bruce

Ah, that would be a bit of a killer for a NEMA 8/11 primary feeder motor then. Well that NEMA 8 is all of 60g, which should be a bit easier to jerk around than a 350g NEMA 17. Certainly you couldn't hit the same top speeds with 60g to 100g extra riding the extruder as you could without it. One reason for the high speed jerks is to reduce stringing, is it not? Perhaps a small stepper could still be useful for applying a bit of back force to stop the oozing? Yeah, it sounds like a small secondary stepper would be pushing forward just to not get in the way of the main stepper, and would only justify its existence if it could help hold the filament back during those moments when you don't want any flow. If it isn't capable of doing that, it would be a totally useless expense.

I don't own a printer, so please forgive me if this sounds stupid... How much force does it take to push filament into an extruder? If actual grams force numbers aren't available, is it effortless like pushing solder onto a hot iron, or annoyingly hard like shoving dough through a pasta machine? It is my understanding that the Ultimaker is fast and accurate because of it's light weight extruder, but that this creates some issues with things like strings because the stepper is too far from the extruder to quickly stop flow on command. Assuming that is an accurate assessment, I was wondering if it would be possible to modify the filament control system using a small, light stepper on the extruder head; perhaps something like a NEMA 8 or NEMA 11, or maybe one of these common printer type steppers, depending on how much force is required. I'm imagining keeping the NEMA 17 stepper at the fixed end of the bowden cable to haul filament off of the reel, followed by some sort of microswitch-based filament tension detector, and then the small and light stepper just managing the feed right on top of the extruder. Obviously that adds complexity and weight, but if it could add better control it might pay for itself. Does that sound at all plausible, or am I trying to solve a non-problem?

Thanks for the responses. Sounds like noise might be manageable, if I can get spousal approval to buy the thing. I just have to figure out what value of X to use in the equation, "but Honey, we can make X!" Some sort of educational toys for our ongoing experiment in biological 3D self-replication, perhaps. And as a bonus, maybe I can work with Daid's idea and justify a CNC milling machine to make covering noise for the printer! Sweet. Then on to the laser cutter and the pick and place and and and...

I've watched just about every Youtube video there is on the Ultimaker but I can't quite figure out what to think of the noise levels. What I want to know is how likely I would be to annoy the downstairs neighbours (and my sleeping family too, I suppose) in my wood frame apartment building if I had one of these things chugging away late in the evenings. Obviously some builds are noisier than others, but I wonder does anyone find themselves tweaking running speed to reduce vibration? Can you configure the software to run fast but corner gently, like the quiet mode on some hard drives? Could you place it on some sort of padding to reduce transmission of noise into the building structure, or would that cause print problems? I'd be curious to hear any noise-related observations or experiences people have with an Ultimaker or similar printer. Thanks, - Bruce