PCD hole checking

[[SH...]]

How can I check these two holes PCD in calypso without using formula??

IMG_20200704_172636.jpg

[[Da...]]

OK, I first want to be sure - is P.C.D. pitch circle diameter? I can't imagine the term right, what pitch?
Anyway, Shabu why don't you want to use formula?

[[SH...]]

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Yes, it is pitch circle diameter,l don't know, in the drawing it mentioned like that.
Using formula l can only calculate the diameter of individual holes with respect to centre. I want to calculate diameter including two holes.
Or
I have to calculate two diameter and add it then divided by two??

[[Ja...]]

We can do it by recall option.

First measure three circle.
Then create a new circle from feature menu.
In the option select recall and select three circle.

It will create a circle passing from three circle.

[[SH...]]

I have only two circles

[[An...]]

To calculate a circle, Calypso needs at least 3 measuring points or three circle elements from a recall.
without a formula, you won't be able to calculate it.

it also makes no sense to specify polar coordinates in xy-axis and a pitch circle diameter

[[Ro...]]

Thats a terrible callout....... the only thing i can think of would be to cheat and create some 'added' data points (read false data points) by creating a couple theoretical circles where the X&Y are "(getActual (circle1),x)*-1", so that circle will appear in the opposite quadrant than the actual circle.
You'll end up with 4 points of data, but i don't know if it will be any good.

[[An...]]

If you convert the polar coordinates into a circle and use the tolerance of 0.2 mm, you get a pitch circle diameter of Ø 76.532 mm with full (+) tolerance and a Ø 75.438 mm with full (-) tolerance.
The tolerance of + - 0.2 mm for the specified pitch circle diameter can only work if the polar coordinates are precisely maintained.
If I calculate the polar coordinate with a (+) tolerance and the other with a (-) tolerance, the dimension is still within the required tolerance of the pitch circle diameter!

The tolerance of one polar coordinate may only be + - 0.1 mm, the other may only be + - 0.05 mm, only then can the tolerance of 0.2 mm of the pitch circle diameter be maintained!
It would be better to provide the two polar coordinates with a tolerance of +- 0.05mm, then the pitch circle diameter is always within the required tolerance.

[[An...]]

Hello Shabu,
I did the math.
I have some pairings here.

This mating would fit, but it's dangerous because the worker
one polar coordinate with (+) tolerance, the other must machine with (-) tolerance.
Calculated with full tolerance utilization.

18,80mm / 33,10mm = Ø 76,132mm pitch circle diameter
19,20mm / 32,70mm = Ø 75,840mm pitch circle diameter


With this pairing, the tolerance of +- 0.2mm of the polar coordinates cannot be
fully exploited, if one would do so, the tolerance of the pitch circle diameter will be exceeded.

18.94mm / 32.84mm = Ø 75.820mm pitch circle diameter
19,08mm / 32,98mm = Ø 76,202mm pitch circle diameter


If the polar tolerance were set to + - 0.05mm, the tolerance of the pitch circle diameter would always be conform
if the tolerance was fully utilized.

Tolerance greatest against greatest 19.05mm / 32.95mm = Ø 76.120mm
Tolerance smallest against smallest 18,95mm / 32,85mm = Ø 75,846mm
Tolerance largest against smallest 19,05mm / 32,85mm = Ø 75,948mm
Tolerance smallest against largest 18,95mm / 32,95mm = Ø 76,020mm

I think you should talk to the designer about which dimensions are more important to him.

[[SH...]]

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Sorry for the late reply,

thanks for your effort in my post, I got it what your telling but I don't think they will change the drawing. I went with formula..