What's going on with Prusa's Nextruder HT hotend?  

RE: What's going on with Prusa's Nextruder HT hotend?

One of the reasons I bought the Core One was that it had the HT upgrade path. At the time I didn't realize all the other changes needed to take real advantage of it. Maybe Prusa is as baffled about what to do as we are, so isn't letting it out in the wild yet. And what about heat creep? I'd think that would be an issue and maybe a bigger better heat sink is needed.

I'm a Prusa fanboy for various reasons. In other posts I've talked about the two Bambu printers we have at work, X1C and X1E. My Core One compares favorably in both performance and price, but now I see trouble for Prusa. The X1E (enterprise version) was terrible because it was always broken and parts took months to get. Most weren't compatible with the X1C. We finally decided to cut our losses, pitch it in the dumpster and just buy another, the X2D. First, I have to make the joke- it's called "2D" because it only prints one layer! Ba-dum-tss! But seriously, this thing has a max nozzle temp of 300C, an actively heated chamber for 65C and a 120C heat bed. Price starts at $650. Yeah, $650, though everybody adds the AMS, so the total is $900. I saw it printing for the first time a couple days ago. Quieter than my Core One, though the structure flexes about as much. Smooth is probably the best word to describe the thing. I don't know much about other features like dual nozzle. No, it doesn't get to 400 C, but the bottom line is it would take some significant upgrades just to get the Core One competitive with it, unless there's something about it that I don't know yet.

RE:

I have my MK3S, it is a rock, never had a single problem in 6 years, so I bought the C1L due to it being advertised to get the HT hotend in Feb and the MMU3 compatibility. Prusa gave-up on the MMU3,  atleast they released the firmware so I could just make my own method to make it work. I am not a Bambu supporter, but after the endless C1L firmware problems with no resolution, CS that can't solve a single problem, can't even read their own G code in the config files, add in the deceptive marketing.  Prusa has driven me to consider Bambu for my next printer. Prusa doesn't need competition to take their business away, they are driving it away on their own.

Tommy on Redit reached out to us over a month ago about the HT hotend and then silence, there is no transparency. Can’t even trust if they’ll actually release it or just another lie. Considering making my own if this continues.

RE: What's going on with Prusa's Nextruder HT hotend?

Since I don’t work at Prusa, I can’t provide any clear or useful information. Those who could certainly aren’t allowed to say anything. This leaves us with nothing but rumors and speculation as to why Prusa isn’t releasing any new information or updates.

That’s why everything I’m about to say is pure speculation and a logical deduction:

I strongly suspect that internally, all resources have been shifted toward the completion of INDX. Planning, research, prototyping, testing, and sales are certainly working at full capacity to keep up with the hype.

That’s why I can easily imagine that the lack of resources for the HT project is being treated as a secondary priority for the C1 and C1L. Furthermore, I think Prusa is working internally to develop the subsystems necessary to ensure successful prints with high-end filament. For example, chamber heating or filament feeding for third-party manufacturers. I won’t even get into the firmware and Slicer 3.0!

I have to agree with Conrad: I only bought the MK4S to C1 conversion kit because I ultimately wanted to fully enter the Champions League of high-end filament with the HT nozzle. Enclosed housing, HT nozzle, 120-degree bed—those were the aspects that sealed the deal for me. I’m sure many other people who are heading in the same direction felt the same way.

So, Prusa, how about throwing a little piece of new information out there? What’s the deal with the HT nozzle? Is it coming or not? If so, when?

You could set up a pre-order—like you always do. Charge everyone 260 euros for the HT nozzle and keep buyers waiting another six months, just like with the Prusa XL or MK4. Or will it even cost more than 260 euros because the hardware needs even more adjustments?

Prusa, tell us what’s going on!

RE:

I asked Tommy to grab an update on this and will discuss it tonight on the hangout session on the discord server https://discord.gg/KqdZJnpz8 tonight (May 4th) at 19:00 CET time and then once that is done I will post the update here on it. 

RE: What's going on with Prusa's Nextruder HT hotend?

Today is May 4th, so was that tonight May 4th or tomorrow night May 5th?

RE: What's going on with Prusa's Nextruder HT hotend?

Apologies, I corrected it... its tonight, Monday May4th 🙂 

RE: What's going on with Prusa's Nextruder HT hotend?

Looking forward to the update posted on the forum, blocked at work, so couldn't get on.

RE:

Tommy has confirmed the following:

• In the last phase of testing
• There were issues testing brittle filaments (assuming stuff like PPA-CF, PPU-CF etc) there were breaking in the Nextruder. Some of this due to the curvature of the Bowden bend. There was a redesign of the idler bogie as well to account for this. There are changes to the Nextruder needed basically. 
• Have to handle the hotend with gloves since oils on the skin will mess up the hotend. 
• Will most likely be released this month. 

RE: What's going on with Prusa's Nextruder HT hotend?

Thank you.

You and Jan already identified the brittle filamanet, glad they addressed it.

The oils I don't grasp, what is happening at 400 that isn't already happening at 280? Assuming the heatsink? Is it the type of plating required that adds the new contact issue? Won't cool properly?

RE: What's going on with Prusa's Nextruder HT hotend?

Thanks for the update.  I am looking forward to this one.  

RE: What's going on with Prusa's Nextruder HT hotend?

Posted by: @ruebarb

Thank you.

You and Jan already identified the brittle filamanet, glad they addressed it.

The oils I don't grasp, what is happening at 400 that isn't already happening at 280? Assuming the heatsink? Is it the type of plating required that adds the new contact issue? Won't cool properly?

Tommy said that skin oils on the hot end can "cake up" at higher temps. 

RE: What's going on with Prusa's Nextruder HT hotend?

Hopefully, no one is touching it at those higher temps. 😖 

Posted by: @hyiger

 

Posted by: @ruebarb

Thank you.

You and Jan already identified the brittle filamanet, glad they addressed it.

The oils I don't grasp, what is happening at 400 that isn't already happening at 280? Assuming the heatsink? Is it the type of plating required that adds the new contact issue? Won't cool properly?

Tommy said that skin oils on the hot end can "cake up" at higher temps. 

RE: What's going on with Prusa's Nextruder HT hotend?

Posted by: @cwbullet

Hopefully, no one is touching it at those higher temps. 😖 

Pretty sure he meant after it's cooled down otherwise would need to worry about your fingers caking up and not the hot end. 

This is the counterpoint of certain fats and oils used by blacksmiths when tempering metals and of the 'seasoning' that builds up on a cast-iron frying pan if used traditionally and almost never washed - a mixture of carbon, nitrogen and other elements migrating into the surface and baked-on glazing of the surface.

Whilst this might in some cases be beneficial and make a better blade or a natural non-stick pan, apparently in extruder nozzles the effect is deleterious.

Cheerio,

RE: What's going on with Prusa's Nextruder HT hotend?

Afair Tommy said that first issue was the filament breaking due to tension because of the curvature ( as stated earlier in this thread).

The second issue is aboit the burned fats -  if filament is touched by hand without the gloves, then the fats are transferred onto the filament, then the fats go with the filament down to the nozzle and there tte fats get burned and thus can end as a residue sticking to the internal parts of the nozzle walls. So they are working on the process to limit that issue (probably mainly procedures to use gloves etc).