Sorry if this is a very dumb question but I still don’t have a complete understanding of tabs as I am still learning. I recently got the Shapeoko XXL and hear all this fuss about setting up tabs and what not. My question is what is the purpose of these tabs? Is it really that bad if tabs aren’t used?
I have a project I was about to run and someone told me not to forget to add tabs but I don’t really see the big deal in running it without them and letting the machine do its thing. Again don’t come for me as I’m a newbie here but I really would appreciate any insight on this.
Tabs are used when you are doing complete parts cutouts, like profile cuts. They are used to keep an attachment between the piece and the rest of the stock. Without tabs the piece would be cut free and possibly (probably) move causing, at the least a damaged part, or at worst a wooden projectile flying around your shop.
Any tool that will cut wood will cut you. That is true of hand tools and even more so with equipment that spins cutters (ie. end mills in routers) at several thousand rpm.
Keep hands safely away from that cutter until the router stops. Better yet unplug the router when your hands are near that bit.
Besides all of the clamps for your projects and double sided tape there is another method. Many use plain painters tape and super glue. You put down a layer of blue painters tape on the waste board. Then on the bottom of your project you put a layer of blue painters tape. Then put a few lines of super glue on the layer on the waste board and push your project onto the wet super glue. Give the glue a few minutes to dry. When the project is done you simply peel the painters tape off both the waste board and the project. Just make sure you have a good layer where the super glue is applied because if it squezes out onto the bottom of the project it will stick your project to it.
As others said above do not cut any project through that does not have some hold down. The router bit will spin your cut out damaging it, possibly injuring you and likely to break or bend a router bit. You can also start a fire if the part gets caught against the spinning bit. You should always have a fire extinguisher in your shop near by just in case. In a wood shop we use many volatile chemicals and fine saw dust is a recipe for disaster. Be a good boy scout and be prepared.
Trying to hold a piece can cause serious problems, it can catch and twist or come loose and you have to avoid the spindle moving around while you are trying to hold it usually with both hands. Other issues include during the final cutout, the previous side will start to lift or move while cutting out the last area and ruin the piece. Trying to hold the piece while it finishes cutting is a very dangerous method and can cause projects to be ruined at the last possible moment, not to mention the loss of fingers or worse.
Some use glue and tape, I prefer tabs. I use snips, sandpaper or a table router to remove them afterwards. I use larger tabs for wood then I do on aluminum, and pay attention to the grain, wood tabs can be very brittle depending on the grain direction.
Also, as a newbie you might be interested in browsing the (free) Shapeoko ebook, it covers the basic concepts to get you going, including workholding options
An E-Stop button (like this) is ideal for emergencies. Wired/connected correctly, it can cut the power to everything that’s dangerous (essentially the spindle) and will stop it (almost) dead in it’s tracks.
A feed-hold switch will pause the project, lifting the spindle away from the stock and, if you have a BitRunner installed (as I have), it stops the spindle running altogether. This is not an immediate process, so wouldn’t be much use in an emergency.
I’ve installed both of these on my machine, and use the feed-hold regularly. Fortunately, I’ve not had to use the E-stop.
This one is a particular favorite of mine. I’ve been working wood for over 25 years and therefore, have been cut a number of times…happily, I still have all of my body parts, however, one of the worst cuts I had was caused by a piece of wood (a cut off from a prior cut) that was laying on my radial arm saw table, innocently. Somehow (they have the habit of jumping into the blade path), I cut through the piece I was working and the blade nicked that other cut off and threw it backwards into the hand that was holding the work piece (which is proper position for Radial Arm saw work)…cut the back of my hand wide open.
Anyone who has experienced kick back of any kind will tell you that while the blade is dangerous, anything the blade puts in motion is almost as dangerous! Keep the work area clear… Anything the blade can get hit can become a projectile and do some damage!
