Packed chips in the cut channel

CNC Machines
1

I’m having a heck of a time doing a v-carve with some small 30 degree vbits I picked up from amazon. The cut channel always seems to get packed full of chips, leading to lots of manual work at the end of my job to clear it all out.

https://www.amazon.com/SainSmart-Genmitsu-Engraving-Degree-Conical/dp/B07P99F3L1/ref=sr_1_4?dchild=1&keywords=sainsmart+30+degree+v+bit&qid=1632786157&s=industrial&sr=1-4

Very little information is available regarding speeds and feeds, so I’ve experimented quite a bit without success. Here’s a visual of what I’m running into:

IMG_20210927_152515974
IMG_20210927_1525159741200×1600 140 KB

I’ve made about 20 of these test cuts. All cuts are done to a depth of 5mm with varying feeds, speeds, and cut depths per pass to try to find a sweet spot. No luck.

The left cut channel was done with 1.5mm cut depth per pass, the center channel was at 1.0 depth per pass, and the right WAS at 0.5 cuts per path. I cleared out the channel on the right side just to inspect the cut quality. It looks great to me, but all those damn chips need to be manually removed.

I’ve tried variations of feeds up to about 150 ipm, and router speeds from about 10k to about 20k, and can’t seem to find a good combination. Dust removal shouldn’t be a problem, as I’m using the sweepy dust boot and a harbor freight 2hp collector.

Any ideas? I might just need to give up on these bits, which is a shame since the final cut quality is great.

2

What are you using for dust collection?

3

There’s plenty of suction with my DC setup. The only other thing I can think of to clear out the chips is compressed air. :frowning:

4

Have you tried running a (literal) cleanup pass where the V endmills make a full-depth pass?

5

Yep, and it does help quite a bit, but a good amount of the packed chips/dust remains.

Here’s a pic of the same test pattern with a final pass of an additional 0.05mm depth. The arrow points to the cut post-cleanup.

IMG_20210927_213618813-cleanup
IMG_20210927_213618813-cleanup539×1595 282 KB

6

I use that bit often and have seen the same chip clearing issue. What help me is I run the feed a little on the slow side so the chips are quite small, usually around 25 IPM and 18000 RPM. Also, keep the dust boot low enough so a few bristles can get in the cut and help lift the chips out.

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7

That design is likely not really made to cut that deep. An upcut would do much better clearing chips rather than the neutral flute design.

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8

Any recommendations for low angle v cutters? All v-bits that I’ve seen that are 30 degrees or less have a very similar design. The 60 degree v bit from carbide 3d is well built and clears chips well, but I need finer detail for most of my jobs.

9

I have been using a 30° vbit that has a single flute, similar to a single-flute endmill but in a V shape:

https://www.cncfraises.fr/pointes-javelots-1-dent-cvd-diamant-queue-3-175mm/302-pointe-javelot-1-dent-carbure-cvd-diamant-30-degres-pointe-0-1-mm-queue-3-175mm.html

This specific link won’t help you since this is a French vendor, but you should be able to find similar 30° vbit locally ? It works wonders for me.

2 Likes
10

Drillman1 has Kyocera endmills which have a helix:

and which clear chips well.

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11

I found similar issues with Amazon bits - the v cut does not eject chips as well as v cutter that has a upward cut to it.

12

I haven’t cut any wood. But I use 15 and 30 degree engraving mills on my machines daily. I have some of the Mills suggested above by Will, they are of good quality, but most of them are 2 flute, and difficult to feed fast enough on my Shapeoko or ballscrew machines for my purpose. I typically use a single straight flute engraving mill. At least with the plastics and aluminum that I engrave, when I have chips packing, I am feeding too slow. Air blast works great if you don’t mind the mess/air quality penalty.

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