Thread: Pcd

I have to drill 6 holes on a 59 mm pcd , what are the x, y coordinates for some reason I can't get my head around bolt circles or PCDs

Hole 1 29.50 0.00
Hole 2 14.75 25.55
Hole 3 -14.75 25.55
Hole 4 -29.50 0.00
Hole 5 -14.75 -25.55
Hole 6 14.75 -25.55

Moving clockwise with the first point on the X axis to the right of the origin

0, 29.5
14.75, -25.55
-14.75, -25.55
0, -29.5
-14.75, 25.55
14.75, 25.55

Edit. Stu types quicker than I do

I can not tell a lie, I wouldnt have a clue how to do it with a pen and paper.
Pitch Circle Calculator

Stuart

If you're using a mill without a DRO it might be easier to "start at the bottom left corner"

0,0 is at BOTTOM LEFT

Hole 1 59.00 29.50
Hole 2 44.25 55.05
Hole 3 14.75 55.05
Hole 4 0.00 29.50
Hole 5 14.75 3.95
Hole 6 44.25 3.95

I think I'd go 4,5,3,2,6,1

Stuart

Originally Posted by welder

I have to drill 6 holes on a 59 mm pcd , what are the x, y coordinates for some reason I can't get my head around bolt circles or PCDs

Hi welder, the radius of your circle will give you your 6 points to centre punch. For the coordinates, multiply the given dimensions by the PCD required, from the vertical centre line is 0.43301, from the horizontal centre line it is 0.25.
This came from MEW number 205 page 34, it has hole pitch circle diameter information from 3 to 12 holes.
Will try to load the pages onto the library if anyone thinks it may come in handy???

< .................................................O
<......................................... O............. O -
<.......................................................... 0.25
< .................................................+------ -
<
<......................................... O............. O
< ................................................ O..... I
<.................................................. I..... 0.43301


Not my best drawing but hope this helps,
Kryn
PS when I started to type this there were no other answers, JEES I must type slow.

dont you just scrib a circle and divide it into 6

If you buy yourself a Zeus book it has all the ordinates in the back up to some ridiculously large amount. (get someone to get you one for Christmas)

Michael

There is a nice chart covering from 3 to 12 holes on Tom's Techniques

I thought that is what DRO's were for

co ordinates of a map...lol

I'm glad I have a dro....for when i will need it...probably still take me longer to work out than asking you guys

Have you just considered marking it out with dividers.

Depending on the accuracy you require you should be able to get it to within a few thou if not spot .

It would be a good learning exercise for you in marking out.

Sin(180/N) X PCD. N= number of holes.

Thanks guys I Got it done