Problem #1

4

4R8

Registered
Registered
Joined
Aug 30, 2011
Messages
151
There would be a few methods i'd say?
What I'd use would be the known angle of 30deg from x0,y0 to the hole and this distance (hypotenuse) which is equal to the pitch circle.
This then treats it as a right triangle and simple trig can be applied to get the lengths of the other two sides.

I won't go through the formulas as I'm the first to view and first to reply.

PM'd answer anyway to check
 
Well, just looking at the drawing the only thing that I can come up with on my own, is that both the X and Y coordinates will be less than 1.5" each. (Radius)
Beyond that, I've got to go look for help. How sad is that? :eek:
 
never mind the first one Bill! I had a 1:20am (Oz time) moment and used 6 for the radius:headscratch:

Just resent with new figures, neither might have come through yet.

7 holes would be just nasty. Doable, but nasty (what would the tolerance be? :p)

Jason
 
Bill Gruby said:
At least I know I posted enough info to get this thing going. I wanted to make it 7 equally spaced holes but that would have been an exersize in futility. LOL

"Bill Gruby"
Click to expand...
That is why my best friend's name is spelled D-R-O. :rolleyes:

Ok, I'm off to class again... :grin:
 
For fun (more so nothing else to do in the office right now) for 7 holes, same diameter, hole 'A' in the same location @ x1.5,y0
I'd work hole 'C' like this:

Work out the hole spacing as an angle value
360/7 = 51.4286deg

work out the angle at which 'C' is from 'A'
51.4286 * 2 = 102.8571

then the angle from the X axis
102.8571 - 90 = 12.8571

12.8571 then becomes your reference angle

sin 12.8571 * 1.5 = .33378

cos 12.8571 * 1.5 = 1.4624

Hole 'C' (with 7 holes) is @ x-1.4624, y.33378

I shouldn't have asked about tolerance on the circle as i had no idea how small a minute was until I Googled it.
They sure are a small thing (unless the circle is massive:rolleyes:)

Jason (with a headache)
 
OK, let's see if anyone knows how to do it without trig and math at all. You have the same print, a machinist's square, a machinist's scale, and a pair of dividers.

Some may know of this elementary method, so let the ones who don't think about it just a bit. And as with Bill, if you want, PM your solutions before posting them.
 
Tony Wells said:
OK, let's see if anyone knows how to do it without trig and math at all. You have the same print, a machinist's square, a machinist's scale, and a pair of dividers.
Click to expand...

I don't know what a machinist square, machinist scale or dividers are! :headscratch:

I could do it with a compass, a square and a ruler. Or are these the same thing but of a lower accuracy?:huh:

Jason
 
Pretty much, Jason....but since this is a Machinist's forum, let's try to use the right terminology. ;)
 
Tony Wells said:
Pretty much, Jason....but since this is a Machinist's forum, let's try to use the right terminology. ;)
Click to expand...

Had a feeling that was the case but never looked into it- self taught in trig, machining, welding, mechanics, etc. (see the hobby part of the forum title?:p)

Bill Gruby said:
Square to find center of the block. 2"x2" to center. Scale to open dividers to 1.5". From center scribe a 3" circle. Use the same measurement as the radius to scribe 6 equal marks on circumferance because the arc is equal to the radius. This is why I chose 6 holes. Don't forget to blue it first.

Jason -- Compass = Dividers, Ruler = Scale, Square = Square.

"Bill Gruby"
Click to expand...

^^What bill said.....
Then using the (machinist) square you can mark and or measure (including your machinist scale) your x,y travels :thumbzup:
 
You must log in or register to reply here.
Back
Top