Monday, January 27, 2020

Acuitas Diary #23 (January 2020)

This month I added some expansions to the goal-driven behavior that I started on last September. First, I had to get the Interpreter to recognize future-tense predictive statements, along the lines of “<Something> is going to <do something>.” Then I set up some code to check the predicted action or event against the cause-and-effect database for additional implications. If it's discovered that some effect will apply a state to Acuitas, it gets reviewed against his goal list for alignment or contradiction. The conversation engine then responds with either approval or disapproval. Illustration:

Me: I will protect you.
Acuitas: Please do.

Predictive statements that pertain to subjects other than Acuitas may yield useful information for the short-term condition database, by indicating that some entity's state is about to change. For now, Acuitas assumes that the speaker is always honest and correct. He also has no sense of future time frame (his ability to process adverbs is weak at the moment), so he assumes that any predicted changes will take effect immediately. So something's immediate condition may be updated as a result of a predictive statement.

Example: if I say “I will protect Ursula*,” then Ursula is presumed to be in the state “safe,” and an entry to this effect is added to the short-term database. For a reminder on how the short-term database works, see this previous article..

The fact that the user can express intent vs. Acuitas' internal goals means that it is now possible to offer assistance … or threaten him. Well what are we going to do about *that*? Find out next month!

In other news that is sort of unrelated, since I thought I would do some location-related work this month and didn't … Acuitas can't yet form concepts for instances without explicit names, such as “Jenny Sue's home.” So for the benefit of the AI, I am officially naming my estate. The house and grounds shall now be known as “Eder Delin,” after this fictional place:

*Ursula née Cubby is my cat.

Until the next cycle,

Sunday, January 19, 2020

QIDI Tech X-one 2 3D Printer Review + Bragging

I decided to make the leap and buy myself a 3D printer a while back, and got it up and running last August.  Now that it's seen heavy action making Christmas presents for all my friends, it's time for me to say what I think of it.  The cost was about $350 (and the price of this model has dropped since then).

The QIDI Tech X-one 2 is a pretty traditional fused deposition modeling (FDM) printer that prints in XYZ coordinates.  The print head moves in the XY directions, and the print bed moves in the Z direction.  The bed is heated, and the print head includes a cooling fan.  The build volume is a cube 140 mm on a side.

Kirby without shoes. Model by SnickerdoodleFP,  This is a relatively low-detail model, so it was one of the first things I made. However, I had some trouble getting all of his tiny toe pads to stay stuck to the print bed. Slowing the print speed down helped with this. Then, partway through the print, the supports for his right arm came loose from the bed, leaving the printer to keep dropping filament on thin air. I caught this shortly after it happened and babysat the printer for a while, flicking away the junk filament so it wouldn't ruin the rest of the model, until the printer managed to connect some of the strings to Kirby's foot and rebuild the bottom of the support on thin air. In the end his arm came out just fine. I never saw that kind of thing happen again, thank goodness.
First, let me say that compared to that robot arm which provided my previous 3D printing experience, the X-one 2 is a dream to operate.  Aside from the fact that this particular arm just plain had ... problems ... having a print bed that is solidly attached to the printer, instead a taped-down piece of glass, is really nice.  You don't have to re-level the bed every time you print, or worry about bumping something midway through and ruining it all.  My co-worker got the arm because he wanted a giant print volume, but if that's not a concern of yours ... don't print with a robot arm.  Not worth it.

Flexi-dragon. Model by Benchy4Life, This was another very easy print. The articulated parts come out of the printer already interlocked and ready to move once you've loosened them up in your hands. Each wing and the body print flat; then you snap the wings into a hole in the back.
The X-one 2 comes out of the box mostly assembled -- I only had to attach some structural parts, like acrylic windows and handles.  The manufacturer was also very thorough about making the printer order self-contained; it comes with its own accessory kit that includes every tool you need for the assembly steps, a scraper, and a glue stick.  The only thing missing is some tape to cover the print bed (perhaps not strictly necessary, but I've never wanted to print without it and risk wear and tear on the surface).

Steampunk articulated octopus. Model by Ellindsey, Each pair of tentacle segments forms a ball-and-socket joint. They print out separately and snap together. I painted the body, but left the tentacles in their natural color so that the joints wouldn't scuff over time. It printed out like a charm, but trimming and assembling all the tentacle pieces was a bit of work.
For temperature control purposes, the printer is enclosed on all sides but the top.  It has a metal frame and is built like a tank.  I like this because, again, it enhances the printer's stability.  On-site control of the printer is accomplished through a touch screen.  I'm not as wild about this, because it seems like the kind of thing that might wear out before the rest of the printer does ... but it is handy.  You can get files into the printer via either direct USB connection to your computer, or SD card.  So far I have only used the SD card.  This lets me keep the printer parked on the tile floor in the kitchen, and out of the overcrowded computer room.

Grizzly bear statue, pre-paint. Model by BenitoSanduchi,  This is a miniature replica of the Grand Griz bronze at U of M. (This was for a friend, mind you ... I'm a Bobcat.) BenitoSanduchi created the model by taking a 3D scan of the original.
It comes with its own slicing software which is just a customized older version of Cura.  I used this for a few prints before switching to regular Cura to get a wider range of settings.  This introduces a mild annoyance, because the X-one 2 is not one of the printers for which Cura has pre-sets.  You have to enter it as a custom printer and figure out the correct parameters yourself (or get them from someone on the internet who already has).  Otherwise, Cura is a capable slicer, and I have no serious complaints about it.

Destiny Ghost. Model by BoldPrintShop,  Ghost was one of the easier things to print -- being very smooth and geometric -- and one of the more complicated things to post-process, since there were many individual pieces to sand and paint.  The striping is "Last City" style, without the other details.
I started out printing a test cube.  Unlike the sad cubes that I got out of the robot arm, it printed with  nice straight vertical sides.  The back was a little shorter than the front, indicating that I needed to adjust the bed leveling.  I tweaked that and proceeded to a more complicated print.  No problems whatsoever.

Iris boxes. Model by LoboCNC, The neat thing about these is that they come out of the printer in one piece; you can't take them apart. The "leaves" of the iris form between the curved walls of the box, already mated to the tracks that they run on. Print-in-place objects like this are tricky, because your printer has to be precise enough to form all the parts without sticking them together. The Qidi had no trouble; every box I made worked.
Many prints later, the X-one 2 has never had a major failure, and the overall quality is fantastic.  I've made several miniatures at 0.1 mm layer height, and tiny details like eyes, teeth, spines, etc. come through in the final product.  With the right kind of supports (use roof!) even the under-surfaces end up looking pretty good.

Voronoi pattern skulls. Model by shiuan, This was one of the more challenging prints. The contact points that tie the entire back of the skull down to the print bed are fairly small, and they kept wanting to pop loose (which would ruin the model). After several failed attempts to get the scaled-up version past its first few layers without this happening, I added a brim to the model so it would stay stuck. The downside is that I had to cut this away afterward. The model comes with break-away support sticks that shore up the more crucial points; still, it has a lot of little arches hanging over empty air. The printer got the basic form down all right, but left a lot of messy loops, strings, and rough edges on the undersides. And since the interior of the skull is an enclosed space, I couldn't just sand them off. I ended up parking in front of the TV with it and going over the whole thing with a craft knife. WORTH IT.

Now, for all the issues I can think of:

* The documentation is sparse, and poorly translated into English.  The PDF on the included thumb drive is more complete than the printed manual, so make sure to refer to that.
* When you want to change filaments, you're supposed to be able to heat the current filament and run the feeder in reverse to back it out.  For my printer at least, this doesn't work.  The sorta-warm filament just below the feed gears develops a bulge, which jams it so that it will feed neither backward nor forward.  Twice now, I've had to disassemble the print head and cut the filament to get it out.  I'm hoping that just heating it, holding down the manual lever that disengages the feeder, and pulling it free will work better.
* It seems to be possible for the printer to retain a bad state or incorrect awareness of position when it is shut down.  Two or three times, at the beginning of the first print attempt after turning it on, it has started by trying to drive the print bed down through the floor of the printer.  I'm not sure exactly what causes this, but I haven't seen it since I started 1) making sure to always push the button on the "print complete" dialogue box before turning off the printer and 2) never removing the SD card while the printer was on.
* I've gotten the "sensor error or power is not enough!" error a couple of times.  It seems to mean that the connector to the heated print bed is loose.  I re-seat or wiggle it and the printer is good to go on the next try.
* The printer sings most of the time, but if I turn up the travel speed too much, it sounds ... bad.  A little grindy.  I don't know if this is evidence of a real issue or not.

Cylindrical box. Model by Alphonse_Marcel, This was a long print, and the supports for all the little bits of relief were a pain to remove. Other than that, it had no problems. It has a really nice twist-and-lock closure.
Overall recommendation: this is a good first printer.  Not perfect, but still usable with a minimum of fuss, and capable of supplying high-quality PLA prints.

Red dragon by mz4250, I wasn't sure if the printer was going to be able to do this. The model has umpteen delicate spines, individual fingers, arms and wings hanging out over empty space ... The first try didn't go so well, because I hadn't figured out the best way to generate supports yet -- the bottoms of his right arm and upper jaw came out a mess. For the second try, I turned on "roof support," which prints a kind of throwaway cradle for the bottom of any elevated part (like the arms). I also scaled him up to the maximum size that would fit in my printer. Success. A couple fingers are a little shorter than they should be -- the tips came off with the supports. Other than that, all the details came out beautifully.
Goals for the new year: learn a CAD program and get some robot parts turned out.

Until the next cycle,