What it is + how you use it A 3D-printable fish finder shuttle designed for a clean, portable ice setup powered by either DeWalt 20V or Milwaukee tool batteries—built around a RAM ball mount so you can pop your existing RAM arm on/off in seconds.

Primary workflow

• Your fish finder stays mounted to your RAM arm (ball-clamp style).
• Clamp that RAM arm onto the shuttle’s RAM ball.
• Power the unit from your tool battery + integrated buck converter adapter.
• Set it where you want on the ice and keep your wiring tidy.

Also great for “boat to ice” without buying a second unit (optional workflow):

• If your boat unit is already on a RAM arm, you can remove the fish finder while it’s still attached to the arm and clamp that same arm onto this shuttle’s ball for ice days—no re-rigging your head unit.

Tool-battery power (DeWalt + Milwaukee supported)

• The shuttle is designed around either a DeWalt 20V or Milwaukee tool-battery adapter that includes an integrated 20V-to-12V step-down (buck) converter unit (sold as one unit).
• The brand makes both a DeWalt adapter and a Milwaukee adapter with an identical mounting pattern, so you choose the version that matches your battery platform and bolt it on.

Compatibility / Compatible Hardware RAM ball & arm Uses a RAM ball interface and works with both:

• RAM B-size (1") ball
• RAM C-size (1.5") ball No preference—the only requirement is the ball must match your RAM arm so it clamps correctly.

Fish finders

• Compatible with many fish finders (Garmin, Humminbird, Lowrance, etc.)
• Any unit already mounted to a ball-clamp RAM-style arm can work,
• Provided the ball size matches (B vs C) and
• You have adequate clearance for your head unit and cable routing.
• Validated example setup used by the creator: Garmin ECHOMAP UHD2 73cv.

Power cable note (don’t skip this)

• You’ll need the correct fish finder power cable from the adapter output to your head unit.
• If your unit’s factory power cable is already installed on a boat (or another rig) and you don’t want to pull it, you may need to buy a second power cable for your ice setup.

Power system

• Uses a tool-battery adapter with integrated 20V-to-12V step-down (buck) converter (single combined unit).
• Adapter includes over-discharge protection / low-voltage cutoff (LVC).
• Example product name (example only, not required purchase): “DC 20V to 12V Step-Down Converter with Switch Compatible with Dewalt 20V Battery, Over-Discharge Protection, DC12V 20A 240W Buck Converter Voltage Regulator…”

Transducer

• Current design is for a Garmin GT8 ice ducer.
• If the you message me, I can easily make a transducer holder sized to your specific transducer.

Bucket fit (secondary feature)

• Designed to fit inside a standard 5-gallon OR 6-gallon bucket, and includes an integrated carry handle.
• Verify bucket clearance if you run a tall screen, long arm, or bulky cable bundle.

Quick “verify before you print” checklist

• Ball size: RAM B (1") vs C (1.5")
• Clearance: head unit + arm sweep + cable routing (and bucket clearance if you plan to run it inside a bucket)

BOM (Bill of Materials) Mounting Hardware (ball) 1x RAM ball w/ 1/4-20 stud (B-size 1" or C-size 1.5", to match your arm) 1x 1/4-20 nut 1x 1/4" washer

Ball attachment method (important): The ball uses a 1/4-20 stud that passes through a THROUGH-HOLE in the printed shuttle and is secured with a washer + nut. No threading directly into plastic.

Assembly Hardware (#10-24 + inserts) 13x #10-24 stainless socket head cap screws 13x #10-24 brass heat-set inserts (Ruthex-style) 2x 1/4-20 round head screws 2x 1/4-20 brass heat-set inserts (Ruthex-style)

Power Components (battery adapter + converter) 1x Tool-battery adapter with integrated 20V-to-12V buck converter (single unit), in the version that matches your batteries:

• DeWalt 20V platform adapter or
• Milwaukee platform adapter (same mounting pattern from the same brand) 1x Fish finder power cable (correct one for your brand/model), from the adapter output to your head unit (You may already have this—just note you might need a second cable if your first is permanently installed on a boat.)

Recommended Safety/Extras 1x Inline fuse (sized for your fish finder load) 1x Strain relief (cable gland, zip-tie mounts, or printed clamp) Heat-shrink + crimp terminals/ferrules (as needed)

Brief print recommendations

• Print in PETG or ASA for durability and better cold performance (PLA can work, but cold + impacts can be rough).
• Use extra perimeters/walls around the handle and ball mount area.
• Keep insert pockets clean for smooth heat-set installation.