So, I'm having trouble with the pen centering. I have "Start with pen centered" checked in the options, but the bot always seems to start a bit low. More like 1/3 up the drawing.

Check out this image. I took this right after drawing. The pen is supposedly returned to its center position, but it seems low in relation to the actual drawing. This is the "honeycomb2" example from the examples pack. The middle hex should be right under the pen, yes?


(larger version)

Quote by: Eggplant!

So, I'm having trouble with the pen centering. I have "Start with pen centered" checked in the options, but the bot always seems to start a bit low. More like 1/3 up the drawing.

Check out this image. I took this right after drawing. The pen is supposedly returned to its center position, but it seems low in relation to the actual drawing. This is the "honeycomb2" example from the examples pack. The middle hex should be right under the pen, yes?

Actually, you are seeing the correct behavior, albeit a not obvious one. You see, the Eggbot Control assumes a template of height 1000 units. The honeycomb2 is using a template of height 800 units. If you change the page size (File > Document Properties) to have a height of 1000 insteadof 800, AND then translate the drawing so that its midline is at y=500 and not y=400, then you will get the behavior you were expecting.

The (long) document http://wiki.evilmadscience.com/Where_will_my_drawing_begin_on_my_egg%3F actually covers this case,

So, how does the Eggbot frame your drawing? It really doesn't frame it at all. Instead, if you use the "Start with pen centered" option, then it assumes that the pen is positioned over the midline of the drawing -- the drawing and not your egg. If you want the drawing's midline to correspond to the egg's equator and your drawing uses a document of height 1000 units, then you can position the pen over the egg's equator and then the drawing's midline and the egg's equator will coincide. What if your drawing is only 800 units high? Well, then the line y = 500 will be 100 units below your drawing's midline. But it's this y = 500 line which the Eggbot will assume the pen is on [4].

Hope this helps.

Dan

AH, yes. It makes perfect sense. Thanks again!

P.S. So if your egg's midline is at y=400 and the pen returns to y=500, why is the pen "down" below the egg's y=400 midline and not above it? Well, in SVG, y axis values increase as you move from the top of the page downwards. That's why the pen is below the y=400 midline by 100 units and not above it. Again, this is discussed in that (longish) Wiki page I cited.

Dan

My problem is that I assumed all of the examples were 3200x1000 in size. This is not the case!

Quote by: Eggplant!

AH, yes. It makes perfect sense. Thanks again!

It would be better if it were just obvious, but it unfortunately it isn't. And, now that we seem to be shifting towards a "standard" document height of 800 instead of 1000, there has been some discussion of making (1) the midline height controllable in Eggbot Control land, and (2) perhaps changing the default midline height from 500 to 400. The older page height of 1000 dates back to at least the
Eggbot beta and likely earlier. A vertical plot range of that amount is achievable with the right sort of egg and careful centering. However, 800 is a more typical range and hence a better choice to cater to for the typical usage case.

Dan

I think having this be a controllable option in egg-bot control and a default of 400 would save a lot of confusion for people.

I think having this be a controllable option in egg-bot control and a default of 400 would save a lot of confusion for people.

I couldn't agree more. We'll release an updated version of the software with that option within the next week or so. Thanks for your patience and understanding.