What tool path to use to make a handle for a tray?

[shapewithsrini (Srini Panuganti)]

I’m designing a tray with handholds on both ends. I plan to route openings for these handholds using a pocket toolpath with a #201 (1/4") end mill, setting the maximum depth to the bottom of the stock, which is 3/4" thick. Since I’m new to CNC, I’d appreciate any advice to ensure this turns out well.

[Brew (Steven Middleton)]

I’d add tabs to make sure the piece you are cutting out does go flying once it’s almost cut out. That would also help keep it clean and not have any tear out.

[via_jon_valiedated (Jon Stephenson)]

Since you are pocketing - I don’t think that a piece flying out would be a huge risk. With pocketing - maybe .03 stepover at full cutter tooth depth would work depending on the rigidity of your setup and the power of your spindle/router.

Some other considerations:

Consider using a profile cutting path - with roughing passes and 1 or 2 finishing path.
Consider a couple of countersunk screws to hold down the part if you are using a profile path

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

Any square endmill should allow cutting a clean flat bottomed pocket (agree that you either want to use a pocket and remove the material compleatly or use tabs to hold the center part in place — it also looks like your stock is thick enough that you should use offset geometry to cut as a pocket down to tab height or the penultimate pass).

You might want to use a roundover tool, or even a V tool to ease or at least chamfer the edges, 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…

Here is how I would do this, assuming that the center portion was large enough to be worth saving (I have a tall stack of bins where I sort pieces by size):

Use the endmill diameter plus 10%

Apply

which would work if using workholding such as Blue painter’s tape and cyanoacrylate which would hold the stock in place. If that’s not the case, or if one wants belt and suspenders:

reduce the thickness by the height of tabs:

Then select the outer geometry:

and assign a No Offset Contour toolpath:

and assign Tabs in the Design tab:

Ok

which then previews as:

If you wanted to ease the edge with a suitable tool you could offset a suitable distance:

Apply

Ok

which would then preview as:

[shapewithsrini (Srini Panuganti)]

Thanks William. Appreciate your suggestion and quick response. This is very helpful. I will try your suggestion. Thanks again.