4th Axis Chuck Basics
Reversing the chuck jaws
The chuck jaws on the stock carvera 4th axis chuck are reversible to allow you to either hold a smaller part more securely, or a larger part. Below are the two options for holding stock with the chuck jaws.
To change the orientation of the chuck jaws, follow these steps: 1. Use the two chuck wrenches to back out the chuck jaws all the way. As they near the edge of the chuck they may become a bit tight. Do not use excessive force to turn the chuck at this point, instead you might have to work the wrenches back and forth/manually adjust the jaws with your fingers to get them to come off.
2. The jaws will come out of the chuck one at a time, in order around the chuck. In the image above you can see the start of a spiral groove that grabs onto each jaw. You might get a more accurate results out of the chuck with the jaws in a particular set of slots. A common practice with chucks is to mark which slot gets jaw 1. Since the jaws are reversible, you might have different marks for the different jaw orientation.
3. Once the jaws are out of the chuck take a moment to clean everything up to remove any chips in the mechanism, add some light machine oil to the spiral and chuck jaw sides, and take note of the numbering on each of the jaws. The last number denotes the order in which the jaws get installed.
4. Using the chuck wrenches, move the start of the spiral thread to just before the 1st slot you wish to add a jaw. From this point you will be adding the jaws in order from 4 to 1 for the larger clamping setup, or from 1 to 4 for the smaller clamping setup.
For the larger clamping setup: Add jaw 4 to the indicated slot, turning the chuck wrenches to grab onto the first thread on the back of the jaw. Keep turning gently until the spiral thread is just before the next slot in the line (you might have to wiggle the jaws/back off on the chuck wrenches to get them to seat correctly). Continue adding the remaining jaws in the order 3 - 2- 1.
For the smaller clamping setup: Add jaw 1 to the indicated slot, turning the chuck wrenches to grab onto the first thread on the back of the jaw. Keep turning gently until the spiral thread is just before the next slot in the line (you might have to wiggle the jaws/back off on the chuck wrenches to get them to seat correctly). Continue adding the remaining jaws in the order 2 - 3 - 4.
5. Close the chuck all the way to make sure that the jaws meet at the center. If they do not, you may have accidentally skipped over grabbing a particular jaw or installed them in the wrong order.
Removing the Chuck
You can remove the chuck from the fourth axis to expose an M14-1 threaded headstock. To increase holding power/accuracy you can thread your part directly onto this thread, or thread on other accessories. 1. You will need a 3.175mm/ 1/8" ground pin to remove the chuck. Look into the hole on the side of the headstock and turn the chuck until you see an indent through the hole. Fully seat the ground pin into this hole, the headstock should no longer move.
2. Using one of the chuck wrenches as shown, gently unscrew the chuck.
3. Be sure not to drop the chuck when it comes off.
4. Reverse these steps to reinstall the chuck/install a different accessory. Before threading anything onto the headstock, be sure that the internal and external threads are very clean. Any chips in here will lead to misalignment/could damage your headstock. Also, it should thread on easily by hand until you tighten the final amount with the wrench. If you need to apply a lot of force you are probably cross threading and could ruin your headstock and chuck. A trick is to start turning the chuck counterclockwise as if you are unscrewing it first. As you press it onto the threads while turning, you can feel a slight click, denoting that you have found the start of the thread. Then try tightening.
Alternatives to the Stock Chuck
Sherline sells an M14-1 chuck that requires some modification to work with the carvera headstock. You will have to reduce the diameter of the chuck backplate to fit into the headstock. https://www.sherline.com/product-category/chucks-collets/ A popular version is the 4 jaw self centering version: https://www.sherline.com/product/4-jaw-self-centering-chuck-2-5/#description or the 4 jaw independent version: https://www.sherline.com/product/4-jaw-independent-chuck-3-1/#description You can thread stock directly onto the chuck/make your own accessories. The headstock uses an M14-1 thread and here are a few options for taps: cheap mid nice
Last updated