Building an octagon table (or topper)

[The Modfather]

Ok, so I have a REALLY stupid question that I cannot figure out. I have searched Google, various poker sites, and here in the forum - so I'm hoping that SOMEONE can help me out.

Here is my question:

I would like to know the formula for figuring out how to create an equilateral octagon. That is to say, if I have a 60" x 60" piece of wood, how much do I have to shave off of the corners to make sure all 8 sides are "equal"?

In reality, I have a 48" x 48" piece of MDF that I'm lookin to cut up and wrap.

Any help would be greatly appreciated.

Thanks!

[The Modfather]

Ahh....my friends " Whatsisname" and "Mathlete" helped me to figure this out.

Sorry for the thread. Mods can close it.

[mindgame]

NOT a stupid question at all, I think.
I’m not going to explain how to derive all this, but here’s what you need to know:

You start with a SQUARE sheet of plywood with a side of length S. The octagon which you’ll make by cutting off the four corners of the plywood will have 8 equals sides each of length = S x (0.4142). To lay out the board you will make a mark S x (0.2929) in from each corner (that’s [S – 0.4142S] / 2 = 0.5858S/2 = 0.2929S). The easiest way to find those marks, though, is to draw the diagonals across your square. They intersect right in the middle of your sheet. Draw a circle with its center on those diagonals and it will intersect the edge of the board at the points you need. The circle will have radius of S x 0.5412.

Now let’s talk about your 48 x 48 sheet. That circle will have a radius equal 25.977â€Â

[The Modfather]

NOT a stupid question at all, I think.

Thanks for the reply, mindgame. I am a noob to the whole poker scene, so I kind of thought it was a dumb question, even though I couldn't find the answer ANYWHERE!

Anyhow, as I stated earlier, my buddies gave me a couple of different solutions. I won't get into details, but I will post the pix that they made for me so others can get an idea. They REALLY helped me out.

Here is the first solution. Please note that edge/1+(sqrt2) is very close to edge/2.414 (In my case, 48/2.414, or 19.88" each side)


Here is the 2nd (and in my opinion, way more creative) solution. I'll let the pic do all the talking.



Thanks for the help - I'm really looking forward to building this, and I will post pix when I'm done!

[mindgame]

Well I have no idea how anyone can post a sketch here, and if I did I'd have posted a drawing for you, but the answer's the same...your edge is 19.88 which is 19 7/8 (=19.875).

Using the circle might be easier, I 'm not sure. Whatever you do, don't use the layout from the lower drawing, as that would be a smaller octagon (and a royal pain to lay out).

[Silencer]

I did a circle table topper thing. Originally I had a more complex design with 2 "layers" with slots for sliding drawers in-between but I couldn't figure out how to make it hinge so I just used a basic flat design. It actually worked out pretty nice but the pictures don't show how cool it is.

It is 4ft diameter. Each half is actually two 1/4" semi-circles glued together (they were already cut for the original design) to make a solid 1/2" thick board. The top is red vinyl that I got a great deal on and has no padding underneath. The entire vinyl top is glued down with normal wood glue (which ironically enough MUCH stronger than the glues I tested which are designed for this type of thing).

It's also wrapped around the sides and stapled underneath. On the sides is some cheap brass nail strip looking thing. I think it makes the table look cheap in the photos but in real life it looks really nice.

http://unrealdev.net/images/temp/ptt1.jpg
http://unrealdev.net/images/temp/ptt2.jpg
http://unrealdev.net/images/temp/ptt3.jpg

As you can see the table top just folds up and over. Not much to it. I was worried the vinyl would rip or the glue wouldn't hold but it seems like it is working fine. You can also see the bottom which is a really nice black fleece attached with spray glue. The fleece for the bottom was actually the most expensive part of it but I had to get it because it was MUCH softer than any other material they had. If I wanted I could put the table upside down and use the bottom as a playing surface too Total cost was probably about $55.

[The Modfather]

I did a circle table topper thing.

Holy crap man! That thing looks very very nice! I currently have about 13 projects going on at once over here, so progress on my table is slow going. I have ordered a few different pieces of 21oz felt (in various colors) so I'm just wating for those to arrive. Damn the US Postal service