Zero-G Chair Frame
Three-motor lie-flat recliner in Alexco 40 Series extrusion. A wrap-around triple-screen gantry and HOTAS pods ride on the backrest. Sized for a 1.8 m rider with headroom.
Drawing
ZGC-01 rev E
Units / scale
mm · NTS
System
40 Series, 8 mm slot
Status
Concept
Position
Limited so your head never drops more than 5° below your hips.
0° is flat out, 80° hangs down for getting in.
Screens
Size
The bar slides along the hoop arms. Side screens angle in so all three stay this far from your eyes.
Readouts
- Recline from vertical
- Side screen angle
- Screen array width
- Highest point
- Overall length
- Legrest toe clearance
- Tip margin, rear
- Tip margin, front
Actuator schedule
Live from the model. Peak is the worst pose across every slider range. Spec adds a 1.25 safety factor.
| Ref | Moves | Mounting | Length now | Min–max | Stroke needed | Force now | Peak | Spec ≥ |
|---|
Cut list
Alexco 40 Series silver anodised, square cuts unless noted. Alexco cuts to any length.
| Ref | Part | Profile | Qty | Length | Subtotal | Notes |
|---|
Hardware
Quantities include spares.
| Item | Qty | Use |
|---|---|---|
| From Alexco | ||
| 40 Series Heavy-Duty Corner Bracket | 56 | Every frame joint |
| 40 Series Adjustable Angle Bracket | 8 | 45° brace ends (A4); wing hinges W1 (top and bottom) |
| 40 Series Bracket T Plate Heavy Duty | 4 | Posts to rails; gantry arms to backrest |
| 40 Series Bracket L Plate Heavy Duty | 4 | Rear base corners |
| 40 Series T-Slot Nut Plate / M8 T-nut | 190 | Brackets, plates, carriages |
| Button head cap screw, M8 stainless | 190 | With the T-nuts |
| 40 Series Adjustable Foot | 6 | Base rails, ends and middle |
| End cap 40×40 / 40×80 | 20 / 8 | Open ends |
| 100 × 10 mm flat bar, mill finish | 1.9 m | Plates P1–P6 |
| Elsewhere | ||
| Linear actuator, 24 V, self-locking, limit switches, Hall feedback | 3 | M1–M3, see schedule |
| M12 shoulder bolt + nyloc nut | 6 | Seat, back and legrest pivots, both sides |
| Flanged bronze or Igus bushing, 12 mm ID | 12 | Two per pivot point |
| VESA 75/100 adapter plate + 30 mm standoff, rated ≥ 10 kg | 3 | Centre screen on F2, side screens on wings F5 |
| Steel safety cable, 3 mm, with crimps | 3 | Each screen to the hoop |
| 6 mm aluminium plate: 300×220 (R), 200×220 (L) | 2 | Pod platforms: stick + mouse (R), throttle (L) |
| 24 V 10 A PSU + 3-channel controller (or ESP32 + 3× BTS7960) | 1 | Drive, presets, head-down limit |
| Foam pads and covers | 3 | Seat, back, legrest |
Build notes
- Sized for 1.8 m with headroom: backrest 900, seat 500 and legrest 420 between pivots. The seat pivot is up to 450 so the longer legrest still clears the floor when it hangs down.
- Clear view: nothing sits between your eyes and any screen. Arms F1 run above the screens' top edges, struts F4 brace them from behind the backrest, and drop tubes F3 and wings F5 sit behind the screens. Use the Rider's eye view to check.
- Screen distance: the drop tubes hang from carriage plates P6 that slide along the arms' T-slots. Loosen eight bolts, slide, re-tighten. Range is 600–800 mm from your eyes.
- Equal distance: side screens mount on wings F5, hinged to F2's ends with adjustable angle brackets. Set them to the "side screen angle" readout and all three screen centres sit on an arc around your eyes, with a 6–33 mm gap between bezels.
- The cockpit rides on the backrest, so the screen distance and your hand position hold in every pose.
- Screens hang over your face when flat. Thread-lock the VESA screws, run a safety cable from each screen to the gantry, and fit stop blocks in the arm slots so the carriages can't slide off.
- Getting in and out: drop the legrest, recline a little, and slide in under the screens. In zero-G the gantry reaches about 2.1 m, so check your ceiling height.
- M2 carries the screens. Its 170 mm crank and forward anchor give it the most leverage near flat, where the load peaks. If its spec is still more than your actuator, add a pair of gas struts between seat and backrest.
- Actuators run in separate lanes so they pass each other: M1 110 mm left of centre, M2 45 mm left, M3 45 mm right.
- Don't use the 40 Series hinges for the main pivots. Use the 10 mm plates, M12 shoulder bolts and flanged bushings.
- Check clearances in CAD before cutting. This is a concept model.