[William McLean]

Hi, I just started with cnc routing. I would like to know the ideal speeds for routing various types of wood. Is there any guide or is it trial & error?
Thanks for reading:violin:

[dlcw]

William,

V-carving is a science as well as an art. The first thing is to make sure your bits are REALLY sharp. Dull bits will burn and create a lot of fuzzies that you will have to clean up by hand. I use a sharp goose-neck scraper to clean up if the cuts aren't clean.

What I've found is that I run the spindle at around 16K rpm and feed at about 1" per second in a climb cut direction and take no more then .08" per pass. Also, on the climb cut, I will leave about .01" of material for a second pass in a conventional direction. What this process does is clean up the fuzzies and makes for a cleaner cut. The feeds and speeds have worked well in bubinga, cherry, maple, oak, hickory, alder, western red cedar, douglas fir, walnut and many other types of woods.

I use Amana tools that have the changeable blades. Initial cost is high but the replacement blades are very reasonably priced. I've found the v-bits made from a cylindrical piece of carbide with the bevels cut in to create the v portion create lots of fuzzies and results in a lot of hand clean up work (not what I bought a CNC for).

Hope this helps.

[William McLean]

Thanks very much for your reply, it was very informative and I shall try what you suggested. I have the Amana tools and the changeable blades. I did notice some burning, probably attempted to cut too deeply in a pass.


Again Thanks
William McLean

[ger21]

Burning is from going too slow, not too deep. Either increase the feedrate, or slow down the rpm.

[louieatienza]

William,

V-carving is a science as well as an art. The first thing is to make sure your bits are REALLY sharp. Dull bits will burn and create a lot of fuzzies that you will have to clean up by hand. I use a sharp goose-neck scraper to clean up if the cuts aren't clean.

What I've found is that I run the spindle at around 16K rpm and feed at about 1" per second in a climb cut direction and take no more then .08" per pass. Also, on the climb cut, I will leave about .01" of material for a second pass in a conventional direction. What this process does is clean up the fuzzies and makes for a cleaner cut. The feeds and speeds have worked well in bubinga, cherry, maple, oak, hickory, alder, western red cedar, douglas fir, walnut and many other types of woods.

I use Amana tools that have the changeable blades. Initial cost is high but the replacement blades are very reasonably priced. I've found the v-bits made from a cylindrical piece of carbide with the bevels cut in to create the v portion create lots of fuzzies and results in a lot of hand clean up work (not what I bought a CNC for).

Hope this helps.

Don, I have just purchased the Amana V insert bit. I have some cheap Ryobi bits and though they cut relativevly clean, the corners leavev a bit to be desired. I got the one that's also used for miter-folding, is this the one you're referring to?

[dlcw]

There are v-carve bits and miter fold bits. The v-carve bits are for just that - doing v-carve work in the surface of your material. The miter fold bits are used to cut all the way through the material and create 45 degree angles on two parts so they can join together in a really accurate miter joint. I won't say a perfect miter joint, because after more then 30 years of woodworking I still haven't achieved the "perfect" miter joint using power tools. I have come really close using a table saw and a hand plane to fine tune.

[louieatienza]

There are v-carve bits and miter fold bits. The v-carve bits are for just that - doing v-carve work in the surface of your material. The miter fold bits are used to cut all the way through the material and create 45 degree angles on two parts so they can join together in a really accurate miter joint. I won't say a perfect miter joint, because after more then 30 years of woodworking I still haven't achieved the "perfect" miter joint using power tools. I have come really close using a table saw and a hand plane to fine tune.

The salesperson at the Amana distributor I purchase from might disagree. I purchased the 90 degree v-carve bit, after reading about it in their catalog. Of course curiosity sets in, so I take the insert out to look at it. And the part number of the insert is the one for the 91 degree miterfold bit! So I call the rep at the distributor to mention this. He followed me through the catalog and showed me all the inserts are pretty much exactly the same (save for the MDF insert which is a different carbide formulation) geometry-wise, and should perform as advertised. Which it did. I did order the MDF insert as well, and aside from the color and edge polish, is exactly the same shape!

I think only God (or God's CNC) can make perfect miters. Of course working on the field, I'd be hard pressed to find a perfect outside corner. No problem on the inside corners as I always cope them, and I have to say I do get them near perfect just with a coping saw, and dead tight if I touch them up with a file... but I only file them on pre-finished moldings...