calculating bolt hole pattern

[RJSakowski]

Not old school but I usually make up a CAD drawing for all but the simplest projects. I let the CAD program figure out the coordinates for the bolt pattern by dimensioning each hole in x and y from the center. I have the bolt circle feature on my mill/drill DRO and as a conversational program on my CNC and I can't honestly say the I have used either of them.

 

[dickr]

You are absolutely right. But if you had the book you could learn how to make a bolt circle. That's the way the "DRO" was invented. A book ! ! !
dickr

 

[willthedancer]

Part of being good at this craft is knowing how it works. Sometimes you find yourself constrained by the limitations of a programmed device, or the errors programmed into the device.

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[kevin]

Here's a link to a spreadsheet I put together to calculate bolt-hole patterns:

https://sites.google.com/site/lagadoacademy/machining---lathes-mills-etc/charts

There are also links to other online calculators and spreadsheets.

 

[Dave Paine]

Here's a link to a spreadsheet I put together to calculate bolt-hole patterns:

https://sites.google.com/site/lagadoacademy/machining---lathes-mills-etc/charts

There are also links to other online calculators and spreadsheets.

Thanks for the link to your spreadsheet. I was about to make a spreadsheet to do this calculation, but you have saved me the work.

 

[willthedancer]

My unsolicited advice on any automated process dealing with trig functions is to do a test circle printout, and verify it with the trig tables. There are some bad algorithms out there that create errors in the second decimal place.

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