This is the calibration prints that I always use when I deicde to try out the new version of skeinforge. I can't find how to make a derivative, so these will be derivative as soon as someone shows me the obvious bright red button I missed.
The thin walled box is Dmatsumoto's http://www.thingiverse.com/thing:1637. it is unaltered, because it's just perfect.
The two other blocks are alterations of Bre Pettis's 40mm cube http://www.thingiverse.com/thing:477.
I learned this technique from several places, but I didn't understand it till I read Makerblock's wonderful blog post at http://makerblock.com/2010/02/makerbot-skeinforge-tuning-and-calibration/, check it out, he makes since (unlike me).
I can usually dial my skeinforge in almost perfectly just using these 3 items.
You will need the Makerbot skeinforge here http://blog.makerbot.com/2009/11/03/skeinforge-0006/. If you use the beanshell versions you will have to do a lot more configuration, but you get a lot of the cool new skeinforge lovin from FABMETHEUS.
If you don't know ANYTHING about skeinforge BfB has the wiki over at http://www.bitsfrombytes.com/wiki/index.php?title=Skeinforge.
Make sure skeinforge is printing the raft at 240. It will stick like heck, but you likely will have a hard time getting everything even at first, so just suffer through scraping.. Now let's get you calibrated.
1st print http://www.thingiverse.com/thing:1637 (also included here) this will allow you to dial in your carve (How much the Z axis goes up for each layer) in skeinforge. You want the layers to stick together well enough that you can't seperate them with your hands, but NOT drag through the layers. Carve is under the Carve setting of skeinforge. Usually for makerbots it's somewhere around .4mm, but every Makerbot is different.
2nd is the 20mm box attached here. You are now going to set your 3 settings in Skeinforge that determine how "thick" your lines are (Skeinforge slows down the head a TINY bit to make the lines thicker using these ratios, if that's confusing, ignore me). They are Skeinforge -> Carve -> Extrusion Width over Thickness (ratio), Skeinforge -> Inset -> Extrusion Perimeter Width over Thickness (ratio), and Skeinforge -> Speed -> Extrusion Diameter over Thickness (ratio). They should all be the same, and somewhere around 1.7. If when your bot is laying down the solid top and bottom the nozzel looks like it's draging through the plastic (it will build up on your nozzle head, and might cause a failed print, or break your printer), turn your ratio up. If when it fills the top and bottom of the block, it looks like spaghetti, you need to turn the number down. Don't worry if you ratios starts looking like 16.5320338023. This is the ratio that really determines how pretty your prints are, so it pays to be obsessive here once you get time. Until them just go to 3 sig figs and call it good.
DON"T DO THIS UNLESS YOU ARE COMFORTABLE WITH YOUR TEMPS!
3rd print is the tower. This one is not absolutely necessary, but if you want good looking tall skinny prints (Mendel gears) this one helps. The game here is to fine tune your temperature. Too hot and your printer makes blob monsters, too cold and you strip your ABS if your lucky, or break a retainer ring if you are unlucky. 1st time you print this tower, you will likely get a blob. Slowly, by 5 degrees at a time reduce your "Temperature of Shape Next Layers (Celsius) in skeinforge. Eventually the tower will look less like an Orc tower, and more like a nice pretty block.
If you are having a hard time getting these to print well at all, no matter what you do, upload the files to your SD card in your printer. They are small and you can just send them instead of having too pull the card out.
I hope this helps, if it dosen't head over to the Makerbot Operators group at http://groups.google.com/group/makerbot. We have all been there before, and would love to help.