Grid Bot: Functional Blocks
Loading
- Pick up and place on track from a distance
- Rotate onto track from gravity-fed slanted tray
- Multiple chains with tabs push beams onto track
- Beams fed vertically down onto track. When the beam moves out of the way a new beam drops down.
- Conveyor chain lifts from gravity fed stack
Clamping
- Many diagonal v-profile clamps push down beam against fixed wall/floor
- Single long diagonal v-profile with cut-outs for drills clamps against wall/floor
- Rollers push down and horizontally
- Centering sprung rollers pushes both sides in, rollers keep down
- Clamp comes down between spindles and pulls down and in towards track
- Clamp methods: pneumatic cylinder, manual, …
- Two separate Clamps come for vertical and horizontal
Moving
- threaded rod on track with clamps attached
- End pusher pushes until force sensor at end detects force
- With beams clamped to “table”, “table” moves along fixed “bed” using stepper motor powered linear actuators (threaded rods), thus moving the beams
Drilling
- Location
- Spindles are static above, table moves up
- Spindles are static below, table moves down
- Spindles are horizontal, table moves into spindles
- Very rigid clamp moves the beam into spindles, no table!
Flipping
- Tumbling
- Don’t actually flip them, just run them through the machine twice
- Don’t actually flip them, just run them through the machine four times!
- Pick up the ends of the beam by the corner so that it rotates 90degs, re-clamp.
- Clamp can rotate?
Unloading
- Spit out onto the ground
- Pushout onto a long angled roller track. They roll down and stack up in a line.
- Pushed out onto track, bumped off into a bin on wheels
- Push back through holes in the fixed fence
- Rotate out with dynamic right-angle arm
- Lift out and dump with a chain-driven bracket
Safety
- Laser beams
- Metal fence to keep hands out with a stop-mechanism when opened.
- With gang drill method, spindles could be surrounded by metal fence, and material moves up into drills so the drills never leave the metal fence. Fence would only need to be opened and closed during maintenance.
Decision Matrix
Things to rate each mechanism on in a matrix-
- reliability (aka low-maintenance)
- accuracy/precision
- effect on speed
- effect on quality
- affected by woodchips/dust
- simplicity vs complexity
| - | Weighting Criteria (higher is better) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Option | Lower Cost | Low Maintenance | Speed | Safety | Simplicity | Effect on Quality | Precision placement of holes | Less affected by dust and woodchips | can handle warped beams | notes | ||
| Loading | Pickup and place on track from stack with robot arm | 3 | 4 | 5 | 4 | 1 | 4 | 5 | 5 | 2 | 33 | |
| Rotate onto track from gravity-fed slanted tray | 4 | 4 | 5 | 5 | 4 | 5 | 4 | 3 | 3 | 37 | will need to load stack correctly | |
| Multiple chains with tabs push beams onto track | 3 | 4 | 5 | 3 | 3 | 5 | 4 | 4 | 4 | 35 | ||
| Beams fed vertically down onto track. When beam moves out of way new beam drops down. | 3 | 5 | 5 | 5 | 4 | 3 | 3 | 4 | 3 | 35 | ||
| Conveyor chain lifts from gravity fed stack | 3 | 3 | 5 | 4 | 3 | 4 | 4 | 3 | 3 | 32 | ||
| Clamping | Many diagonal v-profile clamps push down beam against fixed wall/floor | 3 | 4 | 4 | 3 | 4 | 4 | 5 | 4 | 4 | 35 | |
| Single long diagonal v-profile with cut-outs for drills clamps against wall/floor | 3 | 4 | 4 | 4 | 4 | 5 | 5 | 4 | 5 | 38 | ||
| Rollers push down, and horizontally | 5 | 5 | 5 | 4 | 5 | 4 | 4 | 3 | 4 | 39 | ||
| Centering sprung rollers pushes both sides in, rollers keep down | 4 | 4 | 5 | 4 | 4 | 3 | 4 | 3 | 4 | 35 | ||
| Clamp comes down between spindles and pulls down and in towards track | 4 | 4 | 3 | 4 | 4 | 4 | 4 | 4 | 3 | 34 | ||
| Two separate Clamps come for vertical and horizontal | 3 | 3 | 4 | 4 | 4 | 4 | 5 | 4 | 3 | 27 | ||
| Moving | threaded rod on track with clamps attached | 4 | 4 | 4 | 4 | 5 | 4 | 5 | 3 | 5 | 38 | |
| With beams clamped to “table”, “table” moves along fixed “bed” using stepper motor powered linear actuators (threaded rods), thus moving the beams | 3 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 5 | 36 | ||
| Drilling | Spindles are static above, table moves up | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 21 | |
| Spindles are static below, table moves down | 3 | 3 | 3 | 4 | 3 | 3 | 3 | 4 | 3 | 22 | ||
| Spindles are horizontal, table moves into spindles | 3 | 3 | 3 | 4 | 3 | 3 | 3 | 4 | 3 | 22 | ||
| Very rigid clamp moves the beam into spindles, no table! | 3 | 3 | 3 | 3 | 2 | 3 | 3 | 4 | 3 | 20 | ||
| Flipping | Tumbling | 3 | 5 | 4 | 3 | 4 | 2 | 2 | 3 | 4 | 23 | |
| Don’t actually flip them, just run them through the machine twice | 3 | 3 | 2 | 3 | 4 | 4 | 3 | 3 | 3 | 22 | ||
| Don’t actually flip them, just run them through the machine four times! | 3 | 3 | 1 | 3 | 4 | 5 | 3 | 4 | 3 | 22 | ||
| Pick up the ends of the beam by the corner so that it rotates 90degs, re-clamp. | 3 | 3 | 4 | 4 | 2 | 5 | 3 | 3 | 3 | 24 | bent beams will have ends all over the place | |
| Clamp can rotate? | 3 | 3 | 4 | 3 | 2 | 3 | 3 | 3 | 3 | 21 | ||
| Unloading | Spit out onto the ground | 5 | 4 | 3 | 3 | 4 | 2 | 3 | 5 | 3 | 24 | |
| Push out onto a long angled roller track. They roll down and stack up in a line. | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 21 | ||
| Pushed out onto track, bumped off into a bin on wheels | 3 | 3 | 4 | 3 | 4 | 3 | 3 | 3 | 3 | 23 | ||
| Push back through holes in the fixed fence | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 21 | ||
| Rotate out with dynamic right-angle arm | 3 | 4 | 3 | 3 | 3 | 3 | 3 | 4 | 4 | 22 | ||
| Lift out and dump with a chain-driven bracket | 3 | 3 | 3 | 3 | 3 | 2 | 3 | 3 | 3 | 20 | ||
| Safety | Laser beams | 4 | 4 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 23 | |
| Metal fence to keep hands out with a stop-mechanism when opened. | 3 | 3 | 3 | 5 | 3 | 3 | 3 | 4 | 3 | 23 |