Volcano hitting extruder limit?
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I would be very interested in seeing a test on 0.8 or 1.2 WalterSKW if you got time for it. I'm also tempted going down to a 0.6 nozzle just to test if I can get rid of this speed limit that way. I have my stepper set at 1100mA now
@deckingman Yes, but not before layer 3 and up and these issues shows from layer two. I tried disabling it completly also while testing just to avoid this. A friend just put a volcano soc in the mail for me so tomorrow I will give it a go with sock on it.
Just a sidenote here. With a 1.8degree stepper end the 30:1 reduction gearing in Zesty nimble will that be close to the speed limit of the stepper motor on duet wifi with 16 microstepping? I'm considering those remote direct and it should give me more power also.
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Depends on the motors inductance, low inductance motors at 24v can spin pretty fast.
My attempts to print things with big nozzles didn't really save me great deal of time as you do run into the limit of what you can melt at around 50mm/s, but they did produce some very tough objects, one is a toy for my son it must have been dropped onto a hard floor from 60cm about 50 times and hasn't broken yet.
Interesting to know what is limiting the melt rate, if its not insufficient wattage (which I can test as soon as my 50w heaters turn up), then it must be the length of the melt zone. Maybe someone fancies machining a longer block than a vocano?
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One of the differences between a Volcano and a V6 besides the length of the nozzles is that the heater cartridge in a Volcano is better placed as it is parallel to the melting zone and the heat can travel a more efficient path.
Larger (longer) melting zones have their disadvantages too, as there is a higher mass of liquid plastic that wants to ooze out of the nozzle.@DjDemonD : Where did you find the 50W heater?
@minim : any preferences for a test?
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aliexpress, https://www.aliexpress.com/item/6x20mm-24v-50w-printer-cartridge-heater/32609747337.html
the vendor even measured the resistance for me 11.5 ohms, so they should actually be that wattage, but I haven't received them yet. -
One of the differences between a Volcano and a V6 besides the length of the nozzles is that the heater cartridge in a Volcano is better placed as it is parallel to the melting zone and the heat can travel a more efficient path.
Larger (longer) melting zones have their disadvantages too, as there is a higher mass of liquid plastic that wants to ooze out of the nozzle.@DjDemonD : Where did you find the 50W heater?
@minim : any preferences for a test?
That 40mm Cube would be fine since We can compare it. O4 vs 08 nozzle.
I really dont see how more watts would solve anything as it's no trouble keeping the temperature as it is now with a 30w. The controller won't put more watt through a 50w heater than a 30w heater if it's the same temp goal. PWM duty cycle will be reduced tho but as long as it's well below 100% how will it help?
Edit
Regarding strength of a print. The ones I'm printing now is height calibration blocks for a 2500kg Range Rover so I'm resting over 500kg on each block that is 30mm diameter. Works great with 25% infill -
To bad E3D havent made copper Volcano blocks yet. Maybe that could give you a few percent more.
I also saw that they have socks now for Volcano
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Would it help to use heat paste from nozzle to the block to improve heat transfer to the nozzle or is the limit the area of the melt zone touching the palstic?
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Have no idea Frank,
Seen this: http://print.theporto.com/posts/e3d-volcano-hot-end-tips/
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He seems to have similar experience as me.. 0.5-0.6 layer height on a 0.8 nozzle and he get's problem with layer adhesion and extrusion if going above 30mm/s. Guess it's really the extrusion limit of the volcano then. I might swap down to a 0.6 nozzle then to get back some detail and then I can prolly up the speed to 60 again.,
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I just did some tests with a 100x100x5mm thing. Settings : 210°C, 0,8mm nozzle, 100mm speed set up in S3D for all printing. Layer width 0,96mm, height 0,64mm.
I made a quick and dirty video with of course some troubles in feeding the filament.
I played with the speed. and ended up with 70% as a speed where there was still a nice track. 70% of 100mm/s = 70mm/s.
Here is the video (sorry for the quality. I'm not a professional
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https://youtu.be/Fh8iMHWGRcMI would NOT use any paste to improve heat conductivity between nozzle and block. What you could do (and what I did) is applying some copperpaste (used for cars : brakes) between heater cartridge and block. This has also the advantage that the heater can still be removed without issues when needed.
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Hmm I did some testing now after seeing this. I had my speed set at 30mm/s and even then it was slightly under extruding with 0.4 layer height and 0.96 width.. Had to drop to 80% before it got perfect. I then upped to 250% and it didn't skip steps but it was heavy under extruding. I'm going to test with a bigger new nozzle now to see if it could be partly clogged or smt.
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qube 40x40mm printed at 30mm/s with 1.0nozzle and 1.2 layer width, 0.8 layer height gives me no under extrusion. This was a layer time at 47seconds so 1280mm^3/47 is 27mm^3/s if i calc correctly. INSANE amount lol. It's rough print but def not under extrusion. Going to 130% speed it started to under extrude and making bad corners/adhesion. So then I can get over 27mm/3 with 1nozzle. Should be possible to break the 10-15 barriere on 0.8 then. Must be some kind of block in the nozzle, can't think of anything else..
Edit redid math…
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And new test with 0.6 nozzle where I had 60mm/s speed (slowed to 60% for outer petimeter) I had a extrusion rate of 15mm^3/s with perfect extrusion width. 5-6 more than I can do with a 0.8 nozzle so there must be something fishy with that nozzle. When I pushed up to 18mm^s (35sec layer time 40x40x0.4) it started under extruding also but then i'm close to what people say is the volcano limit again.
Can my 0.8 nozzle become partly clogged?
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Maybe there is a bur inside it or the shaping down to the nozzle orifice is incorrect, or the nozzle isn't really 0.8mm. What diameter filament does it extrude into the air? Good rule of thumb is to allow 20% die swell so a 0.8 should extrude 1.0mm width into the air give or take. Order up another nozzle?
Definitely use copper grease between nozzle and block, it does improve conductivity and helps dismantling.
I think you'll be right about the 50w heater, I expect I'll probably end up limiting it to 80% pwm anyway, so probably not worth the bother, but I'll give it a try see whether it makes any difference.
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Just a thought, wouldn't it be nice to see extrusion volume and heater PWM in the WEB UI? Wish it was possible to select that instead of voltage for example.
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You might like to add that to the DWC wish list.
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Extrusion volume would be interesting to monitor, though easy to show for a layer, but might need to be averaged for instantaneous as it will bounce around a lot especially on small details.
I wonder if it might be possible to build a modular control panel in DWC so you could add in whatever parameter you wanted to see displayed. Almost like a obdII car monitoring app/hud.
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That sounds like a great idea. Im sure there allready is a lof it internal variables that could be interesting to some while debugging. I agreed that it might have to be estimated by layer height after its printed to het it exact but instant value on bigger testpieces wouldnt go that much up/down. Maybe this should be put on the wishlist if its not only me geeking out here ^^
