# Question about planing my spoil board



## MT Stringer (Aug 15, 2012)

I am installing a new spoil board. I carefully measured so it is inside of the limits by about 1/2 inch. I am wondering if I run the gcode to plane the board if it will hit the limits. In order to get a full plane, I need to offset the toolpath a little all the way around. That my be a problem.

So, saying all that, what if I run a profile pass first using the same bit (1 1/2 inch cutter) and the same depth (.020) and run the tool path on the vector. That should make the cutter cut over the edge of the board a little...well, a lot. Then the regular pocket toolpath can be run to plane the rest of the board.

Does that sound reasonable?
Tomorrow is the day. I am waiting on some nylon bolts to come in from Amazin.
Thanks
Mike


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## BalloonEngineer (Mar 27, 2009)

Unless you have some kind of fancy laser limit switch that could detect the edge of the bit the limit switch is based on where the structure trips the physical switch. Put the bit in and jog until it trips the limit and see where it stops. You should adjust the limit switch to be just inside the hard stops. Ideally you do want to surface the entire spoilboard so there is no ridge at the edge that could cause a long board to not lie flat if it extends past the edge of the spoilboard.i

You tell your CAM program what bit you are using, so it knows how wide the bit is and will use the full width of the bit to get to the edge of the specified area you are surfacing. I recommend you do the entire area as one path, not one for the edges and a separate one for the interior. It usually called “area clear” or something like that.


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## MT Stringer (Aug 15, 2012)

Here is what I am working on. The nylon bolts will be here tomorrow and then I can bolt the boards in place. Pretty cool. I designed a file for each width and had the CNC drill the pockets and holes in the spoil boards. Tomorrow I will drill the holes in the factory board and bolt 'em down.

Probotix claims the Asteroid has a cutting area of 36 x 24 inches. My boards as they sit are 36 3/8 x 24 inches. But they are just inside of the limit switches. I jogged the router to and fro to double check the measurements before I started with the new boards. All the T tracks are screwed in place.


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## difalkner (Jan 3, 2012)

I realize it's different in Fusion 360 but I had to tell the CAD portion my spoilboard is 24 x 48 even though the machine will cut 26 x 50. Because the toolpath loops at the end of each X axis movement I was hitting the limit. The loop gets the entire board so all I did was 'fool' it by size and now I can cut the entire board. By default F360 adds 0.04 to the side offset and I just left that in but usually zero it out if it matters.

You're gonna like the nylon bolts; I've hit mine a few times and no harm, so that's a good thing.

















David


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## Semipro (Mar 22, 2013)

I know very little about this cnc stuff,
why could not do it 2 pieces once it is bolt down it would not move?


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## BalloonEngineer (Mar 27, 2009)

difalkner said:


> By default F360 adds 0.04 to the side offset and I just left that in but usually zero it out if it matters.


As is almost everything in Fusion 360, this is configurable. In the drop down labeled “Mode” that shows “Relative size box” in your screen capture, I always change that to “Model” and model a solid the actual size* of the stock I’m using. That way I can also use a model corner (the corner of the stock model, not a corner of my _part_ model) as my X0Y0 point. I locate my stock model to give me room for clamping, the .04 inches Fusion 360 uses as the default is usually less than I need. 

Neither way is better or worse, but my way helps me keep track as I switch between using ArtCAM files and Fusion 360 files since I nearly always use lower left corner of my stock as my reference. ArtCAM, VCarve and Aspire all default to using a corner or center of the stock as the reference point for generating toolpaths.

*Actually, I usually just model stock “big enough” to contain part in rounded up dimensions, and often use a larger piece of wood.


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## difalkner (Jan 3, 2012)

BalloonEngineer said:


> As is almost everything in Fusion 360, this is configurable. In the drop down labeled “Mode” that shows “Relative size box” in your screen capture, I always change that to “Model” and model a solid the actual size* of the stock I’m using. That way I can also use a model corner (the corner of the stock model, not a corner of my _part_ model) as my X0Y0 point. I locate my stock model to give me room for clamping, the .04 inches Fusion 360 uses as the default is usually less than I need.
> 
> Neither way is better or worse, but my way helps me keep track as I switch between using ArtCAM files and Fusion 360 files since I nearly always use lower left corner of my stock as my reference. ArtCAM, VCarve and Aspire all default to using a corner or center of the stock as the reference point for generating toolpaths.
> 
> *Actually, I usually just model stock “big enough” to contain part in rounded up dimensions, and often use a larger piece of wood.


I do the same thing, Richard. Matter of fact, you can right-click on those fields and use your setting as the default. Most of the time my stock is at least 1/2" larger all the way around so I now have that as the default for side offset but I have the top offset default at 0.0". But in this case it just didn't matter that it gave me 0.04" side offset so I just left it alone. I did, however, change the top offset to 0.0" on the spoilboard cut.

David


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## honesttjohn (Feb 17, 2015)

Nice tracks. Look like they belong.


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