Dyne's LD-F1 (D-O concept) build

[Dyne]

T-Minus 4 weeks (and 1 day)

Since post #18, my prints started to be plagued by rapidly decreasing quality and increasing failures (including skipping and gouging at the extruder).



Eventually, I concluded that my print head's PTFE liner was likely to be damaged or deformed.  Swapped it for the spare print head that came with the printer and re-leveled, just in case the new print head was at a slightly different height.  Aside from probably needing to dial in the level a bit more, things appear to be working normally again.


For the tracks, production is in full swing.  As of right now, 50 of the final links have been printed and assembled -- just short of the 53 needed for the first full track -- as well as 16 spare links using the slightly older v5 model.  Turns out that that one wasn't final after all. The only real change, though, was to make the centering mechanism centered from the front of the link to the back; previously it extended out further on one side than the other, over the center interlocking "tooth".  The old links are still more or less compatible with the new ones in an pinch, especially if used one-by-one, but notice how the teeth don't line up at the same height in the closeup below?  I wanted to fix that before full production started in case it wound up mattering, so we're now on V6.


Enough links to complete a full track and then some should be done by tomorrow.  They aren't being printed in Inland Silver PETG as the ones shown here were, but instead with their "Silver" PLA, which is really just a light grey.  They will be mostly hidden beneath the traction pads, so I can always paint the pads if I want a different color.


I've also got the parts for one of the two front driven sprockets printed and the main body for the other, so I just have six toothed wheels and two bodies for the rear sprockets to go.  I have some concerns about how well the teeth are meshing with the links -- it initially seemed right on the money, but I think it's very slightly off.  The design allows me to attach new toothed wheels if I need to tweak them, without having to redo the entire sprocket.

Most importantly, I got several parts of the chassis designed and printed them this weekend.  As such, I'm feeling a bit more confident that I can at least get this thing mobile, even if I have to forego the lift system for now and it doesn't get aesthetically complete or fully programmed until after Dragon Con.


Here's how the chassis is organized:


The blue assembly -- which is not fully designed yet -- is essentially the rear of the droid's chassis, though some of it protrudes into the forward portion.  The main part will carry the lift system, rear axle and sprockets, and the mounts for the track carriers outboard of each track, as well as the mounts for all 6 idlers in each track.  The bit that extends into the forward part of the droid will house many of the electronics and contains a curved recess for the main joint in the neck stalks to rest on when the head is lowered.  The blue parts are all essentially bolted together.

The red assembly carries the front axle, drive sprockets, the motor and pulleys.  This assembly attaches to the blue parts that extend into the forward section via M5 screws through the three horizontal slots that sit just below the motor and the second stage pulley.  This allows the red assembly it to slide back and forth relative to the blue assembly to tension the track.  The forward blue parts also have a slot for the front axle to slide with the red parts.

There are five red parts in total, and these are the ones I printed this weekend: The bottom plate, plus the inboard and outboard plates for each side, all bolted together.  The inboard plate forms the walls of the opening in the middle front of the droid, and the outboard plates faces the tracks.  There is a gap between the two, as well as a captive nut for the forward axle.  The side plates also have bolts that hold on the front shell of the droid.


The outboard plate has the mounts for the motor and the second stage pulley, as well as holes to attach an as-yet-unmodeled brace for the other end of the threaded rod that the second stage pulley turns on.  Between the belts, pulley, idler, and the teeth in the track links, space in this area is tight, as you can see below, so I may end up securing the other end of the pulley's threaded rod in the track carrier instead.


It also has a slot between motor and pulley for the motor wires to pass into the gap between the side plates, where they run forward and into the blue parts that house the electronics.


This is what that red assembly looks like in reality.  Note that the sprocket axle will be a threaded rod all the way through the droid, not a bolt like I currently have installed.  No reason you couldn't use a bolt, but I want a through axle for transverse rigidity.  I have temporarily placed threaded rods in the holes at the front where the front body shell attaches.



I like that the droid's left inner side plate (the one furthest from camera) has a scar defect near the top ... this will be visible once the droid is complete and suggests some "damage" weathering.  I, too, have a recent scar defect, as today this droid received his traditional blood sacrifice (I jabbed myself with the printer's scraper while trying to remove the support from that bottom plate).


I haven't even tried sourcing sounds for the droid yet, or really addressing audio beyond digging out a spare transducer and amplifier.  Since this droid hasn't appeared on screen, I can do pretty much whatever I want.  I think I mentioned previously that I've considered using Michael Perl's Human-Cyborg Relations D-O voice modulator (since this droid is technically what D-O could have looked like).  Unfortunately, that app isn't out yet.  Another idea is to use the sounds that D-O had on stage at Celebration 2019 (before he could speak).





Speaking of sounds ... does anybody have any clean Babu Frik dialogue samples?  Asking for a friend.  I've looked around, but haven't found any yet.  (I do have the stuffed toy that plays them, but I want to trigger them remotely, and accessing the wiring to trigger it is not trivial, and recording the sounds from the toy wouldn't give great quality.  Playing clean samples through the droid's amplifier would work much better than either of those methods.  (Maybe I'll ask Matt Hobbs about the sounds he has in his Mouse when Babu is driving it rather than the Porg.)


At any rate, I hope to have the rest of the main chassis design done and at least partly printed by the end of next weekend.