Proton (Simple and partly Metal)
Clean design and it will documented under CC-BY-SA according to authors’ web pages. It looks like my old Printrbot Simple Metal, but i really don’t know, if it’s a good idea to put another heavy motor to the end of Y axis and increase the inertia moment… (Not to mention there are 3 axis couplers now because of distant extruder motor.)
Interesting I didn’t expect atom to go open source with their designs or produce "budget " designs, interesting! I think the problem with marlin is there hasn’t been a “stable” release in over a year (two years?) so companies are wary of shipping a beta software, even though rc8 is probably mostly fine. Why they don’t go elsewhere I suspect is comfort. I’m reallly intrigued by the screw delta they have on there, here comes printer 3!
There is a feeling I get when a design is posted that is so heavily influenced by my designs… yet no mention of me (printrbot) for attribution. It’s either ego or some sense of ownership… probably not healthy.
It’s definitely a novel twist, but I agree with the skepticism on whether it’s good to have two heavy motors on one end like that. I think a light motor on a gear-reduced extruder is a better way to go.
I think it’s probably fine, the novel approach w the extruder is interesting but there would be no gain, in fact probably the added weight of the lead screw and extra parts is a detriment. You can make any design work, it’s just speed that suffers w all that mass.
If there is a perfect design, I haven’t seen it. I’ve designed dozens and dozens of printers. The Simple Pro is the closest to perfect in my biased opinion. But cost isn’t a goal really. Some think the old simple is closer to the best trade off decisions. It’s all opinion. You have to group comparisons within a tight price envelope to really do an apples to apples comparison.
I’m working on one right now that has different goals… it’s starting to look compelling. The goals are : low part count, easy manufacturability, low price… we shall see where she ends up. Those goals are pretty important right now in view of where the market is.
After some thought, my feeling is that these two printers (the Simple-like Cartesian and the Screw Delta) are design gimmicks. They’re interesting, but there’s minimal benefit.
On the Cartesian, why drive the extruder through a rotating linear shaft? The extruder motor weight is still on the moving stage, and if anything, the mechanism balance is WORSE with both steppers on the rear side. Plus you’re going to get soggier retractions with the motor spinning up all that linear rod mass.
Likewise, placing the Y screw below the spinning rod and fixed rod (instead of between them) is a poor engineering decision. You have a very narrow “stance” for resisting torsion of the Y stage. The Y screw torque transferred to the nut isn’t going to be resisted by much structure. Which means the Y axis is going to want to twist around the large central rod and swing the nozzle side to side during fast Y acceleration.
And… the leveling probe is shown mounted BELOW the nozzle… so it’s kind of hard to imagine that the thing has ever actually printed.
On the screw delta, how much money are you really saving by eliminating three rods and three bearings? And in exchange you get a slower printer that side-loads lead screws? Which requires dead-straight screws to avoid weird-ass delta print flaws, and over time will cause the nuts to wear unevenly? It’s a fun build but not something I’d recommend.
I’ve asked Atom about why the E motor has been moved back, but they didn’t really explain it. Most likely a gimmick, and probably bad for consistency, too, since the slightest wobble in the E-shaft will translate into hotend movement along X and Z.
As far as I know, they’re not planning on selling either design (hence the large volume of RP parts), but are simply releasing playground designs as open source.
@Thomas_Sanladerer It would be cool to have a spline shaft running the extruder with the E motor on the Z stage. Likewise a travelling-screw stepper could be put on the Z stage, if you really want a screw there instead of a belt. You’d save a bunch of moving mass that way.
If it’s in the category of design experiments and fun- I have no problem w that. I’ve done a lot of that. Except I don’t like to release designs that I’m not happy with. My designs are too messy and unorganized. The last 10% after building, testing and finding 100 little tweaks crushes me. I’ve build a lot of not-the-best designs but thinking of passing my clever tricks on to someone who might actually build it makes me qweezy. The more I study Deiter Rams, the more I’m convinced good design should just be obvious. “As little design as possible”…, and THAT is hard to achieve.
Basically I don’t understand this design for 3d printer. The task here is to move less mass possible due to the inertia. What is the reason to move the entire auctiator instead of just the print head along the auctiator length. this really don’t make much sense anyhow. Using simple lead screw for fast movement is disaster as lead screw got enormous losses of the momentum generated by the motors due to friction. Normally around 60% but in fast movements this losses will rapidly increase this is why everyone use them ONLY for Z axis where the movement is rear and slow. if they want rigid movement they can use cheap Chinese ball screws they will offer losses around not more than 20% and accuracy around 0.1mm. Also this design will suffer from massive vibration and resonance problems. While the belts tend to reduce the stepper induced vibration and to calm the stepper motor in general this will not be the case with screws. For accurate and silent print they will need external vibration dampeners. Another issue is that we have two stepper motors close to each other mounted with hard bond that will transfer the vibrations as soon as both stepper got similar speeds or share same pattern the spike of resonance will occur shaking entire auctiator. In overall one of the many bad designs trying to make something to look different and innovative.
+George I’d love to hear any specific feedback. The plus is an older middle and we have put much learning since then into the Simple Pro. I have planned upgrades to all my bots but would love to incorporate any good ideas
+Brook Drumm I love the PB Simple I use every day, so much so that I am hunting for the bones of a plus to transplant my way up into.
I dove in an enjoyed each iteration of simple 2014 bed upgrades. heat, heat+X upgrade both were a fantastic first party upgrade. ubis to 13 then 13s also good. I even have the workhorse of the gear head extruder. the more I put into it now the more I realize I am just baby stepping my way into the product I should have started with.
I have a working octoprint that I adore and so the g2 series boards don’t being me much to the table out of the gate.
do you in PBHQ have a plus set of bones you could sell as a one off or a pre-refurb? having torn down and reassembled my simple a dozen or so ways by now I really want to go hands on, and I really like the plus form factor. I don’t want to stay from the brand, because I like your involvement I like your support desk’s respectful responses. I guess I am a PB lifer because of the people of PBHQ who led to the form factors I find appealing.
What do you think Brook? could we cut a deal? I’d happily ship back all the working simple 2014 bones gratis to show appreciation and give you a few more parts for the repair bench.
And others who aren’t PB’s fearless leader, if you’ve got the bones of a pb metal plus and want to make a deal, lets talk.
Thanks for the kind words! I’m sure we can work something out. I wish there was an easy way to sell the odds and ends I have at pbhq. It always gets complicated. For fans that ain’t scared to build, it’s much easier
So just email me and I’ll see what I can do.
Brook@printrbot…
- why do people keep using old versions?