UNDERCUT-COMPOUND ANGLE

[HEAVY METAL]

I HAVE UPLOADED A MC8 FILE TO THE FTP SITE CALLED UNDERCUT .I CANT GET A CORRECT TOOL PATH ON THE UNDERCUT SURFACE.I AM USING A FACE (SANDIVIK) MILL WITH 1/2 ROUND INSERTS. THE SHANK IS RELIEVED ENOUGH TO CLEAR TOP AS CUTTER NEARS BOTTOM.MAY BE I AM DESCRIBING TOOL WRONG.IT WOULD BE GREAT IF SOME ONE COULD TAKE A LOOK AT IT.I WAS TOLD BY A MC SALES REP THAT YOU CANT MACHINE THIS TYPE OF CUT BECAUSE MC DOES NOT SEE PAST 90 DEG ON THE CUTTER

[mold100]

I cant get to the ftp due to firewall issues but if your surface cutting tell it exactly the cutter you

are using .We have already found out we can cut undercuts,MC cant see past 90 degrees on a regular

endmill,but as cutter geo. changes so does mastercams abilities.

[cadcam]

So you want to use the faceing mill as a large typ lollipop.

the best for this type of undercut is a dove tail.

I have done this many of times.

 

Did you draw a custom tool?

[cadcam]

I did it with a 1" lollipop on one of the wall's.

you can see the file on the ftp undercutcadcam.mc8

[gcode]

You can sometimes surface undercuts by turning gouge checking off. Some surfacing toolpaths

do not have that option (contour for example)

and will not do undercuts.

 

Last week I hade to machine a spherical radis

in a large eyebolt. I used a relieved cutter

with 3/4 round inserts. I could not get a satisfactory tool path using surfacing methods.

I ended up drawing 60 circles stepping down .03

each time and running a 2D contour around them.

 

In another instance I had to machine a relief

groove around the bottom of a large die using a

5 in saw with .125 corner radi top and bottom.

Cadcam from this forum helped me with this one.

The original model was a parasolid converted from a iges file. The undercut surfaces were made up of 12 solid sheet surfaces. MC would not surface them. Cadcam created 1 sweep surface from the solid's wireframe turned gouge check off and MC put an undercut tool path on them using flowline.

 

The tool path was not accurate though. MC comped the tool path to the theorical sharp corner of the saw. I was using a custom tool which back- plotted correctly, but MC could not see the radius on the top edge of the saw.

Lucky for me it was just a relief groove. I offset the swept surface and the results were "good enough"

Had an accurate surface been required, I'd have been in real trouble.

[mold100]

thanks jay,

I gotta admit maybe i would do this wrong but because of the sharp corner I would rough and

finish most of the way down with a 3" sandvik type cutter with 1/2 inserts, use the slot mill

as tool type,this looks like the best type given the info posted,then i would get or have a 10 degree backdraft cutter made to pick out the bottom but it would almost need to be at least 2 inch diameter

and use a 2 D countour for that.But definetly surface the first cutter.Any one agree this could work?

[cadcam]

I agree with this thought Mold100.

This one way.

 

[ 06-01-2002, 01:45 PM: Message edited by: cadcam ]

[mold100]

Jay its comin back to ya M100UNDERCUT.thanks again

[cadcam]

Corey, right back at ya.

I like the thought of the path layout I am going to share your file with my updates on it.

the file on the ftp is called mold100undercut.mc8

 

[ 06-01-2002, 04:01 PM: Message edited by: cadcam ]

[HEAVY METAL]

HEY MOLD 100 I AM CURIOUS WHY YOU ADDED SURFACE AND HOW ALSO I CAN I CHANGE TO CLIMB CUT THANKS

[mold100]

I like to be sure my cutter is completely off the part if so when it z axis plunges it isnt into solid steel,

better safe than sorry,also I like to know it will remove all the material with out leaving an edge..#2you can change the cut to cut one way climb.

 

[ 06-03-2002, 09:43 AM: Message edited by: mold100 ]