# Need help with cuts for a pyramid!

 Forum topic by pashley posted 03-18-2017 09:49 PM 973 views 1 time favorited 17 replies
 pashley1044 posts in 3797 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

 jbay2485 posts in 979 days #1 posted 03-19-2017 01:01 AM 47.4 miter16.1 bevel 66.9 bevel at base jbay2485 posts in 979 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) firefighterontheside18657 posts in 1936 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. pontic622 posts in 688 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 firefighterontheside18657 posts in 1936 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. Lazyman2261 posts in 1467 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. jbay2485 posts in 979 days #7 posted 03-19-2017 03:53 AM waho6o98288 posts in 2657 days #8 posted 03-19-2017 04:08 AM 2 cool jbay, thanks runswithscissors2802 posts in 2105 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 firefighterontheside18657 posts in 1936 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 3797 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 htl3997 posts in 1239 days #12 posted 03-19-2017 03:11 PM Would it come out nicer cut solid, then veneer it, just a thought. -- Learn More About Making Wooden Models. An Index Of My Model making Blogs. http://lumberjocks.com/htl/blog/116729 squazo78 posts in 1725 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. jbay2485 posts in 979 days #14 posted 03-25-2017 04:56 PM * pashley1044 posts in 3797 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

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