Hello, I’ve been using Carbide Create and my Shapeoko 3 for about a year now. I’ve been making some pretty basic things using standard cutters etc but I’ve been really wanting to branch out and expand my capabilities. One area where I seem to get stuck is wanting to use different cutters/end mills and determining the right feeds, speeds and other parameters necessary to do this. I’ve watched video tutorial after tutorial and for some reason it just doesn’t stick. I also made the error of purchasing the G-Wizard software thinking that would help but it just left me more confused. Does anyone know of any online (or in person) courses/training available that provides one on one learning? I need to be able to ask questions to gain a better understanding and I can’t do that when I’m watching a video. Honestly it makes me feel incredibly stupid as it seems many people have very little trouble with this. Any help anyone can provide would be greatly appreciated? I’d even be willing to discuss working with someone here (for a fee of course) to help if that’s something someone would be interested in doing.
We do offer video training:
If you’d prefer to work out your problem face-to-face, you can schedule a 30-minute meeting:
More than anything, we want you to know that we’re ready to help you as much as you need to be successful with your Carbide 3D machines.
We’ve also done various tutorials on various tasks folks have asked about — please let us know what you are having difficulty with and we’ll gladly work up a custom step-by-step tutorial.
Have you seen:
For feeds and speeds, the defaults in Carbide Create work well for most folks, and were recently updated — see:
and you may find the balance of the e-book of interest.
Thank you. I have read the ebook and I want to say that I have an understanding of the basic concepts of feeds and speeds. My problem is how those parameters are determined for specific end mills. Again I know from basic concepts that it depends on the type of material I’m cutting (almost always wood) and the specific type of end mill but where does this info come from? If you have training that can help me with this sort of thing I would be most appreciative.
so maybe you’re kind of overthinking it for now.
meaning… Wood lets you do an insane wide range of F&S (unlikely aluminum for example which is very picky)
One simple approach is to stick with the F&S in carbide create… and if you have an endmill say in metric, interpolate the existing ones.
But also, you can always start slow and go faster as you use the bit more and get familiar with it. Almost all bits will make more rough cuts and/or bad noises as you go towards a too fast speed.
(For depth of cut “half diameter” is a good starting point always)
So yeah I know many videos and sites talk about F&S as if it’s the most important thing in the world. For wood… it’s not really…
sure super super slow will burn the wood, but you’ll know that when you see it:)
Have you seen:
Also see:
http://www.cnccookbook.com.s3-website-us-east-1.amazonaws.com/CCCNCFeedsSpeedsWood.htm
If you are only going to cut wood, with 1/4" and 1/8" endmills here’s a possible shortcut for you as a very simple recipe:
- keep your router speed at a fixed value, the highest you can bear, for me it’s typically 18.000RPM.
- then you only have to determine feedrate, which is chipload x number of flutes x RPM. You can’t really go wrong if you shoot for a 0.001" chipload.
- so when using a 2-flute endmill, you would use a feedrate of 0.001 x 2 x 18.000 = 36ipm
- for a 3-flute that would become 0.001 x 3 x 18000 = 54ipm
- for depth per pass, as @fenrus mentioned 50% of the tool diameter (or less) is usually a good value.
And that’s really all there is to it to get a cut that works just fine.
And THEN, if you wish to optimize it (because the values above are conservative, so cutting times will not be the best they can be), you can:
- gradually try increasing feedrate, keeping the RPM fixed. The machine will tell you when you have pushed it too far
- gradually increase depth per pass: same thing.
Yep,
As Arjan and Julien say, (most) wood is pretty forgiving to learn on, you’re more likely to damage the workpiece than the machine (so long as the work is held down properly).
Using the starter speeds and feed rates Julien describes but at shallow depth of cut on a reasonably chunky endmill, say 2mm deep on a 1/4 inch cutter (1/16 inch depth) get used to the sound that a happy machine and cutter makes. You should hear the cutting frequency of the flutes as they rotate (600Hz for a 2 flute at 18kRPM) a happy BZZZZZZZZZZZZ and mostly just that one note, like a really big happy bumble bee.
When you push the work or the machine harder than it likes you’ll hear other tones or rapid variations appearing in the mix as the cutter, machine or workpiece start to vibrate or resonate in ways you don’t want.
You don’t need to max out your feedrates at all, don’t make fine dust but generally the target for a hobbyist is a quality work product not the fastest output.
I have been mostly using standard end mills but I’m wanting to branch out with engraving bits, bowl tray bits, round over bits and surfacing bits. These are all ones I have purchased recently and those don’t exist in the basic carbide library for suggestions on settings. I would like to at least experiment a little but I’m not even sure of a good starting point for some of these specialty type bits. I’m just afraid of making a mistake and causing some catastrophic failure to my equipment.
Everyone is being incredibly helpful so thank you for all the suggestions so far.
unknown weird bit → START SLOW
you can use the override buttons in carbide motion to go incrementally faster.
also just look at the geometry… for example the bowl tray bit… you can kind of expect that one to not go vertical very well (so go waay back on the plunge speed)… and compared to an endmill with a helix cutting shape… it’s not so advanced… so likely you want to dial down the feedrate as well.
sort of rule of thumb: start slow. you end up making fine dust. as you go faster during cutting, at some point you’ll see that you’re making little chips not just dust, and then you start being in the sweet spot.
@scarr I too struggle to really understand it. My solve is that every time I purchase a new bot and do not have a point of reference, I post the purchase in the forum, the wood type I plan to mill, along with the screenshot of the feeds and speeds I have selected and then I will usually get a response within 24 hours
Example:
The other thing I like to do is troll what others have purchased. One of my best purchases was suggested by @fenrus . That way I know that they will have a good direction for me in terms of F&S
Always make sure to tell them the machine and router because that he has to be taken into account
Just on the topic of the machine sounding happy, here’s my machine working on a piece of really really hard wood today
That’s 14,000RPM, 3 flutes so 700Hz base frequency, despite the stick out from the vice there’s hardly any harmonics and the finish is nice and smooth.
OK so the width of cut is tiny here as I’m doing finishing passes to trim a tiny amount off the bracket, but the machine sounds happy, no rapid variations in sound, no nasty harmonics.
The suggestions to have other people provide their input on f&s is great and I know this community of makers are all pretty wonderful and helpful but I really want to be able to understand things much better myself.
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