Using a round over bit

[david5 (David Mattice)]

Setting up tool path using a round over bit on the rim of a project, do you set as outside perimeter or no offset . Also what should be the depth of cut . I have a radius point cutter bit
Thanks

[Revdlt29 (David Thompson)]

I do no offset on those. My depth of cut varies depending on what I am looking for on the outside edge.

[david5 (David Mattice)]

Would 0.10 be right?

[Jeffish (Jeff de Ruiter)]

When I do edge chamfers or “softening” I try different DOC’s and see what looks best in the simulation. I typically use a 90° Vbit then sand off the edges of the cut to smooth them out

[gdon_2003 (Guy Donham)]

The type of bit matters. If you have a round over with a bearing you need to remove the bearing. Bearings on router bits do not work well with a CNC.

If you have a round over without a bearing then you could do a no offset but giving a little bit of an offset would be best. You could always create another tool path to do just an offset without a few thousands of offset if the round over does not look right.

Just trial and error. Just remember that nonstandard bits require a custom tool and a round over bit would likely be treated as a flat endmill. You could try it as a vee bit but again trial and error.

A roundover bit like this.

A roundover bit like this maybe if the bearing is removed.

Just remember with the bearing removed there is a part of the bit that is sticking down below the round over part. So make sure you material is thick enough for that part to not hit the spoilboard and possibly loose steps.

[WillAdams (William Adams (Carbide 3D))]

See:

Using unsupported tooling in Carbide Create: Roundover / Cove / Radius bits

These are usually used in routers for decorative effects in wood: https://www.whitesiderouterbits.com/products/1570 but they are potentially useful for joinery: They are also useful for rounding off parts to allow rotary motion as for a hinged lid. Unfortunately, Carbide Create does not support this endmill geometry — but using the new support for previewing a V endmill when used in a No Offset Contour toolpath, it should be possible to preview them w/ confidence by stacking a series o…

[Jmcwoodworking (Joe Carroll)]

I’ve used a bit like @gdon_2003 shows without a bearing and it works very well. DOC is really a personal; preference depending on the surrounding geometry. I will say I tested it a good bit before deciding on what I wanted.

[Tod1d (Tod (with 1 'd'))]

One thing to consider is leaving a tiny bit of gap so the corners of the bit don’t leave a mark on the part. You have to measure the bit to determine your desired offset, or the diameter you use to define the bit, and the desired cut depth.

[shawnoel (Shawn Noel)]

Bits_Cheat_Sheet.pdf (23.0 KB)
This should help you get an idea of what the sizes are in different metrics. Hope this helps.

[Jmcwoodworking (Joe Carroll)]

Very handy little sheet there. Thanks!

[Jwjimbo (Jim Colombo)]

I use the CIC 1/4" round over bit with a .02 outside offset (for outside rims, inside for inside) and set the cut depth at .17. It took many tries to get to this point.

In order to get the offset in Carbide Create you need to create a new curve and use the contour tool with no offset.

Hope this helps