Any interest in helping design plans for a three sided plant pyramid?

[barrysumpter]

Triolife Plant Pyramid | Urban Zeal Planters (http://www.uzplanters.com/products/triolife-plant-pyramid)

Can't seem to find one here.

But would love to have a fair go at building it myself.

Anyone interested in designing one for me with the cut angles etc. ?

[barrysumpter]

Compound Miter Saw Calculator (http://jansson.us/jcompound.html)

[barrysumpter]

https://www.youtube.com/watch?v=7aujpCKeuYw

https://en.wikipedia.org/wiki/Tetrahedron

[barrysumpter]

https://www.youtube.com/watch?v=Kz3OpsgDiz0
Cube, Tetrahedron, Octahedron, in Google SketchUp

[barrysumpter]

369217 369218 369219 369220 369221

369222

[barrysumpter]

369225

[barrysumpter]

(apex) height of a tetrahedron

height h = (√6/3)a where a = length of an edge
so height equals square root of 6 devided by 3 times length of an edge
h = .816 * a

a = 1.5
.816 * 1.5 = 1.22

[barrysumpter]

3 Shelf - 35"L x 35"W x 24"H = 90cm L x 90cm W x 61 cm H
5 Shelf - 47"L x 47"W x 47"H = 120cm L x 120cm W x 120cm H
7 Shelf - 59"L x 59"W x 59"H = 150cm L x 150cm W x 150cm H

[barrysumpter]

369640

[barrysumpter]

369641

[barrysumpter]

Compound Angle Calculator ::: Mitered and Butted Joints (http://www.pdxtex.com/canoe/compound.htm)

Compound Angle Calculators

Compound Mitre (values in degrees)
Slope: 60
Included Angle: 3 Sides

Resulte:
End Angle: 90
Bevel Angle: 60

====================================
Calculate Slope
Slope (degrees): 60
====================================
Compound Angle -- Butted Joint (in Degrees)
Slope A: 60
Slope B: 60
Included Angle: 3 Sides

Results
Side A end angle: 90
Side B end angle: 90
Bevel angle: -30

=========================================

I really like these results as the are part of the mystery of 3,6 and 9.

I have no idea how to translate these into my drop saw Mitre angle and Bevel angle.

[billrule]

I thought you were going to get it all worked out yourself the way the thread was developing. I am probably no help, but I can't hep observing that not one of the angles that appear in the photos of the real thing are anything like 90Degrees, so I'm unsure of the "side-angle" parameter.

Since you know roughly how it should look, cut the 30 and 60 degrees from cardboard or scrap, and have a play setting the saw to match those angles in the two adjustable parameters (whatever you'd call them)

Cheers,

Bill

[barrysumpter]

Yes, thanks for the acknowledgement.
The 90° is for Butted-joints I think.


I've sorted out the 30° bevel left and right and the 60° Mitre angle left only.
My 909 12" 305mm double mitre sliding saw will only do a 60° on the left and 52.5° on the right.

So wishing I still had the Makita LS1216.

The first join was easy the next will have to be very accurate length wise as well.

[barrysumpter]

Compound Angle Calculator ::: Mitered and Butted Joints (http://www.pdxtex.com/canoe/compound.htm)

Compound Miter in degrees

Slope 60
Included angle 60 degrees or 3 sides

<calculate>
End angle 40.89
Bevel Angle 40.59


369944 369953 369952369951 369950 369949 369948 369947369946 369945 369943 369954

[barrysumpter]

For some reason I can edit my posts straight away.
And other times I can't.

I wanted to discuss the inaccuracies of my 909.
And setteling for what I make since its just for my back yard, etc.

My worry it that 1mm off on such a small version would be 10mm off on a version 10 times bigger.

And then wanted to discuss how to translate the angles rounded of the 41 and 49 and the limitations of the marked 45° bevel, etc.

Was trying to sort out the 30, 60 and 90 butted-joins but wanted to end the day on a positive note so stopped there.

[barrysumpter]

Just a reminder that I can sand down the joins that don't match perfectly.

TEST
(Edited by U-Beaut 10:55pm 31/01/2016)

[barrysumpter]

Hoping to get back into the project today. Will post more.

Edited successfully.

[barrysumpter]

If it's not too much trouble, could we please move this thread to an appropriate forum?

Thanks in advance.

[Big Shed]

Done

[artme]

Interesting posts Barry. :2tsup::2tsup::2tsup:

When my present slack attitude abates I will have a closer look........
and maybe do something!:rolleyes:

[rrich]

Yes, I will just stand here and catch all the spears. This has been a sore point all my life.

A pyramid has FOUR sides, one square and the other four triangles. The triangular sides of a "Regular" pyramid are also equilateral triangles. (i.e. All three sides are equal in length to the side of the square. BTW - The angles are 90° for the square and 60° for the triangles.) The isosceles triangles maybe substituted for the equilateral triangles where the base must be equal to the side of the square.

A tetrahedron has FOUR sides, all of which are triangles. While I've never seen an irregular tetrahedron, I think that it is possible. A regular tetrahedron has four sides of equilateral triangles and all angles are 60°.

[barrysumpter]

Hi Rich,

Yes, I agree with your definitions.
What do you call the pyramids of Giza where the four side are each angled inwards (concaved) vertically?

I'm pretty sure they call their product a "pyramid" and not "tetrahedron" to attract buyers.

I'm pretty sure whoever built the pyramids chose the four sides to support such a huge weight.
Otherwise they would have chosen a tetrahedron.
As its just so much more eloquent.


If you've had spears chucked at you all your life you should be very good at dodging. :U

[justonething]

Hi Barry
Haven't followed your project exactly and I'm not sure if I understand the web site or agree with their calculation. One thing for sure the corner angle is 60 degree, if you set your mitre angle to say 30 deg then the bevel angle to set is tan-1(1/(tan(corner angle /2 ) * cos(mitre angle))). e.g. the bevel angle to set on the saw is tan-1(1/0.5) = tan -1(2) = 63.4 degree. I hope that makes sense. Have you thought how you are going to clamp the pieces together.

[barrysumpter]

At the bottom of one or both of those web pages is his explaination and formula.

I feel like his calcs are correct for what I was wanting.

One of the posts I made with a bunch of pics wouldn't allow me to edit at the time ( in the plans - no edits forum ) to correct the numbers I posted. But the pic of the web page in that post does have the correct numbers.

[barrysumpter]

How about spotted gum?

Masters on sale for 8.50 / lm 135x19

[barrysumpter]

Pretty much have decided to use the Facia 190 x 30 Prime Treated Pine.
Primed Treated Pine Facia 190mm X 30mm X 5 4M $7 80 LM in VIC | eBay (http://www.ebay.com.au/itm/Primed-Treated-Pine-Facia-190mm-x-30mm-x-5-4m-7-80-lm-/191516983673?hash=item2c974d4179:g:cPQAAOxyLN9Skpgn)

Any suggestions on what color to paint or should I leave it unpainted?

[barrysumpter]

Finished!

Undercoat and overcoat paint left over from house painting.



376139 376141 376140 376138

[Christos]

Nice.

[Lappa]

Love the perseverance :U Well done

[barrysumpter]

Just a reminder that I can sand down the joins that don't match perfectly.

TEST
(Edited by U-Beaut 10:55pm 31/01/2016)


Sanding Not needed if your mitre saw is setup correctly.