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contour fix needed

Anonymous

contour fix needed

Anonymous
Not applicable

I'm using a 1/16" bit at a cut rate of 10"/min and lead in/plunge of 15"/min. 

I seem to be getting all of these points right where the bit plunges in and out. I'm not sure what I've done wrong. The machine is pretty rigid when it cuts so I'm thinking it might be the way I programmed the cut but could use a hand with how to change it up so i don't end up with these points that I have to sand out. Thanks for any help, as I'm still a noob at CAM in general. Included is the project file and an attached picture of what results in how "contour 8" is run

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LibertyMachine
Mentor
Mentor

What is the machine and controller, and how are you holding the part down?

Rigidity is a relative thing, and it is possible that the material is actually the thing that is flexing and giving you these gouges. I'd suggest taking it in multiple depths of cut and/or pocketing the entire thing out. If the slug is coming free in each pocket, it would certainly produce what you are seeing. Tabs can certainly reduce a great portion of this issue, as well as strengthening the part 


Seth Madore
Owner, Liberty Machine, Inc.
Good. Fast. Cheap. Pick two.
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Anonymous
Not applicable

It's a shapeoko XL running carbide motion. I made my own hold down table with threaded inserts and held the piece down on all four corners so it couldn't move. I'm thinking of either adding some strong double side tape to the bottom of the stock too, or slowing down the cut. Perhaps both

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LibertyMachine
Mentor
Mentor
Accepted solution

While a Shapeoko is a great little machine, I would hesitate about calling it rigid, no disrespect. A cutter can exert quite a bit of force and it is possible that it's tweaking the Z axis enough to cause this. Things to rule out:

1) Is the slug/drop biting into the cutter and deflecting it into the part? Solution: tabs or pocket out the hole thing so there is no slug

2) Is the machine deflecting? Solution: Take the cut in multiple depths to reduce the pressure on the tool

3) Is the material deflecting? SolutionTake the cut in multiple depths to reduce the pressure on the tool, also consider vacuum holding, or double sided tape. Tbas can also be the solution here, as it does impart strength into the whole component


Seth Madore
Owner, Liberty Machine, Inc.
Good. Fast. Cheap. Pick two.
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Anonymous
Not applicable

Yeah, I mean, for my purposes the shapeoko is rigid enough, but I'm more woodworker than machinist, that's why I come here for help :face_with_tongue: 

 

i think I'll do some double sided tape and add a tab every couple inches and see how it comes out next time. Thanks for your advice!!!

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Fueler
Collaborator
Collaborator

To the OP. If it makes you feel any better a piece of aluminum similar to your wood size held in 4 corners can and will dance/vibrate in the center.

 

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