I just got my machine and this is my first venture into CNC carving/milling. Just a tiny 2x2 inch carving which allowed me to play with v-carving, contouring and chamfering (using a v-bit).I realized that softwood probably isn’t the best choice for tiny carvings and my choice was especially bad, since it is just a very cheap common board from home depot. Overall I’m really impressed with the quality the Nomad is able to produce, especially with the end mills I used, as they are quite cheap ones.
I have yet to figure out what the right feeds/speeds and plunge rates are, because I definitely had some shrieking from the end mill I used to contour the piece.
Very good start for a first carving. Download the Shapeoko e-book (search this site) and you will get great info and two F&S calculators to adjust your settings.
I have given some thought to using sticky threads, but I don’t want to pollute the front page either, there’s no reason why the ebook thread would be sticky and not many other interesting threads too. So I’m thinking, should we have ONE sticky post that would provide links to the ~top20 topics of useful/inspiring/recurring threads, and we vote (or something) for what should be referenced there ? The wiki already does a good job of referencing useful forum threads for a specific topic, but it’s true that there is no “map” of the forum for newcomers.
Thanks a lot I have tried to do the same in thin walnut today - the letter looks great, but then I broke my first bit while doing the contour. I guess 45 IPM at 0.04" DOC with 5000 RPM wasn’t such a good idea. In addition to @Julien’s book I also found his thread where he talks about feed and speeds that he collected from the internet, which then led me to the Nomad feeds and speeds chart. Since that lists Mahogany at 9200RPM with 72IPM and 0.14"DOC I assume that trying those values when cutting walnut should be much closer to the “correct” values for a hardwood like walnut. The next attempt will tell!
assuming you are using a 2-flute endmill (1/8"?), 45ipm at 5000RPM grants a chipload of 0.0045", which as far as I am concerned sounds too aggressive, I would fall back to a 0.001" chipload as a safe starting point. You could for example double the RPM and halve the feedrate, 22ipm at 10.000RPM would get your there. And then you can increase feedrate from there.
I like to keep my depth of cut to 50% of the endmill diameter for regular (non-adaptive) cuts. So (still assuming you are using a 1/8" endmill) I would go for 0.0625" for depth per pass. Your 0.04" choice is a good/even safer starting point.
the 72ipm at 9200RPM grants…basically the same hefty chipload as 45ipm at 5000RPM. I know this is what the Nomad chart says, but…there’s a catch: that’s because the chart also recommends a very shallow depth per pass of 0.014". At such a shallow DOC, one can get away with a larger chipload/feedrate. But don’t use 0.14", that’s more than 100% endmill diameter, at 0.004" chipload on a 1/8" endmill I’m pretty sure that’s a recipe for breaking a second endmill. But I think it’s just a typo in your post and you just missed a zero
Anyway, congrats on the broken endmill, you can tick that box and now join the rest of us endmill breakers
I definitely had a typo there and did not mean 0.14 I will try these values right away - have some small pieces to plane and no planer, so an end mill has to do for surfacing! I really appreciate all the help!
If you want to plane the top of stock I recommend a larger bit to do that with. I have a Whiteside 1 inch 3 cutter that I use for flattening my spoilboard. If you use a small bit to flatten the top surface of a project it will take forever and you will likely get a lot of lines in the wood. You can just sand them off but if you use a larger bit the job will be faster and better and you will eventually need a fly cutter to flatten your spoil board.
I have the Whiteside 6120 and I run at 80 IPM, 20% stepover, 0.010 inch DOC, 16000 RPM. Whiteside said to run the bit at 100 IPM but I like the 80 IPM better. The reason for 20% stepover is the 3 wings are only .25 inches wide.
That makes a lot of sense! I am aware that surfacing this way takes some time, but I am not sure that I am able to use a normal surfacing bit in the Nomad (Especially since the spindle has a max speed of 10000 RPM). Would you happen to know if this is possible? Since the surfacing bit isn’t flat and the center point isn’t the tallest point of the bit, I do not know how tool length measurement would work in this case.
Doing things like this in a small 1 bedroom apartment requires some compromise
I see, thanks for the info! What about v bits? The one sold by Carbide3D is a 1/4 shank one and also hints at the 1/4 inch collet on the store page. I do have said collet and a v bit, which seems to work fine, I made this carving with it.
I have tried to do the same in thin walnut today - the letter looks great, but then I broke my first bit while doing the contour. I guess 45 IPM at 0.04" DOC with 5000 RPM wasn’t such a good idea. In addition to