Heartwood is adding a 5-day Cruck Framing course to its 2016 schedule from May 16–20; the frame will be similar to the one shown below built in 2011. Cruck frames use large “bookmatched” curved timbers to transfer the weight of the roof directly down to the foot of the posts. It is a traditional method found mainly in the Welsh Borderlands in Britain; here in Berkshire County we have more crucks than anywhere else in North America. They are quite beautiful with the arches soaring overhead, and exciting to build as the scribed crucks take shape.
For more information including a video of a previous class,
please visit our website here .
Instructors: Jack Sobon and Neil Godden
We urge you to register as soon as possible
for this course if you are interested.

Is it true, Jack has built so many cruck frames the Berkshires are starting to sink?

Is this a hand tool only workshop or will you also use some power tool?

Tim,
Haven't noticed any cruck creep yet. This cruck frame will be going to Vermont after we raise it at Heartwood, so we're spreading the load around.
All hand tools except for chainsawing. We will axe and hew or adze the curve on one of the cruck pairs and ties and then use a chainsaw jig to cut another pair, just so people can see both methods. The flat sides of the crucks and ties will be pre-sawn by a WoodMizer and then cleaned up with smoothing planes.

Thanks, Will. Perhaps, and evidently, Cruck Creep is horizontal not vertical, as this one is creeping into Vermont.

Have you see how a band saw can cut the inner and outer curves as well? It is tricky coming out of the curve or going into a rise cut, as the leading cutting edge of the band wants to cut straight but with careful attention it can be done on shallow curves. I feel it puts some stress on the band, I use an older band. The surface still needs a little hewing for aesthetic reasons. No jig here, free hand.

https://www.youtube.com/watch?v=I6NBYTBFDgM

Nice! Would probably use it if we had it. No hydraulics on our little LT10, although I might try it with just hand power. However, we also want the folks in the course to know how to do it with their own tools.

Hi Will,

I am trying to get one of my students to take your Cruck Framing course...I hope it works out.

We have cut many curved pieces on our band mill (Oscar 30") and it works great just as Tim has so brilliantly demonstrated. I have also done this on a manual Wood-Mizer, and Timber King.

With the saw running (and being very careful) I recommend "rounding" (an old boat builders trick when doing band saw work) the back edge of the blade. This seems to assist following the curve.

Tim's demonstration was masterful to say the least, I have never been able to move that fast!!. We have done much more pronounced curves, and in all cases, we draw a "cut line" on the timber to be milled and make a very slow effort to "take the line," as we mill. A fat sharpie pen does well for the layout line.

With a little practice, I think you could do just fine with the mill you have.

Thanks Jay,
We'll try a test piece, and since we have three cruck pairs this could be the third method we use in the workshop.
How much would you round the back of a 1.25" blade; maybe taper the back 1/8" on both sides?

Hi Will,

Here is the approach and tools I find most expedient:

1. I gather a Small piece of emery cloth, flat diamond file (coarse), and then a large black or dark blue sharpie pen.

2. With the engine running on idle...I "ink" the back of the blade. This is the "tell marks" often used by Smiths when shaping blades.

3. With the blade now turning just fast enough to engage the diamond file to "cut in," I do so into the top edge of the blade. I oscillate the diamond file on the top edge first from a 15 degree angle down to a 45 degree angle until a rough 45 degree profile is achieved on the top edge of the blade.

4. Repeat all steps thus far on the bottom edge...

5. With a rough "V" chamfer on the back of the blade...(note: this can be shaped in spots!!)...I now round over the "V" chamfer into a rough "bull nose" or "rondel" profile.

6. Smooth with the emery cloth.

The above are the basic stages of approach, and the tools. The dynamics of attempting this will teach better than my words. I thought I had this in a syllabus someplace, yet can find it. Feel free to cut, past, and edit at your leisure this post for the class if that has benefit.

Regards,

j

On my mill I have encountered a burr building up on the back of my band, it doesn't happen often perhaps from a defect in the hardening process the band went through at the factory, and have taken the burr off with a sharpening stone. Yes, with the mill running very similar to Jay's description. I didn't notice the fine print in Jay's post, so I am taking it upon myself to put it out there. Use extreme caution when doing this, need I say more. I have 27 stitches in my little finger alone from getting tangled in my debarker, luckily not the band. My finger still works, it looked like cottage cheese with some pink mixed in at the time.

I do agree the rounded back would help. You can also get narrower bands than 1.25" I have never tired but I may order in a special 3/4" band for such cuts. Maybe less thick, too. It only need to make a few cuts now and again. It should hold up.

I would suggest if anyone wants to try cutting curves on the band try on sample stock first. The idea of this comes from two different directions. One, running a dull band and seeing it dive two inches and then coming back out of the dive while I was not attending the levers, I was off bearing by myself while the band was self feeding. Two, being impatient when sawing, taking a cut and wanting to rise out of the cut befor I get to the end of the log due to a trashy end on the log that will not yield and decent lumber. Oh, a third example, cutting long stock I have been know to start out cutting 2" thick stock and by the mid point or so, drop the cut to 5/4 or 1" for the other half of a 36'cut.

Tim, Jay,
Couldn't the blade be tapered off of the mill, on a bench with a grinder or Dremel? I know it would take longer and maybe not turn out as uniform, but would be a lot safer.