Need Ideas for Timber Frame Jigs

[jander3]

Anyone have photos of drawings of jigs for speeding up the timber framing process?   Specifically, I would like to make up a jig that can be used to quickly layout the peg holes.  I was wondering what others have used.   

[Brad_bb]

One of the most useful fixtures for laying out mortises, especially for nicely milled material, is the Borneman layout template available from the Guild store:
http://tfguild.stores.yahoo.net/bolate.html

In addition, there's the story stick technique that Rooster demonstrated.  I had not used that technique before, but will now.  That's a fast way of laying out marks and checking your layout to be consistent.

Peg holes are easy and don't really have to be quite as precise as mortise and tenon layout Provided that you are boring those holes while setting up for the raising, thus not allowing shrinkage in between boring and actual assembly.  If you were repeating the same measurement on a frame, you could easily make a marking gage of your own from wood if desired.  But I've never seen any type of marking gage sold for this.

Peg hole boring typically goes like this:  Mark the location and bore through the mortise only, both sides.  Then insert the tenon of the mating member, making sure they are  seated up against each other properly.  Then mark the hole center on the tenon.  Then remove the tenon and mark the offset to that center mark if draw boring and bore the tenon, being careful not to blow out the backside.  When you poke the tip through, flip it and bore back to get a clean hole.  If you are not draw boring, you can bore the tenon while inserted in the mortise.  I like draw boring myself, even if slightly in seasoned material, to make sure everything draws tight together.

I like boring holes with a boring machine to assure that the holes are perpendicular to the surface.  You can use a bit and brace too, though you could bore a little off perpendicular if you're not careful, though it's often of little consequence if you are draw boring and you are fitting everything right there.  Same can be said for a drill and auger bit.

I would bore peg holes when I assemble the bent for raising, or when doing a fit up of other members just prior to raising.  Some elect to bore some of the other brace pegs or girt pegs after the raising and everything is pulled tight together with come-alongs.  I guess that depends on how easy it is to do it once raised.

[shinnlinger]

I think those layout tools are called "Big Al" if an internet search is in order, $115 seems a bit much to me, but I have never used one. A good ol' fashioned framing square has always done it for me

Brad hit on this, peg locations aren't as critical as other aspects of the frame, but if you want to be real precise I suppose a piece of plywood with some 2x on the edge(s) to reference the jig agains the timber would work.  I suppose you could also have some 2x 'on the top as a guide for just a regular old drill.

Good luck!

Dave

[Jim_Rogers]

Some time ago, I wrote a story about how to layout a brace and how to layout a brace mortise.
These stories may be here on the forum, but I’m not sure. I believe I’ve been saving them for some future project or articles in magazines.
Here is part of one of the stories that shows how to use standard tools to layout the locations of peg holes.
To get you caught up we have already cut the brace and are now getting ready to layout the peg hole on the brace tenon…..

……the clips from the story are underlined....

we need to figure out where to layout the peg hole on the tenon. We usually use standard layouts that have the hole 1 1/2" off the shoulder and 2" of the bearing end of the tenon.

This is easily done by using one of the most commonly used layout tools in the timber framers tool box, the framing square (see framing square story to identify which part of the framing square is named body and which is named tongue).

With the tongue of the framing square held against the shoulder and the body of the framing square held again the bearing end of the tenon you draw, with your pencil, two lines on the tenon, as shown below:



And then the second line:



Next you slide the square over and increase the length of these two lines, to create what is commonly called the "cross hairs" (+).







In the laying out of the brace mortise profile on the side of the timber we include the peg hole location.

Again from the story:

While your timber is lying with this face up you should complete your layout by locating the peg hole. To do this we use the “Big Al" layout tool as a square edge from the layout face arris, and butt the framing square body up against it. The “Big Al@ is in line with the 36" mark, so that the body of the framing square will automatically make one line of the peg hole location 2" off the bearing end surface. The tongue of the framing square is flush with the shoulder line of the housing so that the second line of the cross hair will be 1 1/2" off the shoulder. The same as the layout of the peg hole on the tenon.





So the ‘jig’ needed to layout most peg holes is just the regular framing square. And if you have one, which I recommend you have, a “Big Al”…..

If you're working in a shop that's one thing. You can make jigs and keep them there, hanging on the wall and such.
But if you're working in the field or on site, then you only want to bring "just" the "tools" you will need. Bringing all your "jigs" adds time and may not be necessary.

Keep it simple.......

Hope that helps…
Jim Rogers

[Brad_bb]

Great explanation as usual Jim!  I will clarify my previous statement in that brace peg hole location is more important due to the smaller area you are working with, and therefore more important to be correctly located.

[witterbound]

Some shops use a jig for cutting housings with a router.  Pretty sure that's how Clark (the timber frame sketchup guru) does it in his shop.  Seems like he might have posted some pictures over on the timber frame guild website.  He also had some kind of jig / platform he developed to cut the shoulders on braces on the bandsaw. 

[addicted]

Ben at frame1.org has some jigs that look good as well.
Rusty

[jander3]

Jim,

Thanks for the photo.  Exactly what I was looking for.  My wife got a Big Al for me for Christmas, man, does that tool save me some time.

Jon