Prometheus Hot End v2 Build

[ccavanaugh]

I'm getting ready to install a Prometheus Hot End v2 into a new build. This assembly configuration is based on my experience with a v1 Prometheus build.

I had to deviate a little bit from the stock build but ended up with a very flexible configuration. The cause for deviation was an occasional jam on PLA under heavy retracts.

With this configuration, I get no stringing with PLA and ABS and only need short 3.5mm retracts. Nylon is working quite well also and requires 5.5mm retracts with an occasional string.
I've had over 450 hours of run time with this configuration without any jams.

Bellow is the configuration I am using.

Nut configuration

Instead of double nutting after the heater block, I moved a nut to the top side. I am also using a nut at the bottom of the heat sink to create a 2mm heat break.

To get an exact 2mm gap at the heat break and maintain a desired heatsink to heater block orientaiton, you can try out different nuts in the kit or if needed, file a nut down on thickness until you get the 2mm.

Also, A nice trick that may not be evident, is to use the included 2mm hex wrench as a gauge instead of trying to sight the gap with a pair of calipers.

Hex wrench as a spacer

When building a v2 this way, be careful not to tighten the top set screw too much or you risk crushing the entry of the barrel. Having used a jam nut against the heat sink, the set screws can be omitted it desired.

[Glacian22]

Interesting! What's the thought behind the nut above the heater block, and the one below the cooling fins?

[bvandiepenbos]

Thanks for posting your configuration info and sharing your experience.
Being highly adjustable is one of the things I love about the Prometheus.

using the 2mm allen key as a gauge is clever!
-*slaps forehead*-

[ccavanaugh]

Interesting! What's the thought behind the nut above the heater block, and the one below the cooling fins?

Initially, I was having PLA jamming issues under heavy retracts with 2 nuts on the bottom per the build guide. I also had about 2.5mm of exposed barrel.

My thought was to create a bit more of a temperature gradient towards the cold end by moving a nut on top of the heater block instead of two at the bottom. A jam nut is needed to secure the heat sink to the barrel on the v1. The v2 uses set screws now, so this is not required. But, it was working before, so I left it.

Hindsight, the extra nut at the heat sink helps create enough height to keep the Prometheus installed in a relatively same manner as the SeeMeCNC hot end and provide enough clearance for the fan. Without, I think I would need to place it underneath the platform or mount the cooling fan differently.

I'm currently printing PLA at 75 mm/s without issue with a v1 and v2 and will try increasing before too long. I've yet to have a jam with this configuration and no need for cooking oil voodoo that some E3D users seem to need.

[AEK]

In your experience, would you say that the Prometheus v2 is on par if not better than the E3D v6?

Extremly on the fence with my purchase decision!

One day it's the E3D v6, the next it's the Prometheus v2.

I will be printing PLA, T-Glase, Nylon 645 & ABS pretty much in that order or use.

Thanks for your input ccavanaugh!

Andre

[KAS]

For me personally, I like the Prometheus better than the E3D v6. Two reasons, PLA retraction is finicky with the V6. I like the adjustability on the Prometheus, but it comes down to having a stainless steel nozzle vs the brass. You can get the SS nozzle with the v6, although it's an added cost.

[ccavanaugh]

In your experience, would you say that the Prometheus v2 is on par if not better than the E3D v6?

Extremly on the fence with my purchase decision!

One day it's the E3D v6, the next it's the Prometheus v2.

I will be printing PLA, T-Glase, Nylon 645 & ABS pretty much in that order or use.

Thanks for your input ccavanaugh!

Andre

I've not used an E3D, but would have gone that route if it was not for the Prometheus. The Prometheus one piece barrel is more difficult to machine, but more tolerant of machining error and more robust than the E3D in my own opinion. I've seen too many reports of broken E3D barrells and PLA jams.

I've got a Prometheus in both of my machines and have not desire to change to something else. Next to using an original J-Head for PLA and ABS, I don't think you can find a better hot end.

I have run PLA, ABS, Nylon (blue trimmer line), and PETG through it using the same configuration as described in this thread without issue.

[AEK]

Thanks KAS and ccavanaugh!

You've been a great help!

I'm in Ottawa, Ontario so Toronto isn't far from me for the Prometheus v2.

If you guys are getting great results from it, then I'll go that route. Thank you!

To be honest, I never had a problem with the stock SeeMeCNC Hot End, but need all metal for Nylons, etc...

I'll set it up for 2.5mm and 5.5mm as per your other post(s) for retraction.

[ddrumss2112]

Hi,
Sorry to bother you guys, but I was wondering if there are any other changes recommended to get PLA printing with the Prometheus v2? After copying Ccavanaugh's configuration & retraction length I can go a little farther before a jam, but have yet to still get a successful print. The v2 is working wonderfully with other filaments, but not PLA which is my primary.

Any ideas or info would be greatly appreciated & thanks for the knowledge you've already shared.

(I'm using a Rostock Max V2 w/stock extruder, fans & heat sinks on all 4 motors, & a Prometheus v2 hot end.)

[Glacian22]

(I'm using a Rostock Max V2 w/stock extruder, fans & heat sinks on all 4 motors, & a Prometheus v2 hot end.)

An all metal hotend takes more force to extrude than the default one, just because the filament is sliding along metal rather than teflon, regardless of how nicely polished that metal is. I was already using my geared extruder by the time I switched to my prometheus so I can't say how well or not the ezstruder works with the prometheus + PLA, but I've had zero jams with the my setup. My extruder: http://www.thingiverse.com/thing:744759" onclick="window.open(this.href);return false;

[ddrumss2112]

(I'm using a Rostock Max V2 w/stock extruder, fans & heat sinks on all 4 motors, & a Prometheus v2 hot end.)

An all metal hotend takes more force to extrude than the default one, just because the filament is sliding along metal rather than teflon, regardless of how nicely polished that metal is. I was already using my geared extruder by the time I switched to my prometheus so I can't say how well or not the ezstruder works with the prometheus + PLA, but I've had zero jams with the my setup. My extruder: http://www.thingiverse.com/thing:744759" onclick="window.open(this.href);return false;

Thanks! I'll look into it.

[ccavanaugh]

I am using a geared extruder as well. A stock ezstruder does not have enough torque to overcome the extrusion pressure of PLA. Many have reported improved print quality as well by either modifying the ezstruder to use a geared stepper or switching to many of the available geared extruder designs.

[EskimoRuler]

Hey ccavanaugh,

Thanks for a great build. I have been running this configuration for a few weeks now and I think I have it dialed in now. I've been printing ABS needing only 2.2-2.5mm retracts at 30mm/s.

The Prometheus V2 has been great so far. I've added a screw-in thermistor and that makes it even cleaner.

[ccavanaugh]

Thanks for the feedback. I am interested in what others are doing as well for physical configuration and retraction settings.

[ramai]

A very enlightening post. Thanks for sharing this setup. I had the prometheus in the recommended configuration and stock extruder, and it worked for a while, but eventually the extruder was really struggling to get the filament through. I took the hotend apart and switched to this setup, and it seems to be going well now. If it starts having a hard time again, I might have to switch to a geared extruder setup. I'm keeping my fingers crossed for now.

[aehM_Key]

My configuration for printing ABS with a 0,4m nozzle is the following:

Cold Zone
2,5mm Transition Zone
Heater Block
Hex Nut
Hex Nut

[img]http://abload.de/img/wp_20151205_14_09_18_nesqd.jpg[/img]

I use 1,5mm retraction @60mm/s.

I print up to 100mm/s (but usually slower).

I use the stock extruder of Rmax V1 with my flying extruder mod (bowden lenght ~75mm).

Works well!

[Eaglezsoar]

Thanks for the great posts, it will certainly help those who are thinking about purchasing the Prometheus or those that already have one.

[teoman]

That heater block looks awfully close to the effector platform.

The heat could make it go soft or distort.

[ccavanaugh]

That heater block looks awfully close to the effector platform.

The heat could make it go soft or distort.

Agreed. I reduced my spacer height so the hot end fan was just a smidgen above the platform to allow room for layer fans. I also wrapped the heater block in F4 tape to add some additional heat protection.

Platform

[aehM_Key]

That heater block looks awfully close to the effector platform.
The heat could make it go soft or distort.

No problems so far.

[ramai]

Now I know what it feels like to be a borosilicate glass plate