How your Timber Frame is Made

Tools are only a Means to an End

Since our company began in 1990 many of our tools and processes have changed to take advantage of the best practices and technology available for our industry. Our prime motivation and purpose remain unchanged: to find success through attentive service to customers and by offering exceptional quality and value in what we create. In this section you’ll find a short description of the fabrication steps that your timber frame will go through in its journey to you.

Timbers Just Want to be Dry

Cornerstone Timberframes buys rough sawn timbers from a few specialty sawmills. From the sawmill, timbers are taken directly to a commercial drying kiln where they will spend 15-20 days being treated to remove moisture. This results in lower moisture in the outer inch to inch and a half (25-40mm) of the timber, which in turn means more stability and less checking.

Seeking Perfectly Square Wood

When your frame’s fabrication start date draws near there’s a flurry of activity. Days ahead our yard manager identifies the timber for your frame and begins to deliver the pieces to our planer, the first in-shop station in our fabrication process.

It’s a perpetual quest, finding a system that will take imperfectly shaped timbers from the sawmill and transform them into mathematically perfect squares. Our German-made planer is the first of its kind in Manitoba: fully digital and able to mill a smooth surface on all four sides of a large timber in a single pass. Planing all four sides at once ensures that faces are square to each other and a carpenter’s square snugged up to adjacent faces will show the result – if it’s perfectly square it will be “lights out”, with no visible space between the square and timber. From the planer, your timbers are stacked and shuttled across the shop to our newest and most amazing piece of technology: the CNC cutting machine.

Cornerstone Uses CNC Technology

CNC or Computerized Numerical Control has been around since the late 1940’s but began to really gain traction in the 1970’s as digital computer systems came into use. Initially the use of CNC technology was focused on machining high precision metal parts for the aerospace and automotive industries. Then in 1985, a young inventor in Germany developed the first CNC machine that could cut joinery into timber. Forty years on, his company Hans Hundegger AG is at the leading edge of innovation, producing the most capable joinery cutting machines in the world, which has in turn rewarded the company with an impressive 90% market share.

A Hundegger 6-Axis CNC cuts a perfect dovetail tenon onto the end of a floor joist.
When Cornerstone Timberframes considered the impact of using CNC technology we had a healthy conversation about what it would mean for our skilled workers and the tangible results it would provide to our clients. Transitioning to a CNC, we realized, would allow us to enrich our employees’ work experience while continuing in our commitment to produce the highest quality timber frames. Adopting CNC technology promised to be a win-win for workers and customers!

Here's a short summary of our experience in moving from a shop with handheld power tools to one where over 80% of joinery is cut by a Hundegger K2i Robot Drive:

Our Old “Power Tool” Shop
A high percentage of timber frame joinery work is simply repetitious, and it was rare to find a worker who felt fulfilled doing tedious tasks. (Cutting the 50th mortise pocket is exactly the same as the first!)
Small errors happen regularly: when a circular saw drifts off line, a cut runs a wee bit too far, or layout marks are a little off. Usually nothing big, but occasionally it required a replacement timber to be prepared and cut.
Accurate, tight-fitting joinery is a sign of a well-made timber frame. A lot of work and testing went into adjusting and paring back connection faces to achieve a good fit.
In our old shop we used a wide range of power tools and developed computer models to assist us in making the layout (cut) lines on timbers. Worker attention to detail varied from good to great.
A busy timber frame shop employs up to ten carpenters ranging in skill from novice to master and can produce 2 mid-size frames per month. The “power tool” shop for reasons not fully understood tended to be a competitive, male dominated space.

Tapered dovetails were not possible and housed joinery was difficult and time consuming to cut.

Our New CNC Shop
The CNC excels at repetition, which allows our workers to focus on the fun and challenging aspects of a project: finessing a detail, cutting a custom curve, or test-fitting complex assemblies.
A properly calibrated and maintained CNC doesn’t make any mistakes. Robot perfectionism can be so annoying! 🙂
Our new CNC is super-accurate, and consistently produces tight joinery. Very little time is needed to check and test-fit.
The CNC accesses up 24 different tools, and simply connects the computer directly to the right tool via a 6-axis robotic arm. There’s no need for layout, and every piece is consistently handled.
Our busy CNC-equipped shop employs up to fifteen carpenters overseen by a master timber framer and can produce 8 frames per month. It’s a more cooperative environment and one that welcomes diversity and supports gender parity.

CNCs add a host of new joinery types and can cut challenging details in minutes, not hours.

This is the last step before timbers are sent to the Finishing Shop. While CNC timber joinery is astonishingly accurate, there is no system we’re aware of that anticipates how timbers in a truss or wall will need to be handled and positioned to allow for final assembly. To address this need and save valuable time on site, once timbers are through the CNC they are sent to the test-fitting area of our shop. Here workers assemble each section in a timber frame and in the process discover and resolve any sticking points. It’s also the time that we complete the drilling of peg locations.
A few samples of the intricate joinery that can be cut by our Hundegger CNC
Our experience in moving from reliance on power tools to a CNC approach has been very positive. It has meant more meaningful work for our craftspeople, more diversity and gender parity in our workplace and better, more beautiful timber frames for all of our clients.