Cutting speeds & rpm for teak

[brian]

I'm doing a sign in teak
Using a .75 60deg for v carving
Also a .25 bit for clearance
Can anyone recommend speeds.
Also would a .25 straight bit be better than a spiral?
This wood is well seasoned in the sun will that present any issues

Thanks Brian

[Brady Watson]

Brian,
It machines faster and easier than the density would lead you to believe. I always run v-cutters slowly - typically around 0.7,0.5 to reduce deflection when it jacks all 3 axes into a corner, and to minimize stress on the tip of the cutter. V-bits drag at their tip, and without any place for the chip to go, it is basically plowing through the material.

There's no problem running a spiral cutter. In my experience, there isn't much tear out on the top edge. I've had fine edges tear out in Conventional, but nothing major.

As always, your mileage may vary...

-B

[knight_toolworks]

if your just pocketing out letters after the v bit then you just want a bit that makes clean bottoms. so a upcut or straight will do a good job. I usually use down cut bits but the bottoms are not as clean.
depending on how much material you are removing.. if it is say less then 1/4" or so I could go up to 3ips and 8k rpms. more more then that a bit slower or do it in two passes. teak is fairly soft compared to most of the woods I cut.

[brian]

Thanks
Brady when you say 0.7,0.5 do you mean IPS

Brian

[Brady Watson]

Yes - ShopBot speed default is in Inches per second.

-B

[Gary Campbell]

Brian...
I have had very good results cutting Teak with a single O flute. They work very well with slow move speeds.

Watch for some minor surface tearout with upcuts.

[brian]

I did the vcarve today with new bits.
I did slow down the ips to 1.5,1 10,000 rpm and found it cut very cleanly.
There was less noise than normal when running a vcarve file.
So I'm assuming this translates into less stress and a cooler running bit.
Just got some 0 flutes in the mail today.Will give them a try in some scrap left over.

Thanks
Brian