Check back later and I’ll tell you how I made a Hex fillament dryer hit 90c chamber temps complete with an app to control it and network access. Fully utilizing that ESP32 in it now.
I’m starting to think it may be easier to hit the target temps by building a simple DIY filament dryer from scatch, similar in type to:
As long as it doesn’t get so hot that it melts the enclosure, it seems that you can keep raising the temperature limit, as he already demonstrates, by just adding more heating elements, or else possibly driving them at a higher voltage.
There’s a lot of space in the box that he demonstrates. Ideally I could use the same or similar box to anneal a PET-CF print after printing it. I just need to ensure that I use an enclosure that won’t melt or deform at 120C.
Edit: Rummaging around, I see that I have a gasket box that looks very similar if not the same as the youtubers. According to its plastic recycling code (number 5), it is made from polypropylene. According to google,
“Polypropylene fibers have a softening point in the region of 150°C and a melting point at 160-170°C.”
So, not much headroom, but assuming the googled information is correct, it could in theory work as a filament dryer/annealer , even up to 120C without deforming or melting.
Some serious tinkering here, much respect! The furthest I got was sticking a pair of pliers over the rollers and balancing the roll on top to get extra distance from the heating element.
I noticed in both your modifications you completely covered it, isn’t it advised the dryer has good airflow to expel the moisture as it drys?
@NeverDie something like that maybe the way to go. My Cyclops drier isn’t handy to take pics, but it’s so basic, I’m no expert but it’s a heating element and fan, with a some sort of temp cut-off. Honestly, the price these things go for seem excessive for what they are. A basic fan heater that costs a few quid is probably more complex.
I’ve got half a roll of Bambu PAHT-CF that’s been laying around for months (humid UK), at some point I’ll get it back in the drier to see if it works. From my limited experience, guidance temps fo drying are just guidance. I got way too hung up on this. Just leave it for longer than advised if at a lower temp. Again my experience is limited, and I’ve only really dried PAHT-CF, which in some ways maybe easier as it has a higher temp before it goes soft.
Yeah I got sick of manufacturings flat out lie about things. Set up buying every single filling it dryer on the market testing every single one of them and then seeing what it takes to see if It can actually hit the claimed temperatures.
There’s a lot of deceptive practices going on with these dryers. For example the fixed dry dual use a DTH11 for the only purpose of being able to make an offset. It’s actually only a 50C dryer at best. That’s insulated at full power. But what they did they put a 20C offset and the temperature with a curve so at room temperature it appears to be working correctly but then starts ramping up over time. For example I use the temperature forcing unit to force it to 0c I actually have the temperature sensor I actually have the DTH11 out and lowest I would measure was 20C. It is not just them there’s a lot of deceptive practices like this. And most of these units are extremely unsafe. The fixed dry dual is safe and built well They just lie about the specs on it and try to deceive the end user. But They at least used right materials and right place where Eibos Yes I absolute cheapest ABS they can find and then expect it to hold up the heat of 140-170c .
I’m using the new Eibos dryer to try and dry out the PET-CF, however the PET-CF drying instructions on the product page say to dry at 80 degrees C 8-12 hrs. On the box sent to me, the drying instructions say to dry at 60 degrees C 8-12 hrs. Huge difference!! What are the best settings to dry this filament? The box also says temp resistance of the spool is only 70 degrees C. But the spool itself says its resistance to 90 degrees C. Why are none of these consistent??
From my experience, the vast majority of consumer filament dryers are badly designed toys that lie extensively about their capabilities. They’re junk and not worth your money - even if you only print toy filaments.
Of all the options (and sadly I wasted money on multiple) it appears that the Sunlu S4 is the only one worth buying (maybe). Crazily Sunlu only needed like 5 attempts to make a not-entirely-rubbish dryer. Sadly Eibos still haven’t worked out that a circulation fan in the chamber is significantly better than an auto spool spinning motor.
If you’ve stayed current with MyTechFun you’ll know that at max 70°C, the Sunlu S4 will need at least 4 DAYS to properly dry nylon.
For my money, a prosumer food dehydrator marketed as a “Biltong” dryer is a vastly superior option and worth every dollar over a toy. PET/PA/PAHT-CF print like an absolute dream when they’re properly dehydrated with a day at 85°C.
The better toy dryers are only good as preventers to hot-feed filament after it’s been dried.
Yup, I’ve since realized that’s exactly what they mean. Heating air will drop its relative humidity, but it has no effect on the dew point. For reference sake, air which has a dew point of -40c would have a relative humidity of 0.80% at 20C room temperature. So, almost certainly the make-up air that you’re feeding into your filament dryer is already too moist compared to spec. Even a refrigeration type dehumidifier won’t get the air dry enough. What you need is a desiccant enhanced compressor based air dryer to generate the air that gets blasted onto the filament at its specified temperature. Maybe with a mountain of desiccant you could do it with desiccant alone, but the dwell times for desiccants are long, so most likely that’s going to require an impractical amount of desiccant. You need the full package, like is being discussed on this other thread by @IslandBill and others: How are people keeping their filament dry? - #172 by NeverDie
