You just need the blade chuck to loosen the cap, then you can unscrew it: Be careful as the blade is sharp and will stick out of the top of the blade.
It’s not the easiest thing to do, but it is doable. Just line up the nubs on the smoother hole with the blade top and press down and twist. To clean out the auto blade, use the blade chuck. Once it has set the correct length, it will start to cut your design. The machine will pass the carriage over the holes and tap the blade up and down to reset the blade to 10 and then will continue to tap to reach the desired blade length. The Cameo 3 will adjust the blade by using a set of holes in the left hand side of the deck of your machine: Once you have selected the Self Adjusting Blade and have the settings ready, you can send your file to be cut. ((Update: Silhouette Studio V4 now defaults to the Auto Blade))
Connecting via Bluetooth may also not give you the auto blade option (use the USB cord and you’ll be fine). If you have not plugged in the machine with the USB cord, it will not give you the auto blade option.
NOTE: You MUST have plugged in the Cameo 3 and turned it on for the software to give you the Auto Blade option. This will save you from having to remember the perfect settings for your favorite brand of paper or vinyl and save you time! TIP: If you know the brand of material that you work with usually differs from the Silhouette Presets, you can either adjust the presets and save them, or create and save a new material and add in the specific cut conditions. If you want to change your blade depth, speed or thickness of materials, or to turn on double cut feature, you would make those adjustments here: Next, click the edit button to change your blade settings and to select the Automatic Blade. Pick the material you want to cut from the list of materials in your software. To select the auto blade, click on the blade menu at the top of your screen in Silhouette Studio. You need to select the Self Adjusting Blade in order for the machine to use this blade correctly. The Cameo 3 comes with a default of the ratchet blade. You should also hear a small click to indicate that it is now locked in place. Lock your blade in place by pushing the sliding blade holder in until you see a blue dot. Match the positive to the negative and then slide the blade all the way down and ensure there is no gap between the blade and the blade holder. There are ridges in the back of the blade and grooves in the left hand side blade holder. To utilize the self adjusting blade, load the blade into the left hand side of the dual carriage: The “auto blade” can cut a variety of materials including vinyl for home decor, heat transfer vinyl for DIY t-shirts, cardstock to make scrapbooking embellishments and much more. The new Self Adjusting Blade is the “new blade on the block!” This blade comes stock with the Silhouette Cameo 3 machine and can only be used in the Cameo 3 machine’s dual carriage. There are several different varieties of blades available, let’s check them all out and see how they can be used. One of the most powerful and versatile tools you will use with your Silhouette Cameo die cutting machine is the blade.