Suitable Bits for Materials

I run the 400w DC spindle I use at full RPM due to it not having as much power in lower RPM ranges. It is not a brushless motor so it suffer a bit of power lose at lower RPMs I have found. The end mill I mentioned above is the 1/8" (3.17mm) Viper end mill from Destiny with the Stealth coating on it. I love that end and use it on most of my projects if I can get away with such a large sized end mill. I have only had a single issue with such high speed RPM on the 6061 and it was with a 1.25mm end mill in 1/4" stock, if I did not stay right on it and clear the chips, it would gum up and break. But it was a very narrow and deep cut so that was a huge factor.

So is the max speed of the spindle about 12,000 RPM? I’ve got a Dewalt DW611 with a fixed RPM of 30,000. I haven’t tried any aluminum yet but want to soon. With such high RPM maybe I’d be better off with a 1 flute cutter.
I’ve been doing printed circuit boards so far and the high RPM is good for that. Even 2x as fast would probably be good for PCBs.

just got this guy in today. got to get my control PC back up and running then i’ll run it through its paces.

i got some really nice Niagara bits but i accidentally ordered 3/8 shaft -_-
any suggestions on how to get a 3/8in shaft into my x-carve?

Big hammer? :laughing:


The collet is only .365 inches, your bits are .375. This is what we call a difficult problem.

yeah and i bought 2… return shipping is 0.05$ less than the cost of 1 bit. so if i return them i’m out half my cost. which wasn’t much. just wanted to try out the name brand. and i hear they work great on Aluminum which i’d like to give a shot. but the no name brand should be fine for acrylic and wood and maybe aluminum if i get brave. I have a 1/8 version in the mail as we speak.

i figured more flutes = more cutting surfaces = better over all cuts regardless of material… how off base am I guys?

just got my 1/8 4 flute… excited :sunglasses:

Great piece,

Were you able to do the threads in the holes with the cnc aswell? Which bit can accomplish such a thing?


The Shapeoko and X Carve are not able to make treads with their spindles. Only a high end CNC can do that while still on the mill. I tap the threads with a tapping head after I finish milling them. The tapping head mounts to a drill press and allows the tap to drive into the pilot hole, then reverse out of the tapped hole once it is finished. It is one of the most useful tools I have ever bought aside from my CNC mills. I makes sure the treads are tapped cleanly, nice and square every time. I use a 3 flute spiral m3 tap which is meant for a high end CNC, but I mount it in the tapping head instead and it works really well. This is the tap I use and so far it has worked really well as have all the taps of this style I have bought from this seller…

So something like this: , cannot be done?
I wish to know whether this process could make threads in wood?


Hey Jeff,

I was doing some aluminum work tonight and noticed that it seems my machine can move much quicker than the recommended mm/min in Easel and still be comfortable.

Easel recommends ~125mm/min, while a machining guideline recommends closer to 1600 mm/min with an rpm of around 17,000 using a 2 flute 1/16" HSS cutter.

Granted, the feedrate gets cut in half if we switch to an 1/8" cutter.

Have you guys messed around in your shop and seen that you can go faster?

My gear =
500mm X-Carve with Nema 23s
48V, 400 Watt Quiet Cut Spindle


One of the first thing you need to make sure of when milling aluminum at speed is chip clearance. Unless you are set up with a good misting system (fog buster) then you need a good chip clearance system if you intend to cut aluminum at anything close to those speeds. I have has the same spindle you have for over a year on the Shapeoko and it is not really set up for that aggressive of milling in aluminum. The DOC will not be much greater than .25 at most if you are lucky. The main issue is the 400W spindle does not have the power to keep up the RPMs under heavy load like that type of milling will do. A dewalt 611 or a .8KW VFD spindle is far better suited for long term aluminum milling. You can chek out my thread here Production level aluminum milling with .8KW water cooled VFD for an idea of milling with the X Carve in aluminum on a larger scale.

I am by no means an expert, but my experience of milling aluminum on both the Shapeoko 2 and the Carve have allowed me to produce some very good result on some complex parts.

Very cool, thanks for the advice, I appreciate it.

I just wrapped up my first successful 6061 sheet cut of the Inventables bottle opener…I know the plans call out for .125" sheet, but I wanted to test out the feeds and speeds.

I ended up with these numbers working as the best balance between speed and quality of cut:

20 ipm
5 thou DOC
1/16" 2 flute end mill on 1/8" shank
~10,300 RPM…Using the manual control of RPMs and a tachometer bought on Amazon for $14…if you don’t have one, it’s about 2 o’clock, if you treat the middle pin on the knob as 12 o’clock.

We are actively working on a system to improve the speeds & feeds recommendations in Easel. I can’t put a specific timetable on it, but over the next few months you’ll see changes rolling out in this area. It’s something that we’ll keep improving over time as well.


Hey Jeff,

Thanks for the response.

On another topic, one real small change that I think would help out is to have whatever cut type you have chosen stay selected/highlighted.

So if you open someone else’s project you can see whether it’s an outline, on the line or inside cut etc.


The icon does change subtly based on which style is selected. If you look carefully the blue line will either be inside, outside, or right on the thicker gray line. (This is also true of the object itself when it is selected on the 2D design grid.) We could probably change the text that is displayed under the icon to make it even easier to tell quickly. We’ll look into doing that.


Very cool, thanks for the quick response Jeff.

I don’t know if you guys just changed it, but now the name of the path selected in the flyout menu becomes blue. Awesome stuff.

would that be this bit V30808S