# Need help with cuts for a pyramid!

 Forum topic by pashley posted 03-18-2017 09:49 PM 1067 views 1 time favorited 17 replies
 pashley1044 posts in 3959 days 03-18-2017 09:49 PM Topic tags/keywords: pyramid Hi, I need help cutting a pyramid. I will be using ⅜” stock. Here are the measurements of the pyramid when finished: The rise is 2”, and it’s a square at 9 ⅜” It will be mounted to a board. My questions are: What are the blade angles for the miter joints, and the joint that will meet that board at the base? Any other info is greatly welcome! -- Have a blessed day! http://newmissionworkshop.com

## 17 replies so far

 0002859 posts in 1141 days #1 posted 03-19-2017 01:01 AM 47.4 miter16.1 bevel 66.9 bevel at base 0002859 posts in 1141 days #2 posted 03-19-2017 02:24 AM Correction:47.4 is the angle of the triangle piece, the slide saw would actually be set for 42.6Pretty sure the bevel is still 16.1…(or if the scale starts at 90 then it would be 73.9) firefighterontheside19635 posts in 2098 days #3 posted 03-19-2017 02:41 AM By my calculation, it’s a 23.1° angle of cut. You would have to stand your pieces up against the fence to make that angle. You will need 6 layers to get 2”. I’m thinking you glue 3 together that are 9 3/8 square. Then cut them. You probably need to use a sacrificial fence. After you cut that one, measure the short square on top and glue three more layers together that are that size. Now cut them at the same angle. That should make a pyramid that when set on the other one else, makes a pyramid that is 2” tall. -- Bill M. "People change, walnut doesn't" by Gene. pontic664 posts in 850 days #4 posted 03-19-2017 02:51 AM 9 3/8” base but the height of the actual triangle is more than 2” isn’t it? How do you get the true height? so you can calculate the angle. It’s been 30some years since I did any complex geometry.So how did you arrive at those angles? What steps? -- Illigitimii non carburundum sum firefighterontheside19635 posts in 2098 days #5 posted 03-19-2017 02:56 AM Rise over run. We know the rise is 2”. The run is half of the width at the base. I cheated and used a calculator to arrive at the angle, but otherwise it would have been tangents and cosines and the like. I too have forgotten how to use those. -- Bill M. "People change, walnut doesn't" by Gene. Lazyman2711 posts in 1629 days #6 posted 03-19-2017 03:41 AM If you drew that drawing in Sketchup, you can use the protractor tool to measure the angles. -- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way. 0002859 posts in 1141 days #7 posted 03-19-2017 03:53 AM waho6o98539 posts in 2819 days #8 posted 03-19-2017 04:08 AM 2 cool jbay, thanks runswithscissors2928 posts in 2267 days #9 posted 03-19-2017 04:08 AM So is this a solid block, or a hollow pyramid (with thin panels_? -- I admit to being an adrenaline junky; fortunately, I'm very easily frightened firefighterontheside19635 posts in 2098 days #10 posted 03-19-2017 11:55 AM Good point. I assumed solid because that’s the easiest way to make it. Now that you say that and I re read the post, I think it’s supposed to be thin panels. I’m no help with that. -- Bill M. "People change, walnut doesn't" by Gene. pashley1044 posts in 3959 days #11 posted 03-19-2017 12:40 PM Yes, this is ⅜” panels, glued up, not a solid block. -- Have a blessed day! http://newmissionworkshop.com htl4329 posts in 1401 days #12 posted 03-19-2017 03:11 PM Would it come out nicer cut solid, then veneer it, just a thought. -- An Index Of My Model making Blogs http://lumberjocks.com/htl/blog/116729 squazo120 posts in 1887 days #13 posted 03-21-2017 02:39 AM here is how I would figure it out I would cut an over sized triangle then on a table draw a line that is 4 3/16” long and at 90 degrees to that the 2” line then I would take a piece of scrap that is 3/8 thick and line it up on my lines and figure all the angles from there. transfer the angles to the over sized triangle and blamo. Im sure this was not much help but maybee you can get some ideas. 0002859 posts in 1141 days #14 posted 03-25-2017 04:56 PM * pashley1044 posts in 3959 days #15 posted 03-25-2017 05:38 PM Jbay, Please except my apology; I sincerely appreciate your help and thank you very much! -- Have a blessed day! http://newmissionworkshop.com

showing 1 through 15 of 17 replies