Towers B/C

[reed303]

Are there any common objects that have a 29 cm diameter?

The 29 cm circle will be very close to the corners of the 20 cm square opening, as depicted in the drawing at
https://www.soinc.org/sites/default/fil ... t_Base.pdf

If you calculate the diagonal distance across the 20 cm square opening, it will be 28.284 cm. That only leaves 7.16 mm from the 29cm diameter of the bonus circle. Or 3.58 mm in from each corner of the 20 cm opening.

[Unome]

Are there any common objects that have a 29 cm diameter?

The 29 cm circle will be very close to the corners of the 20 cm square opening, as depicted in the drawing at
https://www.soinc.org/sites/default/fil ... t_Base.pdf

If you calculate the diagonal distance across the 20 cm square opening, it will be 28.284 cm. That only leaves 7.16 mm from the 29cm diameter of the bonus circle. Or 3.58 mm in from each corner of the 20 cm opening.

True, but that doesn't help us draw the circle unless we have an object (since we can't really balance a compass in the center of an already-made hole).

[retired1]

True, the minimum chord will be about 21 cm for the 29 cm circle.
If I remember correctly, the min distance last year to span the hole corner wise was 15 cm.
21 vs 15 is a huge difference and thus the bonus.

[reed303]

Are there any common objects that have a 29 cm diameter?

The 29 cm circle will be very close to the corners of the 20 cm square opening, as depicted in the drawing at
https://www.soinc.org/sites/default/fil ... t_Base.pdf

If you calculate the diagonal distance across the 20 cm square opening, it will be 28.284 cm. That only leaves 7.16 mm from the 29cm diameter of the bonus circle. Or 3.58 mm in from each corner of the 20 cm opening.

True, but that doesn't help us draw the circle unless we have an object (since we can't really balance a compass in the center of an already-made hole).

Maybe draw the circle on paper or cardboard, cut out the circle, place it over opening, then mark the circle on the base ??

[Unome]

The 29 cm circle will be very close to the corners of the 20 cm square opening, as depicted in the drawing at
https://www.soinc.org/sites/default/fil ... t_Base.pdf

If you calculate the diagonal distance across the 20 cm square opening, it will be 28.284 cm. That only leaves 7.16 mm from the 29cm diameter of the bonus circle. Or 3.58 mm in from each corner of the 20 cm opening.

True, but that doesn't help us draw the circle unless we have an object (since we can't really balance a compass in the center of an already-made hole).

Maybe draw the circle on paper or cardboard, cut out the circle, place it over opening, then mark the circle on the base ??

Maybe print it out on two pieces of paper ad align it over the hole?

[retired1]

For drawing your circle on an existing stand, get a piece of cardboard. draw the 29 cm dia circle, cut it out , place it on the board and trace your circle. Note, it does not have to line up perfectly.
Alternatively, cut a 20 cm sq board and tape it in the hole of the stand. Draw your diagonals and you can now use your compass to draw the circle.

[Balsa Man]

Mmmm…, the diagonal of a 20cm square is the square root of 20 squared + 20 squared; sqrt of 800 = 28.28427. That’s 0.71573 cm less than 29.0 cm. So, splitting that, a 29cm diameter circle, with center aligned with center of a 20cm square will be outside the corners of the square by 0.357864 cm (say 3.6mm. So, if you set the insides of the legs say 6mm out from the corners of the 20cm square, your legs will be outside the circle by 2.4mm, a good working clearance….

[parthpatel612]

What would be a better design as far as orientation of Z bracings go? Tower A or Tower B? I have not seen a post on this in past year posts yet.
(Sorry for the terrible quality, it was made on paint)
(Red are vertical beams, black are bracings)

Bracings.jpg

[retired1]

Try both to be sure. My thought is that b is better as it will be more effective against twisting. (axiel movement).
Your diagram shows a pure rectangular tower. It should be angled to get the top to a desired size of 5 cm or less.

[baker]

How is the rule written?... Base must span 29 cm circle, It must be a minimum of 29 cm circle...?