QMB Ender 3 hot-end and part cooler

(old 2019 design imported from Thingiverse)

New nozzles uploaded for dual blower configuration

The nozzles with "2" in the name are better for the dual-blower configuration, as the original (smaller) ones are too restrictive and cause the blowers to stall. The smaller onesmay still be better for the single-blower configuration.

QMB ==Quiet,Modular,Blower-based Ender 3 hot-end and part cooler (if you have an idea of a catchier name, feel free to suggest it!)

Work in progress

I've only tested the single-blower version at this point, and it works great.

This was designed for the Ender 3. I don't know if it will fit an Ender 5 or a CR10 or not (I've heard parts are swappable, but don't have access to try). Please let me know the results if you test it on one!

I designed this with several things in mind: 1. Forced air through the hotend heatsink.

I'm amazed at how well the Ender 3 works with fans only blowingat the heatsink with no exit ductwork. I wanted to correct this and have air ductedto,through, andaway from the heatsink. 2. No spillage of air from the heatsink to the part.

This is important for when you don't want airflow on your part, such as when printing with materials that like to shrink. The air is forcedbehind the heatsink, through back-to-front and straight up and away. 3. Larger openings for the part cooler ducts.

Far too many coolers put a high restriction on the fans with very small duct nozzle openings, and fans typically do not flow well through restrictions. 4. Blowers instead of fans.

Fans are great at airflow. Blowers are much better at (an designed for) maintaining pressure through restrictions. 5. Low noise.

Axial fans with the intake facing forward producea lot of noise. They wereby far the noisiest parts of my printers.

I've found that 4020 and even 4010 blowers area lot quieter than 4010 fans, while moving more air through restrictions. The largest source of noise from blowers is theintake. I aimed the intake away from the room to help mitigate this. This is far from perfect, I believe a shroud can be attached to further quiet the intakes down (I may design one in the future), but at this point, the power supply and mainboard fans areby far the loudest part of my printer. 6. Airflow to the part with a place to go.

I've angled the airflow coming out of duct nozzles from both sides so the air flows across the extruder nozzle at an angle to the rear. This will draw in air from the front as well, pulling air across the tip of the extruder nozzle, where you want it. Many part coolers do this, but many simply blow straight at the nozzle from both sides, leaving a dead-zone in the middle with no airflow. 7. Swappable/adjustable/removable duct nozzles

I made the duct nozzles very simple for remixing in case anyone wants to experiment with different shapes, angles, opening sizes, etc. The two sides are mirror images of each-other, so you really only need to design one (you can mirror a part in cura with a mouse-click). The nozzles in the uploaded picture (of just two nozzles) are actually an earlier version, the uploaded model is an improvement on that. Printing variations on the design is quick and uses very little material.

You can trim the duct top (or simply slice it with it lowered slightly through the built plate) if you want it raised higher once pressed all the way in, or lower it easily just by pulling it down a little (it should fit snugly enough to hold, more on that in the Assembly section).

The duct nozzles can be removed if you're not using the part cooler while printing materials prone to shrink when cooled, providing even more visibility to your work. 8. Modular for different fan arrangements.

The back plate forms a duct for cooling the heatsink, and acts as a platform for the front plate which holds the part cooler fan(s) and ductwork. The front can easily be remixed for different blowers. I provided a model for a single 4020 blower and another for dual 4020 blowers for part-cooling. 9. Open view of the nozzle for remote viewing

I didn't want the part cooler making it difficult to see the nozzle from a camera. 10. Good clearance from the heat-block.

My favorite part cooler melted while printing at 280C recently (yes, with an all-metal insert in the hot-end) because it was too close to the heat-block.

The single-blower front housing has decent clearance, and the dual-blower front housing has a very open area shaped to allow convection up from the heat-block.

Note: I've notyet tried printing at 280C with this cooler! It should hold up, but I can't say for certain yet. 11. Access to service the bowden tube

Both front housings provide full access to the bowden tube fitting. The dual-blower front housing also has a full relief for the set-screw (grub-screw) holding the heatbreak into the heatsink.

Backplate octolapse: https://youtu.be/zC_PO1anxJs

Single-blower front housing octolapse: https://youtu.be/bAtzbjC3eqs

Dual-blower front housing octolapse: https://youtu.be/Z1cdWggT7Hg

Duct nozzle octolapse: https://youtu.be/qX8zVnqQ4UM

Large opening duct nozzles octolapse: https://youtu.be/KrtulF2xaNU

October 6th, 2019, 2pm:

Uploaded fixed version of dual-blower front housing (was missing attachment points for 2nd blower - d'oh!).

October 6th, 2019, 6pm:

Uploaded slightly improved version of the dual-blower front housing.

October 13, 2019, 9:40pm

Uploaded version 2 of the duct nozzles. These are far more open and a bit further away from the heater block. These are good for the dual blower version, as the smaller ducts nozzles restricted the blowers to the point of stalling.

Things I may change / possible improvements

As mentioned above, Imay create a shroud to quiet the fans even further. Right now they're quiet enough that I can't hear them over the obnoxious stock main-board fan or the power supply fan (upgrading those will come first).

Imay add a bit more clearance around the heatsink fins (but not at the top and bottom) to provide for a bit of air to bypass the fins (since they're so close together) allowing the 4010 blower to operate a bit more efficiently. It'll be interesting to see if it still cools as well (or better).

Imay put some finishing touches on the single-blower front housing that you can see on the dual-blower front housing. Aside from aesthetic tweaks, I may add a relief for accessing the set-screw (grub-screw) to the single-blower front housing.

Imay experiment with and upload some more duct nozzles. Those are easy to swap and very economical to print.

~~I have a Chinese all-metal hotend I've been thinking about trying. I will likely make a remix/variant of this that will work with that hotend.~~

I have uploaded remixed thing 3947323 that supports a Microswiss clone hotend.

Print Settings

Printer Brand:

Creality

Printer:

Ender 3

Rafts:

No

Supports:

No

Resolution:

0.16mm layer height

Infill:

15% grid

Filament: Any PETG

Notes:

Lay the back on its back to print, it won't need supports. You may need to dig a tiny bit of drooped material out of the holes for the M2 nuts. The end of a pair of hemostats worked well for me. The nuts should fit in very tightly, you don't want them coming out when you're working on the printer (eg: swapping the front during an upgrade).

The fronts both have a 0.16mm layer closing off the left and right ducts, 6mm up from the base. This is intentional to eliminate the need for support for a ledge on both side. This single layer trims out extremely easily with a pair of cutters or an exacto blade after printing.

You will need a small section of support under the very center of the dual-blower front housing. I enabled supports in Cura, "touching build plate only", set to 62 degrees, then used support blocker to block supports under the ducts. I also had

"Fan speed override" enabled with "Supported skin fan speed" set to 100%. The support removes easily if using 0.16mm layers.

The left and right ducts should print without supports with enough fan and low enough layer settings (don't go thicker than 0.16mm, 0.12mm or 0.08mm would be better), just make sure the rectangular flat is against the build plate (flip them over).

Start with the smaller (original) duct nozzles if you're using the single-blower front housing.

Start with the larger duct nozzles (with "2" in the name) if you're using the dual-blower front housing.

Post-Printing

Assembly

The instructions are the same for either front plate.

1. Insert M2 nuts into the 4 slots around the back plate. The one that goes into the corner goes in at a 45 degree angle, the rest go straight in from the sides.
2. Test fit your M2 screws to make sure they go cleanly through the holes into and through the nuts. Don't skip this step! The screws I had were very soft and the head-socket stripped out easily. If it only goes through the nut, but seems to bind afterwards, wiggle the screw side to side in every direction and try it again - this can help to align the nut with the hole.
3. Attach 4010 blower using M2 screws. No nuts are needed as the holes are 1.8mm diameter. Go slowly and the M2 screws will thread snugly into the plastic. The blower will fit snugly, you may need to gently squeeze it at the corners (not the middle!) to seat it fully in place (there should be no gap between the flange and the back plate).
4. Remove the two screws holding your hot-end heatsink in place.
5. Slide the back plate over the posts previously holding your heatsink.
6. Insert M3 screws (stock should work, 2mm longer than stock will work better) through the holes into the stock locations for the backplate.
7. Reattach the heatsink using the same screws with which it was previously attached.
8. If you're assembling the dual-blower version, attach the right-side blower with M3 screws. They should form threads into the plastic as you screw them in, as the holes are 2.8mm.

9.Carefully insert the hot-end wires through the slot in the back of the front housing (those wires are fragile at their attachment points). Start higher where the wires are more flexible and can be separated, then slide it down in place. If you're having trouble fishing them through, don't force them, reverse this step and the previous one, attaching the fan after fishing the wires (it will be a little more awkward, but shouldn't be too difficult). 10. After making sure there is no strain on the wires, insert 4 M2 screws through the front housing into the nuts you previously inserted into the back plate. 11. Mount the 4020 blower(s) with M3 screws into the front plate. These should thread into the plastic and hold firmly and the blower should line up perfectly with the opening(s). 12. Wire up/plug in your fans. 13. The duct nozzles will fit snugly if your printer is properly dialed in. Don't get too frustrated, it takes me a few tries to get them lined up properly, but when they do, they pop right in and hold firmly. In case yours is a bit loose, there are two 1.8mm diameter holes (one on each side) of the front end piece for an M2 screw. The screw should form its own thread going into the plastic and fit tightly enough not to need a nut.

Tip: I've slowed down my heatsink (4010) blower by using a voltage converter. A small adjustment makes a big difference in sound with a small difference in airflow through the heatsink. I used this one: https://www.amazon.com/gp/product/B01N2QBSVE

How I Designed This

I used FreeCAD on Linux (with a SpaceBall 5000 USB) to design this.

I loaded Creality's model of the Ender 3 (on their github page), hid all of the parts not directly relevant to this design, leaving the gantry plate, screws, and hotend visible, exported the remaining parts as STEP, then imported them into a new assembly and designed around that, creating a new body for each part.

Kudos to Creality for publishing the 3D models for the Ender 3. I hope they do the same for their other printers.

Tip o' the hat to the FreeCAD developers - they've created an incredible piece of software.

If you tried it before and had trouble with it, try 0.18, it's a great improvement.

Thanks to 3dconnexion for refusing to provide drivers for Windows 10 for the SpaceBall product line. So many hit ebay at the same time from businesses that could no longer use them, they're quite affordable now for us Linux users.

Category: 3D Printer Parts