Body alignment problem and weird inspect tool readings

[Ilkka_T]

I have a problem of aligning bodies so that CAM side will allow me to do bores. Bodies just won't align perfectly with the sketch profile or the stock body i used to have extruded from it first.. Some bodies i could go with by aligning them with the origin planes and then realigning to the sketch profile (the CAM z-axis). For the last problem body it won't help.

I could've sworn that the inspect tool sometimes showed alignment error of something like 10exp-6 degrees and sometimes for the same case it showed 0. Then in this video i could capture it. At least i don't get what's going on here...

I am also wondering why offset planes created 14.7 mm apart by a parameter, won't be exactly that, but something like 14.69999993. Is this normal behaviour?

Ilkka

[Beyondforce]

Hi @Ilkka_T,

1. Why did you use the Move command so many times?

2. Did you create all those bodies inside this project or did you imported them?

3. As far as I know, you need to convert bodies to components in order to use them in the CAM environment!

4. Do you know about R.U.L.E #1?

Cheers / Ben
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[Ilkka_T]

Hi Ben!

1 & 4. My workflow sure is screwed up. I use Fusion 360 only occasionally, and when starting the design, i once again failed to obey the "RULE 1". That's why i instead of using the components in a separate design for "sheet CAM" -work, I decided to proceed moving and positioning the separate bodies for the CAM work inside the same design. Then i can still revert back to the assembled design by rolling back the design history, and by rolling to the end, i can make the CAM toolpaths, and everything is neatly linked together.

2. The bodies are ply thick slices made of the components in this design, sliced by planes ply-thickness apart. 

3. The bodies here are bodies inside a component(s), and seem to work fine for CAM, except for a need to move and align many times before can get the small alignment differences zeroed, if at all.

To me it looks like CAM side has more precision for alignments than modeling environment, and thus CAM sees bodies not aligned, although modeling environment is supposed to have them aligned (Just my humble opinion, without knowing anything about how the precisions are dealt with in CAD/CAM environment). Isn't the inspect tool behavior strange anyway, that it shows 0 for many times, until one time it shows a minor misalignment for the same profile/face?

Cheers, Ilkka

[Beyondforce]

I have asked about the move command, because I was trying to understand why you didn't use the Joint instead.

In your case, I will make a sketch on top of the plat. In the sketch I will use the Point command to mark where each part should be. This why is much more precise and easy to use with the Joint tool.

I'm not an expert on CAM, but I know @PhilProcarioJr could help with it.

Ben.

[PhilProcarioJr]

@Ilkka_T

There should be no difference in precision between the Modeling and CAM. If there is the Dev team should be notified and the bug fixed.

Working with disregard to rule1 can cause a lot of unexpected results with a lot of things.

When I do CAM work my files are setup correctly and things work as expected.

In order for us to really help you would need to share your file and a video of your workflow.

[Ilkka_T]

Hello @PhilProcarioJr

Yes i have noticed trouble comes in many forms and places, especially when doing things "wrong way". Already struggled a lot with this same design as i bumped into a known sketching constraint bug with project/offset/tangent. Then after got around that, the mostly constrained sketch got so incredibly slow that it was almost impossible to drag anything, and sketch solver failed to solve most of the time. Now after all the struggle, i am not very keen to start it all again pretty much from the scratch to obey the Rule1.

But maybe in the next design i remember the RULE #1 right from the start! 🙂

The design is attached. Quick look into the workflow can be found in the video. In the beginning of the video can again see how inspect shows mostly 0 degrees angle between z-axis profile plane and the top face of the problem body. Inspect also won't show distance between the z-plane profile and the top face of the body. For all the other bodies i tried it does show the distance. Which also seems to indicate that the measured faces are not parallel, no matter mostly inspect shows 0. Strange randomness...

After making the video i once more moved the body around with big moves and rotates and then aligned it back to the z-plane, and then CAM accept it again. But then when moving it back to the correct position on the plane by using the move command's manipulators and "dragging on a plane"-manipulator. No rotates were involved. Then it blows up again and is not accepted by the CAM.

Ilkka