View Full Version : Learning 4th and 5th Axis machining


Shotout
06-12-2007, 11:49 AM
We are looking at trading in a TM-1 and purchasing a VF-2 or 3. I was wondering how difficult, a subjective term I know, it is to learn multi-axis programing. Our Cam/Cad software supports it, and I've gotten fairly comfortable using additional work offsets in my current programing, thanks Geof btw. But I've got this little thing about not running a program I couldn't write myself and wouldn't be comfortable in running a posted program I can't read line for line. What am I looking at in new outlooks on programing? I mean I understand the basic idea of spinning;tilting your work, but what new concepts am I going to need to learn and can anyone recommend some reading material on the subject? What types of new challenges in work holding am I going to need to learn? Like can you tilt a Kurt D688 vise oriented for clamping in Y or do you have to use tabs and indicate the work to the table, that kind of thing.

Thanks
Scott

Geof
06-12-2007, 12:29 PM
... But I've got this little thing about not running a program I couldn't write myself and wouldn't be comfortable in running a posted program I can't read line for line. What am I looking at in new outlooks on programing?....Scott

Are you talking about true 4th and 5th axis, cutting complicated shapes with all axes moving simultaneously? If this is the case you have to get over your hang-up; you probably could read the programs line by line but when the CAM file is in the multiple megabytes I wouldn't want to pay you by the hour to do it :).

But if you are looking at fixturing parts on a rotating axis so you can access three or four sides and complete everything in one setup that is not too difficult; it can't be, I do it.

1ctoolfool
06-12-2007, 09:15 PM
yea, what you probably want and/or need is 3 plus 1 or 3 plus 2 axis positioning which isn't very different from what you're already doing and doesn't require fancy software.
if you want or need 4 and 5 axis simultaneous you have a steep learning curve ahead.
joev

Shotout
06-13-2007, 08:37 AM
Geof,

I guess I overstated it. If something isn't cutting quite like I want, or I don't like a tool entry exit I want to be able to read the appropriate blocks before and after to correct N1200's motion. I don't read every program I post through the software now, just scan for offsets, x,y start positions and check my z depths. Just the way I was taught I guess. Mostly rotating to different faces is sufficient and truely I doubt the extra axis are needed, just using different work offsets and flipping the part the owner feels differently. Personally I'd just like to replace one TM-1 with a more powerful machine with a true A axis to allow shorter cycle times, but he's been reading about other companies and what they are doing so he sees it differently and it is his money and his decision so I told him my thoughts and limitations and leave it to him to make up his mind. I just want to be ready when he decides to move on it.

joev,
Thanks. He bought the multi-axis option before I started in anticipation of needing it someday so we already have it. Just how steep and what kind of hurdles I'm going to be jumping uphill is what I'm trying to get a feel for.

Scott

joecnc1234
06-14-2007, 06:37 AM
If you're doing 5axis simultaneous motion than trying to read the program is crazy. The only way to program is off c/l of the rotary axis but if you are only positioning in 4 or 5 axis and machining stationary than you will be fine using work coordinates as long as you set the job up it should be fine probably a lot of h offsets if you don't program from c/l The real fun is learning how to program 5axis and posting the program and letting it run good times.
BTW if your post processer doesn't give you what you want in 2 axis machining than you need to check with your dealer on your post or change your programming style to output what you want. If I read through every program I wrote I would be weeks behind schedule.
Joe

PBMW
06-14-2007, 08:56 AM
Agreed. The post needs to be rock solid. You are not going to get what you want by trying to read a 5X program and edit it....
You'r egoing to learn the dicipline of taking care of the details in the cam system first and then posting and running it.
That will also have the added benefit of forcing you to develop good file dicipline. I never upload programs to the cam system and pour over them making changes to the cam file. I made sure the cam file was right before I posted it....

Shotout
06-14-2007, 02:28 PM
Joe,

The new post works great, we had been using a generic post now have gotten from the reseller a machine specific one that only requires a replacement of G28 X0. Y0. A0. with G0 Y +# Z homes in the previous block since I like my parts to come to me. Also the 4th axis commands I delete through find/replace. We have the software and connectors on the machines just not the hardware. With the generic post it required a little more editing but not much, changing an address letter or something along those line plus the other stuff.
I don't read my code line for line but I [I]can[I] if ever required to do so to correct or modify something and honestly shouldn't someone in the process be able to or am I just being uptight? I don't want to have to stop the machine, go to the computer, modify the program, repost it, reload and restart from the approriate line number. Much more simple to modify the program at the controller for say a lead in lead out motion, clearance whatever, make a note along with any other fine tuning I do with speeds and feeds and then make all the changes at one time in the software while the machine is productivly cutting part #2.
I've never used anything other that the default G17 obviously, I know that you can program A###.# for 4th axis but what is the difference in an A address and a C address? I get either depending on something in the way I design and apply toolpaths in the software, but what specificly causes the change I don't have a clue. These are the kind of things I'd think I should know. That was why I was asking for reading material references as well. Am I overly cautious reading the Current Command display code as the part cuts when proofing a program? It is what I was taught and the reasoning behind it seemed logical to me so I still do it.

joecnc1234
06-15-2007, 02:41 AM
G17.g18,g19 just change your working planes for circular interpolation. Which has no bearing on 4 or 5 axis as your post should take care of this. as far as axis representation goes a rotates around x b rotates around y and c rotates around z axis so I'm not sure why your post would output a c axis move? Try sitting your reseller down and having them make a program for you. What software do you have? It sounds like the service is terrible.
Joe

Shotout
06-15-2007, 11:50 AM
We didn't renew our maintance so I can't fault the service. I know, cardnial sin, but someone thought they knew better in the front office trying to pinch a penny and now we get to buy everything all over again, yeah :( We have an old copy of MC and Surfcam Velocity, also out of date (which is the one with multi-axis support). Want MCX and may get it since we have no current software. I've been playing with that when I go visit my instructor from school and he is busy. Haven't had time to go up and talk to him about multi-axis, new baby at home and to much lack of foresight on the salesman's part constituting an emergency on mine.

I think I know why it is outputing the code differently now, it may be the way I'm drawing the parts. When in design I am simply switching to front and side construction planes to draw features on a 3D profile of the part, translating, and not changing the tool plane and I only change my tool plane and create new WCS when I am ready to apply tool paths. This has got to be why it is outputting the A0.;C0. depending if I drew it on the front or side construction plane although I'd have thought that as you stated b goes with Y it would output either an A or B not a C.