View Full Version : Extruder too hot?

11-21-2017, 07:21 PM
Has anyone else noticed the extruder getting very warm or hot, when printing at 70 nanometers?

I am getting print failure with stock filament, Hatchbox, eSun, and Makerbot PLA filament that does not clog at the nozzle?

For Hatchbox it is actually plugged up at the base of the feed tube next to the extruder. For the others the filament was ground down as if the nozzle would be blocked, but it was not blocked. So perhaps severe friction in the feed tube with the slight expansion of filament due to heat...?


It seems to me that in-order to get Cube3 reliable to print at 70 nanometers, woudl require a new extruder hub with bowden tubes. Essentially replacing the stock tubes...?

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I will say the Cube 3 prints perfectly at 70NM, would be nice to find a reliable solution. My other printers, so far, don't print as smoothly at 70nm, but then they also don't constantly fail to extrude.



11-21-2017, 07:51 PM
No one wants to pay attention to this but it is real. Your Bowden tube is likely the culprit.

The drive motor should not get hot in the least. I have replaced the fan for the drive motor, but that was because it was noisy and you could hear the bearing struggling until it started to spin freely.

I have Bowden tubes from many suppliers and only one is working flawlessly.

The problem is that the filament flattens out. If the print requires a lot of "pumping" of the filament, it gets flatter and flatter. This is what is restricted in the Bowden tube!
Some prints, you never see a problem because it doesn't flatten much, and then some prints, like Diamond Fill or a lot of pull-backs really tests this phenomena.

The only other thing that works the motors more than others is the filament hardness. I have made one driver with a very small v-groove in the drive gear. This reduces the amount of "squish" required to drive the filament. You do want to maintain the sharp edges at the v-groove if you go this route.

But first, take a piece of well-cycled filament from the Bowden tube and see if there is -any- restriction in feeding it through your Bowden tube.
I learned this early when looking for the best tubing. I have meters and meters of failed tubing. I have purchased the same tubing from the same Chinese eBay supplier 4 times now and every order has worked perfectly. the latest Amazon tube I bought from a 3D printing supplier fails miserably.

I know this will draw an argument from others, but I think I know what I am doing. Clogs are not something I am dealing with, and this is after many kilograms of many filaments from many different manufacturers.

And as an aside, printing the test print is a better measure of filament suitability that purge. Purge seems to created "clicks" (as in filament stripping) more than a true print. Not sure why but I suspect it is less managed by feed speed and/or temperature.

Let the flaming begin! ... but I stand by this and I have enough proof for myself.

11-21-2017, 09:16 PM
Thanks for the response.

I wonder if there is a way to print part that would improve the air-flow from the drive fan?

Yeh, I have a lot of shitty bowden tubing as well (from Aliexpress...), but most works without blockage with my AM8 w "Chinese" Titan and V6. Do you have a link to the supplier you trust? I am tempted to buy some Capricorn tubing from E3D just to end the pain.

Of course, the other issue is all the labor it takes just to change damn filament! I guess I am going to try your hub next.

Is the one of Thingverse yours (nice work!)? Or should I be using KISS cart?


To me is seems like the cube 3 is a great design( linear rails, good belts...), but 3DS tried to be too clever with the filament feed....

11-21-2017, 09:43 PM
We should talk. And I should put a video together. There are a few caveats to consider on the best solution.

11-21-2017, 10:12 PM
We now feature the Capricorn in our e-store too ;)

And I may add a complete printed HUB+HTNozzle+Capricorn for anyone interestred!

11-22-2017, 12:19 AM
Thank you both for your time and effort

What do you need from me? I have two cubes (plus AM8 and Taz 5) + a bunch of reels. I think I will take a stab at the upgrade over thanksgiving with what I have on hand aka, tube, couplers, printed files, lots of power tools, dremel...)

If the motor is "stock" then replacing with a alternative hob gear with a groove such as a E3D HobbGoblin might be possible? http://www.instructables.com/id/Extruder-Drive-Gear-Shootout/ If the motor is "stock" then the mounting hole might be standard to, and a alternative metal extruder assembly can be bolted in place using longer bolts and the existing motor mount holes?

A few options on Aliexpress:


https://www.aliexpress.com/item/Free-Shipping-MK8-extruder-aluminum-block-DIY-kit-Makerbot-dedicated-single-nozzle-extrusion-head-aluminum-block/32351220044.html?spm=2114.search0104.3.98.tRinUX&ws_ab_test=searchweb0_0,searchweb201602_2_10152_10 065_10151_10344_10068_10130_10345_10324_10342_1054 7_10325_10343_10546_10340_10341_10548_10545_10541_ 10562_10084_10083_10307_10178_10539_10312_10059_10 313_10314_10534_10533_100031_10103_10073_10594_105 57_10558_10596_10595_10142_10107,searchweb201603_2 5,ppcSwitch_5&btsid=2de18401-4987-416c-9638-2871398165bb&algo_expid=aa0cbad1-ae3f-466f-a768-e5e5c64160c5-12&algo_pvid=aa0cbad1-ae3f-466f-a768-e5e5c64160c5&rmStoreLevelAB=0

https://www.aliexpress.com/item/Stainless-Steel-MK10-2X-Remote-Direct-Extruder-Part-For-Makerbot-Extrusion-1-75mm-Right-Left-Full/32825639886.html?spm=2114.search0104.3.9.rOgWNx&ws_ab_test=searchweb0_0,searchweb201602_2_10152_10 065_10151_10344_10068_10130_10345_10324_10342_1054 7_10325_10343_10546_10340_10341_10548_10545_10541_ 10562_10084_10083_10307_10178_10539_10312_10059_10 313_10314_10534_10533_100031_10103_10073_10594_105 57_10558_10596_10595_10142_10107,searchweb201603_2 5,ppcSwitch_5&btsid=82dc4bf9-d56f-45c4-9278-01eca2077af5&algo_expid=e30b65f8-c599-49ce-ad5a-a3f21df2dbc4-0&algo_pvid=e30b65f8-c599-49ce-ad5a-a3f21df2dbc4&rmStoreLevelAB=0

Changta (w built-in bowden couplers)

https://www.aliexpress.com/item/CHANGTA-for-3D-Printer-parts-DIY-Reprap-Bulldog-All-metal-Extruder-For-1-75mm-Compatible-J/32810237667.html?spm=2114.search0104.3.7.rOgWNx&ws_ab_test=searchweb0_0,searchweb201602_2_10152_10 065_10151_10344_10068_10130_10345_10324_10342_1054 7_10325_10343_10546_10340_10341_10548_10545_10541_ 10562_10084_10083_10307_10178_10539_10312_10059_10 313_10314_10534_10533_100031_10103_10073_10594_105 57_10558_10596_10595_10142_10107,searchweb201603_2 5,ppcSwitch_5&btsid=82dc4bf9-d56f-45c4-9278-01eca2077af5&algo_expid=32e3b41d-3be6-4eeb-8f69-20c8d9b9104a-0&algo_pvid=32e3b41d-3be6-4eeb-8f69-20c8d9b9104a&rmStoreLevelAB=0

FYI searching "DIY Reprap Bulldog " produces more results..

Ultimately, it might be simply what bolsoncerrado offers as a "kit" might benefit the most people?

I am comfortable making parts and separate sourcing as well.

Or maybe simply and "instructable" or "thingverse" step by step guide?

just thinking...

11-22-2017, 03:32 AM
We now feature the Capricorn in our e-store too ;)

And I may add a complete printed HUB+HTNozzle+Capricorn for anyone interestred!


If you need me to test the TL series tubing, I'd be happy to :)

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Zugok, I have a couple of alternatives options depending on what you want to do for spool management.
I've disconnected the spool-holder from the hub itself to.
I also have a simpler hub if you want to tap the driver with an M5 thread (highly recommended solution).
I try not to overstuff Thingiverse until I am perfectly happy with the results. Here, you guys tend to understand limitations.

I have only run into a few filaments that require the groove... a hard silver one; a glow in the dark one; and a strange white one.
2 of 3 of these went back to the supplier as the PLA temperature range was also less than optimal.

The v-groove I cut in the drive gear is such a small depth that it seems barely effective. But it is! I really wanted to use up that silver color.

I see no reason to mess with adapting another filament driver but knock yourself out. Always good to experiment with something new.

11-22-2017, 06:44 AM
Thank you TD.

I am printing out Megalodon's Cube3 hotend drill guide on my Anet A8/AM8 as the first step.

Any chance of getting STL for the simpler hub?

I am printing them on my Anet (AM8) as it is set up to print ABS, and my cube (besides the failures), I have not tried ABS on it yet. My AM8 has a glass heated bed with a PEI surface so it works awesome w ABS, no glue, tape, slurry, or magic chicken sauce...just 1mm glossy PEI.

Now to find spare couplers....


11-22-2017, 07:26 AM
I can give you the BFB file now that I can decode it easily...

The chip carriers (https://drive.google.com/open?id=0By-9ThR4U7GkdldyZEpreW1yTFU)are here on the forum somewhere as STL (https://drive.google.com/file/d/0By-9ThR4U7GkV2J2NHhGT2tuTW8/view?usp=sharing)... and so is the remote spool holder (http://www.print3dforum.com/showthread.php/1005-Cube-3-Extruder-HUB-KISS-Method-(DiY-version-by-TommyDee)?p=42881&viewfull=1#post42881)...


Btw: if you have some CAD experience, I've learned how to reverse engineer the .bfb files.
Most CAD packages will let you import point sets as a connected curve.
This challenge, to reverse engineer a .cube3 file, is still out there.
Once that code is cracked, I will give consideration to releasing the STLs.

12-04-2017, 05:15 AM
Awesome thank you! I might get the Cap tubing, depending upon my next sets of tests.

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In between cooking and eating turkey, buying 3d printing stuff on "sale", playing Ice Hockey at my local rink, printing out Cube Print head drill guides, and reading...

I like the simplicity of directly threading the pneumatic coupler to the metal extruder, less chances of filament path “edges” near the extruder, as it gets hot and can cause the filament to expand enough to jam right there. The extruder already flattens the filament a bit anyway…

Looking at the various solutions for feeding the filament at the print head.

A: Drilling into the top and telescoping the regular Bowden tube to the 3DS tubing. IMHO, this is bound to fail. Adding a pneumatic fitting to hold the bowden in-place helps a lot. However the constriction + transitional edge when the tubes come together does not seem helpful considering the filament is likely squashed out of round, and has tick marks on the side from the extruder. Fuganater confirms the slight in his youtube video.

B. Don’s fully printed new nozzle housing. Might be tricky to print, and there seems to be 2 filament transitional edges. First the bowden/pneumatic path, second the pneumatic/3DS tubing transition. IMHO, the advantage over option “A” is less potential of constricted filament path.

C. Finding a m3 pneumatic connector that attaches directly to the 3DS metal print nozzle. Something that threads directly into the end.

Not found yet, maybe an air pneumatic fitting… https://www.aliexpress.com/item/GOGO-10pcs-a-lot-high-quality-mini-type-fittings-PC-C-POC-C-PL-C-4mm/32814345399.html?spm=a2g0s.13010208.99999999.284.H tBMVk

Solution “B” Don's printed head enclosure is the way I will proceed for now. Big thanks to Don for providing STL’s

Progress on the Hub:

I want to print the new filament hub using ABS, I have no ABS chips (yet) so I cannot print on my cube.

I have no way of converting a ".cube or bfb file into STL that I can print it out on another printer. I looked around and only found that MAYBE converting .bfb. to Gcode then importing into Blender. Way too messy.

My 3d software experience deals almost exclusively w Maya, Modo, Max, Brush, Lightwave etc…I have only touched CAD once or twice.

Rather than try and copy what TD created, I will simply create one myself. I was hoping I would not have to but now I will. I have a ruler, calipers, tools and can easily design my own 3D files.

I am confident I can make something and then post the STL files for others to use. Might not be perfect, but my goal is a solution consisting of "off the shelf bits" and STL files. No point in keep a formally closed system...closed.

I am grateful for all the excellent feedback and work that has already been done.

Thanks, so far, to Tommy, bolsoncerro, Don, Shane, and several others....

PS: Shane should have given specific credit to the mod ether in his video or in the notes.

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I finally had time to work on the hubcap.

For now, all I have done is made a part that fits onto Cube3 to hold the metal extruder parts in-place, almost a copy of the existing 3DS filament spool housing, now I have a STL to base a mod onto.

I made the hub in Modo using mesh fusion, printed on my Anet AM8 in PLA, it fits nearly perfectly, almost "snapping" into place.

I really like the simple design that Tommy has, so I am inspired by it. :-)


PS: Is there someone in the group in Calgary?

12-04-2017, 09:12 AM
But how do you keep it in place? Just diametral pressure?

12-04-2017, 05:41 PM
You'd be surprised how little it takes to hold it in place when properly aligned.

12-04-2017, 06:35 PM
Yes to both.


This is only the base, I will add a clip/clamp to keep it in place.