Fuzzy edge while v bit engraving

Hello guys,
I am having issues while doing V bit engraving in wooden parts on my CNC (a Chinese one).
Following are the parameters set while machining.
Feed rate: 200 ipm
RPM: 5000-6000
Tool: V bit 30 degree
Spindle power: 9kW
Material: Teak wood and birch plywood

Please refer attached photos that shows a fuzzy top edge. (Birch ply looks awful !)
Sanding will reduce the burrs but rather it should be machined smoothly.
I have seen many videos where they get a crisp edge with a V bit !
I am relatively new to engraving with V bits. I know a DC endmill will resolve the problem but I need sharp corners, that's why I am using a V bit.

Thanks
Snehal

Your chipload seems to be way too high, especially if you have a single edge "half circle" type V-bit. I would try at least 5 times slower, 40ipm@6000rpm.

If the bit is high speed steel and has been used to cut birch ply (baltic birch perhaps) your edge won't last very long regardless of feed or spindle speed. Start with a sharp carbide bit made for cutting wood. I would also slow your feed a bit, but would also increase the spindle speed to something on the order of 15,000 rpm.

Lower feedrate, higher RPM, sharper bit.

I'd go for 75ipm at 14,000 rpm. With a new, SHARP bit.

...what temperature is your machine room? is the wood frozen? anyone try that yet?

Hmmm... How about cryogenic wood machining? I know they do it with rubber...

Quote:

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Originally Posted by MARV

If the bit is high speed steel and has been used to cut birch ply (baltic birch perhaps) your edge won't last very long regardless of feed or spindle speed. Start with a sharp carbide bit made for cutting wood.

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My bit is HSS (2 flutes) which seems to be the root cause.
The chip load with current parameters is 0.017", is it too high? I would surely try out lower feedrate and higher rpm in accordance with all of you.

Thinking whether the grain structure of "teakwood" has a role in it?

The machine room ambient temperature is 100 degree F and wood is in normal weather conditions, so its definitely not cryogenic!!:)

Thanks for all the inputs, will revert soon with outcome by applying suggested parameters.

Snehal

Quote:

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Originally Posted by Snehal_Shah

My bit is HSS (2 flutes) which seems to be the root cause.
The chip load with current parameters is 0.017", is it too high? I would surely try out lower feedrate and higher rpm in accordance with all of you.

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If it's a "half moon" V-bit, it only has one cutting edge, so it's single flute. 0.017" (0.43mm) is already too high, and if you really have a single flute cutter, then it's 0.86mm - definitely too high.

Teak will eat HSS. Get a new carbide bit.

A coat of finish will also help keep the fuzzies away.

Hi SS - I use a 50/50 mix of PVA glue to seal the surface before I do fine work. The PVA binds the grain together and it cuts better. You can use other sealers as well that are compatible with the top coat. sharp tools always...plus a rough cut then a finish cut is helpful for grumpy grain...cheers Peter