Mailbox post help?

[Bill Cooper]

I'm wanting to replicate the mailbox post in the link below, but I can't figure out how the octagon top part is cut out. What's throwing me is the square sides of the post appear to have a shorter taper than the angles that make the octagon. A true eight point octagon should all meet at the same line. I am hoping someone here with better eyes or know how could tell me what they see and how to proceed. Thanks in advance!

http://tinyurl.com/payctbz

[John TenEyck]

It looks like the octagon cuts extend down into the lower post. But the post is four sided and the base of the octagon is sized such that the cuts only intersect the lower post on the four corners. Hope that helps.

John

[lowell holmes]

I would get a 4x4 and a spokeshave or a draw knife and whittle a prototype.

It probably will reveal itself as you work.

[Myk Rian]

You'll be making cuts twice. The first with the TS blade at 90º and the second at 45º.
A jig to hold the post at the proper angle will have to be made. Practice it on scrap.
It's a nice idea for a mailbox.

[Loren Woirhaye]

I have seen this picture before in a thread on another forum. As I recall the consensus was that the material could be hogged off but for a one-off the final faceting should probably be done by hand in order to bring the lines together.

[John T Barker]

Depending on your machines to use I would make a pair of jigs, one that holds the post with its facets flat to the table and one to hold on the 45. I've done pencil post beds that way and the ideal, and most expensive probably, is a straight cut shaper cutter with a bearing at the the bottom.

[Yonak Hawkins]

Somehow this mailbox post reminds me of the White Sox's recent "Rain Poncho Night" promotion. < : )

[Bill Cooper]

It looks like the octagon cuts extend down into the lower post. But the post is four sided and the base of the octagon is sized such that the cuts only intersect the lower post on the four corners. Hope that helps.

John

That is what it looks like to me as well, and that is the part I am grappling with. As others have already suggested, I did play around with this on a piece of scrap lumber yesterday and cannot figure out how to get the deep cuts on the octagon below the notch and maintain a flat face on the square sides as pictured. I am beginning to believe the top is actually a twelve sided polygon or perhaps round, but my old eyes just can't make out the detail on a computer monitor. Thanks!

[Mike Cozad]

To zoom in on the picture enough to really see the detail it becomes quite pixelated. I opened it on my tablet and used a magnifying glass and it helped. The wizard's cap top actually appears to be 12 sided rather than 8. Too bad there isn't another view or pic with a higher resolution available....

[Lonnie Gallaher]

It took me several tries, but I got a good model of the post. As all have surmised, it is a 4 sided post with an octagonal point.

This is how I modeled it.

I turned the groove in the square post.

Looking at one face of the post I cut from the center line at the top of the post to the top edge of the groove. Make this intersection at the center line of the face of the post not to the corner.

Turn the post 90 degs and perform the same cut as on the first face.

Cut all four faces so that there is a four sided point.

Now turn the post 45 degs and make a cut that is the same angle as the first cuts. In my model this cut was about 9 degrees off of the center line of the post.

Turn the post 90 degrees and perform the same cut at each of the corners

The cuts along the faces of the post will end at the top of the groove, but the cuts at the corners will cut down past the groove creating the facet at the corners. This is because the post is wider across the corners than across the flats.

I hope this helps.

I uploaded a interactive pdf file. It can be down loaded and opened in adobe reader.

[Bill Cooper]

It took me several tries, but I got a good model of the post. As all have surmised, it is a 4 sided post with an octagonal point.

This is how I modeled it.

I turned the groove in the square post.

Looking at one face of the post I cut from the center line at the top of the post to the top edge of the groove. Make this intersection at the center line of the face of the post not to the corner.

Turn the post 90 degs and perform the same cut as on the first face.

Cut all four faces so that there is a four sided point.

Now turn the post 45 degs and make a cut that is the same angle as the first cuts. In my model this cut was about 9 degrees off of the center line of the post.

Turn the post 90 degrees and perform the same cut at each of the corners

The cuts along the faces of the post will end at the top of the groove, but the cuts at the corners will cut down past the groove creating the facet at the corners. This is because the post is wider across the corners than across the flats.

I hope this helps.

I uploaded a interactive pdf file. It can be down loaded and opened in adobe reader.

This helped immensely! My sincere thanks for taking the time to put forth such effort and detail on my behalf. It is very much appreciated.

[Lonnie Gallaher]

Bill,

It was a pleasure to help.

[Bill Cooper]

Bill,

It was a pleasure to help.

I did a dry run yesterday afternoon, and after scaling the photo and transferring the measurements to the stock and some slight adjusting, it came out mirroring the photo I posted. Once again, thank you!

For anyone who may be interested, the measurement from the mailbox support to the point at the top worked out to be 38" with the octagon cut extending 28" from the top point to the bottom where it feathers out into the square stock. The center of the 2 1/2" groove is 22" up from the mailbox support and 16" down from the top point. The facets are 2 1/4".

I would like to thank everyone who responded. I am very grateful.