My first Nylon fail!

[cope413]

It was a good one... I think it was caused by a tangle in the spool that caused belt skips but then released and kept printing...

Looked pretty fun when I came in this morning.

Not really even that mad

[edward]

Nice! I just received my spool of that same trimmerline and have been trying to figure the best setup since it is so large.

I'm thinking that it might require an off-machine spool holder...

[cope413]

I made mine...

[cope413]

Also, dry it, dry it, dry it!

I went a little overkill with my dryer box, but I had fun with it...

5 gallon bucket with a gamma seal lid. Got my hands on a super mist separator and a heated compressed air coupler. Hooked it up to a PID with a thermocouple. PTC inlet into the bucket, 1 way valve out of the bucket that releases at about 20psi.

A bed of about 1 inch of rechargeable desiccant at the bottom of the bucket. Spool of nylon sits on the desiccant.

Set the thermocouple to 200F for the alarm, and I pump the ultra dry, hot air into the bucket for an hour or 2.

If anyone knows of a more awesome way to dry filament, I'm all ears

[lordbinky]

If anyone knows of a more awesome way to dry filament, I'm all ears

Is that where this is going? Very well sir. I will return.

[Eaglezsoar]

Also, dry it, dry it, dry it!

I went a little overkill with my dryer box, but I had fun with it...

5 gallon bucket with a gamma seal lid. Got my hands on a super mist separator and a heated compressed air coupler. Hooked it up to a PID with a thermocouple. PTC inlet into the bucket, 1 way valve out of the bucket that releases at about 20psi.

A bed of about 1 inch of rechargeable desiccant at the bottom of the bucket. Spool of nylon sits on the desiccant.

Set the thermocouple to 200F for the alarm, and I pump the ultra dry, hot air into the bucket for an hour or 2.

If anyone knows of a more awesome way to dry filament, I'm all ears

Any source for the 5 gallon bucket with the Gamma seal lid? I've never seen those before.
What about air leaks where the handle penetrates the bucket?

[cope413]

Home depot -

http://www.homedepot.com/p/Leaktite-5-G ... kSK4YYm18E

Handle doesn't go into the bucket, it's got a molded block on the outside that the handle pops into.

I don't want to experiment past 20psi - no need. Filament dries really fast

[cope413]

Oh and I jb welded all the inlets that I installed. Pretty much the most awesome 5 gallon bucket I've ever seen.

I told my wife that I was spending last weekend on my drying chamber... she walked out to the garage after about 5 hours and said, "I thought you said you were working on a drying chamber. That looks like a bucket. What are you doing?"

[cope413]

Had to adjust my pressure down to 12psi...

It lasted a few sessions at 20, but eventually the lid popped off - couldn't handle the pressure. Had to replace it because it bent the tabs on the lid and it won't seal well anymore.


A couple observations from my drying trials...

1) While it may take 18 hours to fully saturate with moisture, 3-4 hours in 40-50% humidity is enough to negatively affect print quality

2) Well dried filament is smaller (duh) than wet filament - I had to adjust my flow rate up a bit to correct for it.


I'm in love with this nylon. It's awesome stuff.

[Eaglezsoar]

Had to adjust my pressure down to 12psi...

It lasted a few sessions at 20, but eventually the lid popped off - couldn't handle the pressure. Had to replace it because it bent the tabs on the lid and it won't seal well anymore.


A couple observations from my drying trials...

1) While it may take 18 hours to fully saturate with moisture, 3-4 hours in 40-50% humidity is enough to negatively affect print quality

2) Well dried filament is smaller (duh) than wet filament - I had to adjust my flow rate up a bit to correct for it.


I'm in love with this nylon. It's awesome stuff.

Could you elaborate on the bucket you made that had the light bulb in it?
I am interested in the bulb wattage and placement, how long it takes to dry the filament.
Did you use the fancy lid with the bulb version and what is a good source of the bulk desiccant and how
you recharged the desiccant. Pain in the you know what aren't I?
I apologize if you already covered this in one of your threads and I missed it.

[cope413]

Sure...

I got a simple bulb socket like this one http://www.homedepot.com/p/Westinghouse ... koMOoYm18E (mine was much older - salvaged from something long ago - but you get the idea)

I mounted it in a 3/4" PVC elbow with RTV silicone. I just filled it with as much silicone as needed to seal it. Then I used hot pipe glue to mount the elbow in the bucket. I did this so that I could point the bulb up or down in the bucket, rather than straight out where it could easily get hit by a spool coming in or out of the bucket.

I mounted it about 3" from the bottom of the lid, and angled mine down so the bulb is just above the center line of the bucket.

Before I got the compressed air moving through it, I was using a 40w bulb but it got too hot - I started to melt one of the spools in the bucket after about 2 hours. I dropped down to a 25w and that seemed to be good. I left it on for about 6 hours and there was no concern about melting anything unless it was directly touching the bulb.

I didn't want to mount the bulb in the lid for a couple of reasons...

1) the gamma seal lids are very handy for many uses and I didn't want to ruin one for no need
2) heat rises - didn't want the bulb to be at the top of the bucket
3) I don't like rotating anything with wires - the lid spins - so didn't want to deal with that


As for the desiccant, I had a half dozen of these guys from my days living on a floating house http://www.amazon.com/Hydrosorbent-Sili ... +desiccant

They're great. 1 would do the trick in a bucket, but I wasn't using them for anything else, so I went overkill.

Recharging is as simple as baking them in your oven for a few hours. 225F does the trick for me.

They change color when they're full of moisture, and go back to white when they're dry. No guesswork needed.

Just an aside - A 10lb bag of rice will set you back about $5 - works every bit as well as desiccant in this application - and can be recharged the same way, or just tossed and replaced.

If you're just using it for filament and you don't leave it out, it'll take you years to saturate the desiccant.

I'm still experimenting with drying, but if you had saturated filament and dropped it in the bucket, I would guess it would take you about 24 hours to fully dry it.

With the heated compressed air, it takes about 30-40 minutes - max.

[edward]

Here's my favorite question again: What print speeds are you using?

After a long dry in the oven this weekend I managed a few parts with this stuff today. From what I've read about Nylons I needed to decrease my speeds (vs those used for ABS), but since you seem to have been using this quite a bit, I'm curious what you're set at.

It didn't seem to like going much over 80 mm/s for me.

[Eaglezsoar]

Thanks for the great writeup about how you did the bulb in a bucket filament dryer. Sounds like one of my next projects.
I know the compressed air one works better but would be cost prohibitive for me at this time. Thanks for the links for the
needed materials. You are one great person to have on this forum.

[cope413]

Yeah, speeds are a little different. I'm still learning, but 80 is about the max I can get for perimeters.

I've noticed that bigger layer heights still give you good resolution, so I'm at .375 layers with a .4 nozzle.

The slower speed is offset by the taller layers, so it's not too annoying.

I'm running at 265 and 110% flow. I'll post some pics of some of my prints.

Very happy with the stuff.

So much so that I reached out to a few manufacturers and will be exploring offering some filament of my own...

Taulman is nice, but way overpriced.

[lordbinky]

On desicants, on one hand I prefer the blue indicator color because the contrast is so large, but those desicants contain cobalt which is bad to be exposed to if you (or for me my asshole pets) somehow gain direct access to the silica. The orange to clear variety are safer but are not as big of a contrast for their indication that they need to be recharged/dried out.

[cope413]

I got my hands on a nifty piece of equipment last week when I got my dryer up and running.

Been running some tests on filament moisture levels and here's what I've found...

I tested 4 different filament samples.

All filament was thoroughly dried by baking in an oven for 18 hours at 185F.

Control sample was left out in the open air for 72 hours
Sample 1 - airtight bucket with desiccant, no heat - 72 hours
Sample 2 - airtight bucket with desiccant, 40w incandescent bulb - 72 hours
Sample 3 - airtight bucket with desiccant, heated and compressed air flow through the bucket at 3psi, 40w incandescent bulb. PID controlled compressed air heater set to 130F - once up to temp, air would kick on every 30-40minutes or so and would take about 6-8 minutes to turn back off.

My shop's average relative humidity over the past week was 44.6%.

I measured the Rh% of each bucket, and then immediately printed a cal-cube with it.



Control Sample:
Rh% 44.6
When left out for, the trimmer line still prints, but it gives prints a very different finish. It's actually kind of cool, but it's noticeably different. I didn't noticed any major issues with layer adhesion, but I definitely got "pops" which left some uneven spots. There was also a fair amount of blobs on corners, and on small radii I noticed a lot of stringing. Nothing that ruined the usability of a print, but definitely not ideal.

Sample 1:
Rh% 31.4
It printed cleaner than the stuff left out in the open, but not a whole lot. There was less blobbing on retracts, but still stringing and "pops" while printing.

Sample 2:
Rh% 18.3
Printed very clean for the first 30-40 layers. Beautiful. No popping, no blobs - just perfect. Started to get messier as it went. I surmise that the outside of the spool dried thoroughly and the filament on the inside winding didn't/

Sample 3:
Rh% 4.8
Perfect print. When I print with this stuff, I never want to print with any other filament again. Great appearance, prints like butter, and amazing strength. Great bridging ability, and excellent surface finish.



Preliminary conclusions:
Nylon absorbs a LOT of water if you let it. There's likely a sweet spot between my Dryer Bucket of Justice and Awesomeness and the simple bulb-in-a-bucket. While I'm thrilled with my results, it's not really practical. I suspect that keeping Rh around 15% with some heat will produce the same results if the filament is allowed to dry for longer periods of time. Ideally, the filament would feed from the bucket to the extruder without being exposed to the air.

I'll post some pics of the prints when I get my SLR and booth set up. Tough to show the differences in surface texture with my phone.

[Eaglezsoar]

Has anyone tried a refrigerator or freezer to dehumidify the nylon?

[Batteau62]

How about a home made vaccum dessicator(custom pressure cooker + rechargeable dessicant) then store the filament in vaccum bags like these: http://www.amazon.com/Large-Medium-Vacu ... orage+bags
-or maybe just the bags with some dessicant in with the filament for storage?

[Eaglezsoar]

How about a home made vaccum dessicator(custom pressure cooker + rechargeable dessicant) then store the filament in vaccum bags like these: http://www.amazon.com/Large-Medium-Vacu ... orage+bags
-or maybe just the bags with some dessicant in with the filament for storage?

Batteau62, that should work fine. I am just wondering if someone has tried the refrigerator or freezer method.

[cope413]

I thought about the fridge/freezer before I made my drying bucket/chamber...

A freezer/fridge will have a lot more difficulty (if it's possible at all) pulling moisture out of filament. I don't know the various vapor pressures and equilibrium points in play, but it's not likely that you'll be able to "pull" the moisture out of filament in a freezer/fridge. At least not in a practical time period.

The idea behind drying is that you're evaporating the water that is in the filament - expelling the moist air (or trapping it in the desiccant) and then keeping your filament in a low humidity environment.

A fridge/freezer should work very well to store already dry filament (a bit of a waste, energy wise, if you ask me), but will likely not work well to dry already "wet" filament.

A good vacuum seal certainly helps for storage, but is probably not necessary unless you're planning long term storage.

Easiest solution right now... bake your filament for 6-8 hours at 175-190F, and then seal it in a bucket that has some desiccant in it (ideally the mol sieve stuff mentioned earlier). If you're printing with ABS or PLA, you won't have to dry it again. They aren't very hygroscopic and unless you leave them out for 1-2 weeks, you'll go through your spool before they need re-drying. If you're printing with nylon, rig your bucket with a ball valve and some PTFE tubing, and you can feed filament from the bucket to the extruder without exposing it to moist air. Remove the filament from the bowden tube when done printing and close the valve on the bucket.

Done and done.

[lordbinky]

I was thinking if the freezer could successfully remove the moisture from the nylon, there's an issue with where the moisture goes. I would think it would end up with ice crystals all over the filament, which could be annoying if your filament is frozen together.

[Nylocke]

Has anyone thought about mounting an airtight box with a system for drying into their Rostock? Would be nice to keep long prints going without worrying about the filament getting soaked

[geneb]

I suppose you could build a fancy enclosure with 10lbs of rice in the bottom of it.

g.

[Durandal]

Or a little HDPE container of Sodium Hydroxide which will pull Humidity down to 3-4% RH. Just be careful, it's really caustic stuff, it's what Tyler Durden uses to burn the narrator in Fight Club. You can find mostly pure Sodium Hydroxide in the plumbing isle at most big stores as dry, acid free drain cleaner, just open the jar and place it in a sealed container with your filament.

[Eaglezsoar]

Or a little HDPE container of Sodium Hydroxide which will pull Humidity down to 3-4% RH. Just be careful, it's really caustic stuff, it's what Tyler Durden uses to burn the narrator in Fight Club. You can find mostly pure Sodium Hydroxide in the plumbing isle at most big stores as dry, acid free drain cleaner, just open the jar and place it in a sealed container with your filament.

About the Sodium Hydroxide, will it harm the plastic spool or filament and do you know how to dispose of it once it is saturated?
Since it is a drain cleaner I assume you just flush it away. If it is anything like LYE, I'm not sure it would be safe to use, that stuff will take your skin off.