V-Bit banding issues

Has anyone experienced this kind of banding when you’re using a v bit? Any idea would might be causing the problem?

Can you post a better pic of the problem? i’m having a hard time seeing what you are talking about. What software are you using? what bit/specs and what kinda tool path are you running ?
Also that is a damn nice dust collector setup you have there I really like the hose support your design?

Looks like maybe your step over is set too high

What’s your RPM setting on Dewalt?
I use 4 to 4.5 for Deep V carving. Also Feed rate must be slower.

Doesn’t that almost look like some kind of chatter?

Here’s a better picture. It seems to maybe be z axis related. What do you think? The mount system weighs about 7 ounces, not sure if that would cause issues. Step over does sound like a possible explanation let me check my vcarve. One other issue is I have noticed pretty bad plunge accuracy, especially on tabs.

now it looks like a calibration issue

What was your feedrate and depth of cut?

Well I tore it down and rebuilt it. You were right I did find some loose v wheels. It is better than it was, but the banding is still present. I guess I need to move on to calibrating the z axis?

My speeds in pine are DOC 0.125, 50in/m feedrate, 20in/m plunge with a 0.50 90° V-Bit.

There is a guy who created a video on checking your vbits.

very interesting way to check them too.

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It depends on your Vbit, most Vbits blades cutting single side especially Chinese bits. Or some bits we’re using here have replacable blade (Amana tools) and you must go twice on rpm. I respect your little machine knowledge but we use here one 1325 chineese machine, two Laguna smart shops and produce almost 50 signs per week. Xcarve which is my hobby machine only do clocks, small boxes and table top name plates. Non of them working less than 18000 rpm for Vbit. Besides, straight edge bits chops badly. Best way to find proper feed rate and Rpm for Vbit is to make straight lines and listen chopping sound change rpm until cuts gets quiter. Some point you’ll find sounds like vistle of mosquito.

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I also run v-bits with a faster spindle speed. Like Alan, I go by the sound of the cut and adjust the speed until it is cutting smoothly.

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Awesome. I was actually wondering if such a test existed as I have long suspected my V-Bit wasn’t the correct angle. Since it’s 10 different tools, how do you keep the gcode exporter from whining?

I’m with you on that. You have Vbit perfectly even blades welded. It’s almost 1 in 1000. Keep it clean, pray for the longer life. When you get another bit with bad blades, you will understand what that means.

This is an accuracy issue. There are several things that I would recommend that you do. First you need to check the z axis for square. The stepping issue could be caused from the spindle not being square to the surface. The best way to resolve this is to tram the spindle I will provide a link to a video you can watch. After you tram the z axis you will want to re-calibrate your machine, do not calibrate first if your machine needs to be trammed and most home built machines do need to be trammed. It will be out of calibration after you tram, thats why you tram first then calibrate. https://www.youtube.com/watch?v=D6pfIoyhgTc&t=355s