In order to get myself a little more familiar with the UJK Technology Router Bushes, I decided to do something fairly straightforward and recreate the curved finger pull detailed in the previous Blog post.
To make this example, the first thing required was a circle jig. Now there are some very fancy, all singing, all dancing jigs that can be built, but I’ve always found that simple usually works best and so I made my jig from an oddment of decent quality 8mm multiply, sufficiently long so that a circle with a radius of about 750mm could be machined.
On the bottom of the Festool OF1400, there are two tapped holes in the base that can be used to attach ‘shop made jigs, but it should be noted that they’re NOT equidistant from the central axis of the router, so some care needs to be taken in marking out. I found a couple of suitable hex bolts which I cut to the correct length and also used a hacksaw to make some slots for a screwdriver. It may be obvious, but I strongly advise not to overtighten the bolts as there’s a danger of stripping the threads in the router base.
The radius was set to 250mm by simply drilling a small hole for a pivot screw at the correct distance.
The router is then set up with a 19mm straight cutter and plunged (with overlapping cuts) several times through the template material to form the curved shape, which is now ready to be used with the router bushes.
In order to obtain the widest finger pull, I needed to select a combination that would give me a small offset, so I opted for a 12mm bush and 8mm cutter. This resulted in a 2mm offset (12-8÷2=2mm) which meant that the final width was 15mm (19-2-2=15mm).
To finish off I softened the hard edge of the finger pull using a small chamfer bit with a bottom bearing in the router. The UJK bushes are very versatile, but the most awkward thing is to fully understand how the offset works, which is why I’ve included the sums.
As I’m no good at sums, it also makes it easier for me!