Blunt transplant dibble with a split depth stop

OR-009 / Form a repeatable pilot hole in loose propagation medium using a blunt four-facet point, while a removable split collar limits travel. The tool makes a hole; it does not prescribe a crop planting depth or compact a hard-soil planting pit.

Capacity and fit

Point-to-handle height 14 in (355.6 mm); 8 in (203.2 mm) cross grip. Point tapers over 3 in to a flat 1/4 in square (76.2 mm taper, 6.4 mm flat). Collar bottom adjusts from 3 to 6 in (76.2 to 152.4 mm) above the tip. Use only with a crop/container protocol compatible with that range.

Limits

Loose potting/propagation medium only. No foot pressure, hammering, levering roots or drilling hard soil; withdraw if significant resistance appears.

Hole width/depth does not replace node placement, media or rooting guidance. Check the actual root/cutting and container before use; do not force a shallow container over the tip.

Hardware

Two #8 x 2 in (50.8 mm) wood screws for the cross grip.

Two 1/4-20 x 4 in (101.6 mm) full-thread hex bolts, four wide 1/16 in-thick washers and two through-thread hand knobs/wing nuts. Do not use a blind knob that bottoms on the bolt before clamping.

One separate rule; soft temporary collar-setting mark. No metal point or blade is installed in the finished tool.

Tools

Tape measure and combination square

Pencil, clamps and safety glasses

Saw with wood blade; drill/driver and piloting bits

120- and 180-grit abrasive

Plane/rasp suitable for hardwood; 9/32 in bit; backing wood

Fasteners

Grip screws cross 3/4 in grip and enter the stem end 1 1/4 in. Collar bolts span two 3/4 in blocks plus 1 1/2 in stem width: 3 in before washers/knobs.

Two 1/16 in washers add 1/8 in per bolt stack. The 4 in bolt must engage the actual through knob fully and leave at least two complete threads beyond a wing nut.

Cut list

Build sequence

1. Cut the stem to 13 1/4 in from straight-grained actual 1 1/2 in-square wood. Mark a line 3 in above its bottom on all four faces; reject a blank with a knot or split across the working end.
2. On the bottom end mark a centered 1/4 in square: its edges are 5/8 and 7/8 in from either original side. These four corners define the blunt final flat.
3. Connect each bottom-square corner to the appropriate 3 in shoulder marks. Clamp and plane/rasp equal facets on four sides, checking symmetry after every pass. Do not sharpen the flat into a point.
4. Sand the four facets and flat without rounding the upper parallel faces. A cloth must pass over the working end without catching; confirm the 3 in taper and 1/4 in flat with a rule.
5. Cut the cross grip to 8 x 1 1/2 x 3/4 in. Center it over the stem at x=-3 1/4, y=0, z=13 1/4 in, leaving equal 3 1/4 in side overhangs.
6. Predrill two vertical grip screws at x=3/8 and 1 1/8 in, y=3/4 in. Drive 2 in screws down through the 3/4 in grip into the stem end 1 1/4 in. Set heads flush and round exposed grip edges.
7. Cut two 4 in stop blocks from actual 3/4 in-square stock. Drill 9/32 in holes through the y direction at local x=1/2 and 3 1/2 in, centered z=3/8 in, using a backing block.
8. Place blocks against front/back stem faces at y=-3/4 to 0 and 1 1/2 to 2 1/4 in. Insert bolts at x=-3/4 and 2 1/4 in; add outside washers and through knobs. The bolts pass beside, not through, the 1 1/2 in stem.
9. With the tool resting on its blunt flat, set both collar bottoms to the crop-selected depth within 3 to 6 in. Measure on both sides so the stop is square, then snug both knobs evenly by hand.
10. Test in an empty trial container filled with the intended loose medium. Push by hand only until the collar just touches the surface, withdraw straight and compare the actual hole to the required root/cutting fit. Do not use the tool where the necessary protocol falls outside its working range.
11. Loosen and reset the collar to another allowed position to verify travel and repeatability. If it creeps, split blocks or damaged stem faces must be repaired; do not compensate by excessive knob force.

Acceptance checks

Tip remains a flat 1/4 in square with four symmetric facets; no splinter or metal point.

Grip screws stay buried and the cross grip cannot rotate by gentle hand inspection.

Both stop faces are square at the selected 3 to 6 in depth; actual trial-hole depth agrees before plants are introduced.

Use

Use the actual crop propagation instructions for the root/cutting, and make only a suitable pilot opening. Backfill/firm the medium as those instructions require rather than treating a dibble-shaped void as a planting specification.

Care

Brush off media after use, dry the wood and recheck the flat tip and collar grip. Replace a cracked stem, loose grip or split block; keep hardware clean and lightly moving.

Dimensioned drawings

Sources and testing

Not performed; no load rating, animal acceptance, yield or durability performance is claimed.

Vegetative plant parts - Stem nodes and propagation orientation; each crop needs its own horticultural protocol.

Home Propagation of Houseplants - Keep covering off leaves and keep plastic-covered cuttings out of direct sun. No universal humidity, rooting-time or crop-success claim.