3d tool path calculating above material...

[esschubert]

Hey all,

We are doing a project that has 2d and 3d tool paths. the 3d cuts are both roughing and finishing... the roughing uses the same downcut .25 end mill as the 2d cuts.

We have done multiple files this way, and after all the tool paths are calculated, the 3d tool paths are all "above" the material... almost as if they are defaulting to machine surface, and not material surface... the job is set up to material surface, and the z0 material setup in tool path is material surface. All the 2d cuts are in the right spot.

I am sure it is something silly I am doing... any help? file is to large to attach. added a screenshot.

[adze_cnc]

Is your model thinner than your material? If so it's just removing material above the model. See Material Setup in the toolpath tab.

[SteveNelson46]

Make sure the z-zero setting is the same in the material setup and at the machine. Don't take it for granite. Check both! I have made this mistake many times.

[adze_cnc]

Reviewing the image a second time brings the question: do you really need 3D toolpaths? Those objects look very flat and seem to have vertical sides.

[martin54]

If your 2D cuts are on the actual model are you using the project toolpath onto 3D component option?
As adze_cnc has mentioned it looks from the image that you could do this quicker just using 2D toolpaths with no need for any 3D toolpaths

[esschubert]

Answers to the replies:

The 3d tool paths are to cut miters at odd angles... is there a way to do this with 2d toolpaths?

The material is .5 inch, and the material is set to .5 inch in the job settings. The Z0 is set to material surface in both the job settings and the tool path material set up.

[Adrian]

Chamfer toolpath might be worth a look. I expect it will machine faster than a 3D toolpath for that purpose.

[adze_cnc]

Chamfer toolpath or moulding toolpath come to mind.

I would expect the material thickness in the Job Setup and Material Setup area would be the same. The question was how does the model thickness compare to the material thickness?

Here the material thickness is 0.5 inches and the model thickness is 0.2 inches. So I get roughing that is "above the model" as would be expected:
 

 
I could set the gap above to 0 and the model will move up within the material:
 

[esschubert]

ahh... I see, yes, the model thickness it .5"... same as the material thickness.

It really seems to be a glitch in Aspire... usually, after I have calculated all the tool paths... 2d, roughing, finishing, and 2d cut out, if I notice that the roughing and finishing (3d) toolpaths are drawn above the surface (interesting to note that they always preview correctly) if I recalculate them after clicking into the material setup, but without changing anything, then they draw correctly and cut correctly.

But occasionally I have to do this a few times for it to work, and once it never would work, and so for those tool paths, even though all in aspire was set to material zurface, I had to zero to the machine bed (.5 inches below material surface)

Just wondering if anyone else has experienced this.

[adze_cnc]

It is difficult to diagnose things with seeing a file, etc. But, something to remember is that if you calculate a toolpath then change material thickness, position of model within the material, Z-Zero, or many other changes and you do not recalculate the toolpath(s) the preview will look wrong until paths are recalculated.

Given the amount of people creating 3D roughing toolpaths you'd think that something this serious would have come up long ago.

[esschubert]

RE: the chamfer tool path, there doesn't seem to be a way to set the step over tight enough to create actual miters with a .25 inch end mill and tapered ball end... just stair steps... all the angles are odd..

[dealguy11]

How big are these chamfers? A 1/8" or even a 1/4" ballnose should be able to cut pretty smooth chamfers with a moulding toolpath.

Without a file to look at, I'm with the other posters. There seems to be something wrong with your order of operations, the model or tool setup causing this. You're seeing something consistently that others aren't, so maybe there's a process issue. This is a part of the software that has worked the same way for a long, long time, so it seems like this would have come up before. Can you share the model so we can better understand how to help you?

[Rcnewcomb]

file is to large to attach.

If the file is too large to upload here you can use a file sharing site such as drive.google.com, onedrive.com, or dropbox.com. They all have free accounts available

• Upload the file to the file sharing site
• Make the link shareable
• Share the link to the file here

[adze_cnc]

RE: the chamfer tool path, there doesn't seem to be a way to set the step over tight enough to create actual miters with a .25 inch end mill and tapered ball end... just stair steps... all the angles are odd..

Unless you have a v-bit with the exact angle of your chamfers you are going to get "stair steps" or cusping no matter whether you use the chamfer toolpath, moulding toolpath, or 3D finishing toolpath. You can only minimize it by making the bit's step-over smaller to make the cusps finer.

The fluting toolpath with an end mill can produce a very smooth cut at the expense of time (both in setup and running).

I have a current student project where he wants a 7 degree taper from the vertical. Thankfully it's on the outside of the piece and he's seen the light that the tablesaw is the best option to get something smooth enough for gluing up straight from the tool. If he hadn't seen the light I would cut it square and take it to the tablesaw myself.

[martin54]

I will echo what a couple of people have already said, I don't recall seeing a question like yours & if it were a software problem then you would expect to see a few questions the same. A file would be really helpful if copyright allows.
Are you generating the 3D models in Aspire or importing the 3D models.
Stair steps to me are quite large & I wouldn't expect that with a moulding toolpath, although I haven't used it that much myself what I have done with it has always given a pretty good surface finish on any type of angled slope