Folger Tech 2020 Prusa i3 Build Log

[markyoe]

Here are some pictures of the latest prints.




I tried to print this: http://www.thingiverse.com/thing:774907
and this: http://www.thingiverse.com/thing:662862


The pictures of the one on the print bed failed. The pictures of it were taken after I had to stop it. Before I stopped it, it still moved in the right pattern, but was not extruding filament. I printed from the LCD screen and an SD card, so it must not have had a Connection Timeout. The nozzle must have clogged right?

Also, I noticed while it was printing that after a travel move, it did not start extruding right away. Maybe this is a firmware issue?

I have cleaned the nozzle a few times by soaking it in acetone, torching it, and running a wire through it.

If the nozzle/extruder is the problem, what extruder would you suggest for me to buy?

 

[ZoomNBoom]

It probably just needs tuning. Too much or not enough pressure on the filament in the extruder can lead to slipping and grinding, maybe the spool cant turn freely or the filament on the spool got jammed, on some extruders it may be an alignment problem and the filament may be pulled to one side and therefore no longer properly gripped by the hobbed bolt, the pulley opposite of the hobbed bolt, between which the filament is gripped may be stuck, .. You'll have to do some detective work as to why its stalling.

 

[ZoomNBoom]

oh make sure the hotend is mounted and tightened correctly so there is no gap between the nozzle and the heatbreak. I dont know yours, but mine comes with very specific instructions, like screwing it on by hand, heating it to 300C, then hand tighten it again. IF there is even a tiny gap, filament will get stuck in there. OTOH, if you overtighten the nozzle, it will break easily, so be careful and follow manufacturer's guidelines.

btw, those pictures nicely illustrate why you need a cooling fan. Notice how the print is pretty decent right until the point where the fan nozzle begins to get smaller, layer times decrease and the plastic gets deposited too hot.

 

[markyoe]

oh make sure the hotend is mounted and tightened correctly so there is no gap between the nozzle and the heatbreak. I dont know yours, but mine comes with very specific instructions, like screwing it on by hand, heating it to 300C, then hand tighten it again. IF there is even a tiny gap, filament will get stuck in there.

I will give that a try. While it was still hot, I loosened the extruder and tried to push the filament through by hand. It wouldn't even extruder then. Maybe it was catching on something because there was a gap between the nozzle and the heatbreak?

BTW, do you prefer a Bowden or direct drive extruder?

 

[ZoomNBoom]

make sure to read my edit too.

Ive only used direct drive, so Im not sure my preference has much weight.

 

[markyoe]

What part of the nozzle would break? The tip?

 

[ZoomNBoom]

the nozzle most likely yes. Its just brass.

 

[wilsonb]

How warm is the extruder assembly after you have been printing? Also, is that fan on all the time?

If the assembly (motor, spring lever, heat sink) are hot, so is the drive gear. That will soften the PLA and cause jams.

I would recommend against using the extruder fan to also cool you prints. I understand if it may be all you have on hand now, but you should really have the extruder fan on all the time (if the hot end is heating, that fan is on) and the print fan output controlled based on the model and material.

 

[pilot1]

Did it come with the heated bed?

 

[markyoe]

How warm is the extruder assembly after you have been printing? Also, is that fan on all the time?

If the assembly (motor, spring lever, heat sink) are hot, so is the drive gear. That will soften the PLA and cause jams.

I would recommend against using the extruder fan to also cool you prints. I understand if it may be all you have on hand now, but you should really have the extruder fan on all the time (if the hot end is heating, that fan is on) and the print fan output controlled based on the model and material.

I think the extruder motor gets hot. I ordered another fan to cool the print. I keep the existing one running the whole time.

 

[markyoe]

Did it come with the heated bed?

Yes, it does.

 

[markyoe]

I have been working on the printer quite a bit now and have been getting pretty good prints. The tube that goes between the heat block and the hot end clogs occasionally. I will post some pictures of some prints soon. Cheers!

 

[markyoe]

I was printing and mid way through the print, it just stopped extruding. As you can see from the pictures, there are barely any webs, so the nozzle did not get clogged. I opened up the extruder and the nozzle was clean. Is there something wrong with the motor? How could I test it? Should I turn the voltage to the motor up or down? Thanks!



Also, should the top of the object be smoother? I tried this print again, and I found it interesting that they failed at about the same time.

 

[wilsonb]

Top layer infill looks a little thin. It is hard to tell with the picture. The filament color/type usually gets in the way of taking pictures of print quality.

I had a similar problem, and the drive gear was slipping on the motor shaft. The set screw had backed out a little. So the motor was spinning, but the filament wasn't extruding. Check that and put some loctite or something on it to keep the set screw in place.

You could increase the Vref on the stepper, but do this in small increments. You really want to have this set as low as possible while still having a functioning printer.

On the plus side, your shapes and circles look great! I bet it feels good to have a working printer.

 

[markyoe]

So in Repetier, I will have it print a few more solid layers on the top? The great isn't slipping. I made a mark on the gear and shaft to make sure I know when they slip. I am going to get some solid color hatchbox filament soon. I am trying to print this right now: http://www.thingiverse.com/thing:650957/#files

 

[wilsonb]

Yeah, I usually set my prints to 4 or 5 top layers. Your surface looks smooth and it could be the translucent filament playing tricks with my eyes.

 

[markyoe]

Yeah, I usually set my prints to 4 or 5 top layers. Your surface looks smooth and it could be the translucent filament playing tricks with my eyes.

No, you are right. There definitely is a mesh on the top.

 

[Basscor]

looks a lot better! so it could be either under extruding (probably slipage of the extruder), or the nozzle size is wrong in the slicer

 

[markyoe]

looks a lot better! so it could be either under extruding (probably slipage of the extruder), or the nozzle size is wrong in the slicer

I agree! I will check the nozzle size in the slicer. Do you have any idea why it would just stopping extruding sometimes, as described in a couple posts back?

 

[Basscor]

It sounds like it could be a heat creep issue, where as the hot end heats up the heat creeps up past the heat break int the all metal hotend and the material gets soft and then jams in the heat break area before it gets to the nozzle. Is the fan on the front of the extruder running full on when the hotend is on?

side note, it looks like your nozzle size is supposed to be 0.4mm according to the website.