Engraving Troubles

[BrMiHi08]

I got a K2cnc 25x14 machine 2 weeks ago and I have been messing around with it on foam which was no its true purpose. I am trying to do some engraving on little acrylic tags. http://specialtllc.com/specialt.jpg . My problem right now is that I use the sticky back that is on the material and place it one the T-slot table then I tell the machine to go it barely engraves the surface on the left side, but as it moves to the right it does. I am wondering if it is a problem with the table, but I am not sure. I bought the machine 100% ready to go so I am thinking it is not assembly problems. Thanks in advance.
Brian

[machineoperator]

Put a dial indicator in the chuck and bring it down to one side of the table, set to zero, then move to the other side of the table. This will tell you if it is the machine. If its not the machine (the dial indicator does not move ) then set the acrylic tags up, then run the dial indicator over it from one side to the other. It could be the thickness of the acrylic tags.

[cbass]

What is the verdict?

Was it the machine, your stock, or something else?

Inquiring minds want to know!

Carlo

[Torchhead]

Are you using a rotary V bit to engrave? To engrave your material has to be perfectly flat and level with the travel of the head. Usually one of the first things you do is mount a spoil board and use a flat router bit to "surface" the top so it matches the travel of the X and Y axis. Then hold downs to keep things flat from there.

If you want to do much engraving you really need to investigate a "floating head" and a nose piece that rides around the bit and controls the depth of cut rather that depending on the material, mounting or table surface to be flat within a few thousandts. Yep, .010 out of level will make a huge difference in engraving with a V tip. In normal routing it's hard to detect a difference of .010 or less across the width of the table. Most general purpose routers are not calibrated that close. Even shipping can move things around.

[BrMiHi08]

I finally got a chance to work with my cnc machine again and it looks like the table is crooked. I was trying to shim it, but that was pretty much useless because it would then end up being crooked on the other side. I am not sure what else to do.... I was trying to find a floating head but I cannot find that much. If any one else has any advice let me know, I would appreciate it.
Brian

[ViperTX]

Two options.....the first is pretty simple.....mount a small table the size of the stuff you normally machine in the location where you would normally engrave.....machine the surface of your small tag table...now the small tag table surface will be parallel with your engraving head.

If you are trying to use the whole table surface, then you'll just have level the whole table, before you waste any time....check with K2 on the flatness of the table, you may find that even if the table surface is level there may be areas that are within the table surface's flatness, but noticeable when you engrave.....so, now you know why there are machines made especially for engraving.

Let us know what happens.