V-Bit Question/Problems

[bigboxkurt]

I'm trying to use an Onsrud 60 degree bit in pine, oak, and MDF. Having tons of problems with chip tearout and bits of (forgive my lack of a better word for it) feathers left in the groove. I've carved a few different designs and they all look really terrible. Any suggestions? I'm also noticing on the bit itself there is like a little metal near the tip, sort of between the gullet and the flute (does that make sense?) It's on one side and not the other. Wondering if it didn't get ground off in the production process. I can post pics if it would help.

Here are the feeds/speeds: 19000 rpm 3in/sec

[rcnewcomb]

Here are the feeds/speeds: 19000 rpm 3in/sec Slow it down to about 13K RPM.


Having tons of problems with chip tearout and bits of ... feathers left in the groove.Pine tends to fuzz much more than oak or MDF. In any case using a sanding sealer before carving will help with the tearout.


I'm trying to use an Onsrud 60 degree bitI've had better results with the CMT 60º bits compared to Onsrud.

[bigboxkurt]

Yes I thought the speed might be a bit high. I put in a cheapo bit and pulled it back to 13000 and about 2ips. That really cuts the tearout and "fuzz" down a lot. I'll try the sanding sealer trick as well. How long should I let it dry?

I still wonder about the bit of metal on the other bit though...we'll see what happens when I try that bit with the new feed and speed.

[bigboxkurt]

From my experience thus far I think I have to agree with you on the CMT bits. I picked up a few comparable (to the Onsruds in the "Starter Kit") from CMT and I have to say they seem to work better for me. But we'll see what the long term use shows. Thanks for the advice.

[rcnewcomb]

I'll try the sanding sealer trick as well. How long should I let it dry? We usually let it cure overnight.

[joe]

I'm not sure I have any for sure advice but here goes. Check the direction of travel. Make several step down passes. The harder the surface is the better. That's what you're working tword with the surface sealer.

Did you know High Speed Steel bits are initialy sharper than Carbine? For short work they can be used.

[Big-Tex]

Tear out can be controlled by feeds and speeds. Some materials will still have it.
Talk to someone that turns stuff they will tell you.

Here is small trick taken from metal milling.
Create regular v caring tool path.
Create another same as above but single pass full depth just to clean up fuzz.
If needed run cleanup tool path.

[bigboxkurt]

excellent suggestions guys. I'll give those a try asap. I like the idea of doing a roughing pass with the vbit...especially when you consider that the little extra time could really save sanding/filing time in the future. Anyway thanks for the help.