tag:blogger.com,1999:blog-313510526071834587.post245296270672508312..comments2021-03-27T13:13:04.718-07:00Comments on The Black Dog's Woodshop: Deriving the Forumulas for Sightline and Resultant anglesSteve Voigthttp://www.blogger.com/profile/18126881073066259306noreply@blogger.comBlogger9125tag:blogger.com,1999:blog-313510526071834587.post-4039073113377938172020-11-16T12:49:44.167-08:002020-11-16T12:49:44.167-08:00I was specifically trying to find how to calculate...I was specifically trying to find how to calculate the resultant angle, so in case anyone needs it, here is the complete formula. Be sure to convert splay and rake to radians first and you can convert the final resultant angle back to degrees when you're finished:<br /><br />a = splay (in radians)<br />b = rake (in radians)<br /><br />resultant (in radians) = atan(tan(a)/sin(atan(tan(a)/tan(b))))<br /><br />(in case it's not clear, atan stands for arctangent)Sammy Joe Ohttps://www.blogger.com/profile/18068100979708198985noreply@blogger.comtag:blogger.com,1999:blog-313510526071834587.post-45086523848131776962020-02-27T03:00:03.958-08:002020-02-27T03:00:03.958-08:00Nice exercise.
When the bottom of the seat is not ...Nice exercise.<br />When the bottom of the seat is not horizontal, the formulas aren't anymore practical unless one put them in a spreadsheet.<br /><br />I think it isn't anymore taught in high school, but I personally enjoyed descriptive geometry (Monge method) 50 years ago.<br /><br />The default of a numerical method is that one tends to use a number of significant digit which is not necessarily meaningful.<br /><br />SylvainSylvainhttps://www.blogger.com/profile/06334251598652872682noreply@blogger.comtag:blogger.com,1999:blog-313510526071834587.post-1827961059236973192020-02-22T19:22:15.709-08:002020-02-22T19:22:15.709-08:00Thanks Ken. If nothing else, when I inevitably for...Thanks Ken. If nothing else, when I inevitably forget where I wrote down the formula, I'll be able to find it here. Steve Voigthttps://www.blogger.com/profile/00682651791126328242noreply@blogger.comtag:blogger.com,1999:blog-313510526071834587.post-49169766137575787932020-02-21T02:26:01.629-08:002020-02-21T02:26:01.629-08:00Steve,
Thanks, nice to have the info in one place...Steve,<br /><br />Thanks, nice to have the info in one place.<br /><br />kenI'm a OK guyhttps://www.blogger.com/profile/11843155822153452980noreply@blogger.comtag:blogger.com,1999:blog-313510526071834587.post-63552042077802501202020-02-18T12:43:21.671-08:002020-02-18T12:43:21.671-08:00Could you repeat that? : )Could you repeat that? : )Anonymoushttps://www.blogger.com/profile/02199099622807116960noreply@blogger.comtag:blogger.com,1999:blog-313510526071834587.post-91354484316400284662020-02-17T11:03:43.736-08:002020-02-17T11:03:43.736-08:00Hey Rick, I should have made it clearer that no on...Hey Rick, I should have made it clearer that no one needs to go through this whole process to find the angles they need. It's really just a matter of plugging 6 numbers into a calculator, something that can be done in a minute or less. But all the other methods, including model making, also work.Steve Voigthttps://www.blogger.com/profile/00682651791126328242noreply@blogger.comtag:blogger.com,1999:blog-313510526071834587.post-71806706322115561282020-02-17T07:40:52.870-08:002020-02-17T07:40:52.870-08:00Lol! I’ll go with Chris’s non-math method. 😉Lol! I’ll go with Chris’s non-math method. 😉Rick Lapphttps://www.blogger.com/profile/18386740108748292539noreply@blogger.comtag:blogger.com,1999:blog-313510526071834587.post-50907098361247321812020-02-17T06:11:06.006-08:002020-02-17T06:11:06.006-08:00Hey Oskar, thanks for catching that--it's fixe...Hey Oskar, thanks for catching that--it's fixed now!Steve Voigthttps://www.blogger.com/profile/00682651791126328242noreply@blogger.comtag:blogger.com,1999:blog-313510526071834587.post-40190150679652228672020-02-16T23:56:00.480-08:002020-02-16T23:56:00.480-08:00nice post Steve. But in the line "The last th...nice post Steve. But in the line "The last thing we need ...", shouldnt it be "resultant angle" instead of sightline angle?Oskarhttps://www.blogger.com/profile/01235541310554319976noreply@blogger.com