Alignment Methods

[[Ja...]]

Hi all

I know on other CMM's we have set up alignments which instruct the operator to move the probe to the centre of the part, press okay - the machine then pulls the XYZ position from the system, and from that we create a theoretical point, origin XYZ, creating an initial 'datum'. The machine then goes into CNC mode and measures the plane, circle etc relative to that initial 'theoretical point'. So all the operator is doing is moving the probe into position and hitting okay. 

I've been setting up Autorun and considering altering alignments in the main programs to make aligning as 'simple' as possible for a inexperienced operator.

Can the method I've written above be replicated in Calypso?

[[Cl...]]

If the fixture is in the same location on the CMM all the time and is also Poke Yoke.

You can perform the initial Start Alignment which tells Calypso were the workpiece

is within the CMM's volume. I usually do this on the fixture itself. Once this is done.

From "Run Measurement Plan" Tick "Base Alignment", Then from the drop-down menu

just below that chose the Base Alignment you wish to run. The software knows the

part/fixture location and the performs the Base Alignment, which I would loop as well.

[[Ma...]]

I would rather spend time to make better fixture, or teach operators.

Surelly you can try, but i think you will hit safety wall with clearance cube.

What you can do is let operators to touch that point manually, then move probe to safe location and hit continue.

[[Da...]]

My experience with "read-point alignments" like this is that they only work easily on an already-aligned inspection fixture. Anything you expect the operator to set up and "tram-in" manually will have a good bit of uncertainty, so you will need very large margins when checking your line and point locations for the machine alignment.

[[Je...]]

I appreciate the feedback on best-practice for locating a workpiece.

However, let's keep in mind that

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 asked if the "manually move to center of part and click 'okay'" method is possible in Calypso.

Jack, yes, this is possible in Calypso as well.  As the others have hinted, this occurs through using what is called a "start alignment," which is a simplified version of the base alignment.  The base alignment then runs (usually in CNC mode) after the start alignment is computed.

[[Ni...]]

We use a 'start' alignment, which we set as a single point. We manually hit the part for the single point and then the program goes into CNC mode and takes the appropriate 'base alignment' features. The only requirement is getting the part 'fairly' square how the part is set up in the virtual space as well as taking the hit point in the correct spot on the physical part as compared to the CAD model.

We set up 99.9% of our programs this way.

[[Ja...]]

Thanks gents; 

So

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 are you saying a simple 'point' is sufficient enough for the machine to go into CNC mode, and have enough information to measure? No plane, origin etc is needed to lock XYZ rotation/translation directions?

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 thanks, we do use start alignments however it still involves manual point taking of planes/circles etc. Can calypso pull machine variables from the software of XYZ locations of where the probe is on the bed? So in theory if I position my probe at the centre of a part, pull in the positions, create a theoretical point based on those positions, set my 'start alignment' on that point. The software has enough information to be able to go into CNC and measure. Hope this makes sense. 

Appreciate all the responses so far.

[[Ma...]]

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 If machine will perform that point touch without problems, then you can create theoretical plane/s to fill primary and secondary datum, origin can cover that point.

I am using this method if i have only secondary. This way it should take from machine alignment.

Or if you want to be sure then make a program which will be used as loaded alignment to have assured axis directions ( aka primary - secondary / rotation in space and the other one )

[[Je...]]

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, yes that is possible but I can't articulate the steps, since I haven't had to do that specific task.

The process you described is similar to how a base alignment is computed, with the difference being that in your method the origin is defined by the center of the probe rather than computed from measured features.

The button labeled "special" in the alignment window may allow that type of an offset to be defined based on a parameter.

My perception is that the reason you would attempt this is either to simplify things for your operators or create an ultra-fast universal workflow for yourself.

I applaud the experimentation and innovation.  However, I do feel that the needs you may be trying to address (without knowing specifics) are fully satisfied by Calypso's built-in alignment process, perhaps with a bit of customization embedded in a template measurement plan.

I'd love to hear more about your thought process and how this project evolves for you.

[[Cl...]]

In a production environment, this whole issue goes away if fixed interchangeable part

specific Poke Yoke fixturing is implemented. Unless of course you work in a job shop