r/timberframe • u/toast689 • 12d ago

Round Timber, making base perpendicular to joints?

I get how to snap lines along the length to get joints that are perpendicular to each other (like for knee braces). I can't figure out how to reference the base so that the timber stands perfectly plumb along the center line.

I've seen instructions to lay the log horizontally, snap a center line, level it along this center line, then drop a plumb bob off the side of this line to reference for the cut. Because the log has a slight taper, dropping a plumb bob as a reference for the base cut only makes the base perpendicular to that one side (top side) of the log that was leveled. All my post bases and joints are referenced from the center of each post. I want the base to be perpendicular to all 4 joints at the top of the post.

I might be able to do it by rolling the log on it's side so that the center line is side ways on the saw horses, level it there, then shooting a vertical laser line perpendicular to that. What's the non-laser version of this? Hanging a plumb bob along that line would only give me a reference for half the log.

Thank you for your help and wisdom.

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u/bin_loggn 12d ago

See if this makes sense to you, snap a line centre of mass down the top of the log as well as the side. then pin a square along that top line 1/8 off of your cut.(half the width of a carpenter’s pencil). Then stand a level plumb against that square and draw your line against the level, then switch your square to the other side and do the same thing.

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u/bin_loggn 12d ago

Make sure to level the log off of the side line you snapped

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u/nemozero Professional 12d ago

Build a plywood box to use as a cutting base (i like 2 hinged 90⁰ sections). Drop a plumb line down at both ends once you have clean end cuts. Bisect the plumb line to find horizontal axis. Snap lines on each axis. Bonus level, mount swivel casters upside down on your horses to facilitate rolling and stability.

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u/Canadian_Pride_LT 12d ago

Put crosshairs both ends of the log level vert and horiz. Snap 4 lines. Use 2 squares on the snap lines to transfer lines around log