# Blade offset illustrated: opinions please



## Nisei (May 4, 2011)

I was figuring out what offset actually is and when asking around I got some contradicting answers.
So what I did was make an illustration on how I think it works. I'm not sure if it's right so please correct me if I'm wrong

Blade offset is the distance from the center of the blade to the tip. So actually half the diameter of the blade. So basically, it's the same for different angled blades as long as the diameter is the same. (see left side of illustration)
But as soon as you're cutting into material this changes because even when cutting the same material, the angle of the blade causes the offset to change. (see right side of illustration)
This means that the larger the blade angle, the larger the offset. And the thicker the material, the smaller the offset.


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## Corel Whisperer (Sep 1, 2010)

Here is how offset was explained to me years ago and how I explain it to others. The offset controls the way the cutter cuts corners. There are a lot of factors involved with this setting, angle of blade, thickness of material, shape of object being cut and the number and placement of nodes in the shape just being a few of them. 
When a cutter cuts along the path of a design the blade has to turn in the direction of the cut. When it cuts corners or tight angles, it goes a little past the corner makes a turn in the opposite direction, making a loop and then continues on the path. This loop is normally too small for you to see unless you get the offset too high. When the offset is set too high you can get little flags of hanging threads of material on the corners. If the offset is too low the corner gets clipped or rounded. I have attached a diagram to show this. Hope this helps to explain this.
CW


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## Nisei (May 4, 2011)

Indeed. When you look at your picture and link it to mine you can see that setting an offset value which is too low, the blade doesn't travel far enough before cutting a corner so you get rounded angles.
Thanks, it means I understood how it's working


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## dcurtisroland (Jun 5, 2007)

Nisei said:


> I was figuring out what offset actually is and when asking around I got some contradicting answers.
> So what I did was make an illustration on how I think it works. I'm not sure if it's right so please correct me if I'm wrong
> 
> Blade offset is the distance from the center of the blade to the tip. So actually half the diameter of the blade. So basically, it's the same for different angled blades as long as the diameter is the same. (see left side of illustration)
> ...


Yohan,
You're partly correct and I would also refer to CW in this thread. Offset was designed to compensate vector cutting quality due to the original technology being based on a pen which has a center tip (or zero offset). In order to adjust for 90 degree corners and sharper angles, the cutter blade must travel a little bit farther to compensate for the tip of the blade not being in the center of the cylinder. Your explanation of the distance from tip to center is a great starting point but has some extenuating circumstances - namely substrate density and thickness. The explanation CW uses is more accurate for predicting the behavior of the blade. This takes into account thicker materials like floor laminate and reflective vinyls and in some cases the offset can be over 1.00 mm which is physically impossible in your definition. On a VersaCAMM, for example, the maximum offset is 1.5 mm for a blade that only has a radius of 1.0 mm. The extra 0.5mm is a virtual offset telling the blade to travel another half mm to compensate for the substrate, but since there's no extra diameter of the blade, your explanation falls into that grey area I talked about above. 

Best practice is to follow the recommendation from the blade manufacturer and compensate accordingly by looking at the test cut which usually has a circle and a square to test whether the vector closes and whether the corners are rounded.

That was a long one, but I hope it helps.

-Dana


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## Nisei (May 4, 2011)

Wow, great explanation Dana! Reason I started this thread was that a renown blade manufacturer couldn't tell me what offset value to use so I just started thinking about it myself. I know others can probably tell me which settings I should use but I want to know _why_ I should use them. Nice to get some feefback, I appreciate it.


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## JoshEllsworth (Dec 14, 2005)

This video may help as well:
[MEDIA]http://www.youtube.com/watch?v=Ne71aXXp4BY[/MEDIA]


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