get a cheap lab oven off Amazon, assuming you’re willing to spend a little extra than the chintzy consumer grade dryers that are out there. This is what we have: https://a.co/d/1XydKDo $330, and it’ll hold 80C all day long.
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PrintDry v3 claims it can go to 85C. I find that it lags though. With insulation you can probably get it to 80C.
The lab oven cited above by Marshal appears to have a built-in PID and overall sounds like more of a certainty that you’ll get what you’re after. In that case the only advantage the Printdry might have is being able to feed the dry filament directly into your 3d printer from within the heated enclosure.
My Sunlu S2 (no fan) did the job just fine didn’t even require the full time required by the BBL suggestions.
That was the PAHT CF, I haven’t printed my PA6 CF yet, but I don’t expect that to be an issue either.
However, both PA’s will suck up moisture very quickly, more so the PA6-CF as its saturation rate is 5.5x that of PLA, and 2.6x for the PAHT CF. This is important, because printing from the spool holder is an issue, especially in humid environments.
Have you set your Sunlus up for printing from them?
No, I just use them for drying. It’s got to be in the AMS because I’m using multi filament supports.
The S2 got it down to 15% (self reported) so I’m running a test part now to see if that’s low enough. TBD
I ask because the PA6 CF is too abrasive and/or brittle for the AMS (at least to use reliably). So keep an eye on that.
It is just talking about the humidity in the air in the unit, not the filament. The best thing is to weigh it and monitor until it stops losing weight.
Here is a spool holder you can put in the filadryer.
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70C will still work however the Sunlu S2 dryer is a closed system so the moisture that is pulled from the filament will saturate the air inside which in turn will increase it’s dewpoint and with that being unable to pull more moisture from the filament. Same will go for Lab ovens,…etc. with a closed internal air circulation systems so effectiveness is far less than systems the circulate the air over external desiccant which keeps the dewpoint of the dryer air low.
This is largely true, but I would imagine the version the OP has, w/fans, will evacuate the air and help alleviate that problem. However, if its just a circulator fan, Panamon is correct.
For mine, w/no fan, I printed a spacer to help evacuate the humid air, and find it works very well.
I have a buddy that prints a ton of PA6 in his AMS and yes, after 6mo of constant service it wore out several items.
Still, if I can get PA6 to run reliably and have to repair the AMS once every six mo, that’s a win in my book.
The PAHT is another option, but according to BL’s specs, it’s not as strong in Z as PA6 which is a definite con for that option.
Interesting mod, but my Sunlu spins pretty freely. I only added a simple PTFE tube through the hole (whichever of the two holes you plan to use) and that really helps to keep brittle filaments from breaking. IMO, the filament path and the non-evacuation of the humid air are the only two issues with this dryer. Both easily mod’ed to be non-factors.
The BBL wiki specifically recommends a forced air blast oven:
https://wiki.bambulab.com/en/filament-acc/filament/dry-filament
At least some of them do allow for an exchange of air:
Wouldn’t that normally be the case for an oven which is meant to dry things?
I think the mod prevents issues when you get close to the end of the spool and it gets light.
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No complaints there.
If you have some, give it a try. IMO, it has many more advantages over the PA6 CF, although the PA6 is going to be the strongest (in the absence of moisture/humidity). For me, the moisture thing is PA6 CF’s biggest downside (even after printing). Just about all PA’s go mushy when they soak up too much moisture. PA12 or BBL’s PAHT have the added advantage of only having the molecular space to bond with a little bit of moisture, vs PA6’s which have the much more space to take in a lot more moisture (greater potential molecules that are available to bond to moisture). I forget the chemical make up, but the 6 and 12 refer to the carbon chains and they determine how much moisture the chain can take. I think Polymaker had a really good video on how the chemistry works and its easy to understand, but apparently hard to remember 
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@marshal We are fortunate to have you among us, since you own the very blast oven you are recommending. Does it or does it not trap moisture inside it in the way that Panamon_Creel conjectures above? If it will do the job properly, the price sounds pretty good to me.
not that I’ve noticed, it has a vent out the top to let the moisture out.
I don’t have any instruments to check for moisture, but it certainly worked for drying some NylonX spools I had. Before the oven, it was super stringy and would hardly print. Threw it in there overnight, and it printed like a dream.
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Both of my Filadryer S2 dryers are the version with the fan. I have never had any visible moisture inside and I keep it closed without any mods. I think it was mostly an issue for the non-fan version.
The moisture is too little to see visible signs. The give away for me is how much the humidity reading changes with a small venting of the unit (opening it up). For example, I find if it is shut, it takes a very long time to dry filament out. However, if I open it up a few time times an hour it dries significantly faster. To address this, I printed a spacer that props the lid open by 4mms. Its enough to vent air out, but small enough for the heater to manage the overall temps. Not perfect, but its effective.
For you, I would simply check if the inside of the unit vents air out in any significant way. If it doesn’t, like Panamon says you are trapping moisture in the unit with the filament. I also dry with the desiccant in the dryer to aid with giving the evacuated moisture somewhere to go. But note, that’s only a quarter measure, as that will dry out and send the moisture right back in to the unit.
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I’ll have to test that out to see the difference it makes.
I finished the print yesterday with the PAHT-CF. It was fresh out of the bag, no drying.
The surfaces that were not overhangs looked beautiful, but the overhangs were blotchy and look bad.
I took the PAHT out of the AMS and put it in the S2 at 70°C overnight w/ a 4mm screw propping the lid open a smidge. It was reading 14% this morning and I popped it back in the AMS and am re-running the part.
I’m running on .08 High quality and the overhang angle (15°) is not generating any supports on the blades. If I crank it up to 45° it’ll generate supports in all the bad areas, but absolutely kills the print time.
When I used to print on an Ender w/ Cura there was a setting in there to print overhangs from the inside to the outside. Is there a setting like this in Bambu?
Or do you think it’s just wet material? I guess I’ll know for sure in 5hrs…
I could see it was curling up on that back edge so I stopped the print.
I had ‘wall loops’ set to 6 and am theorizing that this is problematic for these overhangs. Set it to 1 and am re-running.
I also notice that NONE of the fans are running. Shouldn’t the part fan at least be on?