Drilling 30mm holes

Hi folks. I have a project where I need to drill about 700 holes into lengths of 19mm pine timber.

The holes need to be 30mm wide and cut to a depth of 11mm.

Am I better off using a smaller bit and cutting pockets or is the x-carve capable of supporting a 30mm bit and using the drill function?
What type of bit would be most suitable?

I have run a simulation using a 9.5mm bit using the suggested settings for a pocket and it worked out at about 2.5 minutes per hole. Hoping to be able to shave some time off that.

Can you share more details on the project?

A 30mm drill bit is probably not rated for router-type rpms.

A 30mm router bit could do it, but it will probably wear out as you’re only using the very bottom to cut. You’ll have to take a few pecks at each hole to help clear chips.

If I couldn’t use a drill press or hand drill with a forstner bit, I’d use a good 1/4" endmill and an adaptive toolpath to cut at full depth.

Thanks Neil.
Not sure what you mean by an adaptive toolpath.

I’m using Easel and was hoping that the drill function with a 30mmn router bit may do the trick without killing my machine.

It’s an option in Fusion 360 and other HSM CAM programs. Basically, it would allow for a ramp in and then a full depth cut. No option for anything like that in Easel.

People have been plunging router bits for way longer than people have had X-Carves. Just keep your plunge rate reasonable and take small chunks so you don’t have too much force on that Z axis.
Oh, and have a spare bit.

I would not attempt that since 30 mm is approximately 1.1811 inches. That would be quite a bit for the X-Carve and even the DeWalt 611 to handle using the drill function. Do you have a link to the bit you were thinking of using out of curiosity?

I would do what @NeilFerreri1 mentioned and just use a 1/4" bit to mill out the holes. You can do this using Easel, but you will not get the exact “Adaptive” toolpath that @NeilFerreri1 is talking about when using Fusion 360.

Another thing to keep in mind is that the drill function is really only useful if the hole is only decorative or is exactly the same diameter as your bit. Bits are RARELY exactly their stated diameter. For instance, my 1/4" bit is 0.245", so I could not effectively use the drill function to create a 1/4" hole (inaccuracies of the machine not withstanding).


Brandon Parker

An adaptive toolpath is the magic that a CAM package like Fusion 360 CAM provides which allows much more aggressive clearing of pockets versus traditional pocketing paths where you slowly cut each layer away. As @NeilFerreri1 mentions above easel doesn’t do adaptive bur rather the traditional paths (and in pro does the slightly bizarre raster one like a laser cutter would. Anyway adaptive is magical because you tell CAM how much pressure you want on the tool and it does all the math to keep that pressure constant. Otherwise if you think about an end-mill entering a deep corner suddenly instead of only one side of the tool in contact suddenly 2 sides are. This is quite a shock to the tool and can result in deflection, speed changes, etc. So adaptive does the math to calculate how to do that without a change in pressure on the flutes. The big advantage of adaptive pathways is that you can take a much deeper cut (the normal way you use them as noted above is you helix in (or pre-drill) into the center of a pocket to depth) and take a full depth of cut. It is important to remember adaptive is a roughing strategy and then you typically follow with a finishing strategy like a contour path (typically you leave a specific mount remaining on an adaptive path - in Fusion you can specify radial and axial stock to leave. (in Fusion you have the handy “create derived path” from an adaptive tool path where it can create the finishing path automagically for you.

In your case (in Fusion) I would do a 2D adaptive for each of the holes (a handy feature in the latest Fusion release is detect similar holes so it would duplicate the path automatically) with helical entry (or pre-drill) then adaptive leaving maybe .02 of stock. Then do a derived. As an example here is an adaptive strategy on a group of 30mm holes (in fusion) followed by a finishing strategy with a “boring” operation.