Bit plunging into board.

[AngusB]

Have a compucarve that has been more trouble than not over the years. Have about 50hrs carve time, but only about 8 of that resulted in finished projects. More often than not the machine has some issue and craps out. When I first got it I had serious trouble with the quick change, to the point that it could take 15-30mins or more to get a bit out, and sometimes I just gave up. After talking to support a bunch of times, they finally sent me a new quickchange. It was better but has still had issues at times. After that I had a few bad carves that turned out to be the result of slipping traction belts cause the head pressure was not right. When that was fixed I started getting a lot of axis errors.

At this point I was fed up and wanted to return it for a replacement, but it was too late. I had tried to make it work for too long and could not return it and the warrenty was over. I usually only had a couple hours at a shot of free time and often worked during the hours support was open. So while I blame carvewright for the crappy machine, I do blame myself for getting stuck with it.

Over the years I once in a while pull it out and try something, convinced somehow that this time I will get it to work. Now and then I have gotten something out of it, but usually only if its small or a short run. More often it stops in the midst of a carve and gives an error, which does not repeat. As in I got different errors, not always the same one. This made calls to support just frustrating as they wanted to treat each one as a separate issue, but since the error wouldn't repeat, they figured it 'was working now' each time we ran a test and did not get the same error. Sometimes the machine stops and when I look the carve is only part way done, and the machine is just sitting at the main menu. I have even had the power line load tested, then borrowed a monster of a UPS unit from the server farm and had it do the 'stop and drop to main menu' thing even while on the UPS. So the results of my time with the machine are usually just a few wasted pieces of wood and a bunch of my time wasted.

The guys in the forums were always helpful. Or I should say, were always very willing to try to help, but nothing suggested ever helped. It was suggested I send the machine in to Carvewright, but by that point I just did not have the cash to drop several hundred more dollars ($150 in shipping alone) into a machine that never worked over using it to buy wood or tools for other interests. Especially since lots of people were also still having issues with new machines at that point, indicating to me that even if it was fixed it likely would die again.

I tell you all this not to bitch, as I said it was my own fault I waited too long to return it. I just tell you so you kinda get that I have lots of time invested and am not a quitter, for what thats worth. Oh and that I'm a wee bit frustrated. (

I pulled it out again recently once again with foolish idea of getting it to work this time. I popped in a simple design (just centerline words and a circle cut out around them to make a disk) and set it running. It plunged the 60deg bit deep into the wood. By the time I managed to realize what was happening and reached the stop button (it did not stall on its own, unbelievably. With how many times it stalled before, the first time I needed it to stall and it didn't, ugh!) I heard crunching and after checking it out found it had indeed ripped teeth off the X-drive gears.

I beat myself up for what I assumed was putting in the wrong bit at the wrong time. I ordered another set of gears and installed them. Started up the project again and watched with finger on the stop button. Sure enough it did the same thing. I hit stop. So figuring maybe my project was screwed up, I set up a new one, with nothing but the word test in centerline. Made sure there was nothing else in the carve list and that it was set to use the 60deg bit. Just for good measure I formated the card, force it to reload firmware, and uploaded just the new project and started it up again. Same thing.

Here is what happened. I turned on the machine and go through the menu to carve the project. It homes, then measures the board (measurements seem correct). The board is a little bigger than plan so I tell it to not scale and to carve on end. It asks which vector bit, I choose 60deg, and install the bit. It does its little dance with the bit, touching the board and the side, then goes over to the pop out bar and touches that a couple times. I watched to be sure it is touching next to the board and then that the bar is popping out properly and it is in fact touching the bar each time. It then starts to carve. As it moves the head from the number pad side of the machine to the center of the board where it should start cutting the bit is low enough that it cuts into the board a bit. When it gets to where it should start carving it plunges the bit into the board again. I hit stop.

The head moves freely. The sensors all seem fine. The pop out bar thing is popping out and it is touching it with the bit. The belts are all clean, etc.

Searched the forum for a while for 'plunging bit' and z-truck issues, but don't see any like mine.
Anyone have any ideas?

The .mpc and a pic of the result are attached.
testing.mpc