Welcome to the SeeMeCNC Community

Ok...so Barnett and I have finished mechanical and electrical settings. We have made multiple test pyramids. We had horrible initial results and finally made it to a good looking pyramid but there are "spider webs" between the towers.........our thermistor is not recording, I think, the right temp. Any advice...i feel maybe we are too slow...30mm/ps. We have tried everything but as noobs....we would love advice.......this is number six, wood kit....
It certainly is fun playing with this thing...photos and video to follow...very cool product though, got to say....and the customer service too....

We have lowered the speed, lowered the heatbed, and have been playing with filament size. It just seems like the filament is too hot.....oar the filament cools off too quickly between extrusion. Any time there is retraction, we have to expect a low extrusion......followed by "beaded" extrusions. Also, the initial layers don't seem like the infill is completely full.....?!?!?!? HELP.....
We have many good minds during holidays, but maybe too many......

Not great, huh..!?!!?!? But they have gotten better......IMG_0260.JPG

Having trouble with photos .....Bar..???!!??

JakeCShake, have you been able to print the calibration cube that I show in the manual?

g.

JakeCShake wrote:We have lowered the speed, lowered the heatbed, and have been playing with filament size. It just seems like the filament is too hot.....oar the filament cools off too quickly between extrusion. Any time there is retraction, we have to expect a low extrusion......followed by "beaded" extrusions. Also, the initial layers don't seem like the infill is completely full.....?!?!?!? HELP.....
We have many good minds during holidays, but maybe too many......

Best guess is that the extruder motor is skipping on retracts (probably in the return deom what you sescribe) because the retract speed is too high.
Easy way to tell is to draw a black line on the outer most gear and watch to see if it returns to the same location after the retract.
If it isn't, then you need to turn down the retract speed.
It actually sounds different if it isn't skipping, but if you've not heard what it's supposed to sou d like it's hard to tell.

Thanks guys....GeneB, your manual has solved all our problems...great job. Haven't done cube but tried pyramid. T
Heading up tomorrow to bother-in laws tomorrow....can't wait to produce awesome sample prints.
Thanks all for your help.....

FYI...nozzle diameter seems to be our problem. I was thinking 0.2 or 0.3mm nozzle based on the .PDF descriptions....oops. Can't wait to try 0.5mm tomorrow along with extended retraction lengths.....photos/video soon......

I am struggling too with the pyramid. Please continue writing down your experience here.

Happy Hollidays

Poul

Poul, have you printed the calibration cube yet?

g.

Several things I have noticed since starting to print calibration objects.
If I retract too far, the filament buckles on the return and jams in the extruder body.
Currently I'm retracting 3mm at 40mm/sec, I'd like to retract further.
Calibration of the endstops is critically important, it's not always obvious how far off you are until you try and print something larger. I found my digital caliper was in sufficient, and ended up using a sheet of paper at the 3 outside locations to measure the distance to the bed.
Also when calibrating pick two corners to adjust, and leave the other one alone, otherwise you just end up chasing the calibration in circles.
I've found I need a higher temperature setting for a given filament than on my other printers, I'm printing Ultimachine ABS at 250 where I would print it at 230 on my Mendel max. The thermister seems accurate, a thermocouple in the other hole reads about the same. I think this has to do with the largish size of the aluminum heater block, my guess is that there is a significant disparity in the temperature at the thermister and the temperature of the brass nozzle. Next time I dismantle my nozzle I'll pull out the PTFE liner and measure the temperature inside the nozzle.

Layer alignment is spectacularly good.
I think the default estep setting is about 5% high.

I've printed a lot of test cubes, and 3 or 4 pyramids, the pyramid still needs some messing with, I think I'll have to drop the layer height, and temperature and possible the print speed to get a good print.

Currently printing my first none test object.

Now that's really interesting. I was having extruder jams (and I mean EPIC jams - plastic would eject sideways from the extruder drive) until I upped the temperature to 237. I haven't tried 250.

Can you try yours at 237 and see how it goes? I'm nervous about ruining the liner or the plastic segment of the nozzle body so I'm leery of running it up to 250. (I should note that I'm printing with MakerGear Red ABS, which I'm told is the same stuff as Ultimaker)

Under Cura, I'm doing retracts at 100mm/sec for 4.5mm. I've done it at 55mm/sec under Slic3r for 10mm.

I've been running a hall effect sensor bracket I designed at .25 and they're coming out pretty nice. Not perfect mind you, but good enough. The 13mm cylinder (id) is coming out around 12.5 to 12.7, so I suspect that error is due to ABS shrinkage. However, I'm not sure about it - still new to this whole 3D printing thing.

g.

geneb wrote:Now that's really interesting. I was having extruder jams (and I mean EPIC jams - plastic would eject sideways from the extruder drive) until I upped the temperature to 237. I haven't tried 250.

Can you try yours at 237 and see how it goes? I'm nervous about ruining the liner or the plastic segment of the nozzle body so I'm leery of running it up to 250. (I should note that I'm printing with MakerGear Red ABS, which I'm told is the same stuff as Ultimaker)

Under Cura, I'm doing retracts at 100mm/sec for 4.5mm. I've done it at 55mm/sec under Slic3r for 10mm.

I've been running a hall effect sensor bracket I designed at .25 and they're coming out pretty nice. Not perfect mind you, but good enough. The 13mm cylinder (id) is coming out around 12.5 to 12.7, so I suspect that error is due to ABS shrinkage. However, I'm not sure about it - still new to this whole 3D printing thing.

g.

About the coldest I've successfully printed an object at is 240 but I've only really gone up in 10 degree increments, the extruder skips intermittently at 230. Judging by the pressure required to push the filament through the Hotend by hand without the Bowden tube it doesn't surprise me. Still much higher than my buddaschnozzle, or my jhead.
My first guess is temperature, but it could just be a small melt zone in the Hotend, or a particularly long nozzle, in which case there is some chance of damage to the liner.
Ejecting filament sideways is basically the buckling filament, mine tends to buckle under the drive roller, and is a pig to remove when it does. Ideally there needs to be insufficient space for this to happen. It would probably be less of an issue with PLA or 3mm filament because it's much stiffer.

The firmware caps E moves at 60mm/sec, unless you've changed it.
Any long retract seems to buckle sooner or later for me, it's a full real of filament, and it might just be trying to push it back onto the reel that's the issue, I can see the reel move as it happens.

I'm running KISSlicer but all the slicers do retracts the same way.
It would be interesting to get repetier firmware working, it has a firmware implementation of retract that occurs during the move rather than stopping to do it.

My test cubes are undersized ~19.5mm rather than 20mm, but they look really good, I ran off a Grotux model at 0.25mm layer height as my first multi hour print yesterday and it came out very nicely, layer alignment is very good.

I did see one inconsistency where during the solid layers, the infill did not reach the edge on one side of the model, the GCode looks OK, the cube doesn't do the same thing. I need to try some other objects so see what the issue is.

The only other thing I see, is occasionally when I do long G28 it pauses several times on the way to the home switches. Originally I thought this was an issue with the stepper drivers overheating, but now I'm convinced it's a software issue.

I'll run the stretchlet code John sent me at 245 and see how that goes.
The last time I ran it, I was only able to drive it at a 150 speed multiplier without having holes in the walls. I'll see how it does at 200 to 300.

I've run the first layer at 50 and the second at 100. I'll bump it to 200 when it hits layer five...

Well it appears to be doing very well. I'm at 300 and 31 layers into it, I've not noticed any skipped steps, no extruder jams, no holes in the stretchlet walls and no other artifacts. The last F command in the g-code file is "F1200", which if my understanding is correct is 120mm/sec, correct? If so, this sucker is banging along at 360mm/sec without issue.

Here's a video of the print run: http://youtu.be/6_GMFvdlJ2E - it should be done processing in 20 minutes or so.


I wasn't aware of the built-in retract speed limit.

g.

that looks awesome... I can't get it to slice that nicely... Slic3r keeps picking spots to "jump" to in the middle of some of the layers... I'm experimenting with Cura, but, can't figure out how to get it in the center of the bed (So, I'm printing slightly off to the side)... What program sliced that up??? Any chance you can send me that gcode file and I could try it? I'd love to know how much of what I'm fighting is sw vs harware... I think I'm getting the hardware sorted...

I noticed you said something in the video about increasing the temp... what temp are you running, I tried cooling things down and now my extruder "creeks" and "groans" while the job is running... that's probably an indication I'm running things too cold?

Thanks,

Tony

I don't know what John sliced it with - the code is at http://www.geneb.org/STRETCH.gcode
I used a nozzle temp of 245C.

If you set your machine center to zero, it should work ok for you. I'm going to add a Cura section soon, but just haven't gotten to it yet.

g.

geneb wrote:
I wasn't aware of the built-in retract speed limit.

g.

The firmware caps all moves to a defined speed, it can be changed in configuration.h, On John's firmware the default limits are
#define DEFAULT_MAX_FEEDRATE {200, 200, 200, 60} // (mm/sec)
200mm/s for X/Y and Z and 60 for E
200 is probably faster than you ever want to print, I can run perimeters on my mendel max in the 80-100 mm/s range, but because of the acceleration settings it rarely actually reaches that speed.

ok, I'm done printing that file and it looks great... Here are the 2 of them next to each other... The one on the right I sliced with Slic3r and the one on the left is from you... I'm clearly doing something wrong... Although, I'm fairly sure this wasn't done with Slic3r...

Tony

Tony, try slicing it with Cura and see how it goes. Set your hot end temp to 245.

What speed did you run your stretchlet at?

g.

I printed it at 100% speed and never touched it (so, whatever speed it was sliced at)... i didn't look in the gcode to see what that was... it's not slow (by my standards)...

It didn't do any retractions and there was no noticable pause as it changed in z height between layers... So, I like whatever program came up with the gcode... I'd love to know what it was and what the specific settings were...

I just got back from dinner, I'll try running it again sliced with Cura...

Tony

Hey guys, just popping in here for a bit. That file geneb has from me was sliced wuth CURA. Still waiting for slic3r to get uo to speed, kinda bummed. You guys are getting sime pretty nice prints though!

johnoly99 wrote:Hey guys, just popping in here for a bit. That file geneb has from me was sliced wuth CURA. Still waiting for slic3r to get uo to speed, kinda bummed. You guys are getting sime pretty nice prints though!

FWIW IMO KisSlicer generates the best gcode of any available slicer at the moment, and the current Beta is better than the released version.
There are a few models it won't slice, for those I usually defer back to Cura.
Slic3r just can't seem to remain stable, as one issue is fixed, they introduce at least one new one, I think in part because of the rapid releases, there just isn't enough testing on a release.

geneb wrote:Poul, have you printed the calibration cube yet?

g.

Hi g. Sorry, I didn't catch your question until now.

Thanks for your help with your documents.

Yes, I have done the calibration tube. It was thinner on the middle than in top and bottom. I had a lot of threads hanging between the towers.

And since then I have used many hours trying to figure out how to print simple things like a solid cube.
I have problem with the extruder feeding. The skirt loops 2 times before the filament comes out of the extruder. Then it will not attached to my blue painters tape. It is like the amount of filament coming out is too small.
I am absolutely shure that the extruder has a good grib on the filament.
And the solid layers are just small pieces of thread with a drop on the end.
I have tried to adjust the 2 sliders for Feedrate and Flowrate. It seems like the Flowrate should be 110 to 120 when the Flowrate is 50%. But the settings are not documented very well. And the Flowrate seems not to follow the speedrate.
Anybody knows these settings in detail?



/Poul

kometen wrote: I have tried to adjust the 2 sliders for Feedrate and Flowrate. It seems like the Flowrate should be 110 to 120 when the Flowrate is 50%. But the settings are not documented very well. And the Flowrate seems not to follow the speedrate.
Anybody knows these settings in detail?
/Poul

I assume this is in Skeinforge?
Basically all you care about is the ratio between them, for your purposes they should be set to the same value.
i.e. If you set Feedrate to 50 Flowrate should also be 50, this is the same as an extrusion multiplier of 1 in every other slicer.
The fact they are separate values dates back to when slicers used to be based on the measurement of output filament.

Hi,
No the sliders are in Repetier) Pls see attached screendump.

/Poul