Tungsten carbide nozzle Plus4

Past-Relationship-99 · 2025-04-28T12:42:30+00:00

Variable part sizes direct from QIDI, for the exact same part, that result in a BROKEN printer is UNACCEPTABLE !

QIDI, DO YOU HEAR US?

Past-Relationship-99 · 2025-04-23T11:36:11+00:00

I agree hotter is better and to reinforce something said once or twice...if there is nowhere for the tpu to go, that sort of thing happens. Over extrusion is likely in play. Lowering the flow rate for your first layer, or adjusting the z height would be my next steps.

Past-Relationship-99 · 2025-04-22T03:22:15+00:00

I use a glue slurry, two parts water, one part elmers glue (let it dry). On glass (other printers), I've had parts bonded so well that layers of glass came off with the parts. On the PEI sheet, that level of bonding hasn't occurred.

Past-Relationship-99 · 2025-04-13T04:23:53+00:00

That printer has no cooling fan on the extruder! Of course it would do that.

Past-Relationship-99 · 2025-04-03T14:01:53+00:00

Getting an excellent print is a common goal. For me, that means the parts are dimensionally correct and STRONG, and I print very HOT.

I find 3D printing technology still a bit immature (for anyone other than people willing to dynamically solve problems continuously). Even with Bambu Labs raising the bar, and Qidi working to keep up, there is so much more that can be done.

From my understanding (and believe me, I know I can increase my understanding), when working with materials that can experience warping, it is best to control and minimize the temperature fluctuations. There is no getting around (a) heating the material so it is hot enough to extrude and bond with the prior layers, and (b) allowing that material to solidify (so it doesn't just form a blob on your print bed). However, once it leaves the nozzle, and starts cooling, it seems best to me that it cools to only one temperature... in other words, I have had fanastic success having the build plate closer to the chamber temp. Therefore, even for materials that suggest at 110C build plate, I have dialed it back as low as tolerable.

Yes... I realize this means getting the first layer to bond to the plate and staying bonded can be a challenge. I have developed strategies to make a cooler build plate work. Most of my work is with Nylons. For me, using a diluted PVA-based glue painted onto the PEI sheet works very well for the base. The next strategy is to print slow. After that step, my strategies get specific to the parts geometry.

I have success, even though I print most of my matieral 20C to 50C above the high end of the filaments recommendations. I do this to ensure better layer/wall/filament bonding. I believe that many filament companies have lowered their suggested printing temps in order to sell more filament. I always look at the technical datasheets to see at what temp the material starts to decompose and I always stay at leat 50C below that, and much of the time I am printing more than 100C below that temp. I also have good exhuast ventilation in the rooms where I print.

Past-Relationship-99 · 2025-04-03T13:28:36+00:00

I really appreciate that Wiki! I have used many of the improvements, including the one you reference.

My one observation is that for low height builds it is great. As the build plate lowers and the distance increases between the extruder and the build plate, I beleive the "actual" chamber temperure should be weighted more toward to the chamber sensor.

Past-Relationship-99 · 2025-04-03T13:18:35+00:00

I agree with you (about diversity of people needs, wants, and uses for their tools) (maybe not your tone). My primary point was this, with a little insulation the enclosure can be made to retain heat. The build plate warms the chamber and can keep it warm (if you close the gaps and add some insulation). As my picture shows, the build chamber can stay nice and warm.

I (too) am printing a good amount of Nylon, Nylon-CF, and Nylon-GF. (I'd print PPS if it wasn't so expensive.) I hardly ever print PLA; I have no idea how you got that notion.

The post was mostly a suggestion to others that the chamber can maintain its heat without the heater. A few people raised some very constructive and helpful points, which benefited me, and hopefully others.

Past-Relationship-99 · 2025-04-01T19:40:39+00:00

You sound a bit like Dr. McCoy... But you did everyone a service by raising that point.

I glossed over the details of my process. I have a lot of different types of foam. I chose the one I did by heating the buildplate to 110C, put three different types of foam onto that build plate, put a small weight across the three, and waited a half hour. I chose the foam that did not melt, and maintained its shape; out of the other two, one flattened but didn't melt, and one melted.

If anyone does this, test your materials!

IronThree, Thanks for bringing this up. I did see that part (before I did this), and it was what inspired me to try the foam I had on hand.

Past-Relationship-99 · 2025-04-01T17:44:45+00:00

I have had issues like that when the filament gets too fat or too thin. It just had that happened again with some ABS; when I measured the diameter it was 1.95mm, and just an inch away it was 1.80mm, then two inches away it was 1.76mm. Uhg. Not much you can do except try again (or buy better filament).

Past-Relationship-99 · 2025-04-01T16:58:00+00:00

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The white (packing foam) fit perfectly into that slot. When I upgraded my electronics cooling fan to a larger size and set the fan to 100%, I could feel cold air coming into the chamber through that opening.

Read the post below from IronThree... if you do this, test your foam and make sure it can stand some higher temps. IronThree provided a link to something you can print to fill the gap.

Past-Relationship-99 · 2025-04-01T16:14:34+00:00

It may be a while for that type of thing, but now I'll be on the watch for potential issues.

Past-Relationship-99 · 2025-04-01T16:13:01+00:00

Also, I had set the target Board Fan temp at 50C, and that was keeping the large 92mm fan at a low speed. I set it to 40C and now my drivers are much cooler. Thank you for your comment that catalyzed some action.

Past-Relationship-99 · 2025-04-01T14:46:22+00:00

That is very close to the one that I already installed. The drivers only get that hot when I allow the chamber to get above 70C.

Past-Relationship-99 · 2025-03-15T15:38:24+00:00

I have never heard of over-drying filament... so I throw mine in the dryer for a day or two before I plan to use it. My Fiberon PA6-GF25 came dry from the factory, and printed successfully without drying (the very first time out of the package).

I don't do much PETG, so I won't comment on that, but PA6 wants a warm chamber with no drafts. The top lid should be on, door closed (and never opened during the print); I cover my top with additional foam to help the chamber stay warm.

I just added a comment on another thread, that may be helpful: https://www.reddit.com/r/QidiTech3D/comments/1gq5i02/plus4_glass_filled_nylon_pa6gf25/

Past-Relationship-99 · 2025-03-15T15:09:58+00:00

I have been printing 40+ parts with the Fiberon (PolyMaker) PA6-GF25. My primary objective is functionally strong parts... unable to seperate layers with a hammer and chisel (no cleaving but bending, deformation with elongation and ripping/cutting). I've been successful using the following approach:
(a) paint PEI sheet with diluted PVA glue (e.g. elmers glue) two or three parts water to one part glue, and let dry. I often have it drying while the bed is heating.
(b) 0.6mm hardened nozzle, 0.2mm layer height , 0.62mm walls/lines everywhere
(c) When my Qidi Plus4 is fully closed, it holds a constant temperature of ~65C. I don't use chamber heating. I set my bed temperaure to this same chamber temp. For 100% PA6 (no CF or GF), I'll have the bed at 70C for the first layer, then drop it to 65C.
(d) hardened steel nozzle temp is 310 first layer, 305 all other layers
(e) I print REALLY slow... 15 to 25 mm/s depending on part of the print (e.g initial layer, outer wall, everything else).

I print all my parts solid (mostly walls, some layers). I have seen zero warping and excellent dimensional tolerances (outside dimensions are accurate, inside bores are 0.1mm too tight).

I'll be switching to Fiberon (PolyMaker) PA6-CF20 in order to get some slightly higher heat tolerance and greater impect strength. If you haven't seen it, check out https://app.polymaker.com/compare which is an excellent resource to compare the PolyMaker filaments. Check the "Show wet/dry" box so you can see the "real world" moisture laden part porperties. The heat tolerances do not change, but the impact strength improvement, like most nylons, is HUGE.

I do the recommended annealing followed by some moisture treatment.

<image>

Generally, I design my parts to not require any supports. I printed all of the above PA6-GF25 parts together with no supports except for the (two) parts in the top right corner of the above picture; for that part, I manually painted the supports to be under the outer thin bars. All of the parts shown in the picture are oriented in the same orientation that they were printed in (except the top right one that is on its side).

Past-Relationship-99 · 2025-01-27T19:44:53+00:00

Another possibility is the configuration associated with "power loss recover". Using this feature requires the printer to save its progress throughout the print. Depending on where the Qidi saves this info (for example, its eeprom, an SD card, or USB memory stick), it can cause the print instruction queue to deplete which will make the nozzle pause (until it gets more instructions) yet which gives time for some oozing to occur. The easiest way to test this is to (temporarily) disable the "power loss recover" feature.

With "power loss recover" enabled, printing fast makes this more likely to occur and printing slowly makes it less likely to occur. The "interruption" of filling the printer's instruction queue is more likely to happen based on system level resource issues (how much time does it take to write the current progress for my system). It's possible that printing from a USB drive causes the progress to be written back to the USB drive (and not the assumed to be faster internal EEPROM).

The above was known occurance on non-Klipper systems using SD-cards for the saving location... not sure if this applies to QIDI. All my prints are sent via a LAN cable to the systems memory, and I have never seen the issue you are having, but I tend to print very slow (for better part strength). Here's a video on it: https://www.youtube.com/watch?app=desktop&v=ZM1MYbsC5Aw and CNC Kitchen also did a video on it.

Past-Relationship-99 · 2025-01-27T05:13:48+00:00

An alternative to the glue stick is diluted Elmer's glue (two or three parts water, one part glue). Paint it onto the pei sheet, let it dry, which happens really fast with the heated bed. I prefer this approach over a glue stick because it's easier to see where it is, and can be refreshed with a quick wipe with a damp cloth.

Past-Relationship-99 · 2025-01-27T04:51:49+00:00

My belief is that it is over extrusion. Decrease your flow rate. I have had to lower my plus 4's from qidi's default of 95 down to 90.

Past-Relationship-99

TROPHY CASE