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List of woes after updating to E3D v6

Posted by dlc60 
List of woes after updating to E3D v6
August 24, 2017 12:22PM
First off, to be clear, I'm not asking for help, just providing a running story of the saga of updating my Folgertech Kossel 2020 from its hot end to an E3D v6 all metal hot end.

One day my trusty Folgertech Kossel 2020 stopped being able to print anything without jamming, after another rebuild-it session the PTFE liner popped out the bottom looking like my dog had been chewing on it. I had recently gotten an E3D v6 hot end so I could work with PETG, Nylon, etc. so "OK, I have a replacement". The E3D v6 mounted fairly easily in my end effector, making me think that the printer had come with an imitation E3D hot end. Cool.

E3Dv6 CONSTRUCTION
The E3D wiki has a great set of instructions for building this. It only took a few minutes to have what looked like a sweet little hot end. I am not sold on that tiny heat-sink fan. But since there is no PTFE liner in the heat break, maybe it doesn't need to be as effective as 40mm fans I have used on other hot ends.

Now the trouble started.

BED LEVELING
The E3Dv6 is quite a bit shorter than my old hot end, so my bed leveling "zero offset" probe didn't work because my default Z height was several mm less than the distance to the bed. OK, I "SWAGGED" 10mm to it in the Marlin firmware, found my Z-min probe offset and updated the firmware with that and then the probe crashed into the bed. Huh? G29 should have paid attention to the Z-min switch and prevented that! OK again, I made a more accurate default Z, less than a mm longer than the actual Z-height, problem fixed. My bed leveling is still not working though because it looks like G29 isn't raising it high enough on the first couple of probe points. I think that I will have to deal with a "DELTA_RADIUS" setting change because it looks like the bed may not "look" flat anymore to the firmware. I have not done this yet, more head scratching is required to find the exact problem, that probe should not have dragged.

HEATER PID TUNING
New heater, new hot end, new PID tuning. The reprap WIKI is cool. I ran PID tuning using the suggested " M303 E0 S200 C8" and put these values into my firmware, not fully trusting the EEPROM storage method just yet. The numbers were really close to what I was already using with my old hot end.
But...
A test print gave poor results past the first couple of layers. Sparse support and thin layers - I am under extruding! I tried a couple of hacks in Simplify3D to put out a bit more filament, but it didn't work. I then looked closer at the extruder. DOH! my Mk8 gear had come loose from the bolt and was not extruding. I fixed that and tried again. The print looked like it was skipping layers and I could SWEAR I heard my DIY geared extruder skipping. I raised the temperature on the filament, thinking that once again, a thermistor was reporting the hot end hotter than it actually was. OK, this fixed the skipping.

But still, I was getting layer adhesion issues like strands outside of the print perimeter, "missing" layers, icky looking curves... Which brings up a parallel step,...

PLA PART COOLING
My old carefully crafted part cooling fan shroud will NOT work with the really short E3D print nozzle - there is not enough space between the tip and the heater block to fit it in there! My first alternative gave a great focused blast of air, but I noticed that it was more-or-less pointing directly at the print nozzle. Hmm. Could it be that the thermistor was accurately giving my heat block temperature, but my part cooler was actually chilling the nozzle? I tried turning the fan speed down and it didn't seem to help much. Then I noticed the "silicone sock" that came with the E3Dv6, it covers all but the cone of the nozzle tip. Is this insulation to prevent cooling the nozzle? I have installed this now, but have not tried it out yet.

So, after three hours of tuning and 5 or 6 attempts I have yet to get a good print from my new print head. It looks like I will be starting over with a new construction notebook for just the E3Dv6 hot end, which has turned out to be a lot more finicky than two other hot ends I have tuned to a printer (one of them practically a scratch build). I am treating this as a "teachable moment" and will use the opportunity as a way to re-do how I install my end stops, level my bed, tweak my firmware and tune my hot end.

I will report back in a day after I have tested the tweaks that I mentioned above. If anyone else has tales of woe after updating their printer to an E3Dv6, I'd love to hear them. I would also love to hear from folks who just installed and printed, breezing right past all these problems and being happy owners of their new hot end!

**edit**
Well, the auto-level is still acting wonky, so I don't know what that means,I can get the first level down, so it isn't a total loss.
I put on the silicone sock and it did nothing that I can detect. Even with the fan at half the speed I used to use, the sock installed and running my print 10C hotter than I used to, the head is still acting jammed. It starts out working, but then my extruder just grinds the filament to dust. The attached picture is what I am getting. I will see if I can get my DVM-thermocouple to get me a real temperature to check how well that is working. As you can see, clearly the problem is under extrusion.

More as I know more!
**edit 2**
Check out this second picture. I pulsed a bunch of 10mm retractions to remove the filament before turning the system off and this is what the end looked like. It looks like a clear plastic "sock" around some colored filament. Weird huh?

**edit 3**
There seem to be as many reports of problems with the E3Dv6 as reports of golden goodness. That means that most of the time it works great because happy people don't complain on-line, or give kudo's as a rule... I run a Delta printer, which means a Bowden tube. My retract in the past was 6mm to stop threads. I typically heat PLA to 190-200 for printing. The E3D wisdom is that with a bowden 2mm is adequate, more could jam. Hmm. Have to try that. Common user wisdom says that you need to run the E3D hot end 20-30C hotter than others. Hmm, OK, I'll try that. More common wisdom says to put a drop of Canola oil on your dust sponge to oil the filament up so the sugar(?) doesn't stick in the heat break. I have seen all three of these called the solution to PLA jamming with the E3Dv6. In order, I will try:
Reduce retraction to 2mm
Increase print temperature 20-30 degrees
Prime with a drop of Canola oil

I will report the results as soon as I try them!

**edit 4**
I reduced retraction to 2mm and upped my print temperatures to first layer 230C, 2+ 220C. I got two prints to work, but both of the jammed and un-jammed several times during the prints. Gak! Really not impressed with E3D here...
I have some "cheap Chinese knockoff" E3D nozzles, so I swapped the .4mm for the E3D .4mm and did a 20mm XYZ calibration cube.
The best cal cube I have printed.

So, at this point in time it looks like the E3D .4mm nozzle that I pay $12-$19 for didn't work as well as a "cheap Chinese knockoff" that I paid $9 for a 5-piece variety pack. At least this one didn't. There may just be junk in this nozzle, so I'd have to clean it out for a definitive problem definition. However, this is PLA, so soaking it in acetone isn't going to clean it out. It will be a while before I do the wire auger to the tip...

I will do a several hour print now and see how that comes out, with a different type of filament. Stay tuned, if you care. If it works, then I will close out this post and be done with it.

**last edit**
I did a double sized "benchy" print that took 3 hours. It came out perfect (see picture). It appears that I just got unlucky with a tip whose quality was not up to snuff. The new nozzle on the E3Dv6 works like a champ. Now to try some more exotic stuff than PLA.

'fuff said,
DLC

Edited 5 time(s). Last edit at 08/25/2017 11:26AM by dlc60.
Attachments:
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Re: List of woes after updating to E3D v6
August 25, 2017 03:56AM
"I am not sold on that tiny heat-sink fan"
have a little faith those 30 mm fans do just fine.
Re: List of woes after updating to E3D v6
August 25, 2017 12:01PM
If you have a way to heat the nozzle up to high temps, you can burn out the PLA. I use a propane torch and it will vaporize the PLA and leave you with a perfectly clean nozzle.
Re: List of woes after updating to E3D v6
August 25, 2017 02:50PM
Quote
number40fan
If you have a way to heat the nozzle up to high temps, you can burn out the PLA. I use a propane torch and it will vaporize the PLA and leave you with a perfectly clean nozzle.

I have a MAP gas torch, that should work.

Thanks,
DLC
Re: List of woes after updating to E3D v6
August 25, 2017 04:09PM
That is exactly what I have, but people get confused if they don't know exactly what it is. Get a spoon to hold the nozzle.
Re: List of woes after updating to E3D v6
August 25, 2017 04:50PM
Quote
number40fan
That is exactly what I have, but people get confused if they don't know exactly what it is. Get a spoon to hold the nozzle.

Sounds simple enough.

thanks,
DLC
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