Saturday, May 11, 2013

No Comment #2 - Bandsawing the Tapered Octagon

Cutting the assembled tapered octagon was a lot of fun during this build because I got to use the bandsaw in a way I hadn't before.  Certainly a technique I'll be exploring more in future builds!

Basically, we built a sacrificial jig to hold the tapered octagon "spatially" in the correct orientation for the bandsaw blade to remove planes.  While we could have computed the compound cut at the top of each triangle for the octagon to get a level top, to do two more cuts on each triangle to then remove the part for the table top would have been a lot of error-prone work... any deviation in length would have to be sanded out later (end grain!).  Then add the work of triple the glue-up.  Cutting the plane on the bandsaw, especially with a smooth-cutting Laguna Resaw King, left nothing to sand (sure there were tool marks, but those surfaces were perfect for gluing in this project).

Ah, the mysterious holes in the jig are explained, too.  Had some questions about those :)

Do remember the design episode where I explained how the top part of the octagon changed.  Originally, I wanted the octagon to continue through the table so the top piece needed to be exactly positioned so Dominos could go through the octagon top, the table, and into the octagon bottom.  In the video flashback, I explain that cut that ultimately we didn't keep (but did use).

However, properly cutting off that top piece does have an importance that we'll see in a future episode on the assembly.  As a spoiler, I'll tell you :)  That top piece was used as a template for where the Domino holes in the table top were needed in order to get them to go smoothly into the octagon bottom.  Without that template, it would have been long and messy to position those Dominos; with that template, it was as simple as tracing the revealed mortises.  But you'll see that in more close-up detail in the assembly episode.

I think the next episode will be another bandsaw episode; editing all this old footage with some new narration mixed in has me busy in the video editor, not in the shop.  Not a good thing.  The next planned episode will at least have me running a tool or two!

Here's a link to the video for my email subscribers: