Excuse my ignorance. The G Code selects a tool by #. The operator has placed the tools into the numbered positions for the tool changer.
Now here I guess it gets interesting. Most efficient would be if the G-Code Parser read ahead and signaled the tool changer object that it will need tool # Y next. The tool changer moves and loads the tool into the other side of the swing arm. The carousel then moves back to the position X which is the tool currently in use. When the tool change request finally happens, the arm gets the current tool X, swings around and loads tool Y. The machine continues while the tool changer puts tool X back in place. The tool changer then asks the G-Code parser for the next tool. Way back in the very early nineties I worked on what are called TRIM & FORM machines. They bent and trimmed the leads on integrated circuits. All CAN bus linked and used a REQ, BUSY, AVAIL, RDY handshaking messages. The Press or the Laser marker would just issue a REQ. The pocket tray loader, once it had the part ready to be picked up or moved would issue an AVAIL. Different people worked on different modules. The tool changer should be thought of as a similar module. Request a tool. Get the tool. Handle requests for next tool. Be RDY to supply the next tool. And so on. Am I missing something? John > -----Original Message----- > From: Gregg Eshelman via Emc-users [mailto:emc- > us...@lists.sourceforge.net] > Sent: January-06-19 9:05 PM > To: Enhanced Machine Controller (EMC) > Cc: Gregg Eshelman > Subject: Re: [Emc-users] tool changer with swiveling arm > > I've seen some that have each tool holder coded and read the holders in the > chain or carousel as it moves. The system has no idea where any of the tools > are but it does know the difference between an empty spot and one with a > tool. So when a tool is requested it just runs the carousel or chain in one > direction until the desired tool comes by the sensor. Then it swaps the > current tool for the one in that slot. Should something cause the changer to > drop a tool the system has no idea it's missing. It will just throw a not > found > fault the next time that tool is requested. > It's a slow way to change tools but less complicated to setup since the > operator doesn't have to log where the tools are, but the individual tool > characteristics have to be setup, same as with any changer system. > The fastest setup would be a system that has coded holders that can be > stuck into the carousel or chain anywhere, then the system runs the changer > around once, logging where each tool is. That would also require hardware > to uniquely identify each tool slot. For a high capacity changer, tools could > be grouped by job or by function. That would also allow for bi-directional > movement to speed up changes even more. > > If the changer is uni-directional, then install the tools in the order > they'll be > used and try to minimize needing to go back to a previously used tool. For > very time critical jobs, install more than one of the same tool so the changer > never has to run a full circuit to get back to a previously used tool. Ie, if > the > second tool used is a 1/4" drill then two changes later the 1/4" drill is > needed again, install a second 1/4" drill. Save time and wear and tear on the > changer chain or carousel. > > On Sunday, January 6, 2019, 10:32:42 AM MST, Jon Elson <elson@pico- > systems.com> wrote: > There are two types of tool changers, fixed position and > random position.� The fixed type generally have some kind of > one-at-a-time mechanism, so no pre-prep is possible. > When the tool is to be changed, the tool in the spindle is > placed in the magazine, the magazine is moved to the > new-tool position and the new tool is loaded.� A typical > system is a tool carousel that is moved toward the spindle > and the tool is exchanged directly to/from the carousel, > with no arm. > > A random tool changer swaps the previous tool with the new > one, putting the previous tool into the same holder as the > new tool came from.� This requires the system to keep track > of what tool is in what position of the magazine.� System > crashes may require reloading the tool table with what tool > is in what pot.� The random changer requires some kind of > double-ended changer arm, so the current tool and the new > tool can be exchanged between magazine and spindle. This > system allows the magazine to be positioned to the new tool > before the actual tool change is performed.� You just > program a T## to pre-select the tool at some point in the > program.� This causes the tool carousel/chain to position to > the new tool.� When you program M6, the tool is actually > swapped. > > Jon > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
