Well this is something I haven't seen before

arhi

@fcwilt said in Well this is something I haven't seen before:

I really don't want to make this into fd vs zn flame... I have both, don't really use them any more at all cause both have issues

Low speed? Please define low speed - in your world.

I can drive 3mm filament trough fd (flex3drive, old, not G5, having issues with G5 that are not resolved yet so can't reliably do anything with it attm) 300mm/sec, 0.6mm layer height, 0.7mm extrusion width trough 0.8mm nozzle easy. With 1.75mm filament I can do more but don't have a frame that will not vibrate itself apart if I go faster. I could not do even 1/4 of that with zn, actually reliably not even 1/5 of that.... in some "ordinary" terms, going .2mm layer .4mm nozzle, .48mm extrusion width ZN was for me reliable up to 50mm/sec and fd up to mechanical limitations of the frame - 300mm/sec

And I have no idea how "low power" applies - the power to do what?

power to push/pull filament, pull from spool trough a long ptfe tube, push into nozzle at high speed with high precision and reliability. I pull filament sometimes trough almost 6 meters of ptfe cable from the dry box, no matter how much ptfe is oversized and slippery it's a drag, especially with those 3.6 or 5kg spools on the other end ... I'm designing the new system for the toolchanger where the secondary extruder's will pull the filament from the box and maintain slack for the main extruder to not have to deal with that based on the principle old teartime up was doing... will share, once I finish it

fcwilt

@arhi

Sounds like you might be doing things that most of us can only dream about.

For me printing at 90 mm/sec is "fast".

Thanks.

Frederick

arhi

@fcwilt said in Well this is something I haven't seen before:

Sounds like you might be doing things that most of us can only dream about.

Not really that hard, you use a big nozzle and push 100W into the hotend and it can pass through extreme amounts of plastic... problems are of different kind

it is super unsafe, not sure what temp you need to melt the copper but I already killed some alu hotends with smaller, 80W heaters
the khantal wire does not last too long so every 3-4 months I need to replace it
the print quality is ... well ... acceptable for huge parts & building blocks that you will postprocess...

the dual fd I used cause I can run one custom hotend running 100W .8-1.2mm nozzle with 3mm filament on the input and one .4-.6mm nozzle in the same time and use small one for perimeter and big one for infill ... unfortunately that never worked the way I expected... slicers are still lot behind what is mechanically possible

For me printing at 90 mm/sec is "fast".

hm, wanhao duplicator i3, prints decent quality PLA at 100-110mm/sec, creality ender 5 by only switching to bmg and moving it on top of existing PRC hotend prints 120mm/sec PLA ... yes corners are rounded but you can fill the bed easy and you will reach 120mm/sec in most of the moves, you just need to get the accel up to 2000.... and yes, you need to move away from original 8bit board and use something else (in my case that was redeem and smoothieware, now I'm moving slowly to duet)

now, I don't, any more, need bigm nor fast prints so I'm on .3mm nozzle and "normal" hotends (e3dv6, hexagon, soon mosquito..) printing at "quiet" speeds )(don't have external appt for 3d printing neither any more) ... but back in the day with my cubebot I had to push many many kg's of plastic every day and fd solved me as with fd I could run at super high accelerations achieving high speeds

btw, what ppl rarely mention, one of the HUGE issues with fast printing is quality filament, for e.g. mitsubishi purchased dutch factory that makes AWSOME filament, e.g. one domestic company use them to make filament for them, they have special "high speed PLA", when you go over 120mm/sec printing with that filament looks better than anything else I tried (3d republika pla-x) .. at speeds below 120mm/sec you can tweak any filament to look decent, but when you go over, you really need good filament (they don't want to tell me what is different inside from regular PLA, but the cost is ~x2)

if you are interested I can find one of those hotends and take a few pics ... they are rather uninteresting (piece of copper turned on mini lathe, fire cement, khantal wire... ) but.. maybe when that project finally "expires" I can publish some of that work

big printed parts unfortunately are all very very very very nda-ed as they are part of the special light tank (and also drilled, sanded, sanded, sanded, sanded, sanded, primed, sanded, sanded, coated, sanded, coated...)

now as for ZN - I could not push it to go 90mm/sec with .35mm layer and .5mm extrusion width

fcwilt

@arhi

Interesting post - thanks for taking the time to share that.

Frederick

arhi

lot of interesting things from back then... not too interesting to "high quality - high details" folks

anyhow, I'm much more interested in what will you find out to remove those slanted lines... lot of different approaches, as you can see on that other topic too... I even heard ppl had improvement using those TL-smoothers with TMC drivers. It makes no sense as TMC drivers should not have that problem around zero but ... I recently seen a super weird behavior on one old corexy laser cutter, problem ended up being "worn pulleys" and I was 90% sure there's no way a metal pulley would worn so much that it will affect movement ... but hell, they did so.. I'm collecting experiences on these weird issues ppl have

fcwilt

@arhi

Well I designed and printed a test mount for a Bondtech BMG with a 25mm Stepper that I happened to have in inventory.

But when I went to fit it to the printer I found that I shouldn't trust my memory - a 20mm dimension should have been a 15mm dimension.

Such is life.

Anyway that discovery led to deciding to correct a few minor issues with a couple of existing, related parts.

One of those has been re-designed, the other is for tomorrow.

Then to print all three parts, mount the BMG and found out if it proves the Nimble is the cause.

Frederick

arhi

@fcwilt bummer, so it is the nimble
if you try nimble at lower speed, does it make lines go away?

arhi

@fcwilt said in Well this is something I haven't seen before:

found that I shouldn't trust my memory

funny thing, on most groups/forums/gatherings about 3d printing I was amongst the oldest if not the oldest participants while with duet users I'm younger than most but still I don't trust my memory at all any more, measure 10 times and write all 10 times, lose 9 of them but ...

fcwilt

@arhi said in Well this is something I haven't seen before:

@fcwilt bummer, so it is the nimble
if you try nimble at lower speed, does it make lines go away?

Well based on what I have read here and other places it seems LIKELY that the Nimble is the source of the artifacts.

I did run some prints at lower speeds but it didn't have a significant effect - as I recall.

If the BMG products prints free from that artifact I will conclude the the Nimble is the source.

That testing should happen sometime today.

Frederick

Technology

I have exactly the same artifacts on my Tevo Little Monster, also with nimble. But i tested with a BMG and the artifacts are the same. I changed everything on this printer instead of the beams and the heatbed and still can't get rid of it.

Running now Duet2Wifi, Nimble, Smart-Effector, 0.9° stepper, Magballs, Linear-Rails and Meanwell powersupply.