You are operating a cnc machine and you never have to recall a cnc program from the middle, I can’t believe. Everyday multiple times we have to call a cnc program from the middle or from a known block number. When operating a cnc machine sometimes the tool insert gets so much damaged that you have to change the insert and have to run the cnc program from almost middle.
What is CNC Block Search ?
cnc block search is a facility in cnc machine control which gives us the ability to run a cnc program from a cnc program block which we select. The selected cnc program block might be at start in middle or nearly at cnc program end.
CNC Controls Block Search Behavior
Different cnc machine controls behave differently when we do a cnc block search. When you are going to use cnc block search you must confirm about the behavior of the cnc block search prior to using cnc block search.
CNC Controls which Remember the Current Position and Relative Data for CNC Block Search
cnc program block search is safe in these cnc controls because, when we call a cnc program block they take into context every info and position which is must to make a safe tool travel. When we make a cnc block search on such cnc controls they take into context following important values.
- call up the specified tool
- remember and activate all the cnc M-Codes which have been used since cnc program start till the block search block number
- current position of the axis
This type of block search is a bit slow because the cnc control has to read and execute all the cnc program blocks which are prior to our called block.
EPM (Gildemeister) cnc control remembers the current position and relative data for CNC Block Search.
On Sinumerik 840D cnc control you can choose to make a cnc program block search which remembers the current position and relative data for cnc block search
CNC Controls which Ignore the Contextual Data for CNC Block Search
Some cnc controls just make the cnc program block search but those cnc controls just forget or ignore about anything else, so cnc machine operator have to pay extra attention when making a cnc program block search. On such cnc controls it is best to make a cnc block search not as normal cnc block search but make it a tool search, by saying this I mean now you better make a block search from a cnc program block which has tool call up, so that we can make the cnc control to take into context the proper tool and its relative data.
This method of block search is faster if compared to the other method, because the cnc control makes just the block search and doesn’t care about the contextual data, this way the cnc control is putting all the burdon on the cnc machine operator shoulders.
Fanuc TC controls make a cnc program block search which ignore all contextual data for cnc block search
On Sinumerik 840D cnc control you can choose to make a cnc program block search which ignores all contextual data when making a block search