On 2/19/2010 11:17 AM, Viesturs Lācis wrote: >>> Dave wrote: >>> Do you think you will have any issues with the ultrasonic sensor and >>> the water mist from the waterjet? I was to work on a waterjet system >>> next week but the project has been delayed. That machine has a >>> constant mist/cloud of water vapor around it. >>> >> Yeah, I was wondering about that. When piercing the initial hole in stock, >> the jet can bounce back with immense force, and it is loaded with Garnet >> dust. Unless there >> is a shield that can be flipped in place during piercing, I would suspect >> the sensor would have to be tremendously robust or it will have a very >> short life. >> >> Jon >> > > I do not see that vapor is problem - there was some freaky height > sensor previously installed near the nozzle - all the plugs and > connections of wires have to be sealed and that's basically all. > splashes, especially during piercing, are far more bigger concern, > that's where i agree. > > splashes are the thing, where i have not found a solution yet. > i have an idea that i could make a shield from a material that is > "transparent" for that particular wavelength of ultrasound, but i will > have to check that in more detail, if that is possible. changing the > shield with few cm in diameter from time to time, if it gets damaged, > does not seem like a big cost issue. > another idea is to put the sensor in a shell, which closes during > piercing - that would involve some additional commands in G-code - i > mean M100 - M199 user-definable commands, where that particular > command would activate a magnet for few seconds through some relay and > magnet would close a cover of the shell of the sensor. > > anyway, the working principle for THC for plasma, and for waterjet and > also laser as well is the same, as both of these technologies are > cutting material with some kind of beam and it is supposed to hold the > torch/nozzle in some specific height few mm above the surface of > material > > thank You, guys for Your suggestions on PLC and Classic Ladder. You > have helped me a lot, because now i have a direction, where to look > for a solution, i really appreciate that! > > Viesturs > > ------------------------------------------------------------------------------ > Download Intel® Parallel Studio Eval > Try the new software tools for yourself. Speed compiling, find bugs > proactively, and fine-tune applications for parallel performance. > See why Intel Parallel Studio got high marks during beta. > http://p.sf.net/sfu/intel-sw-dev > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > > Depends on how much data you are moving, what the Modbus baudrate is, and how fast the PLC responds. Using Modbus at 19.2K baud reading and writing 5 words to a Automation Direct 405 class PLC via Classic ladder, I can do a complete read cycle about every 75 ms I believe. That is about 13 updates per second. I don't know how fast you are cutting but that might be plenty fast to create a correction. The other thing to consider is how fast does your ultrasonic sensor update? Plasma cutters on thin sheets need to really move but if you are cutting heavy material you might not be going very fast. If you are cutting at 10 ipm then you have plenty of time for correction etc.
Dave ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
