I have a question about programing. On our CMM we have an aluminum hold down plate. and we have the quick change probes. We only have 1 CMM and I split my time between the 2 multi axis lasers and the machine shop. I am always switching programs back and forth between programs to keep each machine running. When I switch the programs my probe is already calibrated but every time I switch I have to manually align the parts because I move my zero. Is there a way to set up two programs and just switch programs without having to re manual align each time. The reason I am asking is on both machines they are runs of 100 or more pcs and we have to inspect at least half of each job and its time consuming to keep re aligning. Thanks for the help.
We have a big rayco plate that covers our machine. We home-brewed some smaller plates of various sizes that we put on the rayco. Use standoffs to keep the plate at the same location. We can have 3 or 4 parts setup on different plates ready to go. Each part program has an option to do a manual alignment. This is hardly ever used unless we change locations for some odd reason or another
We have a big rayco plate that covers our machine. We home-brewed some smaller plates of various sizes that we put on the rayco. Use standoffs to keep the plate at the same location. We can have 3 or 4 parts setup on different plates ready to go. Each part program has an option to do a manual alignment. This is hardly ever used unless we change locations for some odd reason or another
This is one out of many best ways to setup the CMM especially with programming offline with cad models of the CMM mounting plate, fixture
components and part. Once you know the location of the mounting plate on the CMM and know the location of the part origin from the CMM mounting plate origin you can then use "Part/Machine" to offset the CMM origin to the Part/CMM mounting plate origin. Using this process I only use the Jog box maybe 5% or less of the total time using the CMM. So the main function of the Jog box now is to start the CMM or move the probe for CMM issues. The type of alignments that work with this process is Manual alignments, Read Point and Recall Alignments in which will get used less the amount of time as the jog box is used. This part location process is being used on aluminum and steel casting parts with and without machined targeting points. SolidWorks is the cad software used for the part to CMM plate fixture
components assemblies and setup screen captures. The BOM (Build of Materials) in SolidWorks is used to create a list of the setup
components. You can also create a setup video in SolidWorks with Motion Study using the Explode View and Rotation.
If you are placing next part onto CMM with a fixture or some sort of relocation device you should be able to rerun without a manual alignment. A lot of that is dependent on feature you measure and how close you can replicate placement of next part. Sometimes you may have to change pre-hit retracts motions on initial moves and you may want to add a first align followed by a second measurement of datum features with another alignment to bring it in. I have had geometry where I will use a non-datum feature, I am a big fan of an ID then using "Find Center" in circle auto feature to start a program with depends on what you have to start the program with. absolutely...if you have to run 50 to 100 parts in a row you would not want to and if fixture or stops or what you use can insure this then that is part of the efficiency the CMM offers.
I use a readpoint alignment, given a circle or corner point. This acts as my initial XYZ <IJK> alignment...I then follow that with a small plane to level and a line to rotate...this is my manual alignment. Keep in mind that the readpoint alignment...and the entire program for that fact is in DCC mode....not manual....once you place your probe in the center of the circle ( with equator of probe flush with plane) this acts as your manual alignment...the readpoint, small plane, and small rotation acts as your "refining alignment ".
This is the only way that I do it except I think Wes made a type when he stated you do have to be in the exact same spot. It should have read you don't have to be in the exact same spot. I'm sure that is what he meant.
When placing the probe in center of circle ( used for readpoint alignment), you don't have to be exact! Just roughly...this is the glory of the readpoint alignment...takes operator error or idiot out of the operation...hence "idiot proofing"..
I honestly don't remember the last time I did a manual alignment. We have an Erowa chuck bolted to the CMM (and it's always in the same place). For electrode inspection, I just load up a previously saved template and it knows exactly where that electrode is. For steel, I have a pallet that goes on the Erowa chuck and a template for that pallet. So, as long as I position the part in the CAD the same way I have it on the pallet, the CMM knows exactly where it is
You can also increase your PREHIT/RETRACT values to add a little more wiggle room to where you place your part.
