changing feed for finish path on arcs

[Dave anderson]

I have found the problem i was having getting my tolerances closer to the finished size. I

asked this question a cpl weeks ago and someone suggested slowing down feed on finish passes. Well i tried it and well its alot closer now when milling out a circle within a thou to thou and half im Happy with that tolerance. now my question is what is easiest way to make finish pass go slower without manually adjusting at the machine? lets say for example im milling a 2" circle in .5" aluminum. Im using a 3/8 endmill i do a few passes plunging down on subsequent passes leaving lets say around .06" for final finish pass at full depth keeping tool down. is there a way to change feed rate from lets say 25ipm to lets say 5ipm for final finish pass ? Thanks guys.

[Salahuddin]

Hi Dave

If I understand your question and you are using pocket toolpathes

So you can control the speed and feed for the finish pass using the Override feed speed option

[Kannon]

Dave,

Is it possible to use toolpaths-next menu-circle tlpths-circle mill? then select your circle done-done. Then your xy stock to leave put in .06 you can do multi passes or depth cuts. Then what I do is repeat the process changing your feeds and speeds taking out depth cuts and select the same tool so I dont have a tool change. So in my operation manager I have 2 circle mill paths both using the same tools. Personally I run a drill bit down the center first, then the 2 circle mills

to follow. This way, when I plunge at center point the material is gone from the drill. I dont know if this will help or if it is the right way, its just the way I do it.

 

Good Luck, and I hope this helps!

Brian

[bpa123]

+1 TO KANNON123 I DO THE SAME.JUST COPY THE OPP AND ADD STOCK TO XY TO LEAVE ON THE FIRST OPP.TOLERANCES HIT FOR ME.

[RDub]

+1 to Kannon123 but I use it on more than just holes... I always have seperate operations for roughing and finishing, whether it be a pocket profile or bore.

[Dave anderson]

thanks guys I did know about what you were saying so in essence without adding and extra tool path the feed cannont be changed on the final path . what i was trying to do was to see if feed on the same tool could be changed for finish pass lets say its eg tool #3 without adding a secondary finish pass i guess its not possible to change feed rate. I was wondering if there was somewhere in mcam to do this guess not thanks for your help guys.

[ARP]

+1 to Salahuddin but I think you need to be running version 9.1 with all the patches. I recall seeing an option to control RPM and Feedrate on finish passes but only in the latest version. I agree with Kannon123 and bpa123 though. You can quickly make a second toolpath without depth cuts etc... and slow it down.

Always more than 1 way to "skin a cat" or cut a part.

 

ARP

[Gary]

If you use a pocket tool path you can set a seperate finish feed and if you only want do a contour around the edge of the hole just give the tool a stepover equal to or more than what the radius of the hole is. Also use morpf spiral for the pocketing type so the tool plunges out by the edge of the hole. I like to make a point for a plunge point near the edge or the hole. Its not perfect but it works.

[DavidB]

Just for kicks:In the Job setup Alt+J there is a box you can tick Adjust feed on Arc move.

 

On the Final Toolpath to take out your .06 stock try contour Ramp this will give a better finish

HTH