How to design a 4 sided fire pit
-
- 1 Star Member
- Posts: 16
- Joined: Tue Nov 01, 2022 8:52 pm
How to design a 4 sided fire pit
I am wanting to design a fire pit in fusion 360 with a square center section and 4 trapezoid sides. For the life of me I cannot remember what the math is that I need to do to calculate the angle and dimensions of each side so that when I put each side in place and lift them up to my desired "Depth" that they all fit evenly.
-
- 6 Star Elite Contributing Member
- Posts: 8706
- Joined: Thu Sep 21, 2017 5:22 pm
- Location: Tucson, Arizona
- Contact:
Re: How to design a 4 sided fire pit
If you draw your bottom and top, then you can loft it to create the sides. What are the dimensions of the top, bottom and distance between the top and bottom?
David
David
-
- 1 Star Member
- Posts: 16
- Joined: Tue Nov 01, 2022 8:52 pm
Re: How to design a 4 sided fire pit
I don't have any particular dimensions in mind, I am just looking to start drawing something to practice
-
- 6 Star Elite Contributing Member
- Posts: 8706
- Joined: Thu Sep 21, 2017 5:22 pm
- Location: Tucson, Arizona
- Contact:
Re: How to design a 4 sided fire pit
I'll be back later this evening to elaborate. Are you after a solid model or just the flat pieces to cut?
David
David
-
- 1 Star Member
- Posts: 16
- Joined: Tue Nov 01, 2022 8:52 pm
Re: How to design a 4 sided fire pit
I put in some random measurments and was able to create the loft, now how do I "break" apart the loft so that i just have the individual sides?
-
- 6 Star Elite Contributing Member
- Posts: 8706
- Joined: Thu Sep 21, 2017 5:22 pm
- Location: Tucson, Arizona
- Contact:
Re: How to design a 4 sided fire pit
I don't know of any way to "break apart" the solid model from the loft. But here is one way to come up with the sides. In this case the model was created from 2 squares of different sizes. Bottom square is 27" x 27", and top square is 36" x 36". The loft distance is 15". Construct a new sketch on one of the side faces duplicating the dimensions of the face. Then either export the sketched face as dxf or extrude to material thickness (1/4"), switch to Manufacture mode, and create cut path and post process to create G-code file to cut part. Your process will depend on which programs you have available to use.
There was a slightly more elegant method posted a while back by one of the other members where he projected the face of the solid model onto a newly constructed plane and then exported the dxf from that sketch. Unfortunately it wasn't posted in the Autodesk AutoCAD & Fusion 360 section of the forum, so I don't remember exactly where the thread is located.
David
There was a slightly more elegant method posted a while back by one of the other members where he projected the face of the solid model onto a newly constructed plane and then exported the dxf from that sketch. Unfortunately it wasn't posted in the Autodesk AutoCAD & Fusion 360 section of the forum, so I don't remember exactly where the thread is located.
David
Last edited by adbuch on Thu Feb 02, 2023 1:38 am, edited 1 time in total.
-
- 1 Star Member
- Posts: 16
- Joined: Tue Nov 01, 2022 8:52 pm
Re: How to design a 4 sided fire pit
This is exactly what I was looking for! Really appreciate the help!!
-
- 1 Star Member
- Posts: 10
- Joined: Mon Jul 06, 2020 11:07 pm
- Location: Woodland PA
Re: How to design a 4 sided fire pit
You dont need math to figure out the angles. If I want to make a firepit that flares out at the top, I make the top 4" longer than the bottom measurement 2" per side) usually comes out to 15 degrees. Or you can just pick an angle you want the side to flare out. Then make the top measurement to fit that angle.
-
- 6 Star Elite Contributing Member
- Posts: 8706
- Joined: Thu Sep 21, 2017 5:22 pm
- Location: Tucson, Arizona
- Contact:
Re: How to design a 4 sided fire pit
There was no math involved in the method I described above. In fact, I don't even know what the angles were - although they are easy enough to measure. The angles were automatically determined by specifying the bottom and top sizes, and then the distance between the top and bottom. Fusion 360 did the rest. In your example with the top 4 inches longer that the bottom, the angles will be dictated by the distance between the top and bottom. If a specific angle was required, then either the sizes of the top and bottom and/or the distance between then could be adjusted to create the specified angle. In any case, I certainly agree that there is usually more than one way to skin a cat - as they say.
David
David
-
- 6 Star Elite Contributing Member
- Posts: 8706
- Joined: Thu Sep 21, 2017 5:22 pm
- Location: Tucson, Arizona
- Contact:
Re: How to design a 4 sided fire pit
I just checked the dxf file and it turns out that for this particular fire pit drawing the angle is 16 degrees. So pretty close to your 15 degree typical measurement.
David
David