I’m trying to dial in my settings to do VCarve inlays but can’t figure out where my issue is. I’ve done a couple inlays but more recently I’m having issues just simply creating the pocket.
I’m running on a gen 1 woodworker with Makita router and bb controller.
I’m using a 1/64th radius tbn setup in VCarve Pro as a v-bit. I’ve used the radius all corners gadget set at 0.019” and 0.02” and double checked that the vectors matched that. This should be plenty of clearance for the 0.0156 but radius. However, each time it comes to one of those corners the bit rises more than I think it should and creates a more rounded corner as seen in the picture around the letters and tips of the saw blade.
I’ve tried with just cutting the letter T and no matter what I change I continue to get the same result. I’ve resurfaced my spoilboard, measured my probe block and adjusted it (though there is something weird going on with that) in the machine settings, tried setting up the bit as tbn, engraving, and v-bit, I also tried a 0.5mm radius tbn. I’ve trammed the router and checked the runout. I machined a 1”x1.5” pocket with +/-0.002 tolerance. I haven’t gone larger than that but that’s the scale of my test cuts which still aren’t working. I realize tricking the software by setting up the bit as a v-bit could cause problems, but it’s the same bit many others have used and as far as I can tell I duplicated their process setting it in the tool database.
Any other things to try would be greatly appreciated.
Thanks for the idea @Ken5, unfortunately that isn’t an option with the V-Carve toolpath.
I’m still having difficulty just trying to determine if it is a maching problem or software problem. It almost seems like the bit geometry is off or it’s expecting the material to be just a bit thicker. I’ve checked the Z0 location multiple times and it is right at the surface of the workpiece. I just can’t for the life of me figure out why mine is different than every one of the YouTube videos or pictures I’ve seen of a simple v-bit toolpath pocket.
Attached is my vectric file. Hopefully someone is able to give it a try and find a simple error I’ve been overlooking.
Here is a screenshot of the bit profile I’m using. It’s the 1/64th radius TBN from CIC Workshop. I’ve got a brand new TBN with a different angle and radius I’m going to try to see if maybe the one I’ve been using has lost the tip a bit causing an issue with the geometry not lining up right when it rises in the corners.
Here are some pictures of today’s test. I thought maybe bit deflection was contributing to the issue so I ran the toolpath 4 different times. I don’t see enough difference though to believe that is the whole issue.
I also tried a different bit, at 0.25mm radius 5.62 degree tbn setup as a v-bit. I cut that into a piece of MDF and still get some odd rounding in the corners.
I’m really at a loss. Every video I’ve watched regarding the use of a TBN for inlays has done this exact thing without these issues, at least not nearly as noticeably.
What happens if you set up the tool as a TBN instead of a v-bit? I’m wondering if you have an angle entered in wrong. The CIC bit information isn’t very detailed. It says the angle degree is 6.2 and I see you’ve doubled it because that’s how v-bits are set up. I’m wondering if it really is a 6.2 degree with a side angle of 3.1 degrees (so don’t double the degree)?
You can still do v-carve toolpaths with a TBN. That’s how I’ve done inlays in the past (not many inlays under my belt).
At this point you know what you have isn’t working and I think you’re right that it’s a geometry issue… I would try and enter the tool correctly and see what happens.
So the way I look at it
You have a T with rounded corners according to your file and because you are using a TBN when it is plunging in the corners its over cutting because of the taper
The radius of the model corner doesn’t match the radius of the taper at full depth of cut.
It only shows up on the inside corners do to the geometry of the shape
Hey @TommyObar, thanks for that info. I think I tried it that way but I’m going to give it another go and see what happens.
@PezWoodworks I haven’t attempted cutting the plug yet but my guess is that the plug should have those odd artifacts on the opposite corners. I radius both inside and outside corners so that it’s not an issue. I am curious though to see what the plug toolpath looks like to see if it shows up there as well. I could probably live with it happening to the plug because it would be at the surface which would go into the pocket.
To be completely honest, I haven’t done an inlay yet but will be trying that soon (thanks to this discussion ). The recommendation is to use v-bits. With TBN you’ll need to make a few tweaks. I found an interesting video that compares different strategies for using TBN for inlays.
Can’t wait to see how your project turns out. Keep us posted.
Here are a couple photos from a quick test today. I entered the bit as a tbn with the parameters shown in Tommy’s image, unfortunately still the same.
Out of curiosity I ran a 60° v-bit to see how it behaved and it looks fine. Tomorrow I think I’ll try to measure the tbn bit and see if maybe the angle is off or try Noah’s suggestion using half the angle.
If anyone has a similar bit and is willing to try I’d love to see if it happens on another machine.
I see the same performance from both bits. The bit sweeps the corner up to create a pseudo square corner. The V bit achieves this because it comes to a sharp point but the TBN leave a circular mark the diameter of the end of the ballnose.
I understand the bits are performing the same way, which is what I want. What I can’t determine is why the TBN is creating the small circles. In my pictures the v-bit test doesn’t have sharp corners either because the vectors are rounded. It might be a little hard to tell from the picture, but the v-bit cut the same vectors with rounded corners and the tip didn’t come to the surface of the workpiece to make the sharp point. I’ve edited the corners to make sure that the radius is larger than the tip of the TBN so that it doesn’t try to make the corner sharp like a v-bit would. There are plenty of people using the same bits this way and having success. I’ve even done a couple cutting boards successfully with this method which is why it’s frustrating now.
The YouTube channel Tommy posted above has several videos on using a TBN for this type of work and I’ve duplicated his settings and still get this problem. I might just have to spend some time on my machine and check every motor and axis and see if anything is loose or maybe something mechanical is wrong.
). The recommendation is to use v-bits. With TBN you’ll need to make a few tweaks. I found an interesting video that compares different strategies for using TBN for inlays.
