Error Using Thermwood Post

[JSP Mold]

Morning everyone!!

 

This morning I have been encountering a problem using the post for our Thermwood Model 67 . When I try to post out my operation, I get the following error message. "ERROR-THE CALCULATED BREAK IS OUTSIDE THE MOVES". I have backplotted and looked over the toolpath and everything looks just fine. I looks like the post posted everthing out, but there are some strange moves inside the g-code. The C and B axes want to spin and flip over when the head is no where near its axis limits. This happens many many times through out the entire program. The head is going to be right next to the part when this happens and will certainly cause a crash. Here is a small sample of the g-code.

 

 

X8.2622 Y-10.5486 Z8.503 C136.217 F30.

X8.2033 Y-10.611 Z8.5028 C136.018 F30.

X8.1442 Y-10.6732 Z8.5026 C135.818 B-80.63 F30.

X8.085 Y-10.7354 Z8.5024 C135.618 F30.

X8.0258 Y-10.7975 Z8.5021 C135.419 B-80.631 F30.

X7.9664 Y-10.8594 Z8.5019 C135.219 F30.

X7.9069 Y-10.9212 Z8.5016 C135.02 B-80.632 F30.

X7.8474 Y-10.983 Z8.5012 C314.82 B80.633 F30. (C AXIS SPINS AROUND AND B AXIS FLIPS OVER )

X7.7877 Y-11.0446 Z8.5009 C314.621 B80.634 F30.

X7.7279 Y-11.1061 Z8.5005 C314.421 B80.635 F30.

X7.6681 Y-11.1675 Z8.5001 C314.222 B80.636 F30.

X7.6081 Y-11.2288 Z8.4997 C314.022 B80.638 F30.

X7.5481 Y-11.2899 Z8.4992 C313.823 B80.639 F30.

 

Anyone have any ideas on how to prevent this from happening?? If needed I could send someone a copy of the post im using as well as the MC file I am working out of.

[John Summers]

For 5-axis machines, there is a 'forbidden zone' where the tool axis vector is nearly parallel to a rotary axis. In the thermwood, that means areas where the tool axis vector is nearly vertical. It is futile to try to solve every situation in the post. The best method is to observe the toolpath, and position the part so that the tool never becomes vertical.

I can look at your part if you want.

[Guest CNC Apps Guy 1]

Couple of things, in your operation, at the start of your operation chain a point that is at a safe unwind position, and at the end do the same. What is the range of motion for your C axis?

[JSP Mold]

John,

I just sent a copy of the post as well as the MC file I am using to my local reseller. I can send you a copy of that email if that is ok with you.

 

James,

The C-axis on this machine is 0-360 degrees. I have the post prompt the programmer for a "Safe Z Height" for axis unwinds. The post automatically puts this at the beginning and the end of every operation. I have been trying to figure out a way for the tool to pick up to the "Safe Z" in the middle of an operation if an unwind is neccessary. I have yet to figure that one out.

Any other thoughts/ideas??? I can also send you a copy of the email i sent to the reseller if you would like.

[Guest CNC Apps Guy 1]

I'd love to but I just got something dumped on my lap so I'm going to be a bit busy for the next few days.