Corner rounding end mill problems

[kustomizer]

I think arris is fat finger for axis.
I'm not following what the problem is. It's not April 1st is it?

I think he is trying to learn cad/cam before understanding what it should output

 

[technocrat]

In glasswork arrising is taking the sharp edge off the glass sheet for safety without finishing. An arrised edge is unlikely to cut you, but does not have to look good.

 

[AJ H]

If all else fails 3D contour radii with a bull nose endmill

 

[EPAIII]

You say it cuts the edge that is against the fixed vise jaw OK, but when you turn a corner it gouges. I think we need a better description of this.

WHAT surface of that side edge is gouged? Is it the TOP surface of the part or the SIDE surface? Or is it both?

And does the gouge stay the same size as the cutter moves along the side edge? Is the gouge instantly as deep as it gets at the rear edge just after turning the corner? OR does it start small and get bigger as the cutter progresses toward the front of the part? Or, does it start really bad and get better toward the front.

What I fear here is the old part rising in the vise as it is tightened problem. The rear edge is at one vertical height but the front edge of the part is HIGHER. So the cutter crashes into the top and it gets worse as the cut progresses. If this is the problem, no amount of tweaking the parameters will fix it.

And, if you experienced this problem in the earlier machining steps, your part may not be truly square in the first place. That could also cause the cutter to crash into the side of the part as well as the top.

What type of vise do you have?

 

[Mtndew]

M.
Adjusting the pilot diameter of my modeled tool is the only way I know to pick up the point of tangency perpendicular to the spindle axis. Adjusting the height offsets is the only way I know to pick up the point of tangency in Y. As I am running the tool around the entire part, once I get these correct for the first side I expect that it should not change as my tool goes around the part ... as long as the tool stays in a fixed plane. But, sadly, as I turn the corner and come around the end of the part the tool plows into the material as it comes down the side parallel to the side it was adjusted for. The tool does not seem to work for the edge in the same axis and plane of the one where it was previously working well.

If you can post a picture or two of the part in the vise and the gouge we could help you better.

 

[Mtndew]

your part may not be truly square

This is what I'm starting to think.

 

[Marty Feldman]

I think arris is fat finger for axis...

No, it's an architectural term, although an obscure one in machinist parlance, that he's using correctly. It refers to a feature, such as a corner edge, at the junction between two planes or features. (It was also the undoing of Polonius, if I may be forgiven for showing off the education that my old man wasted his money on).

-Marty-

 

[Franke]

What is arris? what is CREM? Edwin Dirnbeck

E.
Arris is an intersection of two planes. Corner Rounding End Mill (CREM).

 

[Franke]

It sounds like the only side that comes out "perfect" is the side that is up against the fixed vise jaw.If this is true,then your problem might be tolerance build up. Edwin Dirnbeck

E. Spent part of today tracking that ...