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How to figure uv movement to match top plane

zosotd

Aluminum
Joined
Sep 19, 2006
Location
louisville ,ky
Anyone know the formula to set the wire perpendicular to the top of the block by finding three points? How does Agie figure this with there 3d setup?
 
Once you know the angle and direction (orientation of the inclination), you'll then need to know the distance between your guides (or toroids if the angle is anything of significance). From that point, it's a straightforward trig calculation. You could even just model it in your CAD program if you don't want to do the math.

As a matter of fact, you could do the entire thing in a CAD program -- just enter the 3 points "in space" in CAD, pass a plane through them, draw a line normal to that plane, and then pass two planes through that inclined line (separated by the dimension between your guides or toroids). Drag the point where the inclined line passes through the lower plane to global 0,0,0 in your CAD program, and read off the X,Y dimension of the upper intersection point

It's actually much simpler than I'm making it sound. Let me model this quick and I'll post a graphic.

PM
 
OK… here goes:

I created 3 imaginary points “in space” (essentially what could be probing results)…

(Location: X= -10.000 Y= -10.000) ---> Z= 50.000
(Location: X= +20.000 Y= +20.000) ---> Z= 51.123
(Location: X= +20.000 Y= -20.000) ---> Z= 49.567

I then created a new work plane from the above 3 points. I switched to that work plane, then created a line with one end at global origin (0,0,0) and normal to the new work plane. I made that line “plenty long” (just pulled it out to 120mm in length or so).

I changed back to the global work plane, and created an infinite plane at Z=100mm (I chose a random value of 100mm between the lower and upper guides — change number to whatever required). I “trimmed” the line I created at 100mm height in Z, then simply read off the coordinates of the upper end of the line, which are:

X= +0.147mm
Y= -3.891mm

I “think” this should be correct, and the method should work in CAD regardless of your probing points and the location of your guides or toroids.

Anyone seeing error in the above, please jump in and correct! This was a quick stab at a simple solution.

PM
 
OK,I understand doing it in CAD. What I'm really wanting to do is make an Equation to use in a Macro Program on the machine by finding 3
points with an indicator. I want to use it on large blocks that I cant level without shimming. Thanks for your time!
 
with a lot of carefull trigonometry and a spreadsheet you can automate this to work with any three points.

you can simplify it greatly if you probe coinciding to your U,V axis (for instance) x0,y0 x5,y0 x0,y5 then your trig becomes much more simple and all you need is the distance between guides. in fact if you distance is say 5" then it will be the same as your indicted amount. if different, say the height is 1" it will be simply ratioed as 1/5 the indicated amount.

no real trig. your just rotating and ratioing triangles.

I think... this is where careful debugging comes in.
 
Hi guys, I feel I have to weigh in here. On an Agievision machine with 3D pick up, the machine tilts the XY plane to match the top of the part. That is why it is called 3D pick up. This allows you to cut a round hole in the tilted part. Simply tilting the wire but not the XY plane will not produce a round hole perpendicular to the top of the part. KilrB has the right solution or buy an Agie :)
 
This has been an interesting thread, and I thought I would share some recent updates that Makino has developed for our Wire EDM machines with the Hyper-i control. Makino does offer a full 3D Probe option for the machines that is capable of 3D Leveling and Part Location Alignment, but we have just introduced a 3D Plane Find function that uses a simple dial indicator. This new 3D Plane Find function is part of the standard Hyper-i software, and allows the operator to establish a 3D Work Plane so that the wire will be skewed (U/V Axis) to be perpendicular to the work piece. The function can be used to establish a Plane by capturing (3) points on the TOP of the Work Piece (Z-Axis) or by capturing (4) points on the SIDE of the work piece (XZ/YZ plane). Below is a link to a video of this new function, and it shows the 3D Plane alignment by capturing (3) points in the Z-Axis.

Basically, the operator uses a dial test indicator and drives the machine to the first location and sets the indicator to ZERO, and then presses a button on the control to capture and record this first location. The operator then moves the machine to a 2nd location, and then moves the Z-Axis so that the dial indicator is back to reading ZERO, and then presses a button on the control to capture and record the 2nd point. Lastly, the operator moves the machine to a 3rd location, repositions the Z-Axis back to ZERO, and then presses the button to record the 3rd location. Once 3 data points are recorded, then a Calculation button is pressed on the control, and the machine will calculate and move the U/V axes to be perpendicular to the work piece, and it will show the movement amount and calculated angle changes. Our hope is that this new function will be a helpful and time savings feature to the operator!

New Wire EDM Plane Find 3D Feature for Non-Level Workpiece Surfaces - YouTube

-Brian
 
zosotd,

The 3D Leveling type function you are asking about is too complex and beyond the scope of making a user macro variable program...this is not a simple thing to do! You can probably find some mathematical algorithms online on how to calculate angles from 2 planes using 3 points on Google, but these calculations are most likely beyond the capability of NC macro functions. Finding the 3D plane angle of your work piece is only (1 of 3) calculations that is needed to make this function a useful tool on the machine. The 2nd (2 of 3) needed calculations is determining the adjustment movement value of the U/V Axis, and this calculation must also include and compensate the wire at the true fulcrum bending point of the wire over the Wire Guides. Lastly, the 3rd (3 of 3) calculation is compensating the X/Y program size to adjust for Cosine error to achieve the proper geometry size and location. If this last calculation is not performed, then the geometry size and location will be incorrect, and the feature size in the highest plane angle will be progressively smaller and non-proportional in size.

For example…if you machine a perfect hole in a flat plate that is raised up at a 45 degree angle in one axis, the hole will be round/circular. When you then lay the plate down flat on a table, the machined feature will be elliptical with one dimension being smaller than the other.

I hope this provides an education on the complexities in what you are asking for, and I do not want to discourage you in your efforts to be more efficient. Since your current machine does not provide a 3D Leveling function, I do believe that a more practical solution for you is to utilize your available CAD software tools to help calculate this. For best results, you can rotate your CAD geometry (need 3D model of the work piece) to match your work piece conditions, and then create a 4-axis program for the geometry.

-Brian
 
I still have not solved this problem.

Is there anyone who can explain this in simple terms by showing an example?

Not exactly the same thing, but on the wire machines I have run in the past you could calibrate the wire alignment by "sparking out" against the side of a workpiece or a square ground block set on the table. On Sodick machines the service tech showed me how to do this and claimed it was more accurate than the automatic alignment.

With a larger workpiece, if the sides are square you can calibrate the U and V axes by sparking out directly against the block itself or maybe take a ground square block and slide it over the top of the work extending over the edge slightly. Depending on the height this second technique wouldn't be as accurate but it would get you decently close.

Anyways this will bring your wire square to the work, effectively doing the same thing as a plane levelling cycle
 
It's easier to let the machine figure it out.

My set-ups are very quickly done using the built in functions.

The U6 has all sorts of bells and whistles.
 








 
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