Thursday, August 19, 2010

To Tab or Not to Tab

eCraft came up with a novel solution to the fact that they wanted to create digital die cuts without the obligatory mat used with all other digital die cutting machines.  They call their solution "TABS."  But, already the craft community has relabeled them 'Chads."

Whatever the word used to describe them they are very important to the cutting strategy of the eCraft machine.  They hold the cut piece in place while more of the shape is being cut.

Perhaps knowing that tabs might be off-putting to some, the eCraft designers gave us control of the tabs in two ways.  First, we can control the DENSITY of the tabs (how closely they are created) and how WIDE each tab might be.  Tab density can be set from 0 to 2 and tab width can be set from 1 to 3.

When a density of 0 is selected, then the shape will be cut with no tabs at all.  So, yes, it is possible to cut a shape without a single tab.  But, there are practical limitations.  In order for a cut to be successful without using any tabs, there are some criteria that my experiments show must be met.

First, the thicker card stocks work best.  I've had success with the DCWV Textured Mat Stack paper from Michaels.

Secondly, the path of the cut must not reverse direction and back into the piece.  This means that the Tree Shape, with its small limbs would NOT be a good candidate for cutting without tabs.  We want MORE and BIGGER tabs for something like the tree.

Thirdly, a new blade is going to create less drag on the cut piece.  So, the newer the blade, the better.

Here is a very successful cut using no tabs at all.  It was cut from a sheet of 5" x 7" DCWV Mat Stack Brights (Textured).  I scanned this shape in at 1200 x 1200 to permit you to really check out the cut.  This shape is just 2" in size.

Let's analyze why this shape did not need tabs to be cut successfully.  First, the order of the cuts is an important factor.  Each of the 4 empty areas were cut out first.  And, at the critical areas where the blade drastically changed direction there was still a large uncut connection still holding the segment in place.  There are two small cutouts and two large cutouts with relatively continuous paths.  The piece itself was not cut free from the base paper until the inside areas where completely finished.

Had the paths been designed so that the outside was cut first, we could not have been able to cut this shape without tabs.  We need to remember that when we get the software to design our own shapes.  Cut order is critically important.

The next piece might look a lot more complex; but, in reality it is not.

Yes, it has many more internal cutouts.  But, in every case, due to the design and order of the paths, there is still a large area of connection when the blade changes direction, to most critical time of cut failure.  And, once again, while this appears to be many circles, to the cutter it is really just a scalloped outline when making the final cut.  We might even be able to see where that final breakthrough, completely releasing the piece, was made.

It should be obvious why this last chadless example worked.  So much of the piece was held into place by the uncut area until the very last cut.  And, being 5", with the final cut near the base, both the piece and the base paper were in the grip of the primary rollers when the final cut was made.  So, WHERE the path for the shape starts is also an important factor.  Had the start been at the TOP of the piece, the cut might have been only 90% or so successful, since the rest of the piece would have been flopping around as it neared the final cut.

So, it seems to me that we should be able to predict which shapes can or cannot be cut with a DENSITY of 0.  Look for those shapes where the entire base page is the tab until the last cut.


Denise O'Connor said...

Tom, thanks for all the great information! I did a shout out to you the other day on my blog because you have really looked at this the way someone should and I applaud you for it. In regards to the tabs, my guess is that the no tags option is there because of kiss cutting vinyl. I wonder how many images on the SD cards would be able to be cut with no tags out of paper. My guess will be that most of the images will need some tags, and it may depend on the paper as well. I am glad to know that the heaviest weight papers work better than the smaller weight papers because frankly that is what I use the most of. I just might donate some or all of my lower weight papers to my son's school if I can't get them to cut well. I think a lot of this will depend on the software too, as you mentioned the cut order. I hope that Craftwell thought of that with the software, especially since none of the beta testers got to test the software. However if they didn't take that into consideration, I would think that they might be able to add that feature in through an update. Thanks again for all of your hard work!


Tom Meeks said...

Thank you Denise. By the way, I sure wish that I'd known about your airbrushing skills earlier when I was working with testing some 3D printer output. I had a 3D printed rubber ducky I wanted to dress up in a tux.

The most important things that are unknowns to me in terms of controlling the eCraft are (1) can the firmware be updated to add speed control and (2) will the software allow us to control speed and, of course, (3) does speed matter at all.

And, an extra thanks for mentioning this blog on your own. I had hoped that NOT being a paper crafter would help bring a different perspective on evaluating the process of paper crafting in a way that would be useful. So, I'm very happy to learn that you find it so.

Bea said...
This comment has been removed by the author.
Bea said...

Hi sorry here I will try again the removed post had too many errors in!! I saw your you tube video and as I have just bought the ecraft found it very interesting. I used it for the first time tonight but having problems with the machine chewing up the paper after cutting two 8" trees on expelling the paper it got all mangled and I had to take off the bottom. Also I only got the 2 trees and 16 1" leaves cut and the blade needs changing is this normal - I use Bazill card. Hope you may be able to advise.

Tom Meeks said...

Hi Bea,

My own personal feeling is that the tree size got past those that selected the minimum and maximum sizes. There is one limb that causes all the problems and when that starts it, it all falls apart.

For now, I would not try to cut the tree. Use broader shapes and get used to the eCraft with at least 65lb/176g/m2 paper so that you can experiment with the tab density and size. Don't try to go too small at first.

In the meantime, I am using a hi-speed camera to chase down why people are having problems with lighter paper and intricate shapes.

I think I know what is happening; but, until the eCraft engineers have an opportunity to give us some feedback I'd rather see us playing with what DOES work and that is heavier paper.

I can tell you this, that is is a LOT of fun watching the eCraft cut in slow motion.

Bea said...

Thanks for response Tom I will take your advice re experimenting with plainer shapes. Any thoughts about the blades life being quite short?