cutter gouging

[viperdm100]

does anyone have any input as to why I woukd be getting a step between two different cutters when machining aluminum casting molds .I have been having this problem for a while and nobody has given much input on it .

[HuFlungDung]

What kind of software are you using to create the paths?

Does the path look okay when simulated, but not in real life?

Are you using cutter radius compensation?

Throw us a bone here

[viperdm100]

Thanks for the reply hu flung .I'm using a software called camtool from graphic products north america , and the path does look alright on the tube but I can't seem to get away from the cutter gouging . The software was 20grand a seat and is supposed to be an excellent software . We are new to the cnc cutting Industry (about a year with our big bridge machine and a couple years on a Bridgeport ez-trak ) and we have had this problem since we got our machine .It seems that everyone cuts hard steel of some kind and I can't help but wondeer if it's something to do with the type of material we're cutting (aluminum casted molds). Everyone thinks if your just cutting aluminum you shouldn't have any trouble , but the sand casted aluminum may be an issue . I could send a picture but this sight wouldn't support the file size.

[CNCadmin]

Originally posted by viperdm100
I could send a picture but this sight wouldn't support the file size.

You can use free softwear to resize it , send it to me OR you can uplaod it to the CNCzone FTP section.

[wms]

Viper,
Need more info.
When you say gouging, is it the same tool path with a different tool? If so what size tool is #1 and #2? Or is it a step over problem? Or does the second tool make a huge gouge? Is it a tool holder problem? IE: same tool holder always gouges. Is the gouge always in the same direction? Is the gouge due to the part moving between tool 1 and tool 2? Like tool 1 load is too great and "moves" the part, then you come in with tool 2 and it gouges the part.
Just throwing out ideas here.

[viperdm100]

THANKS FOR THE INPUT WMS BUT I DON'T THINK THE MOLD IS MOVING , IT SEEMS PRETTY SECURE .I RECUT THE TOOL THREE TIMES USEING THE SAME PROGRAMS JUST POSTING THEM DIFFERENT BECAUSE I HAD THEM GROUPED WITH SEMI FINISH ROUTINE AND I KEEP GETTING THE SAME RESULTS . I DO THE FINISH CUT AND THE PROGRAM THAT CLEANS UP THE RADII WITH A DIFFERENT , SMALLER CUTTER GOUGES ABOUT .010 EVERY TIME.EVERY TIME I CUT IT I DROP THE G54 .010 TOCLEAN-UP THE GOUGES AND AFTER IT'S HALF DONE I CHECK IT BE FOR THE OTHER CUTTER GOES IN AND IT'S OK UNTIL THE OTHER CUTTER GOES IN.

[wms]

Viper,
Like I said just throwing ideas out.

SMALLER CUTTER GOUGES ABOUT .010 EVERY TIME

Is that .010 in Z or somewhere else?

Sorry don't know a thing about the software you are using..
Went to their web site to look around. Looks like you have several different choices to finish machine. Have you tried a different finish fuction?
How do you select machining parameters for the clean out tool?
Have you looked at those to see if they are ok?
Do you have any other software that you could repost the "clean out" portion of the part to and give that a try?

Again just throwing ideas your way, don't claim any of them will help.

[viperdm100]

THANKS AGAIN WMS FOR RESPONSE

I USE THE DEFAULT PERAMETERS THAT THE SOFTWARE GIVES BECAUSE THATS WHAT THEY RECOMMEND . WE DO HAVE UNIGRAPHICS BUT I'M NOT SURE IF I WOULD BE ABLE TO POST THE CUTTER PATH . WHEN WE FIRST STARTED USING THE UG WE HAD TO BUY A SEPARATE POST SO THE SOFTWARE WOULD POST PROPERLY FOR THE BRIDGEPORT WE HAVE . ALSO THE SEATS WE HAVE OF THAT ARE NOT ALWAYS AVAILABLE .

[HuFlungDung]

What are the two cutter diameters you are using?

Is the gouge more pronounced in a particular axis direction?

Does the part get hot enough to make a difference?

Are you using any tool radius compensation (accidentally)?

[Mortek]

Is it gouging only in the Z or in all axis? How do you set your Height offsets? With a feeler guage, piece of paper, or tool setter? Is it possible you have a chip on the taper which would cause the cutter to cut bigger? Check up in the spindle for gouges or rough spots. Have you had the same experienc on both machines?

[hardmill]

i come from a mold shop and 9 xs out of 10 your problem
is in the model. Theres usuallly a tiny little gap.
Is the gouge where 2 surfs meet?
Try putting a patch over it if that appears to be the case
I've had gaps that you can't see and the tool wants to
find a way in there. You can also try loosening up your gap
tolerance which will allow the tool to go over.


PEACE

[Rekd]

+1 to Hardmill, check for holes/gaps. Also, hang your left pinky over one key to the left and push it down once. (caps lock)

:edit:
One other thing; turn on the toolpath display and z00m in on the area. See if you can see the deviation from the 'normal' toolpath. If so, it's a software setting/issue, if not, it's the machine or the post. Couple of options if it's the software; fix surface holes/gaps, tighten tolerances, manual edit to the toolpath prior to post, or after if unable to do it before. Food for thought.

HTH
:/edit:

'Rekd teh (in the voice of Eric Cartman); "Screw you guys.. I'm goin', home !