Is there a way to bolt the BondTech QR head to a TriDPrinting 5.18:1 stepper, that doesn't cost $90? I am
not paying fifty freaking dollars for two hobbed bolts. The dude from Sweden can find another way to buy a yacht.
I honestly think the TriDPrinting solution ($34 motor, $7 hobbed bolt) is fine. Dual pinch rollers seem like a good way to blow out the PTC fitting. Rather it skip than do that, and if it skips with that fat 12.5mm O.D. hobbed bolt, it means I'm doing something wrong. I think I'll just design a flex filament-capable extruder that bolts directly onto the gearbox of the TriDPrinting motor. I have modded one EZStruder for flex filament, but it's not as good as something purpose-built for that.
In other news, I'm getting an assembled set of six mag arms and matching chromed steel balls from
this guy. The steel balls have M3 studs, and there appears to be enough clearance to install them both to the Trick Laser platform and carriage yokes. Presumably, the ball cups on the ends of these arms are printed either in PLA or ABS, so we have the same problem as Traxxas rod ends. Friction with the steel ball will cause them to wear over time. Fortunately, it's now possible to buy POM (acetal) filament at $50/spool. It's hard as hell to get to adhere to the glass, but someone figured out that you can use a PLA raft and it'll stick to that just fine. Acetal rod ends printed at 50 microns should be pretty damn good!
I think the
Cherry Pi IIIS printer is better still. Instead of the effector and carriage yokes, the steel balls are installed to the rod ends, and the effector and yokes have cups that the balls ride in. He prints his out of regular plastic. I would either use 3D printed acetal, or just buy a block of the stuff and machine it into an effector (with SeeMeCNC standard holes) and carriage yokes. I think machining would be the cleanest and most accurate way to go. Anyway, rather than magnets, he ties a length of Spectra line to the side of the effector, then a stiff spring to the Spectra line, then the spring is hooked up to the carriage yoke. No magnets - the Spectra line and spring hold everything together. Basically, this is mag arms without worry that they'll ever detach. You can see photos of this if you scroll through the gallery.
My end goal is to have a fleet of three MAX METAL printers with either magnetic or tensioned ball-end arms. I prefer to use the Trick Laser platform and carriage yokes rather than designing my own, so hopefully these magnets do the job.
