[Daniel Green]

I got some pretty cheap 1/4 inch shank router bits on ebay. One of them is a 1/2 inch round. I think there are 3 issues that will prevent getting a proper 1/2 inch radius round edge with this but perhaps this is how some bits are?
1) The curve of the blade doesn’t go a full 90 degrees.
2) The pilot bearing it slightly larger than the end of the blade so part of the blade will never contact the work piece
3) If just seems a couple of mm smaller than 1/2 inch.
(Photo attached showing these 3 things)

I did a test with it and the round isn’t too bad but definitely seems like it will need some sanding to get it there and i’d say its a fair bit smaller than 1/2 inch.

So, are these bits rubbish or have I misunderstood round over bits?
Thanks.

 

[Daniel Green]

Thanks. Yeah the shape of the round over I got looks more elliptical, partly due to the bearing being oversize I think as well.
I need the full 90 degree round so will probably need to get a better bit.
I also need to put a round on a curved edge so will probably need it to be bearing guided or I’ll make a mess of it.

Thanks for the feedback.