible post-PT1 path, dependent on real PT1 weight and test data.
    • Electrical planning is effectively complete; next tasks are the updated planning info note/BOM and a separate electrical layout/wiring-diagram deliverable.
    • Wire/electrical planning should assume Pixhawk 6C Mini unless new evidence forces a change.
    • Zeynep should own a bench-integration setup with Pixhawk/CAN-to-PWM/wiring supplies so she can test Spearhead avionics before the Ankara build.
    • FPV is parked for now; Walksnail Avatar remains the candidate direction.
    • ASA IRO for Quiver enclosures is an interesting future weight-saving test, not a decision.

  • Open Items

    • Alperen: continue ASA Aero/ASA IRO print-setting experiments until larger Spearhead skin/nose parts print without broken/stringy infill or internal rattle.
    • Alperen: proceed with Spearhead manufacturing after print settings are solved: print parts and cut ribs/spars.
    • Alperen: complete Spearhead tail design by the end of the week and then write a full structural-design information note.
    • Alperen/Erick/Zeynep: plan PT1 around the 12S 22 Ah semi-solid battery option, while verifying real specs, sourcing, connector details, and discharge/current margin.
    • Alperen/Thomas/Erick: treat early-July Ankara flight restrictions as a likely two-week project delay and coordinate a possible mid-July meetup/test window.
    • Alperen: keep PT1.5 electric-pusher conversion as a post-PT1 option and revisit after the real PT1 weight is known.
    • Erick: update the Spearhead electrical planning information note with the Friday decisions by Wednesday.
    • Erick: update/finalize the electrical BOM by Wednesday.
    • Erick: create the detailed electrical layout / wiring table / wiring diagram as a separate task, target around June 24.
    • Erick: plan wiring around Pixhawk 6C Mini and verify how to connect PDB 5 V/ground/current/voltage sensing to the Pixhawk power port or adapted cable.
    • Zeynep: receive/order Pixhawk 6C Mini and send photos/details of the included cable set when it arrives.
    • Zeynep: review whether there are any concerns with powering Pixhawk through the PDB/regulator path instead of a standard power module.
    • Zeynep/Alperen: buy/assemble bench-integration supplies after Erick’s Wednesday BOM: CAN-to-PWM, connectors, jumper/crocodile leads, JST/servo hardware, and any needed small servo.
    • Zeynep: continue Python FDM/UI/simulation improvements while control-surface deflection data is blocked.
    • Alperen: provide control-surface deflection aero data when structure priorities allow.
    • Zeynep: keep Walksnail Avatar receiver/transmitter/display option in mind for later FPV setup; exact purchase links can wait.
    • Erick/Thomas/KBM/Julius: if ASA IRO printing is solved, evaluate Quiver enclosure/cap test parts for durability and weight savings before any material switch.

  • Open Questions / Risks

    • Can ASA IRO be made reliable on large Spearhead parts, or will loose infill/rattle keep blocking manufacturing?
    • Are the semi-solid battery specs, sourcing, and connector details trustworthy enough for PT1 planning?
    • How much schedule impact will Ankara/NATO restrictions have on ground runs, taxi tests, and meetup timing?
    • Does the Pixhawk 6C Mini power-port/cable set support a clean PDB current/voltage-sense wiring path?
    • Will a PT1.5 electric-pusher conversion be weight-feasible once real PT1 mass is known?

Clone this wiki locally