Control Plate with a large number of drilled holes

[flylikechris]

Hello,
I am working on a machining print of a part with a large number of drilled holes. How would you guys go about dimensioning the Diameters of those holes? The way I want to do it is 4x 15mm, or 12x 5.2mm. Will there be any confusion given the large number of holes of similar size?

Thanks

 

[gfrankreid]

My method is to make a hole chart. A simple chart off to the side with a title space, the column headers and 2 columns with a row for each size. It appears you have four different sizes so that would be four rows after the title and headers. The title could be HOLE SIZES, or whatever, and the headers would be HOLE and SIZE. On the next row down put a letter A in the first column under SIZES on the left and the size in the next column under SIZE. B in the next row with its size and so on.

On the drawing, remove all the dimensions and replace them with a large letter which corresponds with the table. I have Autocad 2008 and I just pull down the Draw menu and select Table. This will bring up a utility that lets you create the table as needed. When finished it will put a table on the drawing where you click and then will open the editor to "fill in the blanks."

I hope this helps.
Frank Reid

One test is worth a thousand expert opinions. - Dan Joos, test engineer

 

[gfrankreid]

I wrote:

>On the drawing, remove all the dimensions and replace them with a large letter... <

I should have said "on the plate remove all the hole dimensions and replace them..."

Also, you might want to add a third column to the table titled QUANTITY and put the number of holes of each size in its row. This allows the machinist to see how many holes to drill before changing drills.

Frank Reid

One test is worth a thousand expert opinions. - Dan Joos, test engineer

 

[MiketheEngineer]

Sounds reasonable to me - just don't screw up the table.

Another thought - color code each hole - RED=14mm, GREEN = 12mm, etc. etc

Or use X, O, P, M or some letter code for each size.

Done all above.

 

[rollupswx]

If you use blocks with attributes you can have the hole table generated (semi)automatically.

 

[chicopee]

gFrankreid has the right method. That's the recommended way when drilling holes in PC boards, however, you will need a reference ponts in one corner of the board. The hole positions can be easily identified with the LIST command and and the UCS positioned at the reference point. When doing the LIST command, you can transfer the information from the history page on to the drawing space for modification, ie, removing all extraneous data.

 

[gfrankreid]

This is the standard method for drilling holes in metal plates. Chicopee is correct that there needs to be a starting point to begin the drilling. The machinist will have it easier for locating the drill locations. In the plate shown the upper left corner would be the reference point. I often use an arrow pointing to that corner with the note 0,0 to make it clear.

Frank Reid

One test is worth a thousand expert opinions. - Dan Joos, test engineer