Use of 1/8 Cutting bit

[Chino]

Hi to all
I have a question about the use of the 1/8 cutting bit.
I want to make a 1/4 wide carve region 28" long in a piece of oak 1" wide
and 3/4" thick. I've layed it out using the rectangle tool.
Can I use the 1/8" cutting bit to cut out this slot? I want to put in this slot to glue in some inlay that I have that's 0.094 thick. The 1/8" cutting bit should give me straight sides.
Secondly where do I set the depth of the slot for 0.094?:confused:
Thanks Chino

[Jeff_Birt]

What you will be creating is a vector cut NOT a carve region. You can draw the rectangle the size of the slot you want and then select 'Apply Bit' and select the 1/8" cutting bit. Set the inset to 1/2 of the bit diameter (1/16"), and set the depth and max depth per pass.

[dbfletcher]

You have a couple options.... if that is all you have on the board, you can leave it as a carve region and then go to board setting and select the 1/8 stright bit for your "pattern" bit. The depth is set by what you set your carve region depth to. You may need to adjust you region as I dont recall if it takes the bit width in to consideration when doing it this way.

Alternately, you can just put two striaght lines 1/8 inch apart and assign the 1/8 striaght bit to them. The depth is set when you assign the bit. By default, the bit travel down the center of the lines you draw... ie.. for a 1/8 cutting bit, 1/16 would fall on the left of the ine, 1/16 on the right of the line.

Doug Fletcher

[Icutone2]

Question- is the board to narrow for the machine or under the Min. width?
Lee

[cnsranch]

Two questions, Jeff

One, the inset only lets you go 3 decimals out - technically, you need 4 - .0625.

Trying your method (always made sense, just haven't done it this small), I need to go inset .075 in order to get the middle to show it's going to be carved out.

Do you trust the math, or do you mess with it till Designer shows what you want? One way or the other, you won't be exactly 1/4" wide, will you?

[Jeff_Birt]

and select the 1/8 stright bit for your "pattern" bit.


That is not a good idea. The feed-rates for the carving bit are completely different as it is much better at the rapid plunge cycles than a flat end mill (cutting bit is). If you try to use the cutting bit as a carving bit you'll' likely wind up breaking it.


Two questions, Jeff

I usually round up and do a small sample cut to see how close it is. Due to the rounding error you can be left with a very, very thin sliver sometimes but it is very easy to remove by hand.

[liquidguitars]

if I am understand this, I would use the 1/4" ballnose bit. The rounded bottom should not be a issue if your inlaying into the dado.
LG

[dbfletcher]

Jeff,

That is not a good idea. The feed-rates for the carving bit are completely different as it is much better at the rapid plunge cycles than a flat end mill (cutting bit is). If you try to use the cutting bit as a carving bit you'll' likely wind up breaking it.

Thanks for the info.. but that leads me to another question. It seems like LHR goes to the n-th degree to protect users from doing silly (not optimium) things with their machine. I always assumed since they allow you to select the 1/8 bit as a carving bit, they took the feed rates in to consideration when making that selection. So if I am to understand you, this is one of they few times where they actually made it possible for you to overstress the machine.

Btw, I've used selecting the 1/8 straight bit for "routing" out large area multiple times... (aprox. 20-25 projects I'd guess) and have not broke a bit that way yet (knock on wood). I'll assume I was just lucky and avoid doing that in the future.

Doug Fletcher

[Jeff_Birt]

Doug, if you notice when you do a vector cut it ramps the bit down into the wood as it moves along the cutting path. That method (or a spiral) is much easier on the bit. The carving bit, being a tapered ball-nose is much more adapt at plunging.

[Digitalwoodshop]

If I were doing it, I would select the 1/4 inch ball nose and install a 1/4 flat bottom PLUNGE bit with cutters on the bottom.

I would use the line drawing and snap to grid to make your art or rectangle or you could use a rectangle drawing and with it selected, select the bit and at that time you enter the depth.

I have used this function with the 3/8 plunge bit and it works well, I did limit my cut to .200 each pass. You will get round corners so some chisel work is required.

I love to watch my machine do CNC type Vector Cutting...

I would design a sled to hold the pieces of thin wood. And run them one at a time of as a group. Here is a sled I used to group together some small stock.

[LittleRedWoodshop]

There is such a bit - that is why it is listed in the bit selection. The 1/8th "CARVING BIT" is used with the Dragster Carving jig that is availalbe with the education package. Click on the video link below that explains that package and talks about the bit.

http://vimeo.com/6018374

Educarve.com (http://www.carvewright.com/education/educarve/EduCarveSite_Home.htm)