G,D & T Question

[Farmer]

Gents, please see the attached. I have highlighted (ringed) some holes that are causing me some trouble. Im really not sure how to apply a true postion tolerance to a dimension that only has a basic PCD and angle to show its position. I am used to x,y and z co-ordinates. It looks screwy to me but hey, what do I know? Hopefully one of you Gurus will have seen this type of thing before. BTW the X Datum is the face that is being viewed.

TIA.






FGDT.jpg

[bw_bob]

It appears everything comes off the C/L so all you have to do is rotate to you basic angle & you also have the bolt hole Pattern.. Rotate to one of the angles & divide one of the bolt hole pattern & check one of your diameters. Bingo you got your answer.

[layout tech]

Do your Main X/Y/Z alignment. Rotate your alignment 30 degrees then you can call TP of one of the top holes with basics of "0" and radius "140". then recall main alignment and rotate -30 degrees and you can call TP of other top hole same basics. Then recall main alignment rotate 45 degrees and you can call one of the bottom holes same basics "0" and "140". Then recall Main alignment and rotate -45 degrees and you can call other bottom hole same basics.

The other TP looks very straight forward. Main alignment basics of "0" and "102.5".

My opinion and worth what it cost you!

My bad!!! Top Tp's have radius of 117.5. Sorry

[Farmer]

Cheers Guys, makes perfect sense now.

You guys are the best..

*passes brews*

[vpt.se]

You could convert the polar coordinates (angle, radius) to cartesian (X,Y) as well. That way you won't have to rotate the alignment - but that will also do the trick.

[phil george]

You can also select Prad & Pang instead of x & y in the true position dimension box.