High Flow Nozzles: Print Speed and Issues

Hi everyone,

I tried to use an aliexpress CHT hotend clone on my X1C but also had a few issues with it. I would like to use this thread to chat about issues with the CHT clone, the E3D ObXidian and the BIQU Panda Revo.

My issues are the following:

  1. After 2-3 prints with the CHT clone, I had tons of underextrusion issues. The only solution I found was to reduce the flow back to 13 mm^3/s (PETG). I tried different nozzles and higher temperatures but that would not fix it. Maybe one or two of the channels in the nozzle are clogged.
  2. Down the road I had issues with changing the filament for support interface layers (PLA as interface for PETG). Sometimes, the interface material (PLA) would not be printed at all because of the extruder being unable to flush the remaining PETG out of the nozzle. The issues looked pretty different:
  • When pulling the PLA back after the (unextruded) support interface layer, the PLA was soft even above the heat sink where it got cut and instead of being pushed back into the PTFE tube by the extruder gear, it got wound up a little in the gear which created a little hook. It cooled there and the hook prevented me from pushing or pulling the filament anywhere. I had to disassemble the entire extruder.
  • The second issue I had was the extruder pushing the PLA down through the heatsink into the heartbreak but not into the nozzle. The PLA got too soft again, and the pressure of the extruder pushed it into the fine gab where the heat break and the heatsink meet. After cooling down, I had to disassemble the entire hotend to get the PLA out.
    I tried raising and lowering the PLA temperature but had no luck. Since switching back to the stock hotend, all issues are gone. I guess that the smaller channels require higher pressure and therefore the flushing does not work all the time

Here are my questions:
a) While the stock hotend (and probably the ObXidian-HF as well) have the heartbreak going all the way up to the top of the heat sink, the BIQU Panda seems to have the Revo nozzle end somewhere in the heatsink. Any issues with filament changes on any of these hotends?
b) How about the flow rates? Are those higher for longer? Does the 60W heater of the BIQU Panda have any advantage over the 48W stock heater?
c) Do you have any other issues with any of these high flow hotends?

2 Likes

Hi,

A) I’ve had an E3D hotend on the go for a while and had no issues at all. Filament change happens exactly the same as it does with a stock hot end. I do reduce the flushing volumes multiplier in the slicer to 0.7, again it seems to work for me with no issues and I could probably go more. This is anecdotal and haven’t ran any measurable tests but has been repeatedly consistent on my one machine.
B) I did a few tests on the flow rates with BL basic PLA and eSun PLA+ - see my results above. The max flow rates were around 43 on PLA. I’ve dialed mine back to around 34 for most prints just for reliability and have had no issues. I’ve done a few big prints where the flow rate has been constantly high and have had no issues at all. I do suspect that the heater is the next choke point. There deffinately is more performance that could be coaxed out of the whole machine, Bambu though caution against a bigger heater. I haven’t looked at their hardware or done the maths. Given the market and the ethos of the company, I’d reckon they are playing it cautious with the heater wattage. Also, I’d be loath to change the heater cartridge when you cant PID tune the hotend
C) It does seem more sensitive to damp filament. I recently tried a new roll of BL Polycarbonate, dried it before use and kept it in my AMS with loads of silica gel boxes and it needed properly dried again within a fortnight. I had similar problems with an old roll of PLA Wood (high % stuff). An awkward filament to keep and use anyway, On the good side, although I’ve never had real major problems with filament sticking to the nozzle or flush being ejected all over the place, it has improved. Again, good dry filament really helps. I did clog my original extruder with PLA a few times by having a higher temp hot bed with and keeping the door closed, my own fault, got heat creep and premelting. Haven’t done it with the E3D hotend yet, might be a bit more difficult to flush. I’ve read on a post somewhere that you can cold pull them, certainly using a needle wont be as easy. Might be a bigger issue with a differently constructed heat break. Also, I’d reckon if your running a print farm it would be great for the slight time savings and the probable long life.

To sum up - the E3D hotend just works like a stock hotend just capable of more flow. No real new problems. It’s under driven and seems as reliable so far.

From a video source I watched giving a in depth review with examples of increasing the volumetric flow, E3D and BIQU aftermarket nozzles can’t perform above 23mm^3/s… they both failed.

So I honestly don’t see how they even say the improved percentages they claim to have. In the end it’s looking like you’d simply buy the E3D for wear resistance and the BIQU for fast swaps…

There’s a few other video’s of the E3D when it was launched that got around the same volumetric flow as me, around 43. Though in practice it’s very rare the printer would ever approach a fraction of that unless the acceleration and max speed are dialed way up.

I only tested changing the max volumetric flow as E3D recommended. Havent seen much reviews since.

This video sold me on the revo quick change over a black nitride coated nozzle with a false 43mm^3/s volumetric speed rating.

The CHT clone has additional metal to reduce heat break bending, but this may be transferring heat to the heat sink bypassing the heat break break zone.
As a result, the heat sink gets hotter, which transfers heat to the extruder, which makes the filament soften more easily, etc.
All of this is based on my imagination from the appearance and I have not experimented.

I am getting 44mm3/s on the E3D 0.4mm w bbl pla tough at 250C and 38 w my normal temps, Idk where you are getting 23 from but that must be a false test. I set my max vol. flow to 35 to keep it in the safer side

I honestly don’t think you are… or if you are then its a flat small part. I’d double check the flow within the slicer and if you cost then post a photo of the model being printed at that speed then compared to a photo of what the quality is.

Although this post is talking about E3D’s direct aftermarket nozzle in partnership with BL, BIQU’s Panda REVO is essentially stating it can hit that same volumetric flow rate but testing shows it degrades quality severely plus no real benefits of print time being shorter.

The larger nozzle you go then yes you’ll start seeing benefits, otherwise I find zero benefits of E3D’s version compared to the Panda REVO since that actually will benefit being hotswappable, various sized nozzles, and future CHT nozzles to be implemented. Otherwise E3D’s is $80 and needs to be replaced versus simply buying a new nozzle for the REVO panda even priced @ $125…

This is my 2 cents

Here’s the video

I am getting 44mm^3/s of flow from the Orca flow test, not on a practical print. I checked the flow by layer graph from the slicer before sending the test, and the test was conducted multiple times using different colors to ensure accuracy. I have no previous experience with the Panda Revo, so I won’t comment on that, but with the stock ceramic heater at 48W, the maximum flow I am getting on E3D aligns with what I have seen others achieve as well.

Whether you choose to use your “super car’s” top speed or just have it and display it is up to you. Just because I can hit 44 doesn’t mean I will be setting my max flow over 35 any time soon, but I increased it from 18, so that $80 nozzle doubled my max flow. My speeds/accel. were not the limiting factors in my case, so it also improved the print times. It didn’t halve them, but still provided a massive improvement on draft/prototype prints that need to be done asap

To each their own I suppose… I’m just not quite sure why someone would want to have simply a +10mm^3/s hotend that costs $80+shipping and comes with no components.

I guess we’ll see more from when BIQU releases the 2 other versions. I yet to find the flow rate affecting my applications when I just use a 0.6mm nozzle @ a .14LH to achieve faster print times.

Glad that nozzle is helping people though :call_me_hand:

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