It is definitely beneficial to have a knob jig in your workshop that can help you make wooden star knobs. Especially when you are building jigs or machines for your shop.
A star knob comes in handy when you need to tighten, fix, clamp or make adjustments to your jigs or essentially to any other thing around the workshop. Due to their ergonomic star shape, they offer a nice secure grip.
It is possible to make knobs without the knob jig, however, it is much faster and more convenient to use one. You can stock up, make several knobs at once and use them later on when needed.
In addition, you also save a lot by making your own wooden knobs. Your wallet will be grateful. If you are building a workshop on a budget this jig is a must.
It is a fairly simple and quick project. You can use scrap wood or any kind of wood you find in the workshop. I built mine from plywood leftovers.
With the instructions in this blog post, you will learn step by step how to make a knob jig and wooden knobs for your workshop.
I hope you enjoy it!
Check out also these other Woodworking Jigs for more workshop projects inspiration.
DIY Star Knob Jig Video
If you want to see how it is done, check out the full video below for a step-by-step guide on how to make a star knob jig.
Table of Contents
*Safety is your responsibility. Make sure you know what you’re doing and take all necessary safety precautions while working with power tools. Safety comes first!
Always be cautious and careful when using any power tool.
What you'll need to build the DIY Knob Jig
Star Knob Jig
2x Birch Plywood – (17 x 10 x 1,2 cm)
Threaded rod ø6mm
Wingnut, T-Nut, and Washer for a ø6mm threaded rod
Forstner Drill Bits – ø10mm, ø15mm
Hole Saw Cutter Drill Bit – ø38mm (ø42mm)
Drill bit for wood – ø2mm
4x Wood Screws – 3 x 20 mm
What are clamping knobs?
Clamping knobs or hand knobs are components used especially for tightening, clamping, adjusting, or assembling. They come in different variations depending on their application. They are available both with male studs or female threads. The most common types of clamping knobs are ball knobs, star knobs, knurled rim knobs, or wing knobs.
What is a star knob?
Star knobs, also known as lobe knobs or scallop knobs are one type of clamping knobs that due to their shape are ideal for tensioning, fixing, and clamping purposes. They offer a nice secure grip thanks to their ergonomic star shape and come both with a tapped hole or a threaded stud.
Make a Knob Jig
Step 1 - Make the base
For the jig base, I cut 2 pieces of plywood (1,2cm). Each is 17 cm long and 10 cm wide.
Marked the corners of one of the plywood pieces (2 cm from the edges), clamped both pieces together, and predrilled with a 2,5mm drill bit. I also used a countersink drill bit to make sure the screw heads are completely flush with the surface.
Then I screwed both pieces together using 3,0x16mm wood screws.
This is just a temporary fix.
Knob Jig Design
Step 2 - Draw the design
I flipped the knob jig over, marked the center, and started drawing the design.
The design consists of 2 circles (inner circle ø38mm, outer circle ø42mm) and lines that are 60 degrees apart.
Step 3 - Cut the shape
Once finished with the design I drilled a 2,5mm hole through both parts on the center mark, just to make a mark on the second piece. (I did not run the drill bit all the way through)
This will allow me to work on the centers separately knowing they would be aligned when put back together.
Then I disassembled both pieces.
I took the first piece with the drawn design and used a ø38mm hole saw with a ø6mm drill bit to drill through the wood piece, exactly copying the inner circle.
A wooden knob with such a diameter can easily accommodate a 6mm bolt or a 20mm T-nut. It is quite a practical size for a star knob.
Then I took the second piece and drilled a ø20mm hole in using a Forstner bit, deep enough to just flush the head of the T-nut with the surface.
To insert the T-nut I enlarged the hole with an ø8mm drill bit.
Again, not going all the way through.
I inserted the T-nut using a clamp, made sure all is flush, and assembled both wood pieces together again.
I cut 3 centimeters from a ø6mm threaded rod, sanded the cut, and screwed the rod in the T-nut. To keep it there for good, you can put some epoxy on the rod (or in the T-nut) before screwing it in.
As an alternative way of attaching the rod, you can also drill a hole through both the plywood desks and attach the T-nut from the bottom. Or directly insert a hex bolt or a carriage bolt from the bottom.
Just make sure both the T-nut or the bolt are flush with the bottom so that the knob jig sits flat on the surface.
Different Types of Star Knobs
The design of this knob jig allows for 2 types of star knobs.
Both have six points and they differ in the depth of the cut.
The first one additionally uses a dowel that fixes the position of the knob when drilling holes. With that, you don’t need to pre-draw the lines on the knob and you can drill right away. That quite simplifies the entire process (see below).
However, if you wanted to make star knobs with a different number of points, you could lay out additional lines on the jig that are not 60 degrees apart – (e.g 120 degrees for a 3-star knob, 90 degrees for a 4-star knob, etc.).
Step 4 - Make the Star Knob
Star knob with a shallow cutout
To make the first star knob, I drew all the lines on a piece of plywood and cut out a circle using a hole saw.
Then I placed the circle on the knob jig, aligned all the lines on the circle with the lines on the jig accordingly, and fixed the circle with a wing nut.
I drilled a 10mm hole using a Forstner bit with the center at the intersection of one of the lines and the inner circle (ø38mm).
Inserted a 10mm dowel in the drilled hole (to additionally fix the star knob) and drilled a second hole right next to the first one at the next intersection.
It is not necessary to insert the dowel in the hole at this point but you can test it out how it would work when making knobs.
Now the jig is ready for the first star knob.
If you drew the lines correctly and made the 2 first holes right, then by rotating the circle in the jig and drilling additional holes you will get a perfect star knob.
The dowel will fix the position of the knob and allow for an accurate six-pointed star knob. Thus when creating additional star knobs you wouldn’t need to draw any lines on the circles.
The video on this page goes into more detail on how the process works and how to make the knobs themselves.
Star knob with a deep cutout
The second type of knob follows the same principle as the first one. However, there is no dowel that would fix the knob in position when drilling a hole.
I am using a ø15mm Forstner bit to drill the holes on the outer circle (ø42mm). To center the circle with the dowel jig at least 1 or 2 lines are needed to align them accurately.
The process of creating these star knobs is the same as in the first case.
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Star Knobs Final Finish
The star knobs are ready to be used at this moment.
Though I like to give them a final touch before use.
I usually slide the knobs on a threaded rod and tighten them from below and from above with washers and nuts. Then I mount the rod on a drill press and sand the knobs.
You can use a piece of sandpaper on a wooden block to sand them, but what I like to do is to use a hand grinding machine.
It is better to use a sand paper disc with a lower grit due to the speed of the drill press and the grinding machine.
Be careful not to hit the threaded rod while sanding.
And this is the result – they look awesome.
How To Make Star Knobs
- Cut out a wooden circle with a hole saw
- Place the circle on the knob jig, fix it with a wing nut and drill a hole in
- Turn it 60 degrees, secure its position with a dowel and drill another hole
- Repeat the process until all holes are drilled
- To finish the star knob sand all the edges and inner cuts with a sandpaper
And there you have it. A nice and simple knob jig for your drill press that will help you make perfect star knobs.
So.. Ready to make a few wooden knobs for your workshop? Let’s do it!
Here are some of the projects where I am using these clamping knobs:
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I hope the information shared in this blog post sparked an idea and inspired you to build this woodworking jig. You can save a lot of money by making your own wooden knobs. And besides, they look amazing 🙂
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