Warm weather causing extruder clogs.

I just wondered if anyone else had ever noticed this. My Ender 3 pro was printing very nicely until it started getting hot every day. Now it starts out nicely when I unclog it and nip off the plastic blob and burn out the nozzle tip but if it is hot it will clog up eventually. I tried lowering the heat at the nozzle and that worked a bit but it always comes back.

I can’t say I’m having that problem. Where are you?

Montreal. It was printing so well when the weather was cooler but just gets “heat creep” when its hot inspite of two fans passing air over the machine.

It may not be the temperature. It is more likely the humidity. You need to try drying out your filament before your print. You can do this in a number of different ways. You can buy a filament dryer, use a food dehydrator, or very carefully use an oven at a very, very low temperature. You want the temperature to be well below the glass transition temperature of the filament. That is the temperature where the filament gets soft. So for most PLA an oven set to about 40c or 104F. Here is a good article about the subject on the All3DP website: https://all3dp.com/2/how-to-dry-fila…abs-and-nylon/

Actually I seem to be prooving that heat disturbs our modern electronics. I will test this later on my printer. The ambient temperature is about 92 F or 34 C according to my thermometer and I just started having trouble with my ancient macbook pro until I put a fan directly on it. I have a feeling that this is happening to my printer, I shall test it later and give you the results. I haven’t seen any bubbling or a sign that humidity is bothering my PLA. PLA doesn’t really suck in moisture like some other filaments. We will see. By tomorrow I will have tested all these theories. I’m waiting for a group family call on facebook from all over so my computer is my priority now. Thank you for your replies.

I am going to try drying the filament in my oven. I think the hot humid weather is the reason. Montreal is an island and it is humid in the summer. I shall keep you posted with my results.

I just ordered a food dehydrator from Amazon. The oven is too hard to dial in. This way I can dare to open my roll of PETG to try printing it. Somebody in the amazon reviews said it would hold 2 rolls and worked well for $55 canadian plus tax and free delivery. We’ll see. I certainly need to dry out this filament.

I’ll deffo be interested to know how the dehydrator turns out for you. PETG is next on my list to buy and try.

Which one did you order?

https://www.amazon.ca/gp/product/B00LNDYJ2I/ref=ppx_yo_dt_b_asin_image_o00_s00?ie=UTF8&psc=1 By the way after melting my thermometer in the oven I decided that the food dryer was the way to go. The more I think about my clogging problems the more I’m sure that Irv was right about moisture. Thanks Irv.


  • I'm wondering what the lowest temp is for your oven. Mine can go down as far as 170F, which was actually low enough to do some PLA, as a test, without melting it. Considering PLA needs 170C or more to melt, I guess I'm not surprised it didn't melt in the oven. Still, a dehydrator is probably a better option; .
  • That dehydrator sure gets some terrible reviews, almost all about cracking trays. Apparently, the plastic gets more and more brittle with use. However, I did find a post from a rep for Salton who said the manufacturer has switched to polypropylene for the trays and, supposedly, it doesn't get brittle after repeated heatings. I will be interested to here your impressions of it. [/LIST]
  • The point where the oven turns on was too hot for my thermometer so I don’t really know. The stove said it was under 150 F.

    I would think 150F should be safe for just about any filament.

    I didn’t even have it up to the 15- mark and it melted my thermometer. I don’t believe I can trust it.

    The point is the stove isn’t registering the right temp. Below their 150 F mark is actually hotter.
    I am experimenting with some alcohol to suck the water out of my filament while I wait for my dryer. I just started now so we will see if that helps.

    I think I have a brand new roll of filament with a moisture problem. My oven does not go below 170F and ovens are notorious for inaccurate temperatures. It is the glass transition temperature that is of concern when drying out a spool of filament. For PLA, I’ve read that you want to be around 40-45C (104-113F) for 4 to 6 hours. I’ve got the parts laying around for this home-made solution.


    While I am waiting for Amazon to bring me a food dryer to dry my filament with I tried spraying isopropyl alcohol on the roll. The same roll of filament that would clog my heating block in 5 minutes is now printing out a test print that seems to be working fine and it has been going for 1 hour and 18 minutes as I write this.

    Yahoo! The same roll of filament that was clogging my heater block every 5 minutes yesterday has now been nicely printing some kind of a test print for an hour and 25 minutes as I write this. All I did was spray isopropyl alcohol all over the plastic on the reel.

    Very interesting idea. I have those same parts lying around.

    Congratulations. That’s an innovative solution. As Darth Vader once said, “Impressive”.

    I’ve never heard of anyone else doing that I just had a brain fart. I wonder how that would work on really hygroscopic filaments like nylon? They say PETG is pretty bad too. I’ve never printed anything other than PLA. I spelled hygroscopic correctly but the spell checker said it was an error. I checked google and it agreed with me. It does the same with isopropyl which I also checked.