E3D V4 All metal hotend

[elmoret]

The ID is 1.75 (and confirmed by E3D Support)

This is incorrect, as I was CC'ed on the email John is referencing. The ID of E3D PTFE tube is 2.0mm, confirmed by both Sanjay and myself.

[McSlappy]

Really? How interesting...

[JohnStack]

The ID is 1.75 (and confirmed by E3D Support)

This is incorrect, as I was CC'ed on the email John is referencing. The ID of E3D PTFE tube is 2.0mm, confirmed by both Sanjay and myself.

Yes, my error. It is 2mm - but it is a crazy rigid 2mm. I've compared both types - the whiter plastic and the clearer version SeeMeCNC uses. It appears that the ID is a bit larger and quite possibly the walls are more forgiving. Does it matter? I'm not sure.

To me, there are two supply chains to solve: Software and materials to the bed. Frustrating weeks of multiple compound failures leaves me scratching my head and not moving my ball forward. (What's your favorite whine? "I want to go to Disneyland!")

[mhackney]

I have now printed well over 100 parts - more than 90 of them were parts that I struggled to print without some form of PLA jamming at some time - with absolutely NO PLA JAMMING. The short .5mm nozzle bore is critical I believe. Not only did these parts print perfectly, I was able to print them at reasonable PLA temperatures of 185-190°C and at speeds up to and above 60mm/s. This is the fastest speed and lowest temps I've ever been able to sustain printing with the Kraken. The same "fix" applies to the E3D hot end as they share the same nozzle and basic geometry. I have not heard back from Sanjay and Josh from my original email so I just emailed them again. I'd like to know if they have followed up on this and tried it out themselves and also what their actual bore length spec is for their .4mm nozzles.

In any case, I would really like to see if someone with a jamming problem could resolve it with a shortened nozzle bore without any of the other debuting and polishing fixes we've tried. I am willing to send a bored nozzle to someone with an E3D PLA jamming problem in exchange for them sending me their original nozzle. Or, simply rebore your nozzle yourself with my instructions published a few days ago.

I am now more confident that the long 2mm bore on the .4mm E3D nozzles has been the root of most, if not all, PLA jamming issues. So much so that I am claiming V*I*C*T*O*R*Y!

regards,
Michael

[Eaglezsoar]

You are a cautious person who doesn't declare victory very often.
Another job well done. I do hope that Josh and Sanjay get back to you on this.

[mhackney]

Me too!

I should say that I do think there is still the issue of heat transfer to the nozzle and the combination of the long bore and marginal (IMHO) heat conductivity to the nozzle play hand-in-hand to cause problems. I think this might be why some folks seem to be ok (that and perhaps they are not pushing their printing as much as I and a few others do) -they might be inserting the nozzle "deeper" or not following the instructions to the letter.

I haven't made any changes to impact heat transfer, that will be next if the problem creeps back in.

[McSlappy]

Well this just made my day!
I've not installed my new e3d yet, but at least I'm now confident that it'll work - if it works for the crazy infills you do, mine should be cake!

Thanks a lot Michael, this sort of information is so valuable and I really really appreciate you putting the hard yards in to work it out!

I hope Sanjay responds, this information is gold!

[Glacian22]

I would definitely be down for testing out your short bore nozzle, it'd be great to be able to print PLA on my E3D! Sent you a PM.

[mhackney]

Let's do it Glacian22. I've replied to your PM.

cheers,
Michael

[mhackney]

A video printing my tenkara line holders on my SeeMeCNC Rostock Max v1 at 80 mm/s on PEI at 50°C. This is the Kraken hot end, PLA at 190°C with my "shortened nozzle bore" mod to the Kraken nozzle.

[youtube]http://www.youtube.com/watch?v=29Y73qZBVdE[/youtube]

I can print all day at these speeds with the Kraken now. I'm also starting to bump up the speeds to see how high I can go. Unbelievably (at least based on my earlier experience) I have not had to bump the temp for PLA up much at all - this is 190°C and I have actually printed at this speed at 185°C but why push it!

All of the rattling you hear are my binder clips vibrating during the sinuous infill. This machine is just amazing!

Here's a pile of finished parts ready to ship:

[bubbasnow]

all that kracken work for just a single extruder lets see some .25mm blue perimeters with .6mm pink infill!!!

[mhackney]

Yeah, yeah. I've done some 2 and 3 color stuff too. Frankly, the slicers are just extremely painful to do much multi-color work right now. I can change color by layers - that's easy - but to do more is a PIA. I have a few things I'm working on though.

[Eaglezsoar]

all that kracken work for just a single extruder lets see some .25mm blue perimeters with .6mm pink infill!!!

Good point, multi colored prints of any sort.

[bubbasnow]

come to the dark side brother... s3d im having pretty good luck with 2 extruders

[bvandiepenbos]

come to the dark side brother... s3d im having pretty good luck with 2 extruders

photos, I want to see photos!

and if you would be willing to share your s3d settings, that would be great.
I have s3d but have not used it very much

[Tinyhead]

A video printing my tenkara line holders on my SeeMeCNC Rostock Max v1 at 80 mm/s on PEI at 50°C. This is the Kraken hot end, PLA at 190°C with my "shortened nozzle bore" mod to the Kraken nozzle.

[youtube]http://www.youtube.com/watch?v=29Y73qZBVdE[/youtube]

I can print all day at these speeds with the Kraken now. I'm also starting to bump up the speeds to see how high I can go. Unbelievably (at least based on my earlier experience) I have not had to bump the temp for PLA up much at all - this is 190°C and I have actually printed at this speed at 185°C but why push it!

All of the rattling you hear are my binder clips vibrating during the sinuous infill. This machine is just amazing!

Here's a pile of finished parts ready to ship:

photo 3.JPG

Watching this was like watching porn. Man I'm jealous of those lines. I'd have strings and bumps coming out the wazoo.

[Polygonhell]

Adding another datapoint to the nozzle orifice length, I just started installing my kraken, and figured I'd drill out the 1 nozzle I'm using for the initial install. When I measured it, it was just over 1mm long as shipped from E3D. So, so far looking at 3 nozzles I've seen 3mm, 2mm and 1mm orifices. That some spectacular variation for a relatively critical dimension. I drilled it out to 0.5 mm, because the other one I have made this change to has shown only positive side effects.

[mhackney]

Thanks for the update Polygonhell.

I've printed A LOT this weekend without a hiccup. In fact, my surface finish is much better than ever. I looked at some parts and old parts under a loop and I can see the difference. The perimeters on the old parts have just a teensy bit of width variability, with the short nozzle bore, they are basically identical. This is resulting in much better fit for my press-fit reel parts. The doggone shaped hole on my reel foot usually required a bit of sanding to get a nice sliding fit. I've printed 4 reels this weekend and all four feet just slid right on perfectly.

I am sure the excess back pressure withe the longer bore results in a bit of start-of-perimeter oozing and less precision in controlling flow. I can physically tell the difference when I extruder into air. With the longer bore, the filament would continue to extrude for a good 4-5 seconds after a 10mm extrusion. With the .5mm bore, it continues for maybe a second.

That is incredible variability Polygonhell! I think it explains a lot. I think even a 1mm long bore is significantly long enough to increase back pressure and contribute to some of the issues with jamming. But a lot of other factors can affect that.

I sent a nozzle that I modified to another forum member that gave up printing PLA on his E3D due to jamming, so I'm looking forward to his feedback.

[Nylocke]

Wait, so what are you guys measuring and how? Ive been having issues with my 3mm E3d oozing with ABS even, mainly leading to blobing where it retracts, but sometimes of times leaving some small ABS strings. I'm using Cura with 5mm of retraction at 80mm/sec, 235C, and a Greg's reloaded (this may be the culprit because its half broken and I haven't been able to print a new one). The ABS isn't as big of a deal as Nylon though, I get a lot more blobbing, stringing, etc with that.

What is the abnormality that you are getting exactly, and how can I experiment to see if I can get better results?

[Polygonhell]

If you go back a couple of pages, you'll see we are talking about the length of the 0.4 or whatever bore yours is. This is a somewhat critical dimension on a Hotend, the longer it in, the more back pressure there is, and the more force required to extrude plastic.
MHackney measured his at 2mm, which I commented was very long, it's 4x longer than say a JHead.
Both MHackney and I have modified our nozzles, using a 2mm drill bit, I did it on my lathe, but he used a pin vice and did it by hand.

[McSlappy]

Poly - I'm curious since you have mentioned before that you don't recommend the e3d for PLA... Now that you've modded the nozzle depth, have you printed with PLA yet?

[Polygonhell]

I just completed what I would consider a challenging print in PLA, I still need to see if I can get retraction to be acceptable, the 2mm I'm running isn't quite enough, and I'd want to ensure that running sufficient retraction doesn't result in jams, but so far I'm pretty happy with the modified nozzle.

[mhackney]

I'm running 2mm retracts at 25mm/s with no stringing. I removed all the slop from the PTFE-PTC connections on my Bowden also. Now that I can print PLA at 180-185°C again, there is mush less problem with stringing. I do use a 2mm Z-lift, which also helps.

[Nylocke]

I read what you did but I'm not understanding it. It was too long so you drilled it out to shorten it? Not making a lot of sense to me..

[JohnStack]

On my (other) printer, I'm running red PLA at 190 with an E3D. It requires a 3mm retract to get clean prints - plus I've had to slow the flow - consistently to about .93 - .94. I think that's due to the red being so stringy but I'm not 100% sure. Z-lift definitely helps with keeping it clean. I'm not sure it does much more though.