[Cerrado] Extruder Drive Gear Slipping on Filament  

Re: Extruder Drive Gear Slipping on Filament

Hi

I have had this happen to me a while back. I cleaned the gear and ensured the slicer settings were correct and all has been fine since.

I would certainly not want to push a Lite6 extruder to any more than 10mm^3/sec and I have that set as a limit in the slicer, even though I am running a V6.

FWIW, E3D have informed me that 11.5mm^3 per second is the "maximum comfortable flow rate" for one type of ABS (pure MG94) @ their specified temperature of 240 degrees with the V6. They specify the Lite6 at half the rate of a V6

Peter

Re: Extruder Drive Gear Slipping on Filament

I assume that to specify 10mm^3/sec within Slic3r would be under Print Settings -> Speed -> Autospeed (advanced) -> Max volumetric speed?

Re: Extruder Drive Gear Slipping on Filament

Hi

I have no idea as I don't use Slic3r. Sorry.

Peter

Re: Extruder Drive Gear Slipping on Filament

Actually, you would have to be printing very quick and thick to achieve that usage. The Prusa is possibly not even capable of that with a 0.4mm nozzle and layers of 0.3mm. And, of course, the results would be fairly poor quality.
...

Quick calculation - that would be 83mm/s with the above layer height/width. Faster with smaller dimensions.

Peter

Re: Extruder Drive Gear Slipping on Filament

OK, just checked further into the feed rate.

The firmware default max E is 25mm/sec which is actually 60mm^3/s, significantly higher than the extruder can handle (according to E3D) and much more that this printer can print.

10mm/sec equates to 24mm^3/s, again way more than it is possible to print with this printer. So the change you have made in the firmware will possibly slow the printer down very slightly (due to acceleration calculation using a different max speed), but will basically have no effect.

Peter

Re: Extruder Drive Gear Slipping on Filament

So then does the firmware for our printers have the incorrect values? Or maybe the firmware is actually being read in volumetric E units (E step per mm^3) and not E steps per mm?

Also, I would like to go through the following steps to fine tune my printer: http://reprap.org/wiki/Triffid_Hunte r's_Calibration_Guide. Under the heading 'Nozzle Temperature', step 3, it mentions "Make sure your idler is tight! really tight! "it hurts my fingers to pull on it and I still can't move it" tight! A too-loose idler gives exactly the same symptoms as too low temperature.", but if I tighten the idler too tight the drive gear starts to slip (makes a clicking noise and doesn't progress filament). Under the 'E steps' heading it mentions "Direct-drive extruders typically use a motor with a planetary gearbox to turn a drive gear, such as the popular MK7", but I noticed it doesn't look like our extruder motors have gear boxes on them. As our motors stand now do they not have enough torque to progress filament at the proper idler tension?

Re: Extruder Drive Gear Slipping on Filament

No, it's not incorrect. It's all to do will acceleration and maximum speed. Theoretically, the motors can certainly turn fast enough to fulfil the numbers. And the printers can be modded with hot ends that will work at much higher volumes (see E3D Volcano).

There are also Lite6 hot end mods which can be carried out to improve the melt. If you really do want to print faster (and with the lower quality that comes with printing faster), then you could look at these first.

1. Turn the heater block over so that the heater cartridge is located nearer the nozzle.
2. Change the heater block to improve thermal transfer between cartridge and nozzle
3. Print a part fan that doesn't blow cold air onto the heater block (or thermally insulate the heater block).

The firmware does specify "per unit" and the units are specified as millimetres.

As for fine tuning, I think it's a matter of common sense and trial and error. All printers are different and are working in different environments, so whatever suits yours best...

Peter

Re: Extruder Drive Gear Slipping on Filament

I never said anything about wanting to print faster. I want to be able to print with filament without worrying about the drive gear slipping and clicking. Still, no one has helped me with this issue. I figured I'd post here to see if anyone else is having this issue and what they have done to fix it.

Re: Extruder Drive Gear Slipping on Filament

Apologies; that response was with regards to your firmware fault suggestion; my attempt to explain what I believe to be the reasons for the apparently high maximum settings should probably have used the term "one" in place of "you"...

I believe that an earlier reply I made does address your query, but there are a couple of other things I have just remembered (sorry, I have an extremely poor memory and things occasionally come to me...)

When I experienced this issue, I did dismantle the hot end (this was also when I decided to install the V6). I had already changed the nozzle a couple of times and was still having the problem.

I found that the PTFE tubing was damaged near the hot end. It was charred and only allowing a small volume of filament through. Changing the tube and nozzle along with a good clean resolved the problem.

Why the PTFE tube was damaged is another issue. I print mainly with PLA at a maximum of 215 degrees (first layer temp), occasionally with HIPS (230 first layer) and rarely with ABS at 240 degrees.

PTFE can become soft and start to deform at around 250 degrees although it can be used as hot as 255 degrees. But mine was black and partially blocked.

A couple of days previously, I had been printing overnight and the printer had run out of filament. I can only assume that this had somehow overheated the PTFE.

You can always try the ultimaker "atomic clean" (from point 3) to see if you have a similar problem: https://ultimaker.com/en/support/149-atomic-method

Peter

Re: Extruder Drive Gear Slipping on Filament

Thank you for your help, Peter. I'll look into your suggestions and hopefully it helps with the problem.

Re: Extruder Drive Gear Slipping on Filament

Pleasure. Unfortunately, I started to have the same issue again yesterday evening. I pulled out the filament at 95 degrees and it was not as smooth as it should have been with some brown deposits near to the end.

Just about to disassemble the hot end again to check out the tubing. I have been printing with HIPS recently @ 230 but that should not have caused the problem...

Peter

Re: Extruder Drive Gear Slipping on Filament

I'm having the same issue now.
Totally disassembled the extruder, heat block, tubing, nozzle … the works. Everything is as clean as it should be. Like new.
It's slipping on the filament consistently. I tried loosening/tightening the extruder screws … no difference. Printing at very low speed, like 20mm/s makes no difference either. I tried different materials. It happens no matter what.

Any tips?

Re: Extruder Drive Gear Slipping on Filament

Try printing the pre-sliced Prusa logo file on the SD card.

Do you have a connector in the thermistor cable at the back of the extruder? If you do check it is firmly seated.

Peter

Re: Extruder Drive Gear Slipping on Filament

The thermistor cable is as tight as I dare to have it.

After more tuning, the clicking sounds and skipping seem to happen less. Mostly for the first 2-3 layers, then it seems to improve. But this is at extremely slow speeds. I was able to print with 50mms before. I'm down to 15mms now.

Re: Extruder Drive Gear Slipping on Filament

The thermistor connector - there may not be one depending on when you purchased.

Prusa Logo print? Need to establish if the problem is model/slicer/printer.

Peter

Re: Extruder Drive Gear Slipping on Filament

The thermistor cable is as tight as I dare to have it.

After more tuning, the clicking sounds and skipping seem to happen less. Mostly for the first 2-3 layers, then it seems to improve. But this is at extremely slow speeds. I was able to print with 50mms before. I'm down to 15mms now.

And please upload a photo of your first layer as it prints

Re: Extruder Drive Gear Slipping on Filament

Thanks for the quick reply's guys.

I'm printing the logo right now.
Here's a picture of the first layer:

Here's a quick video of the extruder gear:
https://cl.ly/2b2O0f3m2Q2H

I'm hearing this sound, like "dnk dnk dnk" while it's extruding now.
All though things seem to work as expected.

Also a close-up video for the nozzle (with the E3D blue cap) while printing:
https://cl.ly/293L1806300C

Re: Extruder Drive Gear Slipping on Filament

When I'm printing my own parts, I'm using Josef's default Simplify 3D settings, btw.

Re: Extruder Drive Gear Slipping on Filament

Finished print