Position Pattern

[[To...]]

8 holes have a composite position. The upper tier is .008(MMC) to A B(MMB) C(MMB). The lower tier is .004mmc to A only.
Note: my example model did not have Datum C Slot so I drew it in.

Any thoughts on how to set this up?

Calypso 2018

Screenshot 2024-10-02 113720.jpg

[[Ma...]]

I don't see a problem. Or you have a problem with what exactly?

For |A|B(M)|C(M)| you just report TP
For |A| you apply BF XY Zrot

[[Ch...]]

Someone explain to me how this is possible(i'm sure it is, but it's not obvious to me yet). You can report diameter and angle between bores and also that angle in relation to the DRF. But how will you establish a single point for position?

I assume the bores are too small to construct a cylinder. therefore you can't intersect the axis with datum B.

How does the print show it?

[[To...]]

Please sign in to view this quote.

I believe the holes could be measured as cylinders but customer is using circles.

Drawing uses F G N as datum labels, but they are a plane, cylinder and slot.

I would assume the expectation is that the tolerance zones are cylindrical, plus the MMC, at their basic locations. and the point, in this case, must fall within that cylindrical zone.

Screenshot 2024-10-02 134102.jpg

[[Ma...]]

Please sign in to view this quote.

Using TP on pattern should report the worst value from all in pattern, then in extended you will see each one's value.

[[To...]]

Please sign in to view this quote.

Hello Martin,

I set this up in simulation and it appears to be working (in 2020) but I am not sure. However, before I select the best fit options, it shows translation in X and Z, which is fine for holes at 6 and 12 o'clock, but what about the other holes? One the rotation is selected, it combines, the X and Z into 1.

My issue is that I was led to believe that hole axes not parallel to the primary face would not work in best fit. I would imagine that 8 holes located around the part would be even worse. I am inclined to think that Chad is on the right track to generate intersection points but then MMC becomes more difficult.

Screenshot 2024-10-02 140636.jpgScreenshot 2024-10-02 140656.jpg

[[Ch...]]

Please sign in to view this quote.

I'm with ya on that. But Tom won't be able to establish a cylinder on those features. He will only be able to establish a circle. I supposed you could project that circle to the OD or ID. But since you don't have an axis (Tom will only have circles) how can we project it?

Let's say its dimensioned using angles and radi, then how do you establish that radi point?

[[Ma...]]

Don't get me wrong, but for first TP 0.008 | ABC | you don't enable any translation/rotation and fillout all datums with MMB on TP page.

For second one TP 0.004 | A | you allow translation X,Z and rotation in Y to make an alignment for TP.
I am not at Calypso so i can not confirm how to use MMC on that pattern.

[[Ma...]]

Please sign in to view this quote.

What circle? There is MMC on diameter of 8 circles. MMB is on cylinder ( diameter toerance ) and slot ( width tolerance )

[[To...]]

Please sign in to view this quote.

One might assume that if translation options are X and Z, the rotation would be about Y, like you said, however I believe the rotational best fit needs to be about the Z, the spatial direction of Datum A

[[Ma...]]

Please sign in to view this quote.

Sorry i got confused. If plane A is in Z vector, then translation in X and Y and rotation in Z.
Because 0.004 have only A so Z height is fixed but X and Y have to be bestfit

[[Ri...]]

You cannot use the old 2d Bore Pattern if you are trying to do a Bore Pattern of radial holes. You need to be controlling the angular spacing and the height of the holes, but the 2d Bore Pattern will not let you control that.

If you cannot use the new GD&T package in 2023+, then you could create a Geometry Best Fit out of the holes, but the issue is going to be that MMB goes out the window for you, and in addition the FRTZF (lower tier) really needs to be utilizing MMC when constructing the Best Fit, as the MMC will affect the Best Fit results.

[[Ma...]]

I was getting only this far ( on Calypso 2018 )

When i did pattern of points instead of circles/cylinders then i was able to get correct nominals for TP, but without MMC on holes.
For slot i was not able to turn on MMB, only with circle.

Any attempts with circle/cylinder was resulting in wrong plane ( YZ, XZ ) with wrong nominals.

[[To...]]

* * * * U P D A T E * * * *

Ok. The customer says the lower tier position problem was solved. First, create a secondary alignment using A (OTE) as Spatial and Z Origin. Next, create a Geometry Best Fit alignment, to the abovementioned alignment, selecting all circles, allowing trans in X and Y and rotation about Z.

In the position, select a circle with MMC and make the Geometry Best Fit alignment as the primary datum. Repeat for each circle.

Zeiss confirmed Best Fit Bore Pattern Position will not work with features that are not in same direction as primary datum.

Can GD&T Beta Engine do this correctly????

[[Ri...]]

Yes

But my interpretation is that the lower tier should be allowed to translated in the Z as well. The translation in the X/Y axis is somewhat meaningless, especially if you are measuring them as circles. 🙁.

[[To...]]

Please sign in to view this quote.

My interpretation is the location of the tolerance zone, located with a BASIC dimension from Datum A, is locked therefore not allowed to translate. I agree that cylinders should be used.

[[An...]]

Please sign in to view this quote.

[[To...]]

Just so there is no confusion, I've added a revised sketch.

For any of you that are new to this post, we are now discussing the lower tier of the composition position and whether or not the 8 hole pattern is allowed to translate in the Z axis. All other dimensions related to the position of the holes are also BASIC.

Screenshot 2024-10-07 102838.jpgScreenshot 2024-10-07 103112.jpg

[[Ri...]]

Please sign in to view this quote.

The lower tier only controls the orientation of the features to the datums(s) listed. The location of the features is controlled in respect to themselves.

[[To...]]

Please sign in to view this quote.

I think I am finally starting to come around to your way of thinking.