Anet A8 fan/extruder issue.

Hello all I'm having an odd issue with my Sain Smart Anet A8 and I'm hoping maybe someone here has encountered something like this and can help me out. Last Saturday I was printing a lighthouse from Thingiverse and about 60% of the way through I noticed that the extruder had stopped extruding several layers prior to where it was currently at. As you can imagine this was a bit aggravating, but clogged nozzles happen and that's what I figured was going on. Well fast forward to today and after trying about 100 different things in the past week I now know what is going on. I don't know how to fix it but I know what's actually happening.

If I print with no fan I obviously just get a big blob of filament, but the extruder continues to extrude. I have my Cura settings set to run the fan at 100% after the first layer, no fan on the first layer. If I leave cooling turned on the first layer goes down fine but as soon as the fan kicks on the extruder stops extruding filament. The hot end temp doesn't drop but the extruder stops extruding. Oddly enough it will still retract, but it won't feed any more filament. I know the nozzle isn't clogged because I can go and print a file where the fan is disabled and it extrudes fine. Also the first layer of a file with fan goes down fine, but as soon as the fan kicks on no more extrusion. I feel like this has to be an electronics glitch somewhere but I'm hoping it's software or firmware related rather than hardware and could be an easy fix. Thanks in advance for any help.

Also if it helps in anyway I'm using
Cura 3.3.1
195 hot end
205 first layer
60 bed
100% flow
100% fan after first layer
no fan on first layer

Update: The problem gets even stranger. I tried a print today with no fan and after about 3 layers I turned on a tiny desk fan on low near the printer. About 2 feet away. That air flow alone was enough to cause the print to fail. This doesn't make any sense considering until a week ago it printed fine with the fan on whatever Cura's default cooling setting is. 100% I believe.

Quote:

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Originally Posted by Kyle M.

I have my Cura settings set to run the fan at 100% after the first layer, no fan on the first layer.

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I have never used the Fan at 100% the maximum is about 50%.
Using a half Circle duct around the Nozzle,

Attachment 11531

I have designed a duct port to cool the throat using only Half of the Heat sink Below.

Attachment 11532

Quote:

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Originally Posted by Kyle M.

I feel like this has to be an electronics glitch somewhere but I'm hoping it's software or firmware related rather than hardware and could be an easy fix.
Thanks in advance for any help.

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I wonder if the fan is not adding more noise to the circuit causing the failure.
Try using 50% to see if that helps.

Does your printer have a restore to factory. On my 3D Printers need to Restore Factory Defaults when it acts goofy.
(This happens when I try different Slicers and they mess with my Defaults.)
M502 ; Restore Factory Defaults
M500 ; Store Settings.

Thanks. I've tried the fan as low as 25% with the same issue. I'm using a fully circular fan shroud off thingiverse. There's no restore factory defaults setting in my printers menu. There is a reset button on the main board but I think that that's more of an emergency stop. Can I just put M502 and M500 in a text file and run it on the printer or how do I do that? Maybe if I restore the defaults and set the max fan to 50% it will fix my problem. It's worth a try.

Are you printing using USB cable or the SD Card.

SD card should be a 2GB SD Card. A-Net A8 SD cards should be formatted to Fat 16 using SD Formatter.

"Was informed that in some cases the supplied A-Net A8 SD card was not compatible with the Controller."
Most of us have 2GB SD cards everywhere could not hurt to try a different SD Card formatted with SD Formatter.

I'm using a Samsung 16gb micro sd card that's been working fine. I never could get the included 8gb card to work right. It works in other devices but no matter how I format it the printer won't recognize it.

I'm getting closer but I'm still not there. I'm currently at 220 nozzle (Inland recommends 215-225) 60 bed and 40% fan. Trying to print a calicat as the first one I did when I got the printer came out perfect. I'm getting a lot of uneven spots on the overhanging parts of the tail. No matter what I do if I go over 50% fan I get total failure. Less than 215 requires 35% fan or lower.

Edit: I tried it several more times changing cooling fan % and extrusion % and I absolutely can't get a smooth overhang. I don't want to give up on this but at the same time I'm so frustrated I kind of want to give up on it. But I know if I can get this model to print as well as it did before I'll have everything dialed in.

Quote:

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Originally Posted by Kyle M.

Can I just put M502 and M500 in a text file and run it on the printer or how do I do that?

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This will work only if your firmware included code for the M500 commands.

Quote:

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Originally Posted by Kyle M.

I'm getting closer but I'm still not there. I'm currently at 220 nozzle (Inland recommends 215-225) 60 bed and 40% fan. Trying to print a calicat as the first one I did when I got the printer came out perfect. I'm getting a lot of uneven spots on the overhanging parts of the tail. No matter what I do if I go over 50% fan I get total failure. Less than 215 requires 35% fan or lower.

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Is it possible that the fan is somehow shorting to another wire some how causing the problems.

Quote:

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Originally Posted by Roberts_Clif

Is it possible that the fan is somehow shorting to another wire some how causing the problems.

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I suppose it's possible.

It seems that I've finally fixed it. The problem started right after I put a stainless steel nozzle in the printer so I bought some brass nozzles and it's been fine. The only thing I can figure is that the stainless nozzles had more threads and they stuck out of the heater block a bit more. I'm thinking maybe that extra few threads was just too far for heat to transfer reliably? I don't know if that makes sense but it's the only thing I've come up with. I realize different materials conduct heat differently but I've never noticed where anyone said they needed vastly different temps when chainging from brass to stainless steel nozzles. With brass I can run 195 with 100% fan, with my stainless nozzle that was too long I could barely run the fan even as hot as 230. When the current brass nozzle wears I'll try again but I'm going to cut the stainless steel nozzles down to the correct length first.

Quote:

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Originally Posted by Kyle M.

It seems that I've finally fixed it. The problem started right after I put a stainless steel nozzle in the printer so I bought some brass nozzles and it's been fine. The only thing I can figure is that the stainless nozzles had more threads and they stuck out of the heater block a bit more. I'm thinking maybe that extra few threads was just too far for heat to transfer reliably? I don't know if that makes sense but it's the only thing I've come up with. I realize different materials conduct heat differently but I've never noticed where anyone said they needed vastly different temps when chainging from brass to stainless steel nozzles. With brass I can run 195 with 100% fan, with my stainless nozzle that was too long I could barely run the fan even as hot as 230. When the current brass nozzle wears I'll try again but I'm going to cut the stainless steel nozzles down to the correct length first.

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Damn ;) AT least you solved your problem. I have had an almost similar experience. I purchased my Anet A8 second hand and was able to get good prints. I started getting adhesion problems and tried to learn what different settings did.
Anyway it all got a bit messy so I sat down to see what was wrong.

I managed to work out the printer will extrude when in the home position but not when printing. Anything over 185 means the filiment will just not feed.. So frustrating....but I dont hve a stainless steel nozzle in.

One thing I noticed is its fitted with a dual blow fan duct but that fan does not blow any more even though it tests out fine.....

Are you using circular saw? Did you try Cordless circular saw tool for wood cutting? I have this, the best cordless circular saw that works perfectly. You can also buy it after reading reviews.