Importing CAD, What am I missing??

[pguillory]

What's up guys?!

First of all thanks again for all the help and resources you guys have been. My last posts and replies were great, but as I've come to learn, I have another question with this demon. Lol

I'm creating a program for the Airfoil of a Turbine blade. So far, everything else has been great for me. Here's the problem that I just can't get right:

When I import my CAD model, I can't never get it to the position of the actual part on my cmm. I've tried Transform, Iterative Aligns, and alignments from what I've seen in the forums. I STILL can't get this thing to be where I want it. Seems like this step, getting the CAD where I want it is the main thing holding me up.

Correct me if I'm wrong but the CAD model has the data (noms, Meas stuff) that I need for reporting right? Lol

Sorry, but I just really want to figure out what I'm missing. Maybe I need a good example or explanation of this process of getting a CAD model where you want it. I even thought I could get 1 over on pc dmis by creating 2 features, finding where they intersect, and transforming the CAD model there. NOPE

[acgarcia]

How are u aligning to it? Are u programming at the machine or offline? Do u have at least PcDmis Cad or Cad++?

[pguillory]

And as far as aligning, it seems like I can't even get this thing to line up even if it's the first thing I do lol

[pguillory]

Programming at the machine, with pc dmis 2010 mr3 CAD++

[Schlag]

CAD++ and you are driving the machine or using the CAD ? Shot in the dark here but you have a CAD model, but are doing it 100% on the CMM ??? If this assumption is correct....
Your program starts out in MACHINE Coordinates but the CAD is in CAD coordinates. If you insist on driving the machine, you must AT THE MIN, take your manual alingnment from the CAD.

[sealevel]

Are there any clues to align it via the DWG?? ()
Without seeing a sketch or anything.... here's a shot in the dark.....certain alignment help CAN be implied in the Standard.

[William Johnson]

Transform is your best option. At least for me it is the only way I have done it. Sometimes it will require you to take a autopoint on lets say the top surface. Then look at the z value. Close autopoint without creating one. then go back into transform and move the z by the measured value that it gave you . So a 2.5mm z measurement would be a -2.5mm Z offset. With trial and error it will work and over time you will understand how transform works.

[pguillory]

Thanks bud, I'm in this morning and will definitely give this a try. I figured that it would be just a trial and error situation and eventually I'll find out the best way for me to get it done

[Mike Ruff]

You don't have to do it with an autopoint. In the transform box, just click select, uncheck X and Y so only Z is selected. Then, click the surface you want to be your Z-zero and click OK, it will show and tell you how far it is going to shift it. If it looks correct, click Apply.

[William Johnson]

Nice tip Mike I did not know this. Sometimes we just get in a rut and continue to do the same insanity. I will try this myself.

[RandomJerk]

Do you mean something like this?

https://imgur.com/a/eIlPX9a

You do that via Quick Fixturing mode. Depending on your version, you'll either go into quick fix and right click for the menu, or a toolbar will pop up. Play around with it, but I HIGHLY recommend finding "No rotation" first and selecting that.

[Matthew D. Hoedeman]

IF you are manually measuring features on the part, then aligning to those, doing a level, rotate, origin, axis offset (3-2-1) alignment, you MUST either type in all the correct XYZIJK nominals for all of those features OR do CAD=PART (which sets the XYZIJK nominals of those features based on your level,rotate,origin,offsets).

[Ego Murphy]

What's up guys?!

First of all thanks again for all the help and resources you guys have been. My last posts and replies were great, but as I've come to learn, I have another question with this demon. Lol

I'm creating a program for the Airfoil of a Turbine blade. So far, everything else has been great for me. Here's the problem that I just can't get right:

When I import my CAD model, I can't never get it to the position of the actual part on my cmm. I've tried Transform, Iterative Aligns, and alignments from what I've seen in the forums. I STILL can't get this thing to be where I want it. Seems like this step, getting the CAD where I want it is the main thing holding me up.

Correct me if I'm wrong but the CAD model has the data (noms, Meas stuff) that I need for reporting right? Lol

Sorry, but I just really want to figure out what I'm missing. Maybe I need a good example or explanation of this process of getting a CAD model where you want it. I even thought I could get 1 over on pc dmis by creating 2 features, finding where they intersect, and transforming the CAD model there. NOPE

1. read up on PC-DMIS Blade.

2. Import CAD model. Use Transform's rotate function to flip it around to the right XYZ direction.

3. Put cursor before 1st LOADPROBE and Insert the Machine definition.

4. F5, part-machine tab, auto adjust, apply, then go back and move it around to fine tune it (like move it up 6" if it's sitting 6" off the granite table, etc).

~~~ All programming is done by creating features by clicking on CAD. Never create a feature with manual jogbox hits (unless that feature doesn't exist in the CAD and you have a blueprint relating it to the CAD). ~~~~

5. Manual alignment all 6 degrees of freedom

6. DCC-rough alignment all 6 degrees of freedom (after executing this on the machine, everything lines up)

7. DCC semi-rough alignment all 6 degrees of freedom

8. DCC final alignment all 6 degrees of freedom

[pguillory]

Thanks everyone for the help and suggestions! I'll try out all of these methods to see what works. I did come up with something I think will work, but might need a little fix here and there. Let me know what you think on this:

1. Import CAD Model
2. Open transform, rotate the part as it is on the CMM
3. Go to auto features, select Vector Points
4. Take a hit in a specific spot on top of part(CAD Model). (A point where I can easily take a manual hit in the same spot)
5. Open new Align, set new Vector point to XYZ Origin
6. Take manual hit on part in same spot(Actual part on CMM)
7. Open Transform, Translate part to the new coordinates of the manual point
8. Then create alignments etc..

Another method I tried:

1. Import CAD Model
2. Open transform, rotate the part as it is on the CMM
3. Take hits on top, side, and face(Face that's facing me) of the actual part
4. Transform the CAD to the Z of the top hit, X of the side hit, and Y of the face hit

Of the above 2 methods I've tried, they seem to work, but I can see that it is a little off. The scans I take on the flip side of the part are barely visible so I'm thinking that the CAD isn't in the "perfect" position. If there's anything I can do to fine tune one of these methods, could you let me know? Or if there's anything wrong with these.

I've been training myself so improvising has become my new flavor as of late lol

Thanks guys!!

[Mike Ruff]

Honestly it sounds like you need to go to some training. You should try to get your company to send you to Hexagon for the basic course. Trying to learn the basic essentials on your own is going to take way longer and be a lot harder than it would be if you got some actual training.

That being said, you NEED to do a level AND a rotate in your alignment. You are only constraining 3 out of 6 degrees of freedom by just translating your alignment. This is going to make the CMM treat the part like it is perfectly aligned to the machine, which it never will be.

[pguillory]

Yeah man no lie I'd love to go to a training. I'll have to look into it a bit more and get the details on that, but it's definitely needed with all this even though learning on the fly has been pretty interesting. Between you guys here and a ton of Youtube, I've actually been getting a lot done. It's literally just positioning this CAD model that gets me irritated! Lol.

As for the level and rotate, after I get the CAD all good, I start up the normal manual alignments then DCC, and go on from there.

[Schlag]

Why would you transform after the alignment ? When the model is " facing" the same orientation that the part will be sitting on the CMM when the program is ran, " transform" is done ( step 2 ) and start the manual alignment ( step 3-5 ). You never need to go back to transform. If you feel you do, your alignment rotation or something else is just wrong. And just to make your life easier.....you have CAD, stop driving the machine to make your program, select the feature from the CAD. They are all "theoretically perfect". When you write a program from a part, your program is based on the "part" with all its possible defects and not the "perfect part " ( CAD ).

Back up 1 second... Do you have access to CAD software ? If you do, create a coordinate system in CAD, then when you import there is no transform and just start at step 3. The transform functions are really only there for people without CAD. No to downplay them as they are needed but its way easier to do those functions in CAD than in DMIS.

[louisd]

When programming from CAD, they are theoretically perfect, so as long as the CAD matches the drawing, lol. I can't possibly count the inaccurate CAD model's I've had to work around.

[pguillory]

Schlag, Ahh okay I got ya! I know how to program on the CAD and all but when you said

"They are all "theoretically perfect". When you write a program from a part, your program is based on the "part" with all its possible defects and not the "perfect part " ( CAD ). "

This clicked for me. The part defects vs the "perfect part". Gonna run this and see what I get. Thanks man!!

[Schlag]

I have more then 1 customer that could send me a print of a pineapple and the CAD may be a strawberry.... We had better make them a strawberry because the print is reference only....