Leakage on M201 hotend

[Ramon]

Dear techsupport,
Since I built up my new Prusa i3 M201 I had several problems.
to fit in the topic I'll mention just the hotend issues:
The hotend is leaking on the small allen screws horrizontal on the hotend.
I dismounted them (hotend at 180°c) to solve the third clogging in not even 3 operating hours.(even with mixer at 50/50)
To reassamble I tighten the screws just as hard I can, regarding it's size and the aluminium body.
It is still heavy leaking and this drops plastic on my printing products. Not very pleasant on a brand new printer...
Also the thermistor was broken after first commissioning, it is clamped on the cable and there was a break. This caused the first clogging.
I soldered the thermistor on new cables and now it seems working again.
Searching for experiences with 2in1out hotends the general opinion is it is "DESTINED TO JAM by design"
Can you help me?

EDIT: added another picture of the other hotend side

[William]

Hi,
1.About the leakage,you can unscrew the two screws on the both sides of the heating block,and then re-screw them,i guess the two screws may be a bit loose:

QQ图片20161130145905.png (751.53 KiB) Viewed 14728 times

2.Concerning the clogging on M201,you can refer to this post to make some troubleshooting:
http://www.geeetech.com/forum/viewtopic ... 432#p32432
Note:Make sure the fan on the hotend is on all the time.

[Ramon]

Hi, thanks for the response!

I heated the hotend up, took out the screws, cleaned them in acetone and re mounted them very firmly...less leakage butt still some.
About the clogging: seems everyone with this printer has these issues..
So I updated the firmware to 1.0.5 took care about the inner tubings, checked the HE temperature (5deg C difference to real...seems ok to me)
I also saved the mixing ratio to 50/50 (no nice colour, but to prevent clogging)
...and finally- it's still clogging and messed up prints -.-
Thinking about trying an 2 in 2 out hotend printer.

best regards.

[William]

Hi,
1.Did you check this post and disassemble the hotend to reinstall it?Make sure the PTFE tube is inserted to metal tube deep enough(6cm or so).
http://www.geeetech.com/forum/viewtopic ... 432#p32432

2.Did you try extruding the filament with hand?Make sure the extruding is smooth and sufficient when extruding manually.You'd better check this before printing(maybe the nozzle has a problem sometimes).
In a word,the issue should be the extruder's if you can extrude the filament smoothly with your hand.

3.Check the fan on the extruder and hotend,the fan is used to cool the extruder motor to protect it from overheating.So it is so important.

4.Try a mixing ratio 100/0 and 0/100 to see if there is a difference when printing with one extruder.

5.Slow down the print speed,like 20-30mm/s to have a try.

[Ramon]

Hi William,
this is the exact same threat you mentioned last time.
I read every single post of it and tried the suggestions.
exept the heating element I dismounted the HE in every single part, I inserted 2 pieces of PTFE tube in the metal pipes just as far so the long hoses from the extruders fit neatless trough the festo-connectors.
If not connected to the HE, the extruders feed very well trough the hoses...even if I build up some resistance by hand.
Since I built the printer the HE and extruder fans were never off, also I haven't tried printing something bigger than 25g yet.
After about 50% it clogged again...
Reducing the speed was already a try.. I slowed the speed down to 50%, still clogging.
Mixing ratio:
I tried several settings, from 50 - 100%, fed from different extruders, made the turns in the feeding hose as smooth as possible... still the same issues.

Is it not common to buy a new machine that will do it's duty without or maybe just minor trouble..?

Here are some Youtube-links, because I can't upload them to the forum:

https://www.youtube.com/watch?v=ZpHQ0dOPxQ0 (broken hotend heating)

https://www.youtube.com/watch?v=zamxbDE2TbI (source of the fail)

https://youtu.be/j_t9KEQskZI (M201 doing weired stuff)

[William]

Hi,
The hotend may not be the key of the issue since it can work fine in the first 1-2 hours,so i guess the problem may be the extruder.
You can increase the driver voltage on the driver A4988 of the two extruders:
http://www.geeetech.com/forum/viewtopic ... 19&t=17097
And check if your extruder's feeder has the similar issues as theirs:
http://www.geeetech.com/forum/viewtopic ... 19&t=18507

[William]

Having seen the videos you attached carefully,the connection of the thermistor has a problem indeed...

[kenich53]

try some medium strength blue gel thread locker, it has a twist base on it, made by Permatex, apply a light coat with a Q-tip to threads and assemble, heat to working heat about 5 minutes, wipes surface for excess gel which will be dry and flake off. I started using this a couple years ago after my first printer, now have 3, what can I say. thread locker description can be found at
permatex item# 24010 just so you know.

[Cup]

Hi,@kenich53
Thanks for your sharing.
Did it work perfectly after add some on the hotend?

[kenich53]

Yes, it works perfectly, I run my delta printers at 120% of normal and no issues with leaks at any time, as for clogs, not ever, unless I change from abs to pla plastics, this thread locker breaks up if not between two hard surfaces, so great stuff in my book, been using it for well over a year now.
Question: I see you have a remote extruder assembly, if it is plastic, check the guide roller assembly, you may find that the roller is binding, take the tension roller assembly off, then just run your finger along the surface of the roller, if it binds in any spot, it is not good, now look closely, you may find cracks in the plastic tension arm holding the roller, now get you a nice metal one, if the information about the stepper motor is not available for your extruder stepper, you might want to get that information or change it out with something compatible to what driver you have, that was one of my problems along with a plastic extruder feed assembly I had these problems with this Geeetech rostock delta printer. Next, make sure the current is set for that extruder stepper, no guessing, it will fail otherwise. I hope this will clear some of the mystery with 3D printing, find a way to cool the plastic under the printhead, a small squirrel cage fan will speed up printing a whole lot for you, plus looks better too. If you want to see a small squirrel cage fan, go to SEEMECNC and look in there part they sell, it should give you an idea I what I am talking about, then design and print a holder for it that can direct airflow to the base of the print nozzle, for me, mine attached to the delta arm assembly with controlled air flow to 10mm of the print nozzle, you may even be able to look at a youtube video about this.