E3D V4 All metal hotend

[Eaglezsoar]

All those positive qualities for it and it sounds like it would need to be run on a 3mm system or a cartesian that could be bored out to handle the inconsistencies in diameter.
That would not work very long on a 2mm bowden setup. It's a shame that they would make something like this.

[McSlappy]

McSlappy - there is a relationship between diameter and length of bore for an extrusion nozzle. If the bore is too short with respect to diameter, you get pig tailing and swelling (aka die swelling) as material comes out. If it is too long, it requires a lot of pressure to push the material through. Sometimes this is desired - like in a particulate filled material, as it can along the particles in parallel with the extrusion flow. For us, this is an issue and is what I've discovered to be the case with the nozzles I have. I spent a few years in a research lab extruding ceramic polymer precursor fibers. I vaguely recall that the optimal diameter to bore length was in the neighborhood of 1 to 1.5 for those materials. Extrusion speed and other factors affect this too. Every material is different and nozzles on 3D printers are a compromise to support multiple materials.

That said, a 1:1 to 1:2 diameter to length seems to me to be reasonable. So, for a .4mm orifice, .4mm to .8 mm bore is probably a good target for very viscous materials like molten PLA and ABS. The larger the orifice diameter, the longer the bore and vice versa. I would anticipate your .25 mm nozzle with a 1mm bore to be problematic. I haven't measured my .25mm nozzle yet nor have I attempted to print with it. I guess that will be next on the list!

Thanks mate, I really do appreciate your methodical approach. I'm a little shotgun in my problem solving, so I rely on the patience and expertise of people like yourself. When I can I'll shorten the nozzle length.

@Sanjay
ABS- You can see my latest ABS print here, I'm extremely happy with the result and it looks very sexy now holding the e3d on the machine! Very very happy. I love the lack of stringing!
PLA- Big sad face I don't want to say it's a total fail yet since I've only run a small amount of PLA through it - I just don't have the time to properly troubleshoot it and that makes me sad. But for now I'll say it does not run great with the .4 or .6mm nozzles. I really wish I had the time to do some proper testing :/

[Glacian22]

I just got my modded nozzle, time to start testing some PLA!

[ceramichammer]

I'm so frustrated I think I might just pop. https://www.youtube.com/watch?v=klVhwlwHhY4
I ground a 1/8" drill bit to around 70 degrees and "hand drilled" 2x 0.35mm nozzles to a bore length of ~0.5mm. I quarantined all of my existing PLA (4042 PLA from an unproven vendor) and bought a bunch of new plastic from Ultimachine. The new stuff is 4043PLA that is perfect and beautiful. I have two more or less identical Ultimaker machines with E3D heads on them. I loaded up a ~10 hour print on each.

• 0.35mm extrusion width
  0.16mm layer height
  18% infill
  50mm/s print speed
  200C temp
  25mm/sec retraction speed
  1.5mm retraction length

After about 2-4 hours of printing beautifully, the heads started to jam and cause filament starving. I'd upgraded the spring on my extruder gear bearing so it takes SO MUCH FORCE to trip up the extruder. I'll post pictures when I get back to the shop but I'm at my wit's end.

[mhackney]

Glacian22, your nozzle arrived here today too, thanks.

ceramichammer, maybe start a little more moderately - a 2 hr print, lower the speed to 30mm/s and see what happens. I am still skeptical on the low thermal conductivity path between the block and nozzle and that might be causing problems too.

[ceramichammer]

Glacian22, your nozzle arrived here today too, thanks.

ceramichammer, maybe start a little more moderately - a 2 hr print, lower the speed to 30mm/s and see what happens. I am still skeptical on the low thermal conductivity path between the block and nozzle and that might be causing problems too.

I'll try a slower print but I'm still cranky about it. I'm not being snarky with you, but what would I learn from doing a smaller print, other than the fact I can't do big prints? I've been snugging the flange of the nozzle against the face of the heater block to maximize thermal conductivity. I don't currently see a disadvantage to this change in assembly. You've been invaluable in this troubleshooting. If you want anything laser cut, I would be thrilled repay the favor. We owe you big time.

[mhackney]

Understood!

I like to create success and then build incrementally. I suspect that 50mm/s with a .35mm nozzle is a bit too fast. There is a big difference between .4 and .35mm diameter in terms of area. Sounds like you are not using an ezStruder correct? So investigating your extruder is a good idea. A fair amount of pressure is required to push PLA through a small orifice. Is the PLA getting chewed up in the extruder when this happens or just slipping?

Hmm, laser cut, I do have a project I would like to see if laser cutting made sense. I need to make some cardboard "dogbones" to package fishing line on. What would you need to do a run of say a 12" square of thick card stock or corrugated cardboard? I guess it pays to be helpful!

cheers,
Michael

[ceramichammer]

Understood!

I like to create success and then build incrementally. I suspect that 50mm/s with a .35mm nozzle is a bit too fast. There is a big difference between .4 and .35mm diameter in terms of area. Sounds like you are not using an ezStruder correct? So investigating your extruder is a good idea. A fair amount of pressure is required to push PLA through a small orifice. Is the PLA getting chewed up in the extruder when this happens or just slipping?

Hmm, laser cut, I do have a project I would like to see if laser cutting made sense. I need to make some cardboard "dogbones" to package fishing line on. What would you need to do a run of say a 12" square of thick card stock or corrugated cardboard? I guess it pays to be helpful!

cheers,
Michael

Got it. One of the many frustrating aspects is there is almost no advantage to a 0.35mm nozzle for our applications. I've thus far refused to spend any more money on these damn things but I should probably just buy some 0.4mm, 0.5mm, and 0.6mm nozzles. I'm going to attempt to print exactly the same way but with ceramic insulating tape between the heater block and the heat sync.

[DavidF]

I have the e3d installed and did 3 prints. First one .2 mm layer printed great. Second print .1 mm layer 200c printed great with lots of retractions.
Third print .1 layer 195c and plugged in less than a minute.
All print speeds were 30mm sec with smcnc translucent pla.
Need to unplug the hot end and do some more testing..print quality is a lot better. Just need to play with it some more.

[mhackney]

And was this with a measured and/or modified nozzle bore length?

[ceramichammer]

Understood!

I like to create success and then build incrementally. I suspect that 50mm/s with a .35mm nozzle is a bit too fast. There is a big difference between .4 and .35mm diameter in terms of area. Sounds like you are not using an ezStruder correct? So investigating your extruder is a good idea. A fair amount of pressure is required to push PLA through a small orifice. Is the PLA getting chewed up in the extruder when this happens or just slipping?

Hmm, laser cut, I do have a project I would like to see if laser cutting made sense. I need to make some cardboard "dogbones" to package fishing line on. What would you need to do a run of say a 12" square of thick card stock or corrugated cardboard? I guess it pays to be helpful!

cheers,
Michael

I just sent you an email to info at eclecticangler about laser cutting.

[DavidF]

Haven't measured it yet, its stock out of the box. I'm going to try a couple more prints before I tear it apart to see what its made of. Started making a drill bit though. LOL

[DavidF]

on its 4th print now .1mm at 40 mm/sec I bumped the temp up a bit and its looking SWEET!!!!
I have to say, it may have plugged up but this is one easy nozzle to unplug...if that makes anyone feel any better

[mhackney]

I'm getting more and more success stories and there are now a few people over on the E3D forum reporting success too. Yippee!

[Eaglezsoar]

I'm getting more and more success stories and there are now a few people over on the E3D forum reporting success too. Yippee!

You're going to be famous!

[mhackney]

I hope not. I'm not a good "people person".

[DavidF]

I hope not. I'm not a good "people person".

LOL me either!
Prints 4 and 5 AWESOME!!!! very nice print quality. Going to keep on running prints and dropping temp as I go. I am running 10'C hotter than what I had been and it seems to be working out ok. I dont have a thermocouple to verify the temp though.....

[DavidF]

Print 6 Fail!! Jammed up, I Had dropped temp to 200c Putting it back to 205 and running again... still the most awesome prints i have had so far when it does print. Part of the problem may have been the intial jam where I was having some trouble getting the support material to stick to the bed and decided that the print nozzle needed to be lowered, but instead of resetting the Z height I decided to just stick a piece of tape on the bed and print on it, Immediately clogging the nozzle so now i reset the z .03 MM higher like I should have from the get go and temp at 205.....well Ill let you know in about 2 hours. LOL

[mhackney]

Out of curiosity, what speed are you printing and how long did you make the nozzle barrel?

So far I've printed on 3 Kraken hot ends (out of 4) with the modified .5mm bore length nozzles and no jams up to 90mm/s and LOTS of prints in single color and a few double and triple color. I almost have the new KISSlicer release for Mac (came out last night) dialed in.

cheers,
Michael

[DavidF]

Out of curiosity, what speed are you printing and how long did you make the nozzle barrel?

So far I've printed on 3 Kraken hot ends (out of 4) with the modified .5mm bore length nozzles and no jams up to 90mm/s and LOTS of prints in single color and a few double and triple color. I almost have the new KISSlicer release for Mac (came out last night) dialed in.

cheers,
Michael

Havent modified it yet, its as it came.

I wish there was some sort of thermal imaging scanner we could use on these things, so much could be learned about what the temp is at the actual nozzle and heat break. I cant get a good thermocouple reading due to the small surface areas. According to Brian Rupnow the transfer of heat is greatly reduced when there is a joint between plates even when they are machined to close tolerance. It has something to do with the molecular alignment of the metals structure. Not that I understand it or agree with it completely but I have to try to get multiple fails and document and baseline the fails according to the temps using the same material over and over. I have no doubt that mchakneys soultion corrects the issue, my question is what is it correcting exactly.....
Yea, im a big dork! But I love challenges and have been thinking about my own design for a hot end...

[DavidF]

Damn, failed to answer the question...im printing at 30mm/sec....

[mhackney]

What it is correcting is this...

I discovered that the .4mm nozzle has a bore length of 2mm (and longer) - take a look at the drawings I posted earlier this week in this thread. That long and narrow bore requires a lot more pressure to push the molten filament through, so much that it can (and probably complicated by the thermal characteristics) momentarily and/or permanently "freeze". Reducing the length of this bore to .5mm results in an obvious reduction in the amount of force it takes to push the filament through and apparently prevents the freezing issue.

[DavidF]

Im not doubting what you are saying, and totally understand the reduction in backpressure by shortening the bore. I just want to play with it some more and experiment before I change things...

[mhackney]

No worries, I knew you weren't. You asked "what is correcting it exactly" so I was answering that.

cheers,
Michael

[DavidF]

No worries, I knew you weren't. You asked "what is correcting it exactly" so I was answering that.

cheers,
Michael

You are just too cool!! What layer heights have you been printing at?? Im running .1mm for testing.....