Cuts not in right position on material....

[Rikk]

Appologies for another newbie question but my heads exploding reading the various manuals and not getting to far.

I have a file to cut out the Z mount bracket, looks fine in Cambam and lines up perfectly with the material, same with cutviewer. But when I load it into mach3 the cuts are offset from the material.

You can beat me with a stick for not finding the answer with search or in the manuals, just tell me what it is first

Below is what I see in mach3, and attached is the nc file



Thanks in advance Hood

                             ...............Rikk

[Hood]

What you will need to do is jog to where the code expects the X and Y zero  position to be then press the zero at the side of each axis.

For example if you set the X and Y zero in your CAM as over the lower left corner of your material you jog there and set the DROs zero.
Hood

[stirling]

That deals with X and Y but note that according to your code the top of material (TOM) is at 9.5 and you're cutting with +ve values in Z. Therefore you need to set TOM to 9.5. Normally you'd set TOM to zero and cut negetive.

Ian

[Rikk]

Stirling, the Z is a little of a red herring as I'm doing that manually at the moment to cut this mount which is for the Z axis.

Cheers Hood, I was doing exactly that, but on my main machine (no mill attached) and expecting everything to line up, tried it on the mill itself and it still looks offset but yep the cut is in the right place

So is it actually meant to line up material/cut on screen?

Thought I'd use pen and paper while I work things out, much cheaper and safer   showed a friend a video of it doing this and got the reply back "oooh, you've invented etcha sketch"....git

Someone should make a tool with a spring laoded pen at the bottom, then you can use it exactly as you would normally testing auto zeroing etc as it's metallic but it would draw rather than cut

[Rikk]

Stirling, aha read you post again. Right so in Cambam the material should be below the Z line NOT above it? Got ya..

[Hood]

Hopefully not to confuse matters here is another way to do things that I often use.
Load the code then jog to a feature in the toolpath view, for example centre of the circle. Take a note of the X and Y DRO positions then jog to where you want the centre of the circle to be on your material, you can then type the numbers you noted into the DROs and regenerate the toolpath and the cursor should be exactly over the centre of the circle in the toolpath view.

For Z, some people like to have Z Zero as table surface and all  material to be cut will be positive but the norm is material top zero and cuts negative. Its an individual choice but I personally prefer the material top as zero and cutting moves negative Z and the majority of machining world I would think the same, possibly router guys may be different.

I think a few people have made sprung pen holders, do a search and you may find something, certainly sticks in my mind I have seen it here.
Hood

[Tweakie.CNC]

Hi Rikk,

Check out Sam's idea with the pen here http://www.machsupport.com/forum/index.php/topic,16012.msg108100.html#msg108100  

Tweakie.

[RICH]

Rikk,

Someone should make a tool with a spring laoded pen at the bottom

Here is mine:

http://www.machsupport.com/forum/index.php/topic,16012.msg108047.html#msg108047

RICH

[Rikk]

Cheers gents, i think the only thing with those pens (like mine) is no metal barrel so you can't use the auto centreing/edgfinding, I understand those are meant for doing drawings and not emulating a machined cut so for a different thing, oh well something to put on my to do list
I'll change my CAM file so the material goes below the zero, if I start off the same as everyone else now rather than change later thats better

[RICH]

no metal barrel so you can't use the auto centreing/edgfinding

An edge finder could be mounted along with the pen and an offset used after center finding or know the distance between them

meant for doing drawings and not emulating

somewhat limited but it does show the pathing and depending on the pen travel you can do pocketing to some extent, the
pen will track accuractely say around .005"

There is software for emulating code or you can just use Mach,

RICH