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mhackney wrote:ceramichammer, your photo clearly shows how little contact surface the E3D nozzle has! The base of the nozzle itself does not snug up against the heated block by design and on top of that, there is an untreated section right above that so heat isn't able to transfer conductively until the first thread (the lowest in your photo). Then, there are only 5 threads total. That is not a lot of conductive pathway!

A quick update: printed all day at 185-195°C with NO filament starving on parts that are usually problematic. On top of that, I started ramming the speed up and was successfully printing at 60mm/s the tenkara line holders I manufacture - again, with no filament starving.

Because I have 3mm filament, I believe I'm at a geometric disadvantage in how much I can shorten the barrel length. Because the tip of the nozzle is tapered, my 1/8" drill bit will leave me with a much thinner cross-section and I'm more likely to blow the entire bottom out. Here's my next test with the flange of the nozzle snugged up against the heater block to promote heat transfer. I'll have to wait on my machinist friend to attempt to drill it out.
[img]http://i.imgur.com/EEnY6bql.jpg[/img]

to get most thermal transfer to nozzle why not screw the nozzle into heater block FIRST until flat seats against block, then thread heat break in from other side until it bottoms against nozzle, then lastly screw heat break into the cooling fin body?? I have not done this yet, but am planning on assembling my E3D that way.
why leave the gap?
am I missing something here?

Because that's not how E3D says to do it - most likely to prevent breaking the heat break at the thin section. You want to tighten the nozzle agains the break, not vice versa.

bvandiepenbos wrote:to get most thermal transfer to nozzle why not screw the nozzle into heater block FIRST until flat seats against block, then thread heat break in from other side until it bottoms against nozzle, then lastly screw heat break into the cooling fin body?? I have not done this yet, but am planning on assembling my E3D that way.
why leave the gap?
am I missing something here?

That is what I did in the photograph above. I agree it sounds dumb but the E3D assembly instructions say specifically to leave a gap. http://files.e3d-online.com/Drawings/E3 ... Manual.pdf
My best guess is having that gap there is confirmation that the nozzle is seating against the heat break and not accidentally the heater block. Either way it seems silly.

mhackney wrote:Because that's not how E3D says to do it - most likely to prevent breaking the heat break at the thin section. You want to tighten the nozzle agains the break, not vice versa.

so don't use your big pipe wrench

mhackney wrote:Yes, I am talking about the .40mm bore's length. There are photos I posted this weekend showing that the E3D bore is 2mm long - much longer than other nozzles. I simply drilled the 2mm hole that leads up to the .40mm bore a bit deeper with pin vise and 2mm drill bit. I'll try to draw something tomorrow.

In an earlier post you said you were planning on boring to a 60 degree angle as well drilling. Did you abandon that plan and just leave whatever countersink angle the drill bit causes?

Yes, I didn't have any 60° bits and was too lazy to grind one. And frankly, after seeing the J-Head with the same angle, I put less emphasis on that dimension. The shorter nozzle bore is certainly performing much differently and much better so far. But, I will not be convinced until I have at least a solid week and 100s of prints on it.

bvandiepenbos wrote:so don't use your big pipe wrench

I think the wall of that heat break is only 0.4mm thick. Look at it wrong and you'd risk snapping it.

mhackney wrote:Yes, I didn't have any 60° bits and was too lazy to grind one. And frankly, after seeing the J-Head with the same angle, I put less emphasis on that dimension. The shorter nozzle bore is certainly performing much differently and much better so far. But, I will not be convinced until I have at least a solid week and 100s of prints on it.

I'm afraid I may have to grind one in order get the angle required for the 3.175 mm bore.

And then there's the bowden tube!!!

I just checked it. I would have never thought this. Check the video highlights!!!

The first is a SeeMeCNC-supplied Bowden, the second is one I got with an E3D purchase.

https://www.youtube.com/watch?v=Xbfa1u76fKY

JohnStack wrote:And then there's the bowden tube!!!

I just checked it. I would have never thought this. Check the video highlights!!!

The first is a SeeMeCNC-supplied Bowden, the second is one I got with an E3D purchase.

https://www.youtube.com/watch?v=Xbfa1u76fKY

You've summed up my sentiments.

What's the measured filament diameter in that video.

bvandiepenbos wrote:to get most thermal transfer to nozzle why not screw the nozzle into heater block FIRST until flat seats against block, then thread heat break in from other side until it bottoms against nozzle, then lastly screw heat break into the cooling fin body?? I have not done this yet, but am planning on assembling my E3D that way.
why leave the gap?
am I missing something here?

I wonder if the heater block is brought up to 300 deg C with the nozzle screwed all the way in, then the cold heat break already attached to the cold heat sink (might even put in freezer) is screwed in to the heater block quickly, you wouldn't have to do more than firmly finger tight with the heat sink (same tightness as E3d's instructions), because the heat break will expand as it comes up to the same temp as the heater block and nozzle and make the connection with the nozzle tighter.

Polygonhell wrote:What's the measured filament diameter in that video.

The ID is 1.75 (and confirmed by E3D Support) and the walls are, I believe 1mm or 1.1. They're thicker than the SeeMeCNC's walls.

Personally, I think this is too tight. The Ezstruder flattens the filament out a bit.

Last night, my filament was measuring reliably 1.74 - 1.76 and today, it's 1.75 - 1.76. When it passes through the extruder and gets flattened, it goes to 1.68 - 1.72 and 1.77 - 1.79 if that makes sense.

I know I can't use theirs. Thank god I have just enough left.

BTW, just a quick stat about the hobbled gear, measuring in the belly of the cut:

New: 11.64 - 11.67
After 20 hours use: 11.44 to 11.56
After 250+ hrs use: 10.84 - 11.10

These things hold up pretty well!

I'll note that I also bought eight steppers from Ultimachine - but they're the same model # as SeeMeCNC's.

I'm at a loss. I'm back to the OEM Hot end this AM. I've got just enough SeeMeCNC bowden tube to print in the center of the bed!

That's odd, all of the E3D PTCs I've received are the black plastic ones that are bored so the PTFE Bowden tube can completely pass through them. This is needed on the hot end side so the PTFE "plugs in" to the top of the cold end. In the extruder side, I've modified my ezStruders so the Bowden tube goes right up to the hobbed gear.

It looks like the new brass PTC you got from E3D does not allow the Bowden to pass through all the way?

mhackney wrote:That's odd, all of the E3D PTCs I've received are the black plastic ones that are bored so the PTFE Bowden tube can completely pass through them. This is needed on the hot end side so the PTFE "plugs in" to the top of the cold end. In the extruder side, I've modified my ezStruders so the Bowden tube goes right up to the hobbed gear.

It looks like the new brass PTC you got from E3D does not allow the Bowden to pass through all the way?

It is you say and no, I'm not going to mod my Ezstruder!!!! LOL

I don't think I implied otherwise - except if you look at my cam, I had a doh moment and went ahead and attached the brass PTC to the other end of the OEM bowden - and now I'm out of all of it. Dammit!

Broose wrote:

bvandiepenbos wrote:to get most thermal transfer to nozzle why not screw the nozzle into heater block FIRST until flat seats against block, then thread heat break in from other side until it bottoms against nozzle, then lastly screw heat break into the cooling fin body?? I have not done this yet, but am planning on assembling my E3D that way.
why leave the gap?
am I missing something here?

I wonder if the heater block is brought up to 300 deg C with the nozzle screwed all the way in, then the cold heat break already attached to the cold heat sink (might even put in freezer) is screwed in to the heater block quickly, you wouldn't have to do more than firmly finger tight with the heat sink (same tightness as E3d's instructions), because the heat break will expand as it comes up to the same temp as the heater block and nozzle and make the connection with the nozzle tighter.

Sounds like a excellence idea.
thanks, I am going to give that a shot.

aerouta wrote:Where did you folks order this hotend? here.. http://e3d-online.com/

http://www.Filastruder.com also sells them in the United States.

JohnStack wrote:And then there's the bowden tube!!!

I just checked it. I would have never thought this. Check the video highlights!!!

The first is a SeeMeCNC-supplied Bowden, the second is one I got with an E3D purchase.

https://www.youtube.com/watch?v=Xbfa1u76fKY

Wow, so is that a new PTC from e3d? Like Mhackney said, this isn't the same PTC I got with my kit - mine are big black plastic ones...

McSlappy wrote:

JohnStack wrote:And then there's the bowden tube!!!

I just checked it. I would have never thought this. Check the video highlights!!!

The first is a SeeMeCNC-supplied Bowden, the second is one I got with an E3D purchase.

https://www.youtube.com/watch?v=Xbfa1u76fKY

Wow, so is that a new PTC from e3d? Like Mhackney said, this isn't the same PTC I got with my kit - mine are big black plastic ones...

No, E3D uses only black plastic fittings. He has installed a different fitting. Considering the E3D PTFE walls are slightly thicker, I am not surprised that this is causing binding.

JohnStack wrote: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.

Really? How interesting...

elmoret wrote:

JohnStack wrote: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!")

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

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.