New i3V owner: A few beginner questions

[printbus]

Here's my Slic3r v1.1.6 ini file used for that print. This is provided for your diagnostic purposes, not as a decree for the best possible settings. I'm changing parameters daily. You'll have to rename the file as .ini, and remember this is set up for 1.75mm filament.

BTW - you could also bring the hot end up to temp, disable stepper motors, and manually rotate the large gear to get a feel for the extrusion. The stepper motor will still have a cogging effect, but the feel should at least be consistent as you rotate the large gear.

Also, I think I was seeing similar results from the steps/mm calibration where the first correction would lead to too much filament being fed. What seemed to have helped me get more consistent results is to always ignore the first long extrusion after I've warmed up the hot end. So, I run an extrusion and ignore it. Then I mark the filament and run another extrusion for the measurement. It could be this helps normalize the temperature throughout the hot end or helps "wash out" any filament that might have cooked a bit in the nozzle as it cooled after the last time I used the printer.

[DanSilov]

Ok, another update. Yesterday I've disassembled my extruder to build new one with parts I've printed before. Turned out small gear was badly deformed, so that might've been the reason for some of my problems. I've assembled new extruder, and when I put new small gear on the motor, I had to knock it hard a few time to fit, and I was worried, that I broke it (when I turn the gear by hand, something inside catches a little on every turn). Other than that, new extruder fit perfectly, even though print quality it baaad. At least everything fits together much better than the original I had in the kit.

I've also decided to switch to ABS, which I also have a roll of, but haven't yet tried. After putting everything together I've calibrated extrusion, and it was perfect 100mm every time! At least that was a small win.

Then I printed the small extruder gear and then the dreaded knob. The knob turned out much better than the last one on the top – no mesh, everything looks watertight. But the sides are awful, as you can see on the pictures. I've used settings that printbus uploaded here, with adjustments for ABS and 3mm.

IMG_8022.jpgIMG_8025.jpgIMG_8023.jpg

The small gear turned out much nicer, but the top had the same issues as my PLA version – it's not closed properly. It might be because of some Slic3r settings, which I set incorrectly. The gear I printed with MakerFarm config and 100% infill.

IMG_8024.jpg

[printbus]

Your issues appear to be beyond what I can help with. If no one else jumps in, perhaps posting in the Tips Tricks and Tech Help forum would get more visibility than the few of us watching the MakerFarm subforum. Maybe using 3mm filament on a 0.4mm nozzle tip requires something special.

What do you think happened to the original small gear? Did it start to fall apart, or does it seem like it got hot and warped out of shape? Just wondering if that could be indicating something.

Do you use a print cooling fan at all? I think small prints like the small gear can be tough to print. Slic3r will default to slowing down the print to ensure 30 seconds per layer, but that's still a lot of heat being applied to a small surface area. Go 100% infill to boot and you could be dragging around in soft material that never gets a good chance to cool down.

Good luck, man.

[gmay3]

DanSilov, I would not recommend printing extruder parts with 100% infill however that print does look like it came out pretty good. I usually print them with 30% infill at a max and this could cut down on some over extrusion errors that could lead to a misshapen gear tooth.

As far as the knob goes, I can't see how your extruder would draw plastic in between the outer grooves in the knob unless something is mechanically wrong with your axes.

Try these and let us know that you have checked them:

1. Check all your belts and make sure they are tensioned pretty tightly (should ring out quietly when plucked)

2. Check for any wiggle in you x and y idlers by verifying that all delrin idlers are tight enough to the aluminum extrusions. You should have no play in any direction other than the axis is intended to move. Make sure the delrin idlers are not too tight where they limit rotation of the bearings.

3. Check the bottom of the x axis where the captive nuts meet the z threaded rods. Sometimes mine have come out of their holes underneath the x idler.

4. Try these prints again at 30% of your normal printing speed, just to rule this out.

Good luck and let us know how it goes!

[DanSilov]

printbus, gmay3, thank you for your help and advice. This all definitely helps as I slowly progress with this whole 3D-printing thing

Will check the axis and idlers, but so far everything looks pretty tight. Just to be sure, how do I set the speed to 30%, is it just by turning the knob on LCD main screen, or is there a general setting in Slic3r I need to set?

[gmay3]

No problem at all!

Yeah you've got it, its just as simple as turning the knob during printing down to 30% on the main LCD. Definitely keep the slic3r settings the same (as far as print speed goes) for this test so we have a control in this experiment

[printbus]

While you're checking over the axis mechanics, you might as well also make sure the belts aren't rubbing on the wood bracket sides at either the x-ider or the y-idler. I don't think issues there could explain your problems but any catching of the belt on the wood could cause things to twitch and affect print quality.

[clough42]

Yow. I just stumbled across this thread. I'll read back through it and see if I can come up with anything else to try.

If you could post a video showing it printing, that would be helpful. To help, I would need to be able to see the X and Y axis movement as well as the turning of the extruder gear. Do you already upload something? Did I miss it?

[clough42]

BTW, a great way to calibrate your Z axis is to print a single layer and measure it. Set Slic3r to print three loops around the next object you print, then peel the loops off after printing and measure the thickness with calipers. It should match your first layer height exactly. Measure at several points around the loop. This will help distinguish first layer height issues from extruder flow issues.

[clough42]

I've read through everything again, and I don't see anything obvious. It definitely looks like you were having trouble originally with your z height, and that was killing your adhesion. Personally, I've never gotten PLA to stick to glass. Cold glass with blue painters tape works great for me. For ABS, the glass and hair spray works best.

The blobby prints you posted recently look to me like a couple of possible problems. If the nozzle is crossing between islands in the print, your retract might not be working right. Try reducing it to 10mm/s if you haven't already.

I don't know how your calibration went, but way too much plastic could cause that look.

If you're printing small parts without a print cooling fan, the hot end just sits above the same area for a long time, radiating heat that re-melts the print. This can cause that look. Of course, if you're using a heated bed, the print coolingfan will make the print curl. No problem with a cold bed and painters tape.

Make sure slic3r is set to print loops around the part to clear the nozzle before printing. This avoids the sparse first layer you mentioned early in the thread. You can also peel up the loops and measure them with calipers to check your bed level and z height. The thickness should match your first layer thickness exactly.

A video of it printing would be very helpful. We may notice something that you don't realize is abnormal.

One other question: where do you live? Do you have high humidity there right now? Is the printer in an air conditioned space?