[racky440]

Hello everyone,
I am using a chinese cnc router mostly for woodworking purpose. For so many days I am having trouble with the quality of the edge finishing. I use vectric aspire software and when I run a profile cut on vector lines, it ends up with bad edge finishing. please have a look at these picture. I used point roundover bit at 12000 rpm. I am confused, please help me.

[rowbare]

I don't know enough about wood to be able to help you much but even if I did, you haven't given me enough information.

What type of wood is this? There is so much variablity in how wood works that it will be nearly impossible to help you without knowing this. You mentioned the spindle speed, but what is the feedrate? It might not be obvious to everyone what a point roundover bit is. It might not hurt to post a picture of the cutter and to provide a bit more information about it (brand, carbide or hss, how much use it has had etc...).

If you reply with these answers it will make it a lot easier for someone to help you without having to go back and forth half a dozen times.

Hope someone can help you out!
bob

[ger21]

You need higher rpm for a pointed tool.
The harder the wood, the better the cut quality will be.

Make sure the bit is very sharp.

[racky440]

Thank you ger21 and rowbare for your kind reply.

There are some further information including bit picture. I used teak wood. Which is a soft type of wood. Feed rate of the bit was 372 inches per minutes at 12000 rpm. Dia of the bit is 20mm where shank dia is 12.7mm. brand- chinese. carbide bit. I used the bit for 6 times only. I checked the sharpness before the work, it was ok. Also depth of the cut was 6.35mm. I applied single pass to cut the design.

@ger21, I can speed up my spindle upto 24,000 rpm. what is your recommendation?

thank you again.

[ger21]

Feed rate of the bit was 372 inches per minutes at 12000 rpm.

Try 100ipm and 18,000 rpm.

With pointed tip tools like that, the velocity of the cutting edge near the tip is very slow, so you need to use a lower feedrate and higher rpm to keep the tip from dragging through the wood, rather than cutting.

[racky440]

@ ger21,

Thank you very much. I am sorry to reply late. I was implementing those strategies. I approached with 100ipm and 18000 rpm. Performance is better than before. but there are still some problem at every corners. should I decrease ipm from 100 to less?

[awerby]

That's not likely to help. Wood needs to be cut fast, or the tool starts scorching the wood. If it dwells there for too long, it can even start a fire. I'd try another style of bit; that round-over bit you show is a specialized tool designed for cutting the corners off square edges, not for general carving. Instead, try a tapered ball-nose bit like this: Tapered 3D C arving Tools