Unwanted tool path.

[helensdad]

I still can't get this right! I have altered speeds and feeds, set pass depth to 0.25mm all looks good until I try to cut. The two holes are in the correct place but the main profile then starts cutting over to the right. I have re done the file 3 times now and still get the same result. I only have 3 squares of aluminium left!

[Adrian]

Verify that you're setting the XY zero on your machine/control software to the same place it is set to in Cut2D. Air cut until you've got it sorted.

[helensdad]

Air cut? Sorry as a complete cnc virgin I am not sure what you mean...

[scottp55]

How do you Z-Zero the bit....paper/touch off plate?
Whichever method, Z-zero as normal, move Z-Axis up MORE than deepest cut, and manually in machine software Set THAT as Z-Zero...That way you are only cutting AIR(Air Cut).

I noticed you have very little Z-travel.... to make sure your machine doesn't "Top Out" Hit your upper Z hard stop and lose position...You can do an air cut without a bit/collet/nut just to see if the cutout is shifting. Even turn router off manually if that is what you have.

[mtylerfl]

Air cut? Sorry as a complete cnc virgin I am not sure what you mean...

Here’s an easy way...No bit inserted. Watch the spindle movement when you run the offending Toolpath to see if it’s on track” with what you expect.

[scottp55]

Also noted that you're running ALL in one toolpath.
In general, holes are Very different settings in wood...never mind metal.
Do the holes as a separate toolpath, and THEN do your cutout?
Then run aircut on cutout, and make sure it behaves in the correct position...then try Hole toolpath(maybe try Spiral toolpath for holes(maybe Profile Cutout as well?))

Think the Holes might be where you're losing steps, BUT you have a bunch of aluminum right there already....I'd got good at holes on that waste piece?
That bit you used is probably toasted by now? Are you using single flute "O" or "Super O" to help with chip evacuation?
This is where I'd hoped the Aluminum People would have kicked in!! Zip-Zero-Zed experience with aluminum CNC'ing

Do a Forum search for other Aluminium cuts, and notice those with lighterweight machines and see what they've done?
Compressed air as cutting to move chips before reweld?

Fell free to ask me dense Hardwood cut questions in Tiny stuff!!!!
At least THERE I KNOW stuff!!
scott

[helensdad]

[quote]Fell free to ask me dense Hardwood cut questions in Tiny stuff!!!!
At least THERE I KNOW stuff!!
scott[quote]
I will be using hard woods, I have Oak, Poplar, Meranti and Ash to hand so far, I have been scrounging offcuts from various local joinery shops...

[TReischl]

Folks, the machine is OBVIOUSLY losing steps.

The holes are in the right place, but the outer boundary is off in right field.

If the machine were not zeroed correctly the holes would be over there in right field with the outer boundary.

BTW, OP? Why not hang that cutter even further out of the collet to see how it does? I am not serious about that. You should have that cutter as far up in the collet as it will go without bottoming out.

[helensdad]

BTW, OP? Why not hang that cutter even further out of the collet to see how it does? I am not serious about that. You should have that cutter as far up in the collet as it will go without bottoming out.

The endmill will not go in any further as it has a 3/8" shank that will not fit inside the spindle. My 1/4" shank tools go right in and only protrude an inch or so... I have finally discovered the cause of the problem, a screw had backed off and was rubbing on the gantry, slowing down movement and knocking everything out of kilter. I was up most of the night dismantling the machine to get to the screw as access was nigh on impossible. Once fixed I got a perfect finished job!

[scottp55]

Congrats on isolating THAT problem
scott

[TReischl]

I have finally discovered the cause of the problem, a screw had backed off and was rubbing on the gantry, slowing down movement and knocking everything out of kilter. I was up most of the night dismantling the machine to get to the screw as access was nigh on impossible. Once fixed I got a perfect finished job!

Alright! Great!

I am doing my best "Happy Dance!".

(No one wants to see my "happy dance", at 6'4, 290lbs it is quite a spectacle)