Round Timber Layout

Hey Kids -- I have a client who wants to have a number of round posts in his new house. These would be peeled logs, two stories tall with rectangular connecting timbers coming in at all four points of the compass at various heights. Of course - these posts will taper from bottom to top, might not be completely straight and will certainly not be "round". Any tricks or tips to establish a plane of reference and layout accurate housings and mortises without tearing out the few remaining hairs on my already balding head ?

Thanks !

Micheal,

Check out Will Beemer's articles in Timber Framing from a few years back on scribing. But the quick answer would be to snap level and plumb reference planes on the logs, set up a level (or even plumb) scribing assembly, and use plumb bobs, lasers, and super fancy level scribes to transfer the intersections.

Brad

Michael -

TW has it there, though square to round is a good way to cut your teeth on round work, and new layout tooling can be kept to a minimum – Trammels on a beam with a bullseye type bubble, to tic off the four corners is really all you need. Situating and stabilizing the layup is perhaps the bigger challenge

I'm just home from a long road gig, to an evaporated project and a hole in my schedule and would be happy to help if the project comes together. Zap me a line and I'll try to help in estimating it if you like.

Thanks for the comments. I'm having trouble finding which TF issues Will's articles were in - Does anybody know offhand ? I'm thinking of attaching 20" x 20" plywood squares to each end of the log and running string lines or maybe a couple of LVLs between these squares to create a reference "box" around the timber to layout from. Anybody tried this approach before, or am I making this more complicated then it should really be ?

Thanks as always --

builders laser for striking horizontal lines and leveling / centering end to end, set of horses that can be shimmed and leveled from end to end. plumb line or level, a smooth floor to strike center an layout lines to 'loft' onto the logs. a plywood box that can be strapped to the log to act as a base for router / layout / chain mortiser / etc. flexible rules and discarded metal strapping also come in handy.

applying ply to the ends will require you to level the timber and accurately square cut the ends prior to any further layout... you can also just use sticks screwed to centerlines on each end as required.

Michael,
The index to issues 1-90 of Timber Framing can be downloaded at http://www.tfguild.org/pubpg.html.
My scribing articles are in issues 76, 77 & 78.
You don't need to use the plywood squares method if you use lasers or Will T's system for layout.

Thanks for the great suggestions and guidance. I've ordered issues 76 and 77, also 41 which has an article on rectangular beam to round post layout. Have to say I've looked for that index before and really needed to study the publications page this time to find the link to it.

The Guild is out of issue 78 - can somebody photocopy the article and mail it to me. Happy to send you some $ and buy you a beer in Quebec next October.

Thanks !

Michael:
I have that article and can scan it in tomorrow.
Jim Rogers

I have not read these articles that mentioned, but I am assuming that they are a version of snap-line square-rule. This is basically the same layout for hewing a log square except, instead of the cross section and snap-lines marking the edges of the timber one is marking the center lines.
These center lines are also the plumb lines. This allows one to use tapered round posts as all measurements will be based off these center/plumb lines.
As for the square timbers that intersect the round posts, keep the ends square/plumb and house them into the round posts. The hard part will be keeping the back of the housings plumb. This can be done with a router equipped with an extended base (24-30"x8-12" piece of plywood reinforced with batten strips), which will ride along two boards wider then the radius of the round timber at that point of the housing. The edge of these boards should run along the center/plumb lines. This setup allows the router base to "hover" over the round timber. One may need to shim these boards to keep them square to each other and not tilt in on the round logs. These "batter boards?" are similar to the box, but are adjustable for different log thicknesses.

I am not sure if this is a good explanation, and I am sure there will be questions, but hopefully it helps.

Thanks Jim -- Will B. sent me the article today.

Ok, so good luck with that....

I'm surprised to see no-one mention the use of a modified bubble scribe for scribing round timbers. I've seen ones that were made up custom by a machine shop for just such a purpose, as well as the joinery produced by such a device, which is impressive. Its basically a log cabin scribe with a x/y bubble level on the axis point. The level can be moved depending upon the position of the scribe. One arm of the scribe is fixed-- like any scribe-- while the other has a trammel that rotates in two axes around an eccentric swivel. I'm probably making it sound way more complicated than it is, but the idea is that you rotate the moving trammel to follow the contour of the round log. Not sure how widely available they are.

I've used a set that was an improved version of the Big Timberworks scribe. It works well, but requires patience.

Hi Michael,

It seems that we are doing almost the same thing. I am attaching square posts to round beams. I am having difficulty doing this. I went to the link you have mentioned but I am unable to find the articles you mention. Would you be able to scan/mail them to me?

Thanks!

This is part 2 of that whole discussion --

http://www.tfguild.org/forums/ubbthreads.php?ubb=showflat&Number=25609#Post25609

Best of luck !