Welcome to the forum, In ver 8.1.1 I create an STL file of the stock piece and of the final part. I verify with the stock piece to check for spindle clearance, then verify with the final part to check for gouging. Make sure you have "Stop on Gouge" and "Display Holder" checked. There are times when a gouge or crash won't be shown when using Turbo, Wireframe or Solid tool in Verify. You should edit the file HOLDER.MC8 to match the geometry of your particular holder, spindle, etc. Even after all of that I don't trust Verify 100% and still look over the g-code and manually add clearance moves between operations if needed. I hope this helps and Good Luck!

Recently, I cut an aluminum piece that left dwell marks in the concave-type area of the surface. I've put a file DWELLMARKS.MC8 in the MC8 folder on the FTP site. The stepover in this example is set at .040 instead of .020 to keep the filesize small. When cutting this surface with Surface Finish Constant Scallop and a 3/8 ballnose, there was a slowdown with incremental type moves when following the contour uphill and downhill leaving dwellmarks. I changed the "G51 look-ahead" parameters at the control while cutting, but this didn't help. The cut was smooth, with no hesitation when moving straight along the back and the overall surface finish is fine except for the dwell. I didn't use filtering here, but have in the past mostly to keep program size down. Would filtering help smooth this out? I'm thinking maybe even filter with arcs might be worth a try. I will take any suggestions or other ideas and try to experiment with these before our next aluminum part. Thanks for your help!! BTW: Using ver 8.1.1 Mill Level 3, xxxxor 8055 Control, Quintax 5-ax router.

Thanks for all the replies so far...Keep 'em comin! quote: It sucks cutting alum on routers been there done that i fu??ing hate it. Millman, don't hold back, tell me how you really feel..... quote: like .002 step over for finish. Wow!! You don't intend to have any hand sanding done on your finish cuts! My final surface is contoured, not flat, and I thought a .020 stepover with a 3/8 Ball Nose was a finecut finish.

quote: At the very least get a coolant mister and then apply coolant manually. Yes, this is exactly what I will be doing.

I cut plastics and pattern foam all the time, but need some advice on 6061 aluminum. I will be roughing out material about 3" deep with a 2-flute, 3/4" endmill, 2.75 stickout, 1.63 LOC starting at 12000 RPM and 50-75 IPM. I will babysit the part applying coolant and air by hand as needed. This will be done on a medium-duty 5ax router (not built for heavy-duty milling). From everyone's experience in terms of tool life, chatter, machining time, etc, is it better to: Cut mostly with the tool tip using a small stepdown (.030") and large stepover (.750")? OR Shave off with the side of the tool using a large stepdown (.750") and small stepover (.063")? Thanks for your help.

[*]1988-1993 Worked and paid way through college - Mechanical Engineering [*]1993 Tired of being broke - time to get a job [*]1993-2001 Ventilation/Manufacturing Engineer for a plastics molding company [*]1995 Married, no kids, wife has job [*]1998 1st kid [*]2000 Wife quits job to stay at home with 1st kid [*]Oct 2001 1st CAM software: Mastercam Mill Level 3 ver 8.1.1 [*]Oct 2001 2nd kid, wife still at home, no job [*]Feb 2002 1st CNC machine: 5-axis router [*]2002-Present Engineering, CNC programming, setup, part-time operator with same plastics company. [*]Still tired of being broke, but enjoy work. We have done some amazing things with Mastercam and the router so far...mostly trimming plastics, foam patterns and some aluminum work. I still get to program, setup and operate the router for all molds, patterns and other special projects. This forum has been invaluable in helping me down the rough road of a new start-up. [ 07-09-2003, 01:55 PM: Message edited by: wildcat99 ]

30 minutes to showtime...here goes nothin!!!

I haven't used this toolpath much, but it's not just your system. Mine does the same thing using ver 8.1.1.

No one wants to touch this one, eh? Did the word plastic run all of you Metalheads off? Or, maybe I just didn't give enough information.... I have ver 8.1.1 Mill Level 3. The part is a 12-in dia. cylinder and will be oriented on the machine just as a trash barrel sits on the floor. The groove cut in the side will be 2-in by 2-in completely around the cylinder. (This would be an ideal part for a lathe) Our router is 5ax with -5 to +365 deg range in the C-axis. All cutting will be with 3/4 endmills. For roughing I plan to use Flow5ax with a lead angle of about 10deg to allow for chip flow. For a very light finish pass only, I plan to use Flow5ax normal to the surface. (A quick test showed that a 1/2-in deep cut, normal to the surface ,with a 4-flute corner radius end mill burns, chars and otherwise fails miserably.) Feeds and speeds I can find by trial and error. But I would like any suggestions for milling a groove in a cylinder. Some of the same techniques for this type of cut in metal might apply here also. Sorry for the rambling, thanks for the help!

Does anyone have any experience cutting Telene (a rigid thermoset urethane plastic)? I will be cutting a groove around the outside of a cylinder with a 3/4 dia., 2-flute high helix type endmill made for cutting aluminum. What is a good starting point for feedrate and spindle speed? Also what is the best technique for cutting a groove in a cylinder? I'm afraid the chips won't have anywhere to go if the cutter is normal to the surface...using a Flow5ax toolpath for example. Thanks for any suggestions!

Thanks Noel, If you go to Start, Settings, Control Panel, System you should see something like this: System: Microsoft Windows 2000 5.00.2009 (build number) Service Pack ___ So far between you and our dealer my toolpath has Regen'd fine on 2 Win2000 machines, 1 Win98 and 1 WinXP Pro machine. We are going to try and re-install Mcam on my machine first. If that doesn't work we'll try upgrading to the latest Win2000 Service Pack. Thanks again. BTW: Has anyone had problems with Mcam and the Matrox Millennium G450 graphics card.?

Noel: What Service Pack are you running on Win2000? Also are you using a similar machine? Thanks.

Oops....I just downloaded your file and see the MC9 extension. Good luck!

What version of mcam are you using? I have 8.1.1 and have been told that ver9 and up will take care of most of the surfacing problems i've had so far.

Has anyone had problems crashing when regenerating toolpaths using a similar combination? Version 8.1.1 Mill Level 3 Pentium 4 1.70Ghz with 512Mb RAM Windows 2000 Professional Service Pack 2 Matrox Millennium G450 DualHead LX with latest driver. Mastercam allocations: pts per spline 10000 surface patches 10000 undelete entities 500 Database 130000 Toolpaths 130000 TOTAL 271.6Mb I've put a file on the FTP in the MC8 folder called Crashfile.mc8. All toolpaths are Surface/Finish/Constant Scallop. Path #3 crashes every time when trying to Regen with a ballnose tool, kicking into a Restart. But it Regens fine with a flat endmill. Path #2 is the same as #3 but at a 45deg angle instead of 60deg and with a different boundary and works fine. Path #1 is similar geometry that Regens fine with a ballnose. Any suggestions? Thanks for your help.

Hello everyone: Please give me some suggestions for a roughing cutter for urethane plastic. The material is a rigid, non-abrasive plastic. I need to remove material quickly from several 2.75-in by 2.75-in x 1.50-in deep pockets with tapered walls. I am leaning towards a 2-flute, probably HSS tool of some sort. Any ideas? Any thoughts on the best toolpath, using Mill 8.1.1, would help also. Thank you.

Does anyone know of any good online classes for MasterCam, CNC machining, gcode, post processor writing, 5-axis techniques, SolidWorks....or other subjects along these lines? I searched the forum first with no luck on this topic. Thanks for your help. [ 02-17-2003, 01:20 PM: Message edited by: wildcat99 ]

I use curve5ax mostly for cutouts, holes, etc in trimming plastic parts. Curve5ax works well in 5ax cuts using lines for axis control. I can draw my own entry/exit paths, but this seems silly with an entry/exit button available. For a simple, flat cutout I can use Contour toolpaths with Lead in/out settings and the cutter feeds into the part fine. In the same flat cutout, I can get essentially the exact same cut with Curve5ax, but with a rapid entry. For me, it's just as easy to 'fix' this by editing the program after posting. Until now I haven't taken the time to figure out the proper way to correct this. Just post and go?.....we're not there yet.

In Mill 8.1, when I use entry/exit in curve5ax toolpaths, the cutter wants to rapid into the part before it starts the entry move. In the entry/exit box I have Length and Thickness values, but Height is zero. I've found with Length, Thickness and Height values it feedrates into the part fine. Also with the entry/exit box unchecked it will feedrate to the feedplane and into the part fine. Is it possible to do what I'm trying to do above? I use this toolpath a lot and am in the habit of editing the G-code to correct this before sending out a program. I'm sure there is a simple solution that I haven't found. Thanks for your help!

That would make killer decoys if they ever open "rubber ducky" season. Actually that might work as a starting point for jagourley with a little modifying and scale to size.

Sorry I can't help you out. But I would also be interested in a duck or goose model.

quote: So far the post works with all of my test examples ................ Thanks for the other ideas. I'm sure there are several ways to skin this cat. I did over-simplify the problem, though, in my original post. In more detail, the G58 needed to be right after the tool change, but the G51... needed to be about 3 lines down after XYZBC moves, etc. There is a switch 'use_g51' already defined that is used in the post. Also the G58 and G51 are embedded in several if/else statements, etc.

Thanks for your help. I wasn't able to put the switch in the right location to make it work, but your suggestion led me to look for other variables already defined that might be useful. What finally worked was a line like this: if t = one & n <= 132, pbld, n, "G58", e I had to throw the n<=132 in there in case we ever grab the first tool again later in a program. Most likely this would occur at a sequence number much greater than 132. So far the post works with all of my test examples....I'm calling it quits for the day!

Roger, Thanks for the quick response. Our dealer added this code in 2 places in the post, trying to solve my problem. In my post it is on lines 854 and 865. I will try the switch approach next. quote: (The devil is in the DETAILS when doing posts!) I once took a programming course where the professor didn't care what the program looked like or how fancy it was. If it didn't work it was an automatic F. It's the details that kill ya.

Wow! I just read Cementhead's thread and realize there are a lot of hard feelings and strong opinions regarding posts. However, if anyone would like to help me out, please read on..... Through trial and error I've got the G51 issue resolved. But I still have a G58 after all of the tool changes. Only need G58 after the first tool change. BTW: This is a custom post that we paid for from our MasterCam dealer. I will get this last post problem solved myself eventually, but I would still appreciate any advice from those with experience writing posts to speed things up a bit. Thanks for your help. No pirates or bad guys here, just someone trying to learn.