E3D V4 All metal hotend

[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.

[mhackney]

[Nylocke]

Ah, the visual helps greatly, thanks Michael. Makes me wanna check mine now.. How did you measure? I dont think the depth gaugeish thing on my calipers can fit there.

[mhackney]

Please go back a few pages for detailed instructions on how to measure it!

[chrahp]

I'm new to the forum, but I've been battling this issue w/ a number of e3d hot ends on my machines for quite some time, saw this thread last week and proceeded to attempt the mod as described. The only issue is, i'm using 3mm filament, and the method of drilling out the nozzle won't work as you will end up drilling through the nozzle tip before you can reach that ideal 0.5mm bore length.

My question is this, do you know of any downsides to drilling out the chamber at a sharper point angle? It seems as if you guys are using standard 118 degree drill bits, as it creates a tapered profile similar to that of the j-head, but for this method to work with the 3mm filament nozzle, the point angle on the drill bit has to be 70 degrees or less. Would you surmise that a more gradual taper (i.e.: 70 degrees vs the 118 degrees) would perform better? I'm in the process of grinding out some new bits to this angle, though I managed to muck up all 4 of my nozzles this past weekend and am waiting for replacements to arrive.

[mhackney]

I would actually PREFER to drill at a steeper angle - especially if you could match the profile of the tip. I just didn't have the appropriate drill bits and was too lazy to grind a bit to do that - I wanted to do a proof of concept test quickly. If you have steeper angle bits, go for it! I think it makes for a smoother transition from the filament to the bore.

[chrahp]

The profile of the tip is 70 degrees. I don't believe there's a reasonably priced 1/8" drill bit that has that sharp of an angle (at least not one I've found). I'll be practicing my grinding on a bulk pack of bits I bought until the nozzles get here later this week. I'll report back once I get it up and running.

Do you yet know if this modification alters the performance with other plastics, namely ABS?

[mhackney]

Firstly, brass is VERY easy to cut/drill so you don't have to be perfectly sharp. I advocate twisting the drill by hand rather than in a lathe or drill - it is much easier to control and only takes a minute at the most to complete.

I have now run ABS and Taulman Bridge with much better results than before the mod. They flow much nicer now, again, no back pressure oozing issue so I'm seeing better surface finishes. The two that I'm especially interested to test are Laywood and Ninjaflex.

cheers,
Michael

[chrahp]

I used bits in a pin vise and drilled by hand using discrete sizes, starting with a 1/8", then 3mm, then 2.5 and finally 2mm, but the stepped taper that resulted didn't help things much, and actually made it jam way sooner than it had with the unmodified nozzle. You're right about doing it by hand, the first one I attempted w/ a small drill press and quickly learned that it was too much, as it punched through w/o even really trying.

The trick now is to build a jig to set the depth properly, so I can drill out each nozzle by hand and not need to measure each time. Has there been any feedback from e3d on this issue?

[mhackney]

No feedback from E3D. I hope they are investigating it. I've got lots of PMs though from folks who have done this mod and it is working for them.

[Broose]

I took an E3d v4 hot end that never worked right with PLA and replaced the heat break and heat sink with a v5 versions from Filastruder, then drilled a newer .4mm nozzle to .5mm depth, and its now working with PLA beautifully