Problem #1

No problem at all, Bill. This was an old trick I learned working with a fabricator friend. We had it back in school too, but I didn't use it until I was burning out some shipping covers for a prefab refinery components. We had drawings for all the flanges to built protectors/covers for, but this was by far the easiest way to lay them out. They were 1/2 plate. Stuff was shipped over to the Mideast somewhere.

Incidentally, this method, with some modification can be used quite simply to locate a 3 hole pattern by skipping every other whole. And can do 12 by geometrically constructing a bisecting line between the sides of one of the triangles, then use the new intersect to establish a new set of 6 holes spaced evenly and timed with the original 6.
 
would this be the same

y=(1.5/2)*-1

x=(square root of 3 * y) *-1

and could you substitute the number of turns from point 0 to point A for the 1.5 in formular and get the number of turns of x and y to get to point C?
 
* is the current symbol used for multiplication, to differentiate from variables in formulas like "X".
 
Uh, no....he lost me with the multiplication by -1, and the number of turns????
 
The number of turns has to be the X-Y table handles, but I haven't seen one where you needed to count the turns, as they had grads.

In fact, the method I chose didn't need a X-Y table at all, but only because there was no tolerance specified. Otherwise, your trig method is spot on.

Hope he comes in and clarifies a bit.
 
sitting at home with the flu and nothing to do

we know we are dealing with a 30 60 90 triangle the sides of a 30 60 90 are in the ratio of 1:square root of 3 : 2 2 being the longest side opposite the 90 angle and 1 being the shortest side opposite the 30 angle we also know that 1.5 inches is longest side of our problem (point 0 to point C) the shortest side of a 30 60 90 is half the length of the longest side so y must be 1.5/2 or .75 the ratio for the side opposite the 60 angle is square root of 3 times the shortest side or 1.732 times .75 so x must be 1.299 i multiplied the answers by -1 so they would be in quadrant IV on a graph the number of handle turns on the xy table is just a question that i been thinking about being this is a ratio problem.
 
just an old wornout auto mechanic looking to start a new hobby
 
Bill Gruby said:
This is a fairly simply problem. You have a workpiece that measures 2"X4"X4". You need to drill 6 equally spaced holes on a 3" diameter bolt circle from the center of the workpiece. Sounds pretty simple so let's complicate it some.

Your machines, only one a Drill Press.

Your Tooling, only two, a Drill Bit and an XY Table that can be bolted to the Drill Press. Nothing else but you and your brain, and the print below. (Click on the pix of the print and it will enlarge for you.)

What I want to know is how far you have to move on the X Axis and the Y Axis to get to Hole location "C" from "0". "0" being the center of the workpiece. Your workpiece is aligned so Holes A&D will be on the Y Axis. I have givin you just enough information to start, you must find the rest.

Please tell us how you arrived at the numbers (formulas etc.) This should not give the Pros any trouble so give the Newbies a chance to figure it out please. Those of you who wish to try and solve this feel free to look anywhere you wish to come up with an answer. Most of all have fun with this. Back away if you get stuck and ask questions. Good Luck.

"Bill Gruby"
Click to expand...

Hi Bill ..

I'm maybe the perfect newbie :confused:.. I don't even have a lathe yet ..

from 0,0 to get to point B .. X axis move 1.3" to the right then Y axis move up 0.75" .. you do the same distance for the rest of the points .. left and up for F, Right and down for C and left and down for E .. all starting form 0,0 of course ..

Ahmad
 
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