Re: [MedievalSawdust] Cutting octagonals on a slope
- If you have assess to a good library there is an article in Wooden Boat
#91 on mast building that includes a very simple tool to scribe accurate
lines for octagonalizing a timber. The relevant couple of sentances are
Start by taking the mast from a rectangular to an octagonal section.
For our mast we made a set of simple marking gauges from scraps of 3/4x1
1/2 lumber, with finish nails for the guide pins and scribers. In use,
the gauges are held diagonally across the mast, the guide pins
determining the angle. As this angle changes with the dimensions of the
mast, the gauge automatically divides the face into the correct
proportions for the octagonal section. The circular saw was used to
rough out the octagonal shape. Be careful here - make sure you don't
stray inside the guidelines. The jointer plane is ideal for completing
this stage accurately.
I don't know if I can do an accurate drawing but it looks something like
l Scrap lumber
l l l
l short internal nails are the scribers
l long external nails are the guide pins
a b c
Hope that helps. If necessary I can scan and send the two pages from
that article about it.
jay sabath wrote:
> Consider using a band saw with a tapering jig. Cut each of the tapers
> but do NOT cut all the way through. leave some room at the bottom and
> shut off the saw and pull the piece off and give it a turn If you
> leave about 1/2 an inch still connected you still have a complete
> thickness at both ends of the piece which should allow it to be solid
> in the jig.
> You can then cut through the rest of the way with a tool of choice or
> if you start with the piece about 1 inch longer, you can very
> carefully cut off that last inch with a power miter / chop saw.
> Please work out any problems out on a test piece first. And let us
> know how which ever idea you use works out.
> Johannes Machiavelli
> On Dec 2, 2007 9:17 PM, Rhys Terafan Greydragon <
> terafan@... <mailto:terafan@...>> wrote:
> Greetings all,
> I am hoping someone knows a good trick for "octagonalizing" a
> sloped piece of wood.
> I have a 3 x 3 that is sloped on all 4 sides down to 1.5 x
> 1.5... (that is what I want).
> What I now want to do is octagonalize it so all 8 sides are even
> and all narrow down evenly from the big end to the small end.
> Anyone have any tips, tricks, or good ideas??
> I can do it with a drawknife and a spokeshave, but I am looking
> for a power-tool-method...
> Master Rhys Terafan Greydragon terafan@...
> Brewer, Tent and Furniture maker, and other things I can't
> Lord Johannes Machiavelli
> Shire of Rokkehealden
> Kingdom of the Middle