Hello: I would like someone out there who is an expert on 3D machining help me on this problem. Anyway I have a piston cad file...and I have a forged piston, the cad file I have is the way they want the piston machined. It's the back side and they're goal is to lighten up the part. Some places I'm only taking about .010 of stock off, other places as much as .200. The way I programmed it...I used the rough pocket surface program leaving .010 stk. and then used finish parallel @ 90 and 0 degrees machining. The problem is the pocket program cuts a lot of air, and air is time, and we all know what time is. How would a 3D experienced programmer attack this type of part. Thank You, Frank

James: That same thing has happened to me, I thought the same thing, was maybe I leaned on the keyboard or something. I deleted all the folders (100's of them), and haven't had another problem. :confused

Thank you Camguy, that is how I have been doing it, if I don't edit depths. It just makes for a sloppy program, it's much neater and faster if you drill chamfer, and tap all your holes in a pattern as they come up, instead of jumping around to do each group of holes that are on the same Z. I don't think editing the depth of the holes individually would be that much of a problem though......if Mastercam would allow me to choose absolute or INCREMENTAL.

How could a post processor do that? I have to give it some kind of depth when I create the tool path. ------------------

That would work good if my referance planes were all the same. Example you have the side of a engine block with 3 3/8 -16 engine mount holes at one plane, and you have (4) other 3/8 -16 all on different levels, and are all different depths, I could find the highest Z and set my referance to that in absolute, and create all my points at their different depths, and use 0 in my increment, but I would cut a lot of air on the lower holes. It is just is a pain to edit using absolute values, and was hoping someone from Mastercam would address this issue. Thank you

I've tried that....then I would have to edit my referance point, which would cause a potential gouge. Thanks

Something I am hopeing 8.1 could fix would be...to be able to change drill depths with increment. Or maybe someone could help me. I drill a lot of hole that have different depths and planes. When I create points I create them at their prospective plane and drill them useing incremental depths....that works fine if they all needed to be, say 1.00 deep, but they are all different. This is where the pain is. The only way I have found to do it is in geometry page, edit depths....the bitch is when I click on a point I have to edit it in absolute mode. So I have to know the position of the point (Z) subtract the new depth + tip comp. Does anyone know an easier way ?? Thank You, Frank

This isn't a Mastercam question, but with all the machining experience out there maybe someone could help. We have been machining engine blocks for a long time, and doing a great job at it. The problem is we are always fighting to get the best finish on the lock tabs we possibly can. The saw cutter that cuts the lock tabs, has to be so far out of the spindle to reach all journals (15"), chatters. We've tried 2 flute to 24 flute, high speed & carbide, slow feedrate, to fast, and still chatter. Maybe somebody out there has some missing link we need to reach our goal of a chatterless lock tab. If so it would also cure the chatter I get from my superiors. Thank You, Frank

Thanks for the replies. I have come to the conclusion that it has nothing to do with the programmer (me), and it's an unavoidable line. (I checked the height of the spot .001). What I did do is put my lead in, lead out at a different place, that isn't as noticable. As far as Mastercam making it easy to go past your lead in spot....just put a number in the overlap spot at the top of the lead in / lead out parameter.

Help me please, as ridiculous as this sounds, I am leaving a mark on my 2d parts when I comp in or out on a line or a arc. Trying not to get into much detail, I'm cutting aluminuim with a .250 ballnose end mill taking a .01 cut and using .150 overlap in my lead in, lead out parameter. The mark that is left is very small but is an issue. Could it possibly be the way I'm programming it, or is it more likely the machine or cutter ?? Also is anyone familiar with billet machining of wheels ? Thank You. Frank

Hi: Frank from Michigan here. I've been using Mastercam for 3 yrs. and still am learning new things everyday. I am the only programmer in a prototype shop with 30 CNC machines.....so I stay pretty busy. We have been making anything from Chevy nascar heads, to complete engines from castings, also billet wheels for show cars. This forum will be greatly appreciated if I have an unanswered question. Thank You