This is pretty cool – a chair created on a CNC machine using kerfing as the technique to give it shape. Opens one’s eyes to all sorts of possibilities.
Episode 92 Amana Tool Dado Blade
Click here to see the blade at Toolstoday.com Don’t worry that the blade is not blue – the photo has not been updated yet to include their latest coating that is now standard on their blades.
Many years ago (I can say that now, being 5 or so years ago!), I wrote a post about bending timber using kerfing. To this day, it remains one of the most clicked-on posts of all time. It would certainly justify a revisit, and expansion to the original post.
Out in the shed today, I was using the Amana Tool Tambour Bit set to make a large tambour door for the toy kitchen (and the full article about the construction will be in the next edition of ManSpace magazine). When I had finished it, and assembled all the slats, it was surprising to see just how flexible the interlocking slats were. It made me think of kerfing, with a different surface texture (obviously). (The bit set is available from Toolstoday.com)
If flexibility was not the desired end result, but the forms that could be created during assembly, this could produce some really organic structures – lounge chairs, curves around structures etc. Although (like kerfing) there are some inherent weak areas, (which don’t compromise the structure if used for a roller door but would if used for a deck chair), these could be easily overcome with good glue, and supporting structure, allowing the form of the tambour, with the strength required for the alternate purpose.
So there is the teaser. The full door (and in this case, it will be a door for the toy kitchen), is 450mm wide and around 750mm in length, and is made up of 52 individual slats that require no joiners, no backing tape or canvas: just pure, interlocking timber slats. Total distance of timber passing through the various machines in getting it sized correctly, then shaped by the router table was around 1/2 a km. Not relevant, just interesting!
When I first saw the miniature bearing router bits from Toolstoday.com, I immediately knew one job that they would be perfect for – kids’ toys. They often have many curves and tight sections where a normal router bit fears to tread (and often cannot get anywhere near following the twists and turns). A typical fine router bit doesn’t have a bearing, and instead has a simple shaft that is part of the bit, and therefore rotates at the same speed (and for such a small diameter router bit, this can be 20,000 – 25,000 RPM). This quickly leads to heat buildup, and friction burning of the timber. It isn’t too much of an issue with such a small diameter, but the area in contact with the work is always rotating, where I prefer a bearing where the contact point of the guide is stationary.
From right to left, there is the non-bearing bit, a roundover bit with a regular-sized bearing, and the Amana Tool miniature bearing router bit. This really reveals just how tiny the bearing is.
Just for a sense of scale, the bearing on the right is a typical 1/2″.
So where it comes to fitting into the smallest of places, this is the bit for the job.
The hippo here is part of an animal train pull-along, and without rounded edges looks very unfinished. With all the tight corners, it was going to take something unusual to get in there (or try sanding it by hand). After rounding over each side, it went from ‘roughly cut out’ to basically finished and ready for oiling in a very quick pass on either side.
The bit really excelled in this application, and did a great job while doing so. Smooth cut and finish without tearout, and a fine bearing that glided over the work.
If you reference back to my previous article (linked below), you’ll see there are a number of other bits in the range, so a number of different tasks can be achieved in very restricted spaces. Available from Toolstoday.com
- Honey, I shrunk the kids! (stusshed.com)