The CNC has been doing great requiring only minor work-arounds (small stuff). Today I was lightly engraving a solid rosewood plaque with a piano finish for a special award for one of my customers. It was then that the machine decided to plot it's own course. Now I have an expensive rosewood piece of junk.
What in the world happened? Yes, I'm a bit upset.
Tight coupling, secured material. Using a 0.125", 60 degree V-Bit. 16,000 RPM, feed rate at 100 and a depth of 0.0625". Nothing streneous and something I have done many, many times before.
Post by Axiom Tool Group on Jun 10, 2019 14:21:17 GMT -5
It looks like the Y or Y axis slipped....the coupling shown above is the Z axis.
Have you checked the X or Y axis couplings or the connection between the handheld and the white control box?
There are a number of reasons that an axis may slip....typically it comes down to shuttle speeds and/or lubrication.
Stepper motors have limited torque and the faster they are asked to move the less torque they will have to hold their position.
If the lubrication is lacking, then those movements at higher speeds can apply greater forces on the motors and make it hard for position holding. Its often not the cutting speeds but the shuttle speeds used when moving from cut A to cut B.
These are listed as Fast Speed, just before a file is began...and should not exceed 1500-2000.
As for lubrication, its recommended that you wipe down the ball screw and guides with a light machine oil (3-in-1 brand preferred) daily when the machine is in use. This will help keep the surfaces clean but also reduce the frequency in which the bearings need greater maintenance.
All couplings are tight. Ways and lead screws are cleaned regularly. Initial clean with WD40 on a shop rag. Lubrication with 3in1. Turned on the unit this morning and it did not completely home itself. Stopped short on the Y axis. Turned off, waited for 15 minutes, turned on and it homed poerfectly. When to touch off on the Z Axis using the probe and it wanted to keep going through the probe. Would not back off. Stopped it, turned it off and walked away. 1 hour later I turned it on and all functions performed perfectly and now it's cutting. So far so good. This is not the first time this has happened. I attributed the first time to being just s fluke. The second time... maybe just another fluke. Now at the 5th time I believe there is a problem. Something somewhere is messing up. I will install a separate ground from the machine directly to an earth ground and will see if that helps at all. I am open to any and all suggestions... please.
Post by Axiom Tool Group on Jun 12, 2019 10:31:21 GMT -5
If you are having issues with both HOME and the touch off puck...as well as position loss....then we'd be looking for a loose or back connection somewhere.
It may be multiple sources since there are several things happening, but it is most likely something that all things have in common...like the cable that connects the handheld to the white control box.
There are a few varieties of this cable, but one type has a molded end that fits onto the handheld specifically...if flipped the other direction, that same end will not quite fit the white box correctly.
It is worth mentioning that WD-40 is never recommended as it may have adverse reactions with internal greases used in the ball nut bearing and as it dries, it leaves a residue behind. Much like a shellac, which can build up and change the diameter of the ball screw as well as the fitment between bearings.