Attn: Deckingman Printing at 300mm/s

  • I found this 3 part article, wondering what you think and based on it im pretty sure your Diamond could pull it off. Not sure what the fastest an e3d v6 could do at 250c without the volcano with a .4 nozzle

  • Interesting article. The tests I did were primary to investigate if pushing 3 filaments through effectively 3 melt zones would lead to higher speeds, which indeed it did. I didn't actually set out to prove anything other than that.

    I had definite signs of under extrusion at 300mm/sec but at 250 there wasn't anything horribly wrong with the print. This was all at my normal PLA temperature of 195 deg C and a (0.5mm nozzle). A 0.4mm nozzle has an area of about 0.123 mm^2 and a 0.5 mm nozzle has an area of 01.96 mm^2 so one could argue that my tests were pushing out about 50% more plastic. In which case, I'd suggest that 300mm/sec with a 0.4mm nozzle Diamond hot end should be achievable (at 195 deg C) - same melt rate but small cross section filament bead should in theory enable faster travel speeds.

    I didn't try increasing the temperature. I note that Dyze calculate that 250 degrees C can lead to 50% more melting than 210 deg C.

    So yes, all in all I'd say that the diamond fed with 3 filaments at 250 deg C should be able to pull that off - maybe even a bit higher. I'll give it a go when I get chance. Busy printing parts for the latest evolution of my printer at the moment.

    The next evolution will be 5 colour - be interesting to see what having 5 melt zones can do….........

  • I think received wisdom would suggest an e3d v6 with the supplied 30w (26w) heater cartridge can probably do 6-7 mm3/sec. But I'd like to test to see if this is true.

    I tried a volcano (with a verified 36w heater and a 0.4mm nozzle) to the point where it started visibly under-extruding at 160mm/s. I think I got to 6.4mm3/sec. With a larger nozzle I don't doubt that you can push more through. As Ian said just 0.5mm instead of 0.4mm is 60% more cross sectional area, a 0.8 or 1.2mm nozzle would allow maximum volume to flow but at a much lower head speed. (Ian I think you meant 0.196 rather than 01.96).

    But this is not going to enable printing at 250mm/s even if my corexy holds together at that speed.

    What surprises me is that it doesn't seem that the heater cartridge power is as important as the length (total length in the case of diamond hotends) of the melt zone, and the amount of extruder force available.

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    I am not surprised that heater power doesn't make much difference, because most extruder heaters are far more powerful than you need just to maintain temperature. After you run M303 to tune the heater, the gain parameter (A in the M307 command) is approximately the eventual temperature rise you will get if you leave the heater running at full power. So a gain of 250 should be sufficient to reach a temperature of around 270C at a typical ambient temperature of 20C. But most hot ends have much higher gain than that, especially if you have a silicone sock over the heater block.

  • I remember doing some tests on using Copper grease around the heater cartridge on a Diamond hot end. Just the brass part sitting in free air with no fan and no heat sinks fitted and a 40W heater. I seem to remember that I was pushing it up to 400 deg C and it took about 300 seconds but was still rising rapidly.

    There is plenty of heat in the brass part. I certainly didn't observe any drop in temperature when pushing 3 filaments through at high speed. The trick is transferring that heat to the filament and for that the important things are contact area and time.

    I expect someone clever could work out how much heat (in Watts) is require to melt x amount of PLA per sec. I wouldn't be surprised if it's as little as 1 or 2 Watts per mm^3 per sec. But you'd still need a bit bigger heater just to speed up the warm up time.

  • A bit like internal combustion engines, you don't need 100 horsepower to cruise at 60 you need about 20 bhp but 100 gets you there a lot quicker than 20. That's why I love this car concept so much, the fuel cell is 15hp but the capacitors (in this case) give you a lot more when you need it, so its built around the ability to cruise at 60 with no stored electricity rather than having to size the power plant to accelerate you to 60 quick enough to be acceptable. Make me wonder whether in the stop-gap between ICE and EV's being standard a very low powered engine, such as 15-20 hp coupled with capacitors/batteries might be a big step in the right direction regards fuel and CO2, essentially an extreme hybrid.

    Sorry got all "future of motoring" there, the parallel was too strong to resist.

    Back to the printers, what's the potential downside to having a longer melt zone, since it seems desirable based on what we've been discussing here? Why aren't all hotends, volcano's or something larger/longer? I have a v6 and a volcano on two different machines and the print quality is very similar.

  • Hadn't really thought about downsides of long melt zone but now that you mention it, my Diamond does tend to ooze a lot from about 160 degrees until it gets up to working temperature of about 195. I wonder if that's a downside of longer melt zone (given that filament expands as it get hot)? Maybe, you need more retraction for similar reasons? Dunno - just speculating.

  • DJ
    Ref cars (or any moving mass come to that). Any force applied to an object will change it's velocity if it's enough to overcome friction (which is just a force acting in the opposite direction). So with zero friction or drag of any kind, once an object is up to speed, it will maintain that speed with no force (think orbiting satellites). But to accelerate an object takes very much more force (thing Space Shuttle or rocket to get that satellite up there). Force = mass x acceleration. I did once do a test with pulleys and string and kitchen weights and it only took about 60 gms to move my 1.6kg X carriage. Of course, all that was needed is the force to overcome friction plus a little bit for the initial acceleration up to a couple of mm/sec. To accelerate it up to say 300mm/sec takes a lot more force.

  • Yes it certainly makes a difference whether you want to just make it move or make it move quickly. It just surprises me to think that engines have been specified by their ability to accelerate a vehicle rather than maintain its speed, and as such have been very much larger than they might be, but then when all you have is an engine that's what you do (when all you have is a hammer everything looks like a nail). Luckily there's a greater range of options available now.

    Ooze is annoying but not particularly a big problem.

  • No offense to anyone, but I'm a little OCD so I can't help myself. An orbiting satellite always has the force of gravity pulling on it or else it would escape in a straight line. And if it is in an elliptical orbit it will accelerate toward perihelion and decelerate towards aphelion constantly varying in speed except instantaneously at those 2 points.

  • No offence taken. The point I was making is that an object in motion will maintain it's speed without any additional force being applied. In the case of an orbiting satellite, gravity and centrifugal forces balance each other out so it maintains it's orbit. Or in the case of an elliptical orbit, there can be two or more gravitational forces being applied, so the forces acting on it vary. The same principal applies though - that is to say, it will maintain it's motion, whether that be in straight line, circular or elliptical, without any additional force being applied and it takes very little force to move it slightly, but a great deal more force to accelerate the object out orbit.

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