# Bolt Hole Pattern Calculator



## papermaker (Mar 21, 2013)

I found this bolt hole pattern calculator as a result of watching one of Tubalcains videos. I'm not sure if everyone has seen it! Very helpful if you have a DRO on your mill. Just Google " Bolt Hole Pattern Calculator". It works great!


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## papermaker (Mar 21, 2013)

http://doov.com/cgi-bin/bolthole.cgi?d=4&num=8&xoffset=0&yoffset=0&angleoffset=0&bolthole=Calculate I think that this is the link to it.


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## lnr729 (Mar 23, 2013)

There is a (free) program to calculate bolt hole circles and a few other things as well. Check it out and download from here.

http://home.scarlet.be/mini-draaien-frezen/engels/program-01.html

I am currently adding more features to the program. I am currently working on calculations for making worm gears and the home made hob to cut the worm wheel.


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## kevin (Mar 23, 2013)

You can find links to a bunch of bolt circle calculators (and others of interst to machinists) here:

https://sites.google.com/site/lagadoacademy/useful-links#calc



papermaker said:


> I found this bolt hole pattern calculator as a result of watching one of Tubalcains videos. I'm not sure if everyone has seen it! Very helpful if you have a DRO on your mill. Just Google " Bolt Hole Pattern Calculator". It works great!


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## kd4gij (Mar 24, 2013)

Most DRO's have that built in.


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## Hawkeye (Mar 24, 2013)

kd, not everyone here has a $1200 DRO setup. Some of us use the basic iGaging version, which can benefit from a facility like these. Even without such a simple DRO, you could use the graduated dials (with care) to follow the coordinates provided by the calculations.


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