Tear out with Oak

[kurt_rose]

Hi Guys! I'm looking for some advise in these medallion's I'm making for a local winery. Ive made them out of cedar and they turned out beautiful so the problem is obviously hardwoods. Whats the secret to getting a clean cut. Both the 60 degree v-bit and the endmill I'm using to cut out are brand new and sharp so I'm leaning towards speed and toolpathing being the problem. I look forward to you guys laying some more of your knowledge on me! Thanks in advance.

[steve_g]

Kurt

Oak is a problem child when V-carving... I have gotten better results by finishing the surface first, at least a good lacquering.

SG

[Brady Watson]

Oak is a problem child when V-carving... I have gotten better results by finishing the surface first, at least a good lacquering.[/SIZE]

Yep...or soak the heck out of it with shellac to plasticize the fibers, then machine it. Sometimes it doesn't penetrate deep enough, so you'll want to Zzero and move the Z say .04" up and ZZ. Then cut. Then soak with shellac. Then re-machine @ full depth.

-B

[srwtlc]

Are we sure that's oak? I go through a ton of red oak and I've never seen it cut that bad, even with dull cutters. Sure, you can lose islands or inside corners of letters when v-carving, but what you have there is extreme.

A closer look at it makes me think of Lyptus or something similar. Very straight grain and almost straw like. Cross grain cuts exhibit tearout much the same as shown and whole islands can chip off.

Unless it's some kind of regional wood called oak, it looks different and cuts different than any I've seen.

On hardwoods, my favorite 90º v-bit is one from CMT (815.690.11). It has what you would call a single/double flute design I guess. One flute goes all the way to a sharp point and the other flute is stopped short of the tip by maybe 0.125". Because of that, you have a nice sharp cut at the bottom of the V and a good clean surface cut while being able to run at higher RPM for the single flute at the tip. I get good results in red oak, but you can still get the occasional chip off on the inside tips of some fonts.
Any online pictures don't show the new profile. At least that's how I've been getting them lately.

[kurt_rose]

Thanks for the replies guys. I found part of my problem. It seems the bearings are shot in my PC router. It has a good amount of play in all directions. Can't believe I couldn't hear it. I have a spare so I'm gonna keep on keeping on. Time to start thinking about a spindle. I have the perfect excuse now.

[Brady Watson]

Looks like it was v-carved with a ball?

-B

[kurt_rose]

Yep! A ball of confusion! LOL! Brady don't make fun of me but when I went to change out the router it was loose in the bracket also. Talk about a wasted day due to stupidity of the operator! I'm just gonna call the rest of the day Miller Time and see what tomorrow brings.

[Brady Watson]

Just make sure you put the time into getting the machine tightened back up. Quality degrades over time and it is hard to realize until you have situations like this...although I must admit, that level of 'degradation' is pretty coarse

Take care of your machine...and it will take care of you!

-B

[Chuck Keysor]

The pictured wood does not look at all like oak, either red or white. I have done maybe 20 v-carved plaques with white oak, and the results were excellent.

And, there was no mention of what bits were used, only that new bits wee used.

When I first tried V-carving, I bought two brands and multiple different bits of each. I got terrible results, in terms of the lines being poorly defined. But when I switched to CMT "Laser" 60 degree bits, my results went from embarrassing/frustrating/disappointing, to exceptional! So a brand new bit means nothing if it is a junky bit, OR a bit that may not be junky, but was not designed for fine detail work. (Maybe the bits I got that gave me crummy results, and I called junky, were great for someone who had different objectives.)

Chuck

[kurt_rose]

Thanks Chuck. I just ordered a couple CMT 60's from Amazon and will give them a try. The price on the CMT was about half the price so I figured what the heck. I have been running an Onsrud 60 for the lettering I've been doing lately and have been very happy with it. I just installed the new router and all is well again. I'm gonna give my machine a complete once over before jumping back into production so my pal Brady won't have to school me for a while! Thanks for all the help everyone!