Table coordinates out of whack?

[myxpykalix]

Ok i'm confused. This has happened about 3 times now. It may in fact be human error but i'm not sure. Looking at the picture that is the lower left corner of my table. I took the carriage to the lower left corner and set my bit right at the corner of the wood. I tell it to Zero X,Y. I do a Z zero on top of material. I load up the file and it went to the middle of material and started cutting approx. 6" up and 4" over.

I went back took the bit out did a jog home, went back to lower left corner I Zero X,Y again and start file and it went to same place to aircut it. Seems to me either the table coordinates are stuck at some previous setting or there is something screwy with the file. Any advice? This has happened about 3 times before.

7135

[trakwebster]

I had an interesting situation, that might possibly be related. I was cutting a thing on the front, and then turning it over to cut it on the back. I had holes drilled for index pins on the first, top surface, and I had bolt-holes drilled, to hold it all down.

When I flipped it over, the index pins wanted it to go one way, and the bolt holes wanted it to go another way. After cutting the back, it was mismatched to the front by about 1/4". Ouch.

I puzzled and puzzled. There were a couple of other happenings which similarly showed me that the 'home' one time was different from the 'home' another time.

I had just about resigned myself to doing some sort of offset on the back side, due to unknown planetary instances. However, before doing it, I decided it was time to grease the machine.

While I was greasing the machine I noticed that the Y-sensor was not vertical. I touched it. It wiggled. I looked at and touched the X-sensor. It was loose, too.

Either (a) I had failed to clamp these fellers down when originally setting it up a few months ago; or (b) they'd come loose from vibration.

So I clamped them down nice and tight. Then I super-glued the sensors, the nut, and the bolt. I don't think it will move now.

Luckily, I had a reference drill hole in my tabletop so I re-did the offsets for my 'home' program onto this drill hole, so that, in theory, I'm back to as close to the original 'home' as possible. (So as to match my jigs.)

Today I cut another identical thing. I cut the front including index holes. I inserted index pins and flipped it over. It fit very sweetly. I cut the back. It matched up exactly.

Moral: do not let the sensors be flopping around, or your ShopBot will precisely home you to whereever your sensors happen to be that day.

[gus]

When you designed this and located it on your design sheet did you place it in the lower left corner of you sheet and use the lower left at the zero ref when you generated the tool path. If you placed it up and over on the larger design sheet and use the lower left as a zero ref then the tool path may well be cutting it up and over on the sheet just like it was placed in the design.

Look at the tool path and see it does a jog up and over prior to making the first -Z move. If it does it is in the toolpath.

[harryball]

Like Ted was saying, check your material settings and see where you have the 0,0 point set. Then check the position of the design on the sheet. If it still happens and you think your toolpath is correct, email the file to me and I'll run it on my bot tomorrow and see what happens.

Robert

[blairjj]

You mentioned table coordinates. Zeroing x and y does not zero the table coordinates. That is a separate command (ZT I think.) Also, giving the C3 command does not zero the table coordinates, though it should. I have changed my xyzero file so that the table coordinates are also zeroed.