DIY V-Block Jig for Drilling Round Dowels on a Drill Press with Full Dimensions

Trying to drill perfectly centered holes through a round dowel without a jig usually ends in frustration. The dowel rolls, the drill bit wanders, and the hole ends up crooked or off-center. That is exactly why a V-block drilling jig is one of the smartest workshop accessories you can build. Simple, accurate, and easy to make from scrap wood, this jig turns your drill press into a precision dowel drilling station. Access over 16,000 woodworking plans 

This DIY V-block jig securely holds cylindrical stock in a 90 degree groove so your drill bit stays aligned every time. Whether you are drilling holes for joinery, handles, furniture parts, or dowel connections, this setup gives repeatable and clean results with very little effort.

Why a V-Block Jig Matters

Round material is difficult to clamp flat against a drill press table. Even small dowels tend to rotate under pressure from the drill bit. A V-block solves the problem by cradling the dowel between two angled faces that automatically center the workpiece.

Once clamped down, the dowel cannot roll or shift, allowing you to drill straight through the exact center. This is especially useful for:

• Dowel joinery
• Furniture pegs
• Tool handles
• Wooden toy parts
• Center drilling pipe or rod stock
• Repetitive drilling tasks

The design is compact enough for small workshops but accurate enough for precision woodworking projects.

Overall Jig Dimensions

The jig is designed to sit comfortably on a standard drill press table while providing enough support for longer dowels.

Main V-Block Dimensions

Part	Measurement
Overall Length	25 cm
Overall Width	10 cm
Overall Height	8 cm
V-Groove Angle	90 degrees
Groove Depth	4 cm
Base Thickness	2 cm

These dimensions work well for dowels ranging from 10 mm to 50 mm in diameter.

Materials Needed

This project can be built almost entirely from scrap wood.

Materials List

• 1 hardwood or plywood block
• Wood glue
• 40 mm wood screws
• Scrap clamping block
• Sandpaper
• Optional toggle clamp

Hardwood is recommended because it resists wear from repeated drilling operations.

Cutting the V-Groove

The heart of the jig is the centered 90 degree groove.

Method 1 — Table Saw

The easiest method is using a table saw blade tilted to 45 degrees.

1. Set blade angle to 45 degrees
2. Run the block through once
3. Flip the block and repeat
4. The two cuts form a perfect V

Method 2 — Router

A 90 degree V-groove router bit also works well for cleaner cuts.

Method 3 — Circular Saw

If you do not own a table saw, two angled passes with a circular saw can still produce accurate results.

Building the Base

Attach the V-block securely to a flat base plate. The wider base gives the jig stability on the drill press table and creates room for clamps.

Recommended Base Size

Part	Measurement
Base Length	30 cm
Base Width	15 cm
Base Thickness	18 mm

Center the V-block on the base and fasten it with glue and screws from underneath.

Workpiece Locking System

One clever feature of this jig is the simple locking method using a scrap piece and screw.

Place a small scrap board over the dowel and drive a screw lightly into the side supports. This presses the dowel into the V-groove and prevents movement during drilling.

This simple clamp system works surprisingly well and costs almost nothing to build.

For faster operation, you can also install:

• Toggle clamps
• T-track hold-downs
• Wing-bolt pressure blocks

Using the Jig on a Drill Press

Using the jig is simple:

1. Place the jig on the drill press table
2. Insert the dowel into the V-groove
3. Align the drill bit with your marked center point
4. Clamp the dowel securely
5. Drill slowly and steadily

The V-groove automatically centers the dowel beneath the drill bit, helping eliminate wandering and angled holes.

Accuracy Tips

For best results:

• Use brad point drill bits
• Start with a pilot hole
• Clamp the jig to the drill press table
• Drill at moderate speed
• Mark hole locations carefully

If you drill many identical parts, add a stop block to the jig for repeatable positioning.

Optional Upgrades

Once you build the basic jig, you can improve it even further.

Useful Additions

• Adjustable stop fence
• Replaceable sacrificial insert
• Built-in measuring scale
• Toggle clamp system
• T-track adjustments
• Dust collection hole

These upgrades turn a simple jig into a professional drilling fixture.

Final Thoughts

A V-block drilling jig is one of those workshop helpers that seems small until you use it. Suddenly, drilling centered holes through round stock becomes fast, easy, and highly accurate. Instead of fighting rolling dowels and crooked holes, you get clean repeatable results every time.

Best of all, this jig can be built in less than an afternoon using scrap wood and basic tools. It is inexpensive, compact, and useful for countless woodworking projects. Once you make one, you will wonder how you ever drilled dowels without it.