Blockage troubleshooting.  

Re: Blockage troubleshooting.

When I printed the next model (not Marvin but same PLA filament) at the same temps i got layer separation and splitting. Before the multi material upgrade I fixed splitting and separation by dialing up the temps closer to 220.

Also, on the next print after about 2 hours I started to get extruder skipping. Intermittent at first but then around the 3 hour mark it became frequent and eventually stopped extruding anything. It was jammed below the heat break. Tried changing out the filament but that only bought me another 20-30 minutes

After this I tapered the bottom outside of the ptfe tube more and tightened it back into the heatsink. Runnkjng it again and will report back on my results.

Re: Blockage troubleshooting.

I feel like I've hijacked this thread and feel really bad. I'll stop after this post, but i'm completely fed up with the continued issues. Before multi-material this was a dream printer, and now it haunts my dreams.

My first print (after the last post): ran great on the first color for about 1 hour, had a few successful color changes, then the original (Black) filament got stuck in bottom of the cooling tube or right below it, can wouldn't unload. I had to remove the multiplexer and push it back through the bottom.

Second try at the same print: got a little further into the print, then the third color (white) got stuck in the heat-break or below. At that point I gave up and called it a night.

If Marvin prints fine then it can be done. I haven't messed with the SLIC3R settings much, other than to incorporate bridge support and other small stuff. Why am I doomed to failure? This printer's function is to print tap handles for my brother's brewery in San Diego. They are already looking at other alternatives because I can't perform.

I've attached a pic from the first print along with my GCode of the last failed print. Any help is very much appreciated!

Re: Blockage troubleshooting.

I feel like I've hijacked this thread and feel really bad.

This is exactly why I started the thread, don't worry, continue posting or just create a new thread and where we can resolve your difficulties.

If Marvin prints fine then it can be done.

As you will have seen, it can indeed work very well. However, what you are going through right now is exactly what us beta-testers went through over a 6-month period. Actually is was worse for us because in the first place the hardware wasn't right, so we had to "fight" both that and the filaments.

Bottom line is that I believe you haven't yet found the right settings for your filament. Mainly settings, but also retraction and speed settings.

The MM upgrade does require more precise filament settings than the direct-drive single filament printer.

If you want to try something different, you could upload your STLs and I will slice them with KISS + my post-processor to see if that will print for you.

Peter

Re: Blockage troubleshooting.

Travis

It also looks as though you have some issues with the supports nor being supported...

Peter

Re: Blockage troubleshooting.

Thank you for taking the time to tinker with my STL files.

I will research what the recommended range is regarding speed and retraction for PLA, then start adjusting slowly to find my happy place. I will also try to print in normal(.2) vs. fast(.35). A few posts I read mentioned fast(.35) still in beta.

Also on the agenda is looking into another slicer. I love Slic3r because there is no post processing in the newest version (1.35.5.16) but KISS might have better built in settings for multi material.

Your continued support has, once again, given me the drive to keep pushing forward. Thank you!

Re: Blockage troubleshooting.

I will research what the recommended range is regarding speed and retraction for PLA, then start adjusting slowly to find my happy place. I will also try to print in normal(.2) vs. fast(.35). A few posts I read mentioned fast(.35) still in beta.

OK, I think I posted GCode for temperature calibration; maybe at the start of this thread.

I sliced at 215 first layer and 200 for remaining layers, 3 colours E1 logo, E2 32N and E3 body and support. Printing at 0.35mm layer height is, in my opinion 0.03mm too much, based on layer height being a maximum of 80% (better 75%) of nozzle width. I think you will find the KISS-sliced GCode slightly faster anyway, so you should not have to use greater layer heights.

Also on the agenda is looking into another slicer. I love Slic3r because there is no post processing in the newest version (1.35.5.16) but KISS might have better built in settings for multi material.

I have written a post-processor for KISS. Available on request (but Windows only).

GCode attached.

Peter

Re: Blockage troubleshooting.

I tried printing on normal slic3r setting instead of fast (as in earlier failed prints) and the attached print was a success!

Then I tried to print the entire tap handle on normal setting and it failed. Stuck in the cooling tubes first time and below the tubes the second time. Both failures were about 2 hours into printing black. Not during a color change. It just stopped printing filament all together.

I feel like If there are regular color changes I'm good but this print has one color for the first 4 hours before the first color change. It fails long before that point. I've looked up my filaments recommended temp range and I'm in it.

I still can't find preferred settings for retraction, speed, and other multi material related preferences.

Re: Blockage troubleshooting.

Peter,

I'm very sorry, I forgot to thank you for the gcode. THANK YOU!

Unfortunately I couldn't use it because my e3 is not working great so ive bypassed and use e4 instead. I'm not sure how to change extenders in the code.

Looking into other slicer software and will report back on my findings.

Re: Blockage troubleshooting.

Unfortunately I couldn't use it because my e3 is not working great so ive bypassed and use e4 instead. I'm not sure how to change extenders in the code.

Hi Travis

OK, simple edit of the GCode (I use Notepad++) to replace all instances of T2 with T3. It's possible to do the same with temperatures to replace "M104 S205" with your required temperature.

BTW, the main temp in the GCode is 205 and not 200.

Peter

Re: Blockage troubleshooting.

Peter,

I took your advice to focus on my filament and print settings. The big change was reducing retraction from 4 to 2.5 (speed from 50 to 25). Matter hackers PLA first successful print ran at 220C, with lots of stringing. Next at 215 and third at 210. All successful but very stringy. Tomorrow I'm going to start with retraction at 2.8 then 3 to try and reduce/ eliminate the strings while keeping temp at 210C.

I know this isn't technically blockage anymore but I wanted to share my findings. I'll post pics with specs soon.

Thanks again!
Travis

Re: Blockage troubleshooting.

Travis

That's good and it is an indicator that there is possible a gap between PTFE and heat break.

A good MM setup should be able to operate with more than 6mm of retraction without issue (but with the retraction set to 4mm, additional tower retract of 2mm and preload retract). You are not using either preload or tower retract.

According the MatterHackers, the PLA I looked at should be extruded at 205 degrees (± 15 degrees) so I think you are maybe still too hot.

Peter

Re: Blockage troubleshooting.

Peter,
I'm going to get a production run complete and then take your advice and dial in the e3d once and for all.

I got prints down to 205c with good results. Monday I'm going to increase retraction (pushing to 3) to try and reduce/ eliminate the strings.

Thanks again for your continued support. If you are ever in southern California hit me up..... beers are on me.

Travis

Re: Blockage troubleshooting.

Thanks again for your continued support. If you are ever in southern California hit me up..... beers are on me.

Hi Travis

Pleasure, and thanks for you kind offer. Unfortunately, I will not be close anytime soon, but I do know a man in Redding - Jonathan, the author of KISS... 😉

Peter

Re: Blockage troubleshooting.

I feel like I've hijacked this thread and feel really bad. I'll stop after this post, but i'm completely fed up with the continued issues. Before multi-material this was a dream printer, and now it haunts my dreams.

It just helped me! I wish I read all the way to the end of this thread a few days ago. I thought for sure this filament (Hatchbox) just wasn't worth the trouble as my Prusa filament was working so much better. I dropped the retraction speed even lower (as you did to 25mm/sec) and retraction to 2.5mm and I'm finally getting somewhere. Will start working up from there, but if I hadn't seen your post I was going to just put my old extruder back on! 🙂

Re: Blockage troubleshooting.

OK, more information regarding PTFE tube:

The tube is specifically made for Prusa Research by Festo. No other tested tubing met the precision requirements.

The tube is currently (and maybe for the foreseeable future) only available from Prusa Research. Sorry.

If it helps, I can get some sent to me with my next order and then send it on to you via regular postal service.

Peter

I would be interested in this, but looks like I can't send you a private message (since I'm a new user). Is there any other way to contact you? Thanks! 🙂

Re: Blockage troubleshooting.

I dropped the retraction speed even lower (as you did to 25mm/sec) and retraction to 2.5mm and I'm finally getting somewhere. Will start working up from there, but if I hadn't seen your post I was going to just put my old extruder back on! 🙂

The interesting thing here is that until the most recent firmware versions, retraction speeds (MAX_E_FEEDRATE) was limited to 25mm/sec. It's only with the MM upgrade that this has been increased to 120mm/s.

So even if you had your retraction speed set to higher than 25mm/s, that was the maximum.

Peter

Re: Blockage troubleshooting.

I would be interested in this, but looks like I can't send you a private message (since I'm a new user). Is there any other way to contact you? Thanks! 🙂

If you look at the right hand side of every one of my posts, you will see I have linked my web site. You therefore have my domain. I put my name at the end of each post. I am pretty sure you can figure out how to contact me... 😉

Peter

Re: Blockage troubleshooting.

I dropped the retraction speed even lower (as you did to 25mm/sec) and retraction to 2.5mm and I'm finally getting somewhere. Will start working up from there, but if I hadn't seen your post I was going to just put my old extruder back on! 🙂

The interesting thing here is that until the most recent firmware versions, retraction speeds (MAX_E_FEEDRATE) was limited to 25mm/sec. It's only with the MM upgrade that this has been increased to 120mm/s.

So even if you had your retraction speed set to higher than 25mm/s, that was the maximum.

Peter

That's exactly when I started with MM, the newest firmware, so that all makes sense. I'm sure I can tune it from there, but was just happy to get a result. This thread has been enormously helpful!

Re: Blockage troubleshooting.

Billchurch,

I'm very happy to hear posting my experience helped you.

I continue to have issues when running one filament for more than an hour, and took a few days off to calm my frustration. As long as I have frequent color changes I'm good. I never did push to 3mm retraction.
I've been focused on getting larger prints completed successfully.... no luck yet. I can only print the tap handle face. When I try printing the body + face it jams up about 1hr in during regular printing, not load or unload.

Soon I'm going to take Peter's advice and search out the ptfe/ e3d issue so I can get the legendary prusa reliability back.

Best of luck in your 3d printing adventure.

Re: Blockage troubleshooting.

That's exactly when I started with MM, the newest firmware, so that all makes sense. I'm sure I can tune it from there, but was just happy to get a result. This thread has been enormously helpful!

Bill

There is, of course another factor involved. With the direct drive system, retraction was less than 1mm and with acceleration it would not be possible to achieve a maximum speed of 25mm/s. With the MM upgrade and 4mm (or more) retractions higher speeds are now possible - but not necessarily wanted.

If you retract too fast you leave a blob of filament behind in the nozzle which will then ooze. Basically, retraction is used to overcome the pressure built up by the elasticity of the filament between the drive motor and nozzle; you only have to remove the molten filament from the nozzle bore (0.4mm diameter x 0.8mm long - E3D) to prevent oozing during moves.

Peter

EDIT: I have now received a correction from E3D that in the case of nozzle sizes 0.25 to 0.4mm, the bore length is 1.5 times the diameter.
https://wiki.e3d-online.com/images/3/3a/V6-NOZZLE-ALL.pdf