GIB OR DOVETAIL SURFACE

[HEAVY METAL]

I AM ATTEMPTING TO MACHINE A VERITICAL WALL THAT TAPERS IN FROM TOP TO BOTTOM 10 DEG.LIKE A SIDE OF A DOVETAIL. I AM USING A BULLMILL TYPE CUTTER WITH 1/2 ROUND INSERTS 1/4 RADIUS.I AM USING THE FINISH COUNTOUR TO STEP DOWN THIS ANGLE .05 PER STEP.CUTTER WAS MODIFIED ON SHANK TO GIVE CLEARANCE WHEN STEPPING THE UNDERCUT.I WAS TOLD BY A MC SALES REP THAT THIS WOULD NOT PRODUCE THE ACURATE ANGLE I WAS AFTER.HE SAID MC ONLY SEES THE BOTTOM OF THE CUTTER AROUND TO THE 90 DEG MARK ON SIDE OF INSERT. IS THIS TRUE . MY VERIFY LOOKED GOOD AND I MADE THE CUT STAYING A LITTLE BIT AWAY AND IT MEASURED ON THE MONEY PLUS STOCK I LEFT.

[mold100]

I have done this also>Cut backdraft not quite 10 degrees but 7 in a large rubbermold cavity with a 1 1/4 sandvik 2 insert tool,coincedently its a 1/2 round insert, it works.MC knows the goemetry of part and cutter,why not?It knows where it can and cant fit.Oh yea,did it along time ago in 7.2 with a polishing ball,lollipop cutter in some graphite.Forgot about that.

[Mick]

It works a treat. I've machined undercuts like that plenty of times. Mastercam is smart enough to know wether a cutter (if defined correctly) will be able to cut the geometry

[TheePres]

I cut many closed angle walls as you describe, but resort to old wireframe toolpaths and ignore undercut error. It is great to hear that u can now do surface toolpaths using dovetail cutters.

Question; If using 1.375 diam dovetail with .125 rad., should I describe as 1.375 or would I use the resulting diameter after rad in this case about 1.320 ?.

[mold100]

Pres,

It depends,if your cutting surfaces then you tell it exactly what it is.If 2d cutting then

youll have to tell it actual dia the1.32 .I am pretty sure thats how it would work.

[cadcam]

When I do it with surfaces I tell it the Dia of te tool and the Radi.

 

Have done this many times.

I even have 4 more parts that I will have to do this to in the next week.

Hope this helps.

 

[ 05-14-2002, 09:30 AM: Message edited by: cadcam ]

[TheePres]

Mold100 and Jay,

To clarify this again, If surfacing I would describe as 1.375 or 1.320 diam ??

[cadcam]

When I do undercut I call the tool to size.

I just did one that is on this FTP lastnight.

Under the MC9 folder called undercut cadcam.mc9

 

[ 05-15-2002, 08:44 PM: Message edited by: cadcam ]

[mold100]

Pres,

To clarify,If surface cutting,1.375,and put your corner radius in the prompt.Hope this

helps.