Okay obviously the title is a little clickbaity but what can you do. Magball arms are a great option if you're looking for convenience and an easy build, but end up being far heavier than the competition.
Hi I'm Haydn Huntley, the person who builds these MagBall Arms. Engineering is often about evaluating relative advantages and disadvantages and choosing which you'd prefer. There are a few key advantages which my magnetic joints have over using fisheye (Igus/Heim) joints. The first one is they are zero-backlash and they *stay* that way. Other joints are looser and develop even more backlash, which causes problems when printing and makes calibration difficult. The second is precision -- these are individually measured and labeled. A set typically matches to within less than 30 microns. This makes it easy to auto-calibrate and consistently produce excellent first layers. You seem to think that the increase in weight is a huge disadvantage, but I beg to differ. A little extra weight is undesirable, but what good is a light-weight printer which produces sloppy parts? I want to print excellent quality parts! I print at 60mm/sec, with 250mm/sec for non-printing moves. That's fast enough for me. I've experimented with going faster, but the limiting factor was the rate at which the E3D hotend could reliably melt PLA. I've tried a lot of experiments to improve delta printers, but the best improvements have come from using magnetic joints, auto-calibration, diagonal frame bracing, 32-bit controllers, cooling fans, a silicone hotend cover, flying extruder, polished titanium heat break, Bondtech dual gear extruder, 0.9 degree motors, 9mm belts, 16-tooth pulleys, and stronger carriages. For me, the proof of the pudding is in the quality of the parts I can print.
Great to hear from the man himself! I have plans to incorporate many of your experiments into Phoenix (namely 0.9 steppers, 16t pulleys, flying extruder, and diagonal frame bracing). One thing I am really not keen on changing is (perhaps ironically) the arms.
I have a set of your arms I'm going to find a good use for someday (maybe a 6 axis delta where the range of motion is a big win) but I fear they'd have backlash or even yeet the effector at the speeds I'm going for on the printer I'm building now (1500+ mm/s, 250k+ mm/s²).
@@daliasprints9798 The nice thing about Magball arms is they have no backlash. But I dont think they'd hold on at those speeds!! What printer do you have going that fast?
@@mitsubishimakes It's a WIP. AWD (6 motor, 1 at each end of belt, no idlers), 48V, ultra light effector with remote direct drive via rigid CV shaft, CPAP cooling.
I'm questioning how much of a difference it actually makes and I'm contemplating going in the opposite direction with my arms; heavier, stronger and stiffer. Though I'm also working with a much stiffer Predator frame. Weight is just one factor, you can have the lightest setup in the world, but if it's flimsy or has a bunch of backlash you're going to be worse off. I think it matters more where that weight is, like with that effector, all the weight is cantilevered below it. Any mass a the end of that lever arm is going to have considerably more impact than if it were closer to the center.
Hiya, these arms will definitely pop off given a high enough acceleration. That being said, I've pushed my machine up to 8,000mm/s^2 acceleration and have had no issues
Backlash can certainly be a problem with ball and sockets. I'm far from an expert on building deltas (and certainly not qualified to recommend parts yet, lol), so I would advise you join Rolohaun's discord and ask there. discord.gg/T69bGDU4
Can try RC helicopters ball ends see those 3D flyers bashing around I Was imagining its stress on the heavy 3-4Kg helicopters which I once flew. The weight of the delta is not that heavy as a 3D helicopter. Can also try RC off-road suspension & steering ball ends they are tough. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-9cK201lJhCI.html
@@mitsubishimakes yeah, and in this case, I’m probably just gonna stick with the super cheap $12 arms I ordered… unless of course they’re absolute garbage
