Saturday, August 14, 2010

eCraft - Repeatability and Registration Tests

These tests are not exhaustive.  They are simply a quick and dirty try at seeing if we have any chance of reliably making cuts at the same size and place on multiple pages.

First, some observations about things that Craftwell inexplicably missed in their design that would have made our lives a LOT easier.

Missed Item #1:  Digital X-Y LCD Readout on the head position

The eCraft has an LCD and, internally it at least should know the precise position of the head on the 'X' axis.  The 'Y' axis is a bit more troublesome since that is always going to be based on our placement of  the paper into the printer in manual mode.  But, even here there are things that can be done in future versions that would improve repeatability.

If you take a look at the front edge of the eCraft, Craftwell thoughtfully provided a ruler.  But, it is not near the head.  If Craftwell adds a printed line just in front of the cutting head then we can accurately line up our paper on that line every time.  Fortunately, we can do the very same thing with a fine permanent marker.  But, if it were a factory installed feature the cutter, itself, could use that line to calibrate the "Y" location for an LCD X-Y readout.

Missed Item #2:  Pointer on the head that can be placed at a starting location

The head system of the eCraft is quite sophisticated.  But, it lacks one more useful thing that is VERY easy to correct.  And, that is an accurate pointer that allows us to line up the head on a particular mark on the page.  The eCraft, like other cutters makes all its cuts, in manual mode, relative to the starting position of the head.  So, if we have a way to precisely place the head, relative to the paper we are cutting, we should expect at least some measure of repeatability.

Again, fortunately, we can improvise.  So, here is my attempt to overcome some of the limitations of the eCraft in terms of repeating registration precisely from page to page.   I simply taped a broken toothpick to the cutting head.  Since it appears that magnetism is used to drive the cutting head and pen, I wanted something that would not affect the magnetic field.  Quite Hi-Tech, eh?

Then on the papers I would be using, I drew two intersecting lines to be used as each page was cut to precisely line of the head with the paper.  I cut 3 sheet of paper in this fashion.

Here is a scanned image of cuts 2 and 3 overlayed and you will see that the cuts are very precisely lined.  We are looking through 2 sheets of paper here.

There is a reason I am not showing page 1 as well as pages 2 and 3.  Interestingly, the first cut was about 1/16 of an inch off of both of the subsequent cuts.  That tells me that I might have to throw away the first cut each time to set up the repeatably precise cuts in subsequent pages.  To me, this says that we are at least in the ballpark with being able to reliably print and cut in manual mode.  There was absolutely no differences at all in cuts 2 and 3.

I have not tested the precision with the tray loading method. 

A Suggestion for Craftwell

The eCraft head, itself, provides the platform for an inexpensive pointer system that mimics my test.  Of course, they might also be testing something like this or even more precise solutions.  Our experience has been that eCraft listens.  So, for what it's worth, let me make this simple suggestion.

The two large, round cylinders on either side of the cutting head provide us with a place to mount a simple plastic pointing device that merely clips onto the cylinders.  Off to the left side of the clip would be a pointer to hangs down, like my toothpick, to allow us to place the head precisely over a point on our page.

The top red object shows what it might look like from the front.


Obviously, printing just three pages using a toothpick pointer is NOT an exhaustive test.  But, it certainly it does show promise that we not only can; but, WILL find a solution to repeatability.

It is still unclear whether or not the eCraft firmware can be upgraded.  If it can, I would urge Craftwell to find some way to give us precise X-Y reading and positioning.  In the meantime, offer this quick and dirty plastic fix or some other way to help us precisely align our eCraft head.

In the meantime, I know that a toothpick and tape works.  And, that doesn't bother me at all.  If it weren't for duct tape (actually gaffer's tape) and bubble gum a lot of video productions would not have happened in the early days of video.  There is nothing at all wrong with being creative and improvising.  Works for me.


Beth said...

I am very interested in print and cut and so your information is very helpful tome.

Tom Meeks said...

Thank you Beth. The means I propose may or may not be the answer. But, I am convinced that either eCraft or users WILL find the best method.