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.
There are a number of other miniature router bits offered, so a number of different tasks can be achieved in very restricted spaces. Available from Toolstoday.com
Originally posted on October 2nd, 2012 by Stuart
Read the original article here.