PC-DMIS +CAD Alignment

[johnmtraverso1]

Hello again,

Here's more info for the PC DMIS masters out there who might be able to heklp me

Hi,
Not quite, but I am so **** close that it's making me batty!!
First I want to say thank You, so Thank You!

Okay, here's the deal for the masters out there

I do not have a fixture

I have left & right and a fore & aft bore........ which all lie on the same plane, I am manually measuring these 4 bores, then I construct a "baseplane" from their respective Ctr points... I will use this to level my (Z+)..........

I then construct a line using my "aft and fore" Ctr. Pts. this is the longest axis (40 In.) and the one that I will use to align/rotate...(Y+)...............

I use my left and right Ctr Pts. and I construct another line,...........


It is at this intersect point (of the two lines at the "baseplane" (where my XYZ .000 is on the model and the one I need the model to align to
If I could just get the model and my manual alignment to "Synch" then I can run with it






Hello,

I am somewhat new to PC-DMIS, but not new to CMM's I have worked with
MM4, AVAIL, VERISURF, and LK STUDIO, I have been in inspection for over 20 years.
My question I am sure will be basic for most of you, maybe someone can help me,
I have started a "new" program, the probes I need were calibrated previously, I have yhe CAD model aligned to the machine axis, the part is sitting on the table exactl the same way that the model is, so everything is good as far as that goes,
NOW, How do I get my Part Coordinate System in alignment with the model????
i did a manual inspection earlier but it is a complex part and we have many to run, I need to get the model and part aligned so that I can begin inspecting features/entities
PLEASE HELP,
John T.

[Matthew D. Hoedeman]

3-2-1 alignment if using a fixture (WITH cad=part)
Iterative alignment if no fixture.

see this:

http://cmmprogrammer.19.forumer.com/viewtopic.php?t=434

[Wingman]

Hello,

I am somewhat new to PC-DMIS, but not new to CMM's I have worked with
MM4, AVAIL, VERISURF, and LK STUDIO, I have been in inspection for over 20 years.
My question I am sure will be basic for most of you, maybe someone can help me,
I have started a "new" program, the probes I need were calibrated previously, I have yhe CAD model aligned to the machine axis, the part is sitting on the table exactl the same way that the model is, so everything is good as far as that goes,
NOW, How do I get my Part Coordinate System in alignment with the model????
i did a manual inspection earlier but it is a complex part and we have many to run, I need to get the model and part aligned so that I can begin inspecting features/entities
PLEASE HELP,
John T.

If you have run Studio it is very similar. Pick points on the model and measure them manually (you can use as little as one point if you want to - that is what I usually do when the model is oriented correctly to table but that is another thread). Align to these parts and the model snaps automatically. No need to 'snap it to cad' as in LK.

To do it 'correctly' you need to do a full manual align. Just make sure the points used for alignement are defined by CAD.

Go to DCC and do your DCC Alignment by picking features on CAD.

[Paul Sarrach]

3-2-1 alignment if using a fixture (WITH cad=part)
Iterative alignment if no fixture, .see this:
http://cmmprogrammer.19.forumer.com/viewtopic.php?t=434

you can also use Iterative alignment with a fixture if you have balls, tooling balls. Just make sure your "Avoidance Distance " is high enough to clear the fixture. I also do it with edge points on the fixture with balls, and construck a point at the J-corner as my origin.

[Wingman]

It is much simpler than all this to get the Model and the Part synched (assuming I understand what you are trying to do).

Lets say you have access to 0,0,0 on the part. Measure it with the point defined as 0,0,0 from CAD. Translate XYZ to it and your Cad = Part.

Just saying you don't have to do a bunch of extra stuff to get your part and CAD 'synched'. From there you can simply start selecting features for DCC Alignment from the Model and everything will smooth right out. Just like in Studio.

[johnmtraverso1]

CAD Alignment

Okay so I will manually probe the features and then create an alignment, I have a plane, line and an intersect point, this is what I need in order to get the same XYZ 000 that I have on the model,
Can someone PLEASE tell me what the next step I will take once I am manually aligned, so that I can now get the model "synched"
I sincerely appreciate the help you guys have given me, Thank You!

[Matthew D. Hoedeman]

Okay so I will manually probe the features and then create an alignment, I have a plane, line and an intersect point, this is what I need in order to get the same XYZ 000 that I have on the model,
Can someone PLEASE tell me what the next step I will take once I am manually aligned, so that I can now get the model "synched"
I sincerely appreciate the help you guys have given me, Thank You!

IF you have measured the plane that is Z zero and IF you have measure the line that is X zero and IF you have measure the line that is Y zero and IF you have constructed a point at the intersection, go into ALIGNMENT

1) Level to the plane
2) Rotate X+ (or X-) to the Y zero line (it will depend on WHICH direction you measured the line)
3) Set X origin to the intersection point
4) Set Y origin to the intersection point
5) Set Z origin to the intersection point
6) Click on CAD=PART

IF your rotate does not come out right, that will probably mean you measured the line in the - direction and rotated to the + axis or vise-verse.

[Paul Sarrach]

Easiest way with CAD. Click on any 3D Features ( 3 Circles ( all on same Plane), with one of them being the XYZ Zero) check them( another circle should be the -C- Datum rotate the XYZ Zero and that hole to Rotate). Then do an iteritive alignment. Then click on DCC and you are ready to go.

[ag162]

Hey John, did u get it?

A.Gore

[Wingman]

First thing you need to do is turn on program mode with the red 'tip' icon on your toolbar. It isn't exactly like STUDIO. You have to tell PC DMIS to activate the program mode. You will know the program mode is on when you can pick a point on the CAD Model and it shows up that you took a point.

[johnmtraverso1]

CAD Alignment

First thing you need to do is turn on program mode with the red 'tip' icon on your toolbar. It isn't exactly like STUDIO. You have to tell PC DMIS to activate the program mode. You will know the program mode is on when you can pick a point on the CAD Model and it shows up that you took a point.

Hi,
Not quite, but I am so **** close that it's making me batty!!
First I want to say thank You, so Thank You!

Okay, here's the deal for the masters out there

I do not have a fixture

I have left & right and a fore & aft bore........ which all lie on the same plane, I am manually measuring these 4 bores, then I construct a "baseplane" from their respective Ctr points... I will use this to level my (Z+)..........

I then construct a line using my "aft and fore" Ctr. Pts. this is the longest axis (40 In.) and the one that I will use to align/rotate...(Y+)...............

I use my left and right Ctr Pts. and I construct another line,...........


It is at this intersect point (of the two lines at the "baseplane" (where my XYZ .000 is on the model and the one I need the model to align to
If I could just get the model and my manual alignment to "Synch" then I can run with it
Hey man, Thank you very much for your help,

John T.

[ag162]

Hey John,
I'm not at work right now, but have a cpl questions.
Can you upload a sketch of your part, so that we can get a better idea of your situation?
Are you attempting to do a manual alignment or an iterative?

If an iterative, then you can lay the part on the table in any position and still achieve the proper alignment.
You can even use any feature on the part to achieve the alignment and then once this is accomplished, you can measure the Datums and do a proper alignment a little easier.
With the iterative alignment, you also do not need to construct the lines and planes. As a plane and line are not going to work easily.

A.Gore

[Wingman]

Hi,
Not quite, but I am so **** close that it's making me batty!!
First I want to say thank You, so Thank You!

Okay, here's the deal for the masters out there

I do not have a fixture

I have left & right and a fore & aft bore........ which all lie on the same plane, I am manually measuring these 4 bores, then I construct a "baseplane" from their respective Ctr points... I will use this to level my (Z+)..........

I then construct a line using my "aft and fore" Ctr. Pts. this is the longest axis (40 In.) and the one that I will use to align/rotate...(Y+)...............

I use my left and right Ctr Pts. and I construct another line,...........


It is at this intersect point (of the two lines at the "baseplane" (where my XYZ .000 is on the model and the one I need the model to align to
If I could just get the model and my manual alignment to "Synch" then I can run with it
Hey man, Thank you very much for your help,

John T.

John,
I would do all of that AFTER I synched the model. That way you can do it in DCC instead of doing it manually every time.
Here is a very quick and dirty method of getting where you want to be. Bear with me and try it and the process will make more sens so you can develop upon it. If you don't want to try it with this particular part then try it at some point in the future. It realy simplifies things and you can go to DCC immediately.
Find a point on the on the part that you can pick and hit repeatably within 5mm or so. In hits mode (program mode) pick that point on the model and write down the coordinates (XYZ) of this point. Go ahead and hit 'end' to select that point as a measurable point. Make sure you are in MANUAL when you do this. Then tranlate your alignment to the point and OFFSET your alignment by the values you wrote down in the first place. All you have to do is change the sign of the values. When you RUN this section of the program your model will be 'synched' with your part within the tolerance of the point you took.

From there you can go to DCC and start capturing the Plane and Holes to create a proper alignment. The key is to use a point or feature within the prehit zone you use to capture your alignment features. (hope that makes sense)

Basically, all you have to do is pick a point on the model to measure. When you measure that point on the part and align to it your model is 'synched'.

If you WANT to manually measure the 4 bores and the plane then you will have to pick points on the model representing all of those features. I know with STUDIO you could just define the features yourself and it would all synch up. I believe PC DMIS works differently there. I believe you HAVE to actually 'pick' the points / features from the model.

As an alternative, I think you can do your alignment and select CAD = Part and it might synch up for you. I don't go that way because I don't like taking all those manual hits. Somebody else here will have to direct you if CAD = Part works that way.
HTH. It sounds like you have already progressed into the part past the initial alignment.

[T Miller]

Make sure of your work plane when you construct your plane and lines If you level to z then you need to be in that work plane to make your plane and line

[Matthew D. Hoedeman]

IF you are measuring the bores, THEN constructing a plane from them, you must:

1) Measure them as circles
2) Measure a minimum of 3 surface sample hits with them, otherwise, the 'up/down' will ont be correct.

If these are in a flat surface, just simply measure a plane on the surface and use it for level and Z origin. Other than that, it sounds fine.