Yes, I think you're right... maybe the cooling isn't even necessary. But it would help with overhangs. =)by jbayless - General
cluso99 Wrote: ------------------------------------------------------- > Just a thought. What about two nozzles near the > printhead? One blows heated air and the other > cooled air, both under software control. Yes... Yes!! I think this idea has a huge amount of merit. The cold air nozzle could be an upturned compressed air canister; those emit a very cold blast. And a heated air jetby jbayless - General
My intention wasn't to float the plastics on water or to take advantage of buoyancy in any way, just to make use of the rapid cooling to avoid the need for support. If weak inter-layer bonding turns out to be an issue, then the water level might need to be lowered during some print operations to reduce cooling, and raised at other times (such as when support is needed or faster cooling is benefiby jbayless - General
Here's an image by aka47: On the other hand, my thought is that a rather high-resistance secondary would be ideal, so that we can avoid high frequencies. So almost the entire nozzle could be made of a non-conductor like glass or high-temperature plastic, with a thin ring of stainless steel embedded inside to absorb the eddy currents.by jbayless - General
Hello, Last night in the shower I had an idea. What if, instead of heated beds and build chambers, the answer is just the opposite - flash cooling of the printed filament? So here's my proposal: A Darwin-style axes arrangement, with an X and Y gantry above and a Z bed below. The Z bed is put just above a bath of water (the height of which is under closed-loop control via a pump and drain), so tby jbayless - General
It might actually allow for more simply-constructed extruders, if it's done well. But it comes at a cost of more electrical complexity; for example, there might need to be power capacitors to balance the inductance of the circuit.by jbayless - General
I've got two questions... 1. Has anybody done the math as to what kinds of frequencies and currents would be required? 2. What's the advantage compared with using a heating element? I mean I can probably think of a few; for example, you could replace the barrel without having to replace the heating element, making the parts more interchangeable. But what's the main advantage?by jbayless - General
I'll be testing PLA when the nozzles arrive, so we soon shall see!by jbayless - General
I'm pretty sure it's something else. Probably a finely drilled brass dome nut. But Wade would know better than me. =)by jbayless - General
Yeah, probably, it would have been better if they'd done that. But on the other hand, we shouldn't have accused them of plagiarism.by jbayless - General
Can't speak for MIG tips (although just yesterday an engineering PhD friend of mine suggested using them too). But the extruder nozzle currently used by the SpoolHead team was probably closer to 0.9 mm. It still produces acceptable prints, but much less fine than the parts we got from Wade (who uses an 0.5 mm nozzle I believe). We really desperately just needed to get the printer working for ourby jbayless - General
I assume that the Thingiverse part was deleted because PP3D were probably the ones who originally uploaded it, as a courtesy, but took it down when they found people using it to accuse them of plagiarism. As for the Chinese economy spewing CO2, this is going off-topic, but I should mention that while they certainly do produce a lot (more than any other country), there are also a lot of people inby jbayless - General
Those look awesome! Nice work! I can't wait to try them out.by jbayless - General
If it helps, I have access to a lathe and could certainly make something like that, though I won't get the chance for at least a week.by jbayless - General
Good point! Pencil lead also comes in 0.5 and 0.3 mm sizes, and could probably be removed even more easily than metal wire. =)by jbayless - General
I don't get why people seem hostile about this. Their printer looks to be a very high quality, low-cost RepStrap. Isn't that a good thing for all of us?by jbayless - General
A problem I see is controlling the "flooding" of the interior. It's easy for a human, but not necessarily for a machine, unless some thought is put into it. For example, if you pour infill/hot glue material into a part and it doesn't have a smooth, level top, then when you try to print the top layer of ABS, it won't have a level surface to print on, and the print head might crash into a lump. Ifby jbayless - General
I don't know if you could cast an 0.5 mm nozzle; at least, I'd be surprised if you could. I think the part is really ideally set up for glass drawing, but again, I don't have much glassworking experience.by jbayless - General
Hm... Is it not possible to use fasteners or adhesives? Or print snap-clips to hold the parts together? I think it'd be hard to move a part on the print head and still have it aligned precisely enough for the machine to know where it is. BTW, here's a crazy extruder idea: A big "paintbrush" extruder head for doing rapid infill of large parts.by jbayless - General
By the way, SandFire declined to provide an estimate for producing a glass extruder nozzle.by jbayless - General
Why would you need to build next to a cliff - wouldn't it be better to print those layers before the cliff is printed? Also, in aka47's design, the bowden tube is squeezed between the brass nozzle and the PEEK block, so I think it's unlikely it could slip out. I don't have too much experience with PTFE though, so I might be wrong.by jbayless - General
I won't find out the shipping total until it arrives, but pre-shipping total was $74.76 US. The most expensive part was the 6mm-1/4" reducing coupling at $16.55, because it's made out of type 316 stainless which is always quite expensive. When I test the glass nozzles, I'll check if the 1/4" side of the coupling will work, since 1/4" is just 6.35 mm, and I don't want to compress the glass too tigby jbayless - General
I agree that, since it's a wiki, we should avoid using words like "I". Because multiple people will often author a single article, "I" requires the reader to examine the edit history to see who wrote that. The best way to solve the problem, to me, is to use proper writing style. I'll see if the SpoolHead entry uses any of these; it probably does. If so I'll try to fix them. Jacobby jbayless - Administration, Announcements, Policy
Here's AKA47's illustration. I'm going to try something similar, though not exactly this - although it's a good idea, I want to first see if I can get away with using just off-the-shelf parts. Then maybe I'll try it next. So I've put in an order to McMaster-Carr to try testing this, a luer-lock extruder, and also some bowden cable ideas. It was an expensive order, but it's for the sake of sciencby jbayless - General
Oh, the UP! is $1500 going to $3000? I thought it was $750 going to $1500. That does curb my enthusiasm a bit.by jbayless - General
Yeah, I was thinking of buying some of those tubes too, but I don't know how to work glass. (Yet). Sent a PM though. I think I'll experiment a bit with compression fittings, so if you can make some flange-free tubes, thick or thin, that'd be good. =) Embedding wire in glass - interesting. I wonder how they do it for safety glass, with those steel wires in it (although Nichrome is a far cry fromby jbayless - General
Ah - that feeder motor is very clever. It looks like their support material is also ABS?by jbayless - General
This sounds really good. But if problems occur, these might be the reasons... - Thicker nozzles might be somewhat worse from a thermal performance point of view - more heat will conduct up the length of the tube (lengthwise thermal resistance 44% less than a 6mm OD tube), for example, and less will conduct into the interior (widthwise thermal resistance will be 60% greater than a 6mm OD tube).by jbayless - General
Or perhaps that's not a part for their extruder, come to think of it. Not sure. I'd like to wait and see a review before I buy one..by jbayless - General