tool axis limits on 5 axis programs

[steev]

Need help to understand how to use the tool axis limits on 5 axis programs. Tried to figure the logic on keeping my C axis constrained to 0-180 degrees and at the same time limit A axis to 0-90 degrees.

Having limits on the x and y axis does not translate well into rotation limits of two rotating axis. I have managed to control one tool path through trial and error (not a good way to understand the kinematics of the limits) but when programming the very same tool path but mirrored (y axis) I cant seem to archive the same result. The A axis is easy enough to understand and control, but how x and y limits control c axis is the issue. And I have not found a good explanation on how limiting x and y will provide controlling c axis. 

Edited January 28, 2022 by steev
corrected a typo

[Greg Williams]

Got a sample file? Your question will be easier to answer

[crazy^millman]

What I normally do it draw a line normal to a feature I know on the machine will be the mid point of a rotation I want the machine to stay with in. I then use limits like and pick the last option conical limit. When a programmer picks that option they have X-Y-Z-Line-Dynamically to leading curve as options to use. I pick that line and will go from there. I might need to make it normal to the start of end of a rotation since it is limited to 0-180, but this works really great to limit certain conical limits on a machine. In 4th Axis Tool Axis control process then we don't really get a conical limit we get a angle limit. In full 5 axis under Tool Axis Control then we will lime our 2 Axis we have in the kinematics of our machine. IF you go look up CamInstructor I have a 5 Axis part I shared with them and it as lot of different toolpaths and process crammed into it. We didn't go over limits, but any programmer can use it to get a grasp of different things they can do with 5 Axis toolpaths.   

 

[Shiva.aero]

On 1/29/2022 at 7:36 PM, crazy^millman said:

What I normally do it draw a line normal to a feature I know on the machine will be the mid point of a rotation I want the machine to stay with in. I then use limits like and pick the last option conical limit. When a programmer picks that option they have X-Y-Z-Line-Dynamically to leading curve as options to use. I pick that line and will go from there. I might need to make it normal to the start of end of a rotation since it is limited to 0-180, but this works really great to limit certain conical limits on a machine. In 4th Axis Tool Axis control process then we don't really get a conical limit we get a angle limit. In full 5 axis under Tool Axis Control then we will lime our 2 Axis we have in the kinematics of our machine. IF you go look up CamInstructor I have a 5 Axis part I shared with them and it as lot of different toolpaths and process crammed into it. We didn't go over limits, but any programmer can use ti to get a grasp of different thing they can do with 5 Axis toolpaths.   

 

Can you please share some pictures on this? & Can you please elaborate on this

"I might need to make it normal to the start of end of a rotation since it is limited to 0-180"

[crazy^millman]

Just now, Shiva.aero said:

Can you please share some pictures on this? & Can you please elaborate on this

"I might need to make it normal to the start of end of a rotation since it is limited to 0-180"

Sorry I need an example file to share pictures. I can imagine hundreds of part in hundreds of machines so without a specific part, machine, and setup. If you're thinking about specific then anything I can imagine is not going to help. Mock something up then I can give my thoughts, but for me to just throw out something is going to create an echo chamber.

[Shiva.aero]

5 minutes ago, crazy^millman said:

Sorry I need an example file to share pictures. I can imagine hundreds of part in hundreds of machines so without a specific part, machine, and setup. If you're thinking about specific then anything I can imagine is not going to help. Mock something up then I can give my thoughts, but for me to just throw out something is going to create an echo chamber.

For example in Impeller part, during blade finishing with Morph toolpath, I like to control my B axis within -10 to 95 degree, since thats my machine limit. Just by trail & error, I could get the toolpath within limits by setting conical limits with respect to z axis. But I couldn't understand how it actually limits the B axis & if I want to use line option for this case, then where that line should be? I see the limits can be give only from 0 to 180 degrees but my machine can travel in negative B upto 10 degrees. How to specify this in limits? 

Also whenever I limit the axis, I end up with a messy/wavy toolpath in some zones. I switch between exact & approximate step over calculation but still there will be some messy toolpath zone.

Right now I don't have example file. You may please consider the HTEC impeller from tech exchange.

Thank you!!!!

[crazy^millman]

21 minutes ago, Shiva.aero said:

For example in Impeller part, during blade finishing with Morph toolpath, I like to control my B axis within -10 to 95 degree, since thats my machine limit. Just by trail & error, I could get the toolpath within limits by setting conical limits with respect to z axis. But I couldn't understand how it actually limits the B axis & if I want to use line option for this case, then where that line should be? I see the limits can be give only from 0 to 180 degrees but my machine can travel in negative B upto 10 degrees. How to specify this in limits? 

Also whenever I limit the axis, I end up with a messy/wavy toolpath in some zones. I switch between exact & approximate step over calculation but still there will be some messy toolpath zone.

Right now I don't have example file. You may please consider the HTEC impeller from tech exchange.

Thank you!!!!

Well that is where knowing the kinematics of your machine become very important. With any part I always try to have the kinematics of any machine built in my head. Then from there I start my programming process. If I know I have a certain limit of travel I need to stay within then I map that travel on a level and have it as reference. I will bring in solid models of my machines if I have them for many reasons, but one if to help me envision axis travels with parts. Machine simulations or CAV becomes other method I use to help decide my limits. The easiest way based off your description of what you just mentioned if the part is not put in TOP/TOP/TOP in Mastercam. The Moduelworks toolpaths Axis Travel limits for rotation only work in that WCS and orientation.  If you use a Custom WCS for your part the only way to get them to work predictability is to make a line normal to a feature and use cone.