A rather simple and solid accurate project, with flattened 180 degree pole sections for blade position reference by feel of thumbs and fingers, edges being 90 degrees to flattened sections on pole. Mine has an Arms and Armor 12th Century spear at one end and a Windlass Viking Hewing spear at the other. Overall length is 89 7/8 inches tip to tip and exposed ash pole is 54 1/2 inches.
First to hone ends use a ruler from 45 degree increments to find the exact center of pole ends, mark with pencil then awl or shallow narrow drilling use narrow straight object to insert into pole housing, mark depth with pencil at outer rim of housing onto object. Transfer at 45 degree increments onto pole ends with pencil and score into wood. As a reference to said housing dimensions, spray inside with WD40, insert narrow object with small internal bend and 90 degree outer bend . Upright melt wax until filled to brim, let cool and Extract. Honing ends must be accurate and straight. Or speartips will be off center. Use wax molding as honing guide. Before mounting and having cleaned out the oil use hotmelt inside housing, insert pole ends so that both spear edges are. Horizontally exacting to one another, this is crucial! Cut 2 1/8th" thick nails 1/4" longer than total depth at 1/2 to 3/4" centerpoint from housing rim. Drill holes completely through exacting to rivet size. Have flat steel on floor ready for Nail head side. Hold nail with pliars handles wrapped with heat resistant material, get tip at least near red hot, insert, pound through, position nail head on prepared flat. Steel and with heavy hammer pound flat.
On pole 180 degrees draw line down length of pole then scribe same, these need to be 90 degrees to blade edges. Gradually flatten these two sections until 1/2 to 3/4" wide. Smooth with rasp, file and flat substrate mounted sandpaper. Coat pole with lemon oil.

Bob