How to layout holes on an 8" diameter plate

[homebrewed]

I checked my spreadsheet and discovered an error in the formulas I used to calculate the coordinates . I apologize for that. I've attached the revised version and also will revise the version I put on the Resources forum.

BTW, although the spreadsheet gives the coordinates for 12 bolts, of course you'd only use the first 4 for a 4-bolt circle, 8 for 8 bolts etc.

 

[extropic]

I checked my spreadsheet and discovered an error in the formulas I used to calculate the coordinates . I apologize for that. I've attached the revised version and also will revise the version I put on the Resources forum.

BTW, although the spreadsheet gives the coordinates for 12 bolts, of course you'd only use the first 4 for a 4-bolt circle, 8 for 8 bolts etc.

The chart seems to work now. Thank you for fixing that.
I was hoping you would explain the fix so that I (we) could learn something about Excel.
I've tried to compare the two versions, cell by cell, but can't see a change.
The fix is obviously 'over my head', so I would appreciate it if you would provide a clue where to look.
Thanks,

 

[homebrewed]

Sure. The difference is in the table calculations, columns C & D, lines 11 through 22. I incorrectly added the angle offset -- I'd already done that in the angle calculations in column B so the calculated coordinates were incorrect.

If you click on one of the cells in the table you will see the formula pop up in the edit box that's near the top of the window. Dollar signs in front of the cell ID (like $C$4) tell Excel not to update that particular ID when you copy and paste it into another cell. Cell C4 is the radius of the bolt circle so that stays the same for all the calculations. The angle changes so you DO want that ID in the formula to change.