Thread: 100mm roundover... What router bit?

I hope you mean 10mm radius roundover....??????

Originally Posted by Mr Brush

I hope you mean 10mm radius roundover....??????

I wish I did

It's the real deal.. a 4" roundover. The biggest I've heard of from a friend of mine is 2"...

Eeeeek......if anyone makes a bit that size (which I doubt), I wouldn't want to be in the same room when its running.

That kind of radius would normally be done on a huge spindle moulder or (manually) on a disk sander.

I have just bought one of these, 1/2 x 2" Round Rounding Over Router Bit Tool Dual Flute - eBay, Equipment, Machinery, Woodworking, Industrial. (end time 06-Nov-10 11:18:02 AEDST) pt=LH_DefaultDomain_15&hash=item5adcab8630 .......may I suggest you get similar and round the top edge first then the bottom! (two stages) I dont think you would be able to handhold a router bit that size!

Originally Posted by Dave50

I have just bought one of these, 1/2 x 2" Round Rounding Over Router Bit Tool Dual Flute - eBay, Equipment, Machinery, Woodworking, Industrial. (end time 06-Nov-10 11:18:02 AEDST) pt=LH_DefaultDomain_15&hash=item5adcab8630 .......may I suggest you get similar and round the top edge first then the bottom! (two stages) I dont think you would be able to handhold a router bit that size!

Yeah I should've cleared that up... no ay am I expecting a plunge router to have a bit that big. (Massive bloody router, if that's the case! haha)

I'm think that might be the way to go and just be VERY pedantic about sanding it.

Mr. Brush... I was initally thinking the same as you... perhaps a spindle moulder job... but I wasn't 100%; as I don't work with them everyday, so I can't really comment on them.

when I do a top in this fashion I always do it on a good router bench, this keeps the timber at a uniform distance for both faces!

Glue up four pieces of the cross section to approximately final shape, longer than needed, with end diaphragms to reach the center of curvature. Dimple each end diaphragm at slightly more than 4" radius. Place it in "bookends" with dead centers. Connect the bookends to each other, as explained in the third paragraph here: https://www.woodworkforums.com/f8/car...e-horse-57412/

Adjust the cutter height for 100mm radius. Run the whole affair along a router table, rotating the workpiece slightly for each pass, limiting the rotation to 90 degrees. A jointer may be needed to achieve perfect tangency of the flat portions. Sand to final contour.

Miter cut the ends, wasting the end diaphragms, for assembly. Bob's your uncle.

Cheers,
Joe