I installed the Hermes on my old Mk2 with the bear conversion frame. It was a new build especially for this extruder. I seem to be getting real inconsistent extrusion horribly similar to the MK3 debacle and the swept under the rug 602 issue. 1. I have calibrated the extruder and had to lower the esteps from 409 to 397.23 (i think that was the number) since I was over extruding about 4mm. 2. I have edited the firmware and have .525 v on the vref pin on the mini rambo. 3. Stock boar with a external driver board for X and Y using 2209 drivers. 4. All the driver gears look fine from what I can see. 5. Tried many different settings and all end with the same results regardless of slicer. I have used my same S3D profile and prusa slicer as well with the same results. 6. I have tried the tension gear loose and about 5 clicks in and now I tightened it until he white part was flush with the arm , which seems really tight , but I have not printed with that yet. Anyone have the same issue or have any ideas?
With what tension did you perform the extrusion calibration, which speed and what is the type and diameter of your filament? You might want to determine your maximum extrusion rate measuring 100mm extrusions using speeds ranging from 2mm/s to 6mm/s. See if or how the steps per mm differ, if or when you encounter skipping or grinding. Also, if you didn't re-use the heater cartridge and/or thermistor from your previous hotend perhaps the actual printing temperature is also different from your previous setup.
Everything was new, it was a complete Hermes kit. I did the calibration through the printer menu just manually extruding; but with that I already had to lower the esteps from 409 as mentioned. From the test cubes it seems to be close tot he right value overall. I did small adjustments with the extrusion mutiplier as shown but anything lower that .90 extrusion multiplier begins to have gaps and honestly there is no difference in the side wall look no matter the extrusion rate. It looked basically the same no matter calibration or extrusion mutipiler so definitely something fishy with the extruder itself it seems. I am going to attempt to calibrate using proterface and see what I get. At this point not sure that these extruders are the greatest thing since sliced bread. Might should have just stuck with the old straight v6 style but I am not giving up ..... yet
Well went back through it all with the tightened filament tension bar flush with the arm as some have mentioned. The eteps were close it was a bit under extruded at 393.27 so I went back to 397.24 for it to be spot on. I did a test print of a hollow 25mm cube with the extrusion on auto in S3D at .48mm. The walls were .54mm so it was over extruding a bit still somehow. So lowered it back to .95 and printed the same model. Now the walls are close at .52 but the extrusions are still rough and really no change from the first set of solid cubes. Lowing it yet again to .90 and will see what that yields but seems like this is viscous circle now and has to be something eitehr mechanical with the extruder or these units just produce rough surface quality which I find unacceptable. The surface finish is not acceptable. There is nothing else to check in my opinion other than maybe a nozzle issue but it was new and came with the Hermes. I also checked the other axis just to make sure and they were all spot on as far a moments. Nothing is loose and I have check all I can. Surely there has to be something wrong with the extruder itself? Am I the only one with poor extrusion quality? Filament is Filamentum Ivory @210 50mm sec
Second round of test, pictures are labeled as the extrusion multipliers used. https://drive.google.com/open?id=1BaVHRYdK1L1ciVCCS62-Hb2KQKoElmzG
With an extrusion width of 0.48mm you're amplifying variances in filament diameter. Try 0.42 or 0.45mm. Also, since you also changed thermistor and heater, you may want to re-tune your printing temperatures. But most importantly, using a hollow single perimeter cube is not a good method to calibrate your extrusion multiplier. Consider the 0.48mm you're using more like a center-to-center spacing of the extrudates, but don’t expect a single wall to be of that exact size. The actual thickness of a single perimeter wall printed at 0.20mm layer height should measure be about 0.52mm. Some reference links included below. With 0.20mm layer height, a wall of two 0.48mm perimeters should measure about 0.92mm, with three perimeters the wall thickness should measure about 1.35mm. https://reprap.org/wiki/Triffid_Hunter's_Calibration_Guide https://reprap.org/forum/read.php?1,704450 https://manual.slic3r.org/advanced/flow-math http://hydraraptor.blogspot.com/2011/03/spot-on-flow-rate.html?m=1 http://www.desiquintans.com/flowrate Edit: I'm not saying that underextrusion is the issue in your case, but troubleshooting becomes much easier when the basics are in order.
There's definitely a regular slanted pattern on the cube's surface, which I'm guessing has the same frequency as the frequency of full steps (which have more torque) made by the extruder stepper motor. That sort of rules out a random loss of extruder steps I guess. But the layer lines not being stacked uniformly could be something mechanical, such as resonance, belts, bad bearings, backlash or a binding lead screw for the Z-axis. Could also be a partial clog due to heat creep, too high/too low temperature or too much retraction. Did you check where the limits of your extrusion are at as suggested earlier? Sometimes a drastic change of approach brings interesting insights and help determine where to look. Go print at 20mm/s. Or disable all fancy options, such as mesh bed leveling, linear advance or S-curve acceleration. Set acceleration to just 200m/s. Experiment with temperatures, see how low you can go and what happens. Reset your EEPROM. Use a different slicer. And so on. P.S. If you use a heated bed, is it heating in bang-bang mode or using PID control?
If you want to be (fairly) certain that Hemera's gears aren't slipping intermittently, follow this procedure on Youtube. Don't forget to remove the heat break first before disassembly, otherwise you may damage the heat sink when removing the hob assembly.
As far as the extrusion width for testing I have done many many test. First was the solid cubes and then I moved to the hollow larger cube as well. Basically I was following this information after my typical test were not yielding good results. http://3daddict.com/3d-printer-extruder-calibration-steps/ Kind of the same answer to your second statement as the first. I only moved to that after the other 14 or so test cubes I printed. However I will check out the other links but at this point I suspect something mechanical since it seems to not change no matter what I do. It improves slightly as I decreased the flow rat or extrusion mutiplier but nothing significant.
As to point 1- I do not seem to get any extruder skipped steps. I can hold the filament and it take a lot of force to stop the motor. It will extruded all day long fairly consistently while not printing- meaning the filament is smooth and free flowing. There is not any clicking or grinding while printing. Point 2- That's a possibility however all the bearings are new, all Misumi (rods are not new but also Misumi and seem to be in perfect condition) and I cleaned and packed them prior to install. The axis move quite smoothly with the belts removed and will free fall under gravity. Of course they are not perfectly smooth as a linear rod but I do "feel" anything odd with the rods or bearings or sense any vibrations. Also with that said its on all axis, not just x or y , seems to be on all for side fairly uniformly. That's about the only thing reason I have to say they are in good shape but nothing scientific. Heated Bed and Hotend- I did a PID tuning on the machine prior to any print. All parts on this machine were new so I treated it as such. Ill do a slower print but I have not gone about 50mms on any of the previous prints; most all were done at the stock Mk2 S3D settings of 2400 mm a min or 40mms. . I'm going to look at the gear assembly but really do not want to have to dissemble the entire x axis to take apart the extruder. That's not the easiest thing to do the way this machine is set up and wired. I am hoping to see if I can manually from the top move the gears independently to see if they are separated as the video showed.
This was at .87 extrusion multiplier and 20mms no change at all to be honest. At this point I am thinking something mechanical with the extruder itself or I could be wrong but have no clue what else it could be at this point?
Still having the same issue before I took the extruder apart. Everything looked fine from what I could see. Gears seemed to be one piece. Reassembled the unit we print again tomorrow, I upped the steepper current a bit more just in case. It always ran cold to the touch anyway so I doubt the bump up would hurt anything. https://drive.google.com/folderview?id=10CtaS_NxVlPCsB2t6mEefM1J2UZur3gT
It is now, that was the only thing left mechanically to change. I had it handy and it was brand new, however 99% of the testing etc was with the nozzle the kit came with being standard brass .4
Phew, tough case! The Teflon feed tube in your photos seems yellowed, is that the white balance? And I cannot explain what seems to be a scuff mark on the inside of your heatsink just below where the idler is. Some ideas (but almost running out), all intended as separate test cases. These are meant to provoke a change in behavior that might lead to a clue of the cause. Use the TMC2209 driver of your X-axis as your extruder driver. So switch the E and X (or E and Y) drivers around. Lower the Vref to where the extruder starts skipping at 4mm/s extrusion rate and keep it there for experimental purposes. Restore the Vref when you see no change in print quality. Print the cube twice as large. See if the pattern changes or scales up. Use a coarse 0.28mm layer height. See if the problem scales as well. Might as well try the same with a fine layer height of 0.08, or whatever is a multiple of your magic number. Try to complete a print with the bed heater turned off completely. Or shut it down after the first few layers if the print doesn’t stick. Print at 80mm/s. Print with a 10°C or 20°C lower temperature. Are you in a very humid climate? You’ve shown different colors of what I believe is PLA filament, so wet filament is less likely. If you already dry your filament before use, ignore this bit. Use no retraction at all. Set retraction to zero for all moves. Disable any layer fan. Re-route your thermistor wiring. Measure the resistance of the heater cartridge and thermistor. Keep an eye on the stability of the temperature of the hotend and bed. Try Cura, Slic3r++ or PrusaSlicer. Find a way to determine if the voltage of the PSU doesn't drop or fluctuate too much.
The tube is Capricorn PTFE , it's just a brown color, was intended to be orange but came out brown and was reasonable priced so that's why the ugly color. You mentioned some new stuff to try and some I have tried. I was shocked to to still find such terrible artifacts in the extrusion quality at the 20 mms cubes. Before hand I tried larger cubes at all print heights from but mainly .16 and .20. I even used prusa slicer and 100mms with linear advance and the pritna honestly stayed the same. The temps seme spot on , we according to the thermistor reading. I did PID turning before I ever printed even the first blue colored Marvin and I don't see any fluctuations in temps and these machines are in a cabinet so not much indirect temperature change. I'll try a few things this evening but it just doesn't make any sense at this point. Seems like if it was truly a printer issue separate from the extruder assembly it would do it at a decent speed but not at a crawl this seems to do it no matter what the situation. I feel like at this point I threw $90 in the trash can .
If you take a cylinder as a test subject that you print in vase mode, you have eliminated factors such as corners and sudden layer changes. You may be able to better distinguish any pattern (if there is one). I’m also curious if the inside of the cube exactly mirrors the inconsistencies. Stupid question probably, but you do hot-tighten the nozzle at 285°C after every nozzle-swap, right? I also found some very helpful troubleshooting strategies with the Repap people here: https://reprap.org/wiki/Inconsistent_Extrusion_Troubleshooting_Guide BTW, judging from the last photo, I think your corners seem to be stacked pretty precise and square without blobbing, so that doesn't make the XY motion system a prime suspect. A more logical assumption would be that 1) something in the Z-direction is binding (lead screw, bearing) or 2) pulsing (could be the bed expanding suddenly when current supplied, acting as a ‘speaker’) or 3) the filament delivery is pulsing (could be temperature related, mechanical (gearing, stepper rotor), supply voltage related, electrical interference or loose wiring/poor conductivity).
Well been trying a few more test this evening. This is a 100mm circle printed at .2 layer height and 60mm a sec for 3/4 and 100mm a sec for the top 1/4 all at 205 / 60. I did turn the bed off about 1/2 way and the part cooling fan was at 50%. Still seem the same pattern as before this even after I took apart everything and check it all for the last time. The inside and outside of the circle seem identical. I don't see any real difference in the two. If it's not the extruder assembly I'm starting to contemplate a different board but not sure what firmware is available. E3D support emails have been helpful at first (getting it started) but now pretty silent. Z rod movement is very smooth , those are new POM nuts and bearings as well. I don't see ant binding and it's easy to move by hand. I don't have any slack or play anywhere on the other axis and the frame is probably the best I've ever seen or built and solid as a rock. Not saying I'm perfect but in this case I just can see any other fault than the extruder and issues like 602 was with the board and geared extruder produce. Or maybe the mini Rambo is just not suitable for this setup?
