drilling operation questions...

Hello All...

Anyone have experience using drill bits on the ShopBot?

Working on a design where I need to drill multiple holes and hoping to add a drilling operation CAM setup.

Is it possible to use standard twist bits in CNC with the RPM set appropriately accordingly (~3000-4000, depending on bit diameter)? I'm using Fusion360 for CAD/CAM. The software supports drilling but want to know about the hardare.

Also, does anyone have a recommendation for constant shank diameter drill bits? For example, a 1/8" drill diameter with a 1/4" shank diameter?

Thanks in advance for any help!

I use boring bits on my CNC all the time. NOT drill bits. Boring bits are much more appropriate for CNC operations. I get them at ToolsToday.com. I set my spindle at 6400RPM with 1IPS plunge rate. The holes are perfect and chip free on melamine, plywood and solid wood. The bits are 10mm shanks.

I've done a LOT of drilling using high quality jobber bits:

https://youtu.be/S1Mt85X57pc

I believe I got these bits from McMaster. They're nothing special, just not the cheapest ones.

Can't really reply without knowing more about what you are drilling. More specifics the better. Material, thickness, size of hole.

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Originally Posted by bleeth

Can't really reply without knowing more about what you are drilling. More specifics the better. Material, thickness, size of hole.

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Hi Bleeth...good point, those are helpful details :)

I'm intend to drill 0.25" holes but may hove to go up to 0.5" if design requires. Using 3/4" birch plywood.

Thanks for the help!

What you're seeing in my video is this bit:

https://www.mcmaster.com/2908a21

It's a 1/4" jobber bit. I've used these for thousands upon thousands of holes in birch ply and HDPE. They continue to work great.

I typically don't drill much larger than 1/4", occasionally I'll run something a bit larger than 1/4", but if I get to 1/2" holes or larger I just run an inside toolpath using the spindle. That air drill I have is great, but when you put larger bits on it you can't plunge as fast.

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Originally Posted by EricSchimel

What you're seeing in my video is this bit:

https://www.mcmaster.com/2908a21

It's a 1/4" jobber bit. I've used these for thousands upon thousands of holes in birch ply and HDPE. They continue to work great.

I typically don't drill much larger than 1/4", occasionally I'll run something a bit larger than 1/4", but if I get to 1/2" holes or larger I just run an inside toolpath using the spindle. That air drill I have is great, but when you put larger bits on it you can't plunge as fast.

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Thanks Eric!


One detail I left out, I only have a spindle on my ShopBot - i.e. don't have the air drill. Can I still use a boring bit or twist bit?

for wood I often us a bradpoint bit 3500 rpms it works well and good ones are easy to get locally. a boring bit would be nice if I knew ahead of time

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One detail I left out, I only have a spindle on my ShopBot - i.e. don't have the air drill. Can I still use a boring bit or twist bit?

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In a spindle you can only use a bit that's the exact diameter for your collet, so if you have a 1/4" collet you could use a 1/4" drill bit (that's rated for the speed you'll be spinning it at of course)

The advantage of the air drill is that it's got a chuck so you can chuck up just about any size bit in there.

Not to be all 'Captain Obvious' here...but you can also - ready for this - Use a drill...

There are lots of drills out there with the higher RPM for drilling wood, such as this 2-speed (0-1200 / 0-3500) DeWilt

It doesn't take a genius to add it to your existing Z axis and the price of entry is cheap...Then you can drill what you want (including steel) using whatever size bit you want - AND you'd be using the right tool for the job.

Using a spindle to drill is a real stretch...especially on a SB models where the spindles are programmed to go no lower than 5,000 RPM. You can put in whatever RPM you want, but it will never go below 5,000.