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How to eliminate mouse ears when using radiused V bit
I've been playing around with Carveco Maker and I'm getting this strange issue where the corner cutting operation during V carving goes too far and leaves a radius when using a low angle V bit. Its as if it's not accurately calculating the angle. I've tried changing the angle of the tool to be more and less than the 5.4 degrees the V bit I'm using is as well as using both the radiused carving bit and V bit tool set up and cant eliminate it. I'm trying to dial it in for V carve inlays.
Can someone please tell me what I'm doing wrong and how to fix this problem?
Cheers
Adam
Comments
What do your vectors look like, What is your choice of a tolerance in your toolpaths, mine is .001??
Your bit is a tapered end mill not a v-bit.
Mike
The tool is most likely not defined properly. The specs listed in the tool database most likely do not match real world measurements. This is actually quite common with v-bits where the advertised angle is actually +/- a degree or two off one way or another.
Screenshot and post a pic of how you have the tool defined in the tool database.
I have tried adding up to 5 degrees and removing it until it was a 1 degree V bit ill add a photo of all the trials I did none of them affected it much to be honest. The radius is set as 0.8 im not at home at the moment and the only 2 logins I have are on my PC and laptop running my machine so cant screen shot it.
Ive tried defining it as a V bit and as a radiused tip bit with + and minus for the angle. Although it looks like the hole is a square wall it used the V bit to cut the walls but when it gets to the corners its like it doesent take the tip radius into account when riding up the sides but does them right on the vector.
The vector is a square created by Maker 50mm sides 6mm deep.
The thing is...the vcarving engine isn't made for that type of tool. It's only made for either a proper vbit with a sharp point or a ball end mill. Taper tools are not officially supported with that strategy. So the game here involves doing it another way. Have you tried smart engrave? I'm not sure what the hobby versions do/don't have.
If I were doing it, I'd scrap the tapered bit in favor of a straight shank ball end mill and let the vcarving engine figure out corner sharpening. If there was no other way than to use the taper tool to get the desired shape, I'd most likely make a test square, do corner sharpening and modify the vector (offset inward a little at a time) or adjust the tool parameters and keep running simulations until it looks right. The simulation doesn't lie so rely on it until it looks right before burning through material...but since it doesn't officially support tapered tools, you'll have to account for the bottom diameter and diameter at max material depth. That may mean multiple tool paths and sets of vectors (offset in to prevent corner overshoot)
As a last resort I would generate gcode for corner sharpening (either using the vcarving engine/strategy or feature machining) and use a simple non-arcs post processor to hack apart the code in notepad. I might even just write the code from scratch using the vector XYZ coordinates for start/end vector nodes and the appropriate z height to hand code the sharpening action in the corners. That's a rare case ...but certainly doable. CAM is what I call a compromised offering. It does a lot or most of what you'd want to do, but not everything. If you have smart engraving start there.
I see people using Vcarve Pro all the time with tapered ball bits figured it's just a thing... guess I'll have to splurge and buy that instead of Carveco Maker. I know I can edit and offset and multiple tool paths for a simple shape that's fine.. for a very complex carving though it will take the rest of time.
tapered ball end mills can cut shapes faster than a straight bit (end mill) because of the added material in the shaft, if you have a tapered ball with an 1/16 ball it will cut faster than a straight 1/16 ball nose bit, this is what the taped balls are for your bit though it looks to have a flat on the end will not do what you are after. Brady has some good advice.
So you are after inlays, right? How thick are they, how deep do you wish to go? When you are after using a v-bit the depth or the thickness of your material isn't going to be very much or shouldn't. if it's going to be an inch you will have problems, if it's say a 1/16 or may-be an 1/8 you can do that with a 60 deg v-bit. Using a v-bit will help a chive a good mesh with the 2 different materials. if you are after putting an inch into a pocket using the bit you have chosen then no matter the software you are in a losing battle. If it is thick material than a toolpath a straight bit will do, just choose one inside of vector and then the other choose outside vector.
mike
I make end grain chopping boards and built a CNC after seeing this guy do this
https://youtu.be/jXKLyGUiqE4
Hopefully links work here.
I have tried larger angled V bits and yes they work great but as soon as the gap between the vectors is narrow they dont go deep enough. Even with the bit im using in some places it doesent go deep enough so 60 degree wont work.
Thanks for the help btw im determined to make these bits work I see no reason why they cant (obvisouly there will always be a small radius but the issue is that they go out PAST the vector line for no reason)
Surely this is just a coding problem with the pathing not taking into account bit tip radius.
I know im being stubborn but I have seen these bits do exactly what im trying to do its just every one else uses VCarve pro but 1000Aud is a tough pill to swallow.
Consider toolpath strategy of PROFILE!!!! Nothing but a Profile toolpath is what you need to accomplish what you wish, you, like us all over think things,.
What you need to do is cut out your part to fit inside another cutout, a pocket if you will. You can do this with a tapered end mill so your part will fit inside, just use the same tapered end mill on both the inside and out side cuts, the part and the pocket. The part will fit very nice, sweet as a mater of fact.
Hope this helps
mike
Forgot to say that when you do the profile toolpath with one of these tapered ball noses you will want to set the cutter to the size of the ball end, if it's an ,125 that is the size you will be wanting use.
mike
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