Question about 5-axis control softwere - CAM or Controller specifies trajectory?

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02-28-2015, 03:05 AM
mcphill

Question about 5-axis control softwere - CAM or Controller specifies trajectory?

I am working on a 5-axis machine. I currently use Mach3 on a couple CNC's, but want to try FlashCut on this new machine. My issue is that after speaking with FlashCut, they state they "only support trunnion format 5-axis machines" with the current software.

I don't want to build using a trunnion, I want to use a B and C head for the spindle mount. My question is, does it matter? I have to set up my machine style/format within my CAM software (BobCAD v27), defining what axis is where, how the spindle is mounted, etc. All the details are defined in the CAM portion. So, does it "matter" if FlashCut "only supports" trunnion format 5-axis machines? The guy I spoke to said it could result in the feed rates being off. I know Mach3 does trajectory planning, so I could see if that ended up coming in to play here. Clearly as "far out" as the tool tip can get on a B-C head, the speed of the tool tip can vary a LOT compared to a 3-axis or a trunnion 5-axis machine. Will this cause me issues, or does the CAM "sort that out"?

Any input to help me out? I don't want to invest in FlashCut and make it a paperweight...
03-25-2015, 03:54 PM
mcphill

Re: Question about 5-axis control softwere - CAM or Controller specifies trajectory?

Anyone have informed thoughts?
03-25-2015, 05:30 PM
MichaelGolden

Quote:

Originally Posted by mcphill

Anyone have informed thoughts?

You can't use trunnion type kinematics for a head head configuration or vice versa. Your control software doesn't care what your machine is. It just converts distances into pulses. But you will need a cam package post processor setup specifically for your machine to create the correct gcode distances(moves in xyzabc).
03-25-2015, 05:59 PM
mcphill

Re: Question about 5-axis control softwere - CAM or Controller specifies trajectory?

That's good to hear, and I hope you are right... The only "fear" I have is around feedrate. If the machine gets C60 on one line and C120 on the next, it knows to move 60 degrees, but how does it know to the speed to do that (in order to keep the tool tip at the right feedrate). This is the type example where a Trunnion and a Head Mounted C axis would be "totally different" even though the same GCode would be used... At this point I am willing to "give it a try" and if I need to crank down the feedrate, so be it. I can always "fall back" to using MACH if I need to, so I think I will go with FlashCut and help them to help me if I run in to issues...

Thanks for your feedback!