Originally Posted by litterbug
I'd think that if you need an actual shim you're going to run through scrapers pretty fast, unless you're talking about something a fraction of a mm thick. I wonder how Mantac does it? Has anyone taken one apart?
Pics of Mantac sharpener.
Pic of the top shows the feed groove is at an oblique angle to the cutter. The leaf spring in the feed groove keeps the scraper tight against the opposite wall. The oblique feed angle into the cutter allows for a smoother finish cut on the scraper. No scallops on the scraper edge, at least in the cross wise direction. The installed cutter is a ½” diameter x ¼” shank carbide straight router bit. For the home built unit with a right angle feed, a smoother cut can also be accomplished by using spiral flute straight router cutters.
The cutting debris is collected in the cavity at the bottom of the unit. Usually trapped against the bench top - a pain. The side view shows a step above the feed groove. The step is 1/32” shallower on the out feed side. They just molded the out feed side of the feed groove higher to support the sharpened portion of the scraper. The support is necessary to eliminate snipping at the end of the cut. The 1/32” step is perfect with the UHMW tape I posted earlier. Also the UHMW tape makes everything super slick.
The actual power unit is much smaller than a normal trimmer motor. I can tell from the weight – about half if not smaller. The RPM is quite high, more than 20K. I used hearing protection with it.
Overall, this is just an inexpensive take on a fixed jointer concept.
So since we’ve completed our reverse engineering process, who is going to build the first knock off?
BTW, what is all these talk about dowels. Thought they went extinct 20+ years ago. Killed off by the biscuits. If you need more beef than a biscuit can give you, go for the Festool Domino.