drilling operation questions...

[yurtkuran]

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!

[dlcw]

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 (https://www.toolstoday.com/brad-point-boring-bits-57mm-long-10mm-x-27mm-shank-right-hand.html). 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.

[EricSchimel]

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.

[bleeth]

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

[yurtkuran]

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

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!

[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.

[yurtkuran]

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.

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?

[knight_toolworks]

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

[EricSchimel]

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?

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.

[Brady Watson]

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 (https://www.amazon.com/DEWALT-DWD520K-2-Inch-Pistol-Hammerdrill/dp/B002IAW0DA)

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.