Here’s a wiki topic while we experiment towards an automated drilling machine. 
- Concepts
- Functional Blocks
- Village Kit team progress
Grid Bot: Concepts
Super block gang drill.
An entire length of timber is fed into the machine and one block of drill heads come down and drill all the holes in one hit, one drill head per hole.
Inspiration:
- Multi Spindle Drilling Machine with Auto Loading & Unloading
- multi spindle drilling machine
- Ritter Machinery Company R46 – 46 Spindle Double Row System Drill
- Multi Spindle CNC Drilling Machine With Auto Loader
Pros - fastest machine, holes always aligned (at least on one axis)
Cons - need a lot of power to drill all at once, expensive to make machine
Indexing block gang drill.
As with “Super block gang drill”, but with a block of drill heads (where the block of drill heads corresponds to a connected sequence of holes) less than the total number of holes.
Either the drills or the part step sideways between each drill. The travel distance is equal to the full length of timber.
Inspiration:
Pros - fast, small
Cons - possible misalignment between drilling operations
Indexing spaced gang drill
Related to “Indexing block gang drill”, but with a set of drill heads are spaced equally along the length of timber.
Either the drills or the part step sideways between each drill. The travel distance is equal to the (full length of timber / number of drill heads).
Inspiration:
- PZSD Series Multi-Spindle Drilling Machine for Sieve Plate
- multi spindle acoustic panel drilling machine
Pros - fast, less travel distance required
Cons - possible misalignment between drilling operations
Rolling through feed drill.
The timber is fed by driven rollers through a drilling station that drills each hole at the correct location. Possibly in conjunction with a gang drilling head.
Inspiration:
Pros - fast, tiny, could use many at once. if encountering a knot in timber could adjust spindle speed.
Cons - misalignment possible
Pushing / pulling through feed drill.
The timber is fed by a clamped pusher / puller through a drilling station that drills each hole at the correct location. Possibly in conjunction with a gang drilling head.
Inspiration:
- Automatic Material Feeder with Custom Drill Press by Kentucky Gauge
- DS-B: Automated Drilling Machine
- CNC Fully Automatic Tube Drilling Machine
- QWDK-1000 Automatic pipe drilling machine
- Pipe Drilling Machine with Cold Saw Cutting Equipment with Full Automatic Loading System
Pros - simple mechanism
Cons - slow if single spindle.
Gripping through feed drill
As with “Rolling through feed drill”, but the timber is moved using a set of grippers, doing synchronized actions of clamping, unclamping, moving, and re-clamping to move the timber in specific distances.
Inspiration:
Pros - unlikely to misalign vs rolling version.
Cons - slow to clamp and move?
4-Way through feed drill
As with "through feed drill"s, but the drilling station drills the 4 holes using 4 independent drill heads.
Inspiration:
Pros - fast, continuous process, no punchout at exit of hole, could control each hole drill speed independently
Cons - still slow compared to other methods, possibly annoying to replace drill bits.
X-Y table drill.
A whole bunch of timber is laid out on a table side by side and a machine moves the drill head(s) over these to drill several parts in one batch on the machine.
Pros - frees up time between setups.
Cons - chance of misalignment if beams are not precisely machined to 40mm as errors propagate
Through + X-Y table drill
As with "through feed drill"s, but the drilling station is actually a mini “x-y table drill”.
Through + 4-Way X-Y table drill
As with "through feed drill"s, but the drilling station is actually 4 independent mini “x-y table drills”.
Inspiration:
Robots!
Use a generic robot to move a drilling tool relative to the timber, or the timber relative to the drill.
Pros - multifunction, could load and unload jig
Cons - slow, expensive maintenance
Oscillating mechanical pushing
Similar to “Pushing through feed drill”, but pushing happens through an oscillating motion thanks to a special merchanical chain.
Inspiration:
Pros - reliable mechanism
Cons -
Hole punching
As with previous ideas, but the drill heads are hole punchers.
Probably only feasible when beams are made from aluminium square extrusion.
Pros - no drill bits to replace, no wood chips / dust
Cons - punch out at rear difficult to control. knots could be a problem.
Lasers!
As with previous ideas, but the drill heads are lasers (!!!)
Probably only feasible for miniturized beams made from a lighter material.
Pros - low maintenance, clean-looking holes, no sawdust.
Cons - expensive high power lasers, smoke management, charring, fire hazard.
Decision Matrix
| Weighting | 4 | 2 | 4 | 4 | 5 | 5 | 3 | ||
|---|---|---|---|---|---|---|---|---|---|
| Option | Speed | Budget | Maintenance | Easy-to-use | Clean holes | High-precision | Semi-automatic | ||
| 1 | Perfect | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 135 |
| 2 | Block gang drill | 4 | 2 | 3 | 3 | 3 | 3 | 2 | 80 |
| 3 | Indexed gang drill | 4 | 3 | 3 | 3 | 3 | 3 | 3 | 85 |
| 4 | Through feed | 1 | 3 | 3 | 3 | 3 | 4 | 4 | 81 |
| 5 | 4-Way through feed | 1 | 2 | 2 | 2 | 5 | 4 | 5 | 84 |
| 6 | X-Y table | 2 | 3 | 3 | 3 | 3 | 2 | 2 | 69 |
| 7 | Minimum | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 27 |
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 |
Grid Bot “Hex” (6 Spindle)
Progress towards an “indexed gang drill” automated drill machine for grid beam: Grid Bot "Hex" (6 Spindle)
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