Intro: Making Wooden Knobs on a Drill Press
So you've just made this great thing out of beautiful wood, it could be anything: a jig, a solid wood tool, whatever. The last thing you need is to a knob to tighten or hold down some part of your fancy new creation but you don't want to use some cheap looking plastic off the shelf knob. No you want something that looks good and does a good job to. The only problem? You don't have a lot of fancy tools in your workshop.
Never fear all you need to made some truly beautiful solid wood knobs is a drill press and a few inexpensive bits/accessories. It only takes about 15 minutes to make one of these knobs if you make them one at a time. If you are going to be making more than one complete each of these steps for each knob before moving on to the next step. Doing so will save you a lot of time changing back and forth between bits/accessories on your drill press.
Step 1: Tools & Materials
Required Tools- These are the bare minimum tools that you need.
- Drill Press (I would not recommend using a hand drill for this project)
- Hole Saws (Usually sold in a set with several different sizes)
- 3/4" drill bit (Forstner bit recommended)
Optional Tools - These are highly recommended and will make the final product either better or easier to achieve)
- A pattern (Several are provided in this instructable)
- 3/4" Sanding Drum
- Palm Sander, Disc Sander or Belt Sander
- Threaded Insert Tool (or some other reliable way to install Threaded Inserts)
- 3/8" Drill Bit (For drilling hole for threaded inserts)
- 1/8" Drill Bit
- Wood (Scrap wood is fine as long as it is large enough for you to hold safely and comfortably.)
- Super Glue (Optional)
- Stain to match the rest of your project (Optional)
- Lacquer (or some other wood finish) (Optional)
Step 2: Making Marks
Start by installing a 2" hole saw in your drill press. You can of course use a different size but I find 2" to be just about right for most applications and gives you enough to hold on to in some of the later steps.
Plunge the hole saw into your work piece just enough to leave a groove ~1/16" deep.
Select one of the patterns below or one you created yourself. Place a nail through the center of your pattern and into the hole created by the hole saw. Make a mark on your workpiece where each line crosses the groove created by the hole saw.
Repeat this step for each knob that you are making before moving on.
Step 3: Drilling the Notches
Optional: Change the bit in your drill press to a 1/8" drill bit. Drill all the way through the workpiece at each of the points you marked in the previous step. Do this for each knob you are making.
Change to a 3/4" forstner bit.
If you skipped the optional part about then drill all the way though at each mark you made in the previous step.
If you drilled the optional holes noted about only drill about half-way through your workpiece at each of the holes you made. Flip the workpiece over and drill through the same holes from the other side. Doing it this way will give you a much cleaner and smoother top and bottom to your finished knobs because there won't be any tear-out from the bit going all the way through.
Do this step for each of your knobs before moving on.
Step 4: Finishing the Cuts
Switch back to the hole saw and cut about half-way through your workpiece then flip it over and cut the rest of the way through. Doing this will prevent tear-out on the face of the knob and will make it much easier to remove the knob from the hole saw because much more of it will be exposed.
If your knob is stuck in the hole saw you may have to remove the hole saw from the drill press chuck to get a better angle. If all else fails you can try pushing the knob out through the holes in the hole saw that are meant to let air escape during use.
Do this for each of your knob.
Step 5: Sanding the Knob (Optional)
This step is entirely optional but highly recommended.
I recommend using a 3/4" sanding drum but you can hand sand if you don't have one; it will just take longer.
Change out the hole saw for a 3/4" sanding drum. Carefully begin sanding all of the edges of your knob. The 3/4" sanding drum should fit perfectly into the 3/4" notches that you made with the forstner bit.
I like to round over the edges where the notches intersect the outside of the circle. his is mostly an aesthetic thing but I think it improves the comfort of the knobs a little bit as well.
Once all of the outside edges are smooth you can move on to sanding the top and bottom of your knob either with a power sander of some flavor or a flat sanding block.
A small piece of sandpaper wrapped around a dowel can be used to round over the top/bottom edges of the notches which will improve comfort during use.
Step 6: Installing Hardware (Screw)
If you are going to install a 1/4"x20 machine screw the hole created by the guide bit part of the hole saw is probably already the correct diameter for your screw. If it's not or if you plan to use a different size screw you will need to drill through the center hole with an appropriate size bit: larger than the minor diameter and just slightly smaller than the major diameter of the screw you plan to use. If your knob is made from a very hard wood you may have to make the center hole the same size or slightly larger than the major diameter of the screw. If this is the case you will have to glue it in place.
Determine the diameter of your screw head and drill a recess in the top of your knob just deep enough so that the head of the screw is completely below the surface. This is for aesthetic reasons. If you don't mind the top of your screw sticking up you can skip this step.
Begin screwing the screw into the knob. The treads on a machine screw aren't really designed to cut into the wood so it may be difficult. If you find it too difficult you can remove the screw and enlarge the central hole.
When the screw is most of the way in but before the gap is closed completely you can put a few drops of super glue into the screw head recess. This will allow the knob to hold onto the screw much better and is required if the screw is loose within the central hole and is highly recommended when making knobs from softwoods that won't grip the screw very strongly.
Tighten the screw the rest of the way and set aside to let any glue that you've added to dry.
Once you have installed hardware in all of your knobs move on to the finishing step.
Step 7: Installing Hardware (Threaded Insert)
These direction are for installing a 1/4"x20 threaded insert. If you are installing a different size of insert you will have to adjust the size of the hole you drill.
Insert a 3/8" drill bit into your drill press and drill through the center hole flipping the knob halfway to prevent tear-out. Using a threaded insert tool install the threaded insert being careful to make it square. Glue is not be required though it can be used if your knob is made from a softwood like pine and you are worried about it pulling out.
Installing a threaded insert in a very hard wood like rock maple, hard cherry or walnut can be difficult but resist the temptation to make the hole large because it will weaken the connection between the threaded insert and the knob.
If while installing the threaded insert you scuff the top or bottom of your knob go back and sand again.
Note: It is possible to install a threaded insert without the threaded insert tool. Directions for how to do this can be found elsewhere on the internet.
Once you have installed hardware in all of your knobs move on to the finishing step.
Step 8: Applying a Finish
You are almost done. If you've used a stain on your project you should stain your knob to match and apply a matching finish. You can easily apply finish to all sides of your knob at once if you screw it loosely onto another knob. Apply the finish according to the directions on the container and allow all coats to fully dry/cure before using your knob.
Step 9: Tips
- If you want to have more than 5 notches you will probably have to switch from a 3/4" forstner bit to a 5/8" or smaller forstner bit to drill the notches.
- A Two notch Knob can be created by drawing a line across the knob from one side of the groove to the other through the center point.
- If you want a knob without any notches you can run either to the top, bottom or both past a 1/4" round-over router bit. You have to be VERY careful if you try this: It can be highly dangerous. You have been warned and I am not responsible if you get hurt trying this.
- If you want to add a plug to the screw version of knob to hide the screw hardware then drill the recess deep enough that your plug will cover it.
- If you want to add a plug to the threaded insert version of knob to hide the threaded insert you have to use wood that is thick enough to completely contain the threaded insert with enough space left for the plug (3/4" or more)