Good evening to all. For the past few years I have been making and selling the Triquetra Touch Plates. I have been asked and answered more questions about touch plates for a variety of CNC machine controllers, from Easel, Carbide Motion, Mach3, Mach4, UCCNC, Bob’s CNC, PicSender, UGS, and the list goes on. Of course I provide tech support for the Triquetra as well.
I can’t tell you how many people have called me because their touch plate keeps getting pushed across the machine until it errors out. I have diagnosed a number of things that caused probe failures, all of which would have either resulted in a broken bit, grinding belts, or stalled motors - IF - probing was done pressing the touch plate against the wood instead of just pushing it until the probing cycle limit was reached.
A probe failure is not inevitable. There are a number of things that can cause a probing failure, including but not limited to, dirty or burnt bits that aren’t conductive, paint on the collet nut, incorrect wiring, and believe it or not, forgetting to put the magnet (ground) on the collet. Even if you have all your bases covered there, you can still have an electronics failure.
Imagine a machine as stout as the OneFinity having a probe failure while pressing the touch plate against a securely mounted piece of wood. Something has to give. There is no scenario where it’s not a bad experience. So if it is so bad, why would you want one? Because probe failures are very rare, if you pay attention to what you are doing. 3 axis probing opens up all sorts of possibilities. I answered a challenge a few years ago about the repeatability of the Triquetra. I shot a video where I engraved a Triquetra Logo and hit the E Stop half way through. I marked the spot where the bit stopped with a pencil, removed the piece of wood from my machine, rebooted my computer and cnc controller and then mounted the wood in a different location. I re-zeroed with my touch plate and started the carving over. It cut air until it caught up with where I hit the E Stop and then finished. Were it not for the pencil mark, you would not have been able to tell where it had stopped. That’s just one of many reasons a 3 axis touch plate is worth having.
So what about bumping it with the bit and moving it since there is nothing to hold it in place. If you run a zeroing routine with a feed rate of 15 inches per minute then it will probably move it because the controller can’t detect contact and react quick enough to stop it. However, if you use a more reasonable probing speed like 3-5 inches per minute then you shouldn’t have any problem unless it is self inflicted. Then if you do have a probe failure, it won’t be a big deal and you’ll be thanking Mark for not breaking you bit. If you are really worried about it moving you can always hold it in place with one hand. I used to do that but don’t any more. I just start it and let it do its thing. I never worry about it moving and I am putting it on aluminum 99% of the time. Aluminum on Aluminum is as slippery as it gets and mine does not move.
The wiring I chose for the OneFinity is extremely flexible. It has ton of strands of copper with a silicone jacket. There is a generous length of 5 feet available to reach about anywhere on the machine. It also has a magnetic ground connector using a N52 rare earth magnet. It won’t fall off and if you put it on the collet nut it won’t get in the way either. There are two holes drilled in the touch plate and you can use either one for the banana plug. When not in use, you do not need to disconnect anything. In fact, I just let my magnet attach to the frame of my cnc when not in use.
I believe that a 3 axis touch plate will soon be a tool you will make you wonder how you ever got by without one.
I am be happy answer all of your questions. I can even tell you how to do 3 axis zeroing With a Fly Cutter, or a tapered ball nose.