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Newbie looking for some bit sense

2136 Views 13 Replies 11 Participants Last post by  Merijeek
Hi all -

Brand new to this, my wife got me a Bob's CNC E3 for my birthday, and I've gotten it assembled with no issues. I'm pretty competent with design software, though I'm leery of spending on vCarve until I've managed to produce something of value from my machine.

I can do some carving in general relatively well, but when I try to do a project of my own, I'm failing pretty hard. I assume it's because I genuinely don't know what bits to use.

For example, I've tried a whole bunch of different bits, but am unable to get this project (which can be seen at to get quite right. Either the words are barely legible (60 or 90 v-bit) or they get ground into blobs (say, fluted spiral up/downcut). The one that seems like it might work is a 10-degree v-bit, and according to software I'm looking at ~55 hours to carve it.

Which is obviously nuts for a 4x4 coaster.

So, I'm just looking for advice on bits. Once I have that going well enough, I'll probably be asking about the best way to securely mount a piece.

Thanks for any help!


A working link:
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hello and welcome to the route forum
Welcome to the forum, Joe! Add your first name to your profile to clear the N/a in the side panel. Add your location, as well.

We do like photos and we'd love to see your CNC, shop, tools, projects, etc. In this case, photos of the failed work pieces may help in getting good responses for you. Also give us the feeds/speeds/depth of cut/percentage of step over, etc.

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Are the bits you are using set up correctly in the tools database? A 60 degree V bit should work fine. I also use a 30 degree V bit with a .030" flat at the tip.
One time I did have a 60 degree bit labeled as a 30 degree and could not figure out what was happening until I noticed my mistake.

You might also be able to use an 1/8th inch to clear it out then the V bit to finish it off. That coaster should not take more than about 6-8 minuets to carve
Hi Joe and welcome.
Welcome to the Router Forums Joe.

I would use a 30 degree bit for the edges of the pocket and a small end mill to clear the remainder of the waste. I'm not sure what feeds or speeds you CNC is capable of so I can't say if they are correct.

Another thing to consider is the material you are using. If it is soft you might get a lot of fuzzies or chip out.
Welcome, Joe, there are a several experts on CNC here ,and they love to help out a newbie.
Welcome, Joe.

I looked at the coaster. Unless I'm missing something, it's not designed for V-carving. I has a pocketing toolpath and raised letters for the ring, and the center "A" is just pocketed. I zoomed in on the image and it doesn't use a v-bit anywhere. The bit apparently used for the coaster is 1/32" straight end spiral. If you can program it with your software, I'd try roughing with a 1/8" spiral bit, and using a 1/32" spiral for finishing.

As far as cut time, I'm no help. The smallest bit I have is a 1/16" taper, but I don't usually go smaller than a 1/8" straight or ball nose spiral. 1/32" is pretty fragile and can't be pushed or it will break. 55 hours can't be right, but I'm guessing it will take a long time.

The attached 3d rosette is 3.5" x 3.5" and is cut with roughing and finishing passes. The bit is 1/8" spiral ball nose. It takes around 20 minutes to cut. I designed it in Aspire.

Finally, as far as holding down small pieces, try the blue tape & super glue technique:



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Joe, what ever you decide to do to the file you might want to node edit the file before you generate gcode. All those nodes can greatly slow down your CNC.


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Thanks for all the help on this one, everyone. I haven't had a whole lot of time to do too much experimentation, but I did eventually give in and purchase Vcarve Desktop.

I'm getting closer to what I'm trying to accomplish. I actually had a file get lost (somehow) and so am having to redo my relatively successful one from scratch.

Can anyone give me a suggestion on how to fix what I've got in the picture attached? If you'll notice, the "D" in 'lead' has a nub in the center, rather than the interior of the D being completely removed.

I've also attached the Vcarve file for those who can look at it.


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Looks like you created a profile along the vectors using a vbit instead of a VCarve toolpath. Try selecting a “vcarve” toolpath. You will want to use a flat depth and add a separate bit for doing the clear.

Here’s a basic tutorial

VCarve keeps a list of “recent” files and you should be able to reopen your other file even if you forgot where you saved it, at least as long as you did save it. Remember to save your design file (just do a regular windows file save) as well as saving your g-code files. Save early, save often!
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Remember to save your design file (just do a regular windows file save) as well as saving your g-code files. Save early, save often!
Yeah, that's what had happened. I was exporting gcode files, but apparently hadn't saved the actual project for a long time.

As for the bit, I'd actually done an 1/8th endmill. I'm still trying to work out an understanding as to when I'd want to vcarve using a vbit and when I'd want to profile.
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