Excited about this, I really like the JR’s design…
http://printrbot.com/2013/03/30/printrbot-jr-files-are-available-non-commercial/
With a few major changes, the basic design might be usable, but I have no intention of designing a “Wallace jr” in the foreseeable future. Wallace 3 should be configurable to something similar, though.
Rich fixed a girls Printrbot jr. at our last meetup ( yes, we occasionally get females visitors at the shop) so I can vouch for his expertise and opinion on this one.
And yes @Whosa_whatsis actually talked to her through normal human style (verbal) communication. ; )
For the record, he’s referring to my aversion to speaking in general (especially about non-technical subjects), not specifically about speaking to females.
Can I get a link to that rant @Nils_Hitze , @Whosa_whatsis ? I’ve recommended the JR and if there’s something wrong with the design is like to learn more about it.
I suppose I could do a virtual teardown of the machine (from memory) the way I did with the solidoodle if you guys want, I just kinda feel bad always talking shit about other people’s designs. I really don’t mean to be so negative, it just pisses me off that these terribly-designed products are being sold to consumers who don’t know any better, and giving them a bad impression of the whole industry.
I don’t think it has to be “talking shit” so to speak, but frank discussions of design choices, etc. is key to making things better. It also illuminates choices that might not be ideal for all applications but could have perhaps unclear explanations, or could be remedied once discussed.
It’s like code review, it doesn’t have to be negative if everyone is in it to get better 
(and you’re just damn good at it @Whosa_whatsis
I know, it just feels like I’m talking shit when I can’t find anything nice to say…
I dont think the jr is that bad. Yeah theres some odd things with it but it does work and is only $400, $550 by the time you “fix” it. I’d like to get rid of that big, heavy lc extruder and go to direct drive to reduce some of the weight on the floating y axis. That kind of design is a similar problem faced by the Makibox, except on the x and y. Id be curious what @Whosa_whatsis had to do to the jr he worked on?
I wasn’t trying to rebuild it into something it wasn’t designed to be (a decent printer), just make the best of a bad situation with the parts it came with. I tightened the many things that were loose, fixed a bunch of wiring issues, re-mounted all of the endstops (X was configured as min, but mounted in the max position… I wonder how it’s meant to work…), redid the platform mounting (it was level, but ridiculously far from tram, and I had to chuckle to keep from crying when she pulled out the spirit level), re-mounted the Z endstop adjustment screw (self-threading a machine screw through plywood for a precision adjuster? really?), etc. The machine clearly wasn’t square, but there really wasn’t any way to adjust that, and the X axis isn’t linear on the X/Z plane due to fundamental design flaws, but I got it close enough to make the first layer stick.
I don’t even think the design is suitable for a direct-drive extruder, though a similar design could be made workable with a bowden. Like the Makibox, the axes aren’t constrained well enough to move around the mass and weight of a full extruder, though at least the Makibox isn’t pretending that they are.
Yep, our hot end weighs around 20-30g. I wouldn’t put much more than that without going to a platform with bearings to keep everything aligned.
Oh, I can tell that @Jonathan_Buford has already considered this. I can’t yet evaluate with confidence whether the mechanism is sufficient for even such a small and light hot end, but I know that he knows that it’s not sufficient for something more massive.
I think our beta design is borderline, but we are making some updates to stiffen up the production design more and to reduce the drag on the supported arm.