I am beginning to attempt to program off a cad model. I have a sample part, every time I press cad=part my alignment moves off my cad model. I am actually trying to program off of cad on a part I have a sample for before I make a program off a part that I have no sample for.
can you or do you have the ability to TRANSLATE your cad model?
When you say translate my cad model I assume you are saying can I set my alignment on the cad where the cad is orientated the way the part is positioned on the table. The answer to that is yes.
Are you looking for help creating an alignment that will represent in-car co-ordinates? If you are then you should probably forget about using a readpoint to start your alignment and stick to using iterative alignments using the part's datum features. I've read a few threads and I haven't found one person that said they use readpoints successfully with in-car co-ordinates. I hate doing the manual alignments so if you find a way to implement the readpoint-start then please share. Otherwise you should just be doing 2 iterative alignments - 1 manual and 1 automatic.
If you know how to create an iterative alignment using in-car co-ords then you can ignore the rest of this post.
Basically you have to figure out your workplane, then use the auto-features to pick your 4way, 2 way, and net points off the cad (click beside the hole on the cad and the co-ords and vectors should autogenerate which makes this really easy. Use the provided co-ords on the GD&T for your nets). Align the part to them and take your manual hits. Then copy-paste the alignment with slight name changes right below it, create your movepoints to avoid crashes, then run it in DCC mode.
If you're using a fixture with tooling balls or holes (as opposed to a free state setup) then it's a little different but not much more difficult. Set your workplane, create 3 spheres with the co-ords labelled on the fixture for each tooling ball. They'll form a triangle on the fixture. The sphere that's in the middle is your master, the short side is your plane and the long side is the line. Create an iterative alignment with the three tooling balls. Align the part to them and take your manual hits. Then copy-paste the alignment with slight name changes right below it, create your movepoints to avoid crashes, then run it in DCC mode.
I attached an alignment using datum features below.
If you didn't need any of this info then sorry for the text-dump. I'm relatively new to programming pc-dmis too so I don't have 1/10 the knowledge that most of these guys do (but I can create programs from scratch and they work great so I've got that going for me which is nice).
CAD=Part is pretty handy when using a read-point while programming online too. If you have access to CAD software, set the origin on the model to match your XYZ on the machine, then set-up the part and put the tip of the styli centered to where you want to start the program. In the demon, set a read-point and align to the read-point with auto origin. Import your model and hit CAD=Part.. It'll snap to your read-point. Measure a circle afterward and align to it with auto origin.. No more manual alignments. Then start measuring stuff.. I only do this for production parts so I spend less time on the cmm.
CAD=Part is pretty handy when using a read-point while programming online too. If you have access to CAD software, set the origin on the model to match your XYZ on the machine, then set-up the part and put the tip of the styli centered to where you want to start the program. In the demon, set a read-point and align to the read-point with auto origin. Import your model and hit CAD=Part.. It'll snap to your read-point. Measure a circle afterward and align to it with auto origin.. No more manual alignments. Then start measuring stuff.. I only do this for production parts so I spend less time on the cmm.
