Printing with Line trimmer

[tom10122]

Has Anyone on here done it? I was in the middle of trying when my computer crapped out on me. Pics please

[Jimustanguitar]

I looked into this a little bit. I think it's very doable.

Haven't tried it though. What source did you find for the filament? I couldn't find the exact diameter that I needed.

[tom10122]

I didn't, I used what i had around the house, I use 3mm so 2.89 mm wasn't too different. I only had square line but it worked, you CAN fit a square peg in a round hole if the peg is smaller then the hole. I managed to print a Delicate ring a thing but that was it. I Had to print slow.

[Eaglezsoar]

I looked into this a little bit. I think it's very doable.

Haven't tried it though. What source did you find for the filament? I couldn't find the exact diameter that I needed.

See this link at Amazon:
http://www.amazon.com/gp/product/B003VP ... UTF8&psc=1
Works out to 1.65mm

[lordbinky]

Taulman's website says this about the nylon trimmer line.

Can I just use plain Nylon trimmer line?

Trimmer line does "look" like and contain nylon, however, trimmer line or weed-whacker line also contains various additives that are destructive and or dangerous for your 3D Printer.
First, it has fiberglass to strengthen it, as without fiberglass, the ends will fray/split and cause trimmer jams. Next, nylon on it's own is too flexible in a thin line, so fiberglass hardens it for cutting. Fiberglass will foul your nozzle because it requires a higher temp to melt along with the nylon. The higher temp will actually boil the nylon and other additives giving off a smell. The additives are there to reduce the bulk % of nylon as nylon is more expensive than the additives. These additives are usually calcium based and can clog or foul your nozzle

Since I only have one nozzle atm for my E3D hotend right now, I haven't tried it. Once extras I ordered come in I'll definitely try though since this nozzle isn't flat/funky inside so it'll get reworked either way to .5 (from .4) when I won't be SOL if I screw up.

[tom10122]

Taulman's website says this about the nylon trimmer line.

Can I just use plain Nylon trimmer line?

Trimmer line does "look" like and contain nylon, however, trimmer line or weed-whacker line also contains various additives that are destructive and or dangerous for your 3D Printer.
First, it has fiberglass to strengthen it, as without fiberglass, the ends will fray/split and cause trimmer jams. Next, nylon on it's own is too flexible in a thin line, so fiberglass hardens it for cutting. Fiberglass will foul your nozzle because it requires a higher temp to melt along with the nylon. The higher temp will actually boil the nylon and other additives giving off a smell. The additives are there to reduce the bulk % of nylon as nylon is more expensive than the additives. These additives are usually calcium based and can clog or foul your nozzle



Since I only have one nozzle atm for my E3D hotend right now, I haven't tried it. Once extras I ordered come in I'll definitely try though since this nozzle isn't flat/funky inside so it'll get reworked either way to .5 (from .4) when I won't be SOL if I screw up.

I tried with a .4 mm nozzle, I Did get some jams, the fiberglass explains that

[Generic Default]

I've been printing with nothing but trimmer line since I got my rostock, and I've already gone through ~4.5 lbs of it. The 1.65mm round line works great, and with the 3 lb spools on amazon for $22, it turns out to be about $7.50 per pound to print, which is much cheaper than ABS or PLA. Before I started printing I emailed Desert Extrusion (the manufacturer) and asked about the composition of trimmer line. The guy said it's 100% virgin nylon. I think only the more expensive stuff has glass fiber in it. I've actually been looking for glass fiber trimmer line since it has about 1/4 the thermal expansion of regular nylon, which means a lot less warping. Taulman gives the warning about trimmer line because it benefits him to have a monopoly on printer nylon.

I haven't had any hot end jams yet, and all of my cold end jams have been from bad first layer height. Trimmer line doesn't shred in the cold end or break under any circumstances. I just switched to the E3D hotend because 240 degrees is about the minimum temperature you can print nylon without serious delamination. 260 degrees makes extremely strong parts; I can't pull apart a magnetic arm cup joint with pliars.

I highly recommend trimmer line if you have a hotend that can print over 250 without melting its own PEEK.

[Flateric]

I'm gonna have to fess up here and also admit I have done a number of different prints with various line trimmer with exactly the same observations as Gerneric Default.

While I agree that perhaps some of the additives may in fact be cheaper than the nylon itself, mixing them into said nylon is not cheap. I have found the cheaper trimmer line to be much more pure than the expensive line.

I also would never dream of attempting to print trimmer line without using a all metal hotend.

My last point however is that if given the choice I will always prefer the Taulman product. More consistent, definitely more pure and never a single jam.

Warping however has not ever been a issue since I started printing on a 40c bed with a UHU glue stick coating. Removing said parts however is a different new problem, LOL.

[ApacheXMD]

Can you post some pictures of your trimmer line prints?

[Generic Default]

Thar ya go.
And yes, the bearing does spin nicely with low friction and no lubrication or wobble.

I have a big cardboard box full of everything I've printed so far, but most of it is proprietary stuff that I can't post here. I printed my magnetic effector upgrade entirely from trimmer line, as well as a greg's extruder and a custom side mount for it. It can take screws without pre-tapping just like a lock nut.

I'll just say that trimmer line works great for just about anything mechanical. I've printed gears down to ~10mm in diameter and 0.2mm thick that worked, and so far none of my nylon prints have broken from mechanical use. They don't wear like other stuff, either.

There is a drawback that I just figured out yesterday;

Nylon does generate some force on the build surface as it contracts from cooling, but this was unexpected. I have printed larger objects than this before with no problems. All of them have been held to the glass surface with regular glue stick, which means that the glass that seemecnc sells is both overpriced and low quality. It was weaker than the glue stick that stuck the part to it. When it cracked, it jerked up and smacked the hot end so hard that it knocked the magnetic ball joints out and luckily didn't break the E3d hotend. This print was at 260 degrees with a 40 degree heated bed.

In the mean time I bought a $6 12" mirror from hobby lobby that's just as thick as the borosilicate one. I'll try to get a replacement from seemecnc this week, but this incident makes me wary of printing larger objects on 1/8 glass plates. I might try 1/4 or 3/8 next time....

Don't be discouraged from using trimmer line by this. I've gone through ~5 lbs of nylon without any problems. ABS would probably do the same thing since it has a similar coefficient of thermal expansion.



Moral of the story:

Get a thicker plate. At least until we can get glass-filled filament that contracts much less.

[cope413]

Just got my first roll of this stuff and my first print is on the machine now....

First impression is that it's buttery smooth through the hot end. Also, pleasantly surprised that the color is good and there's no smell at all. I baked it last night and haven't heard even the slightest pop or hiss.

Couple of questions:

1) Generic - were you printing directly on the glass? I put glue down per Flateric's suggestion in another thread, but I'd much prefer bare glass or hairspray if either of those will suffice.

2) Is there a way to get higher than 260 in RepHost? I'd like to bump it up to 265-270 in order to print faster. As it is, it's set at 260, but I don't get much over 257-258

3) RE: warping & glass plate - do you think that a layer of PET tape on the glass would prevent that kind of breakage in the event of major contraction?

[edward]

Just got my first roll of this stuff and my first print is on the machine now....

So is everyone actually using the stuff Eaglezsoar recommended here? http://www.amazon.com/gp/product/B003VP ... UTF8&psc=1

2) Is there a way to get higher than 260 in RepHost? I'd like to bump it up to 265-270 in order to print faster. As it is, it's set at 260, but I don't get much over 257-258

Are you sure you don't have a max temp setting in Configuration.h that is limiting you? I don't think RepetierHost limits this, as I can hit 325 no problems (I am on Marlin, though).

Edit: Added second quote and response/question.

[Generic Default]

I print on the glass with a thin layer of glue stick applied. I found that using the heated bed actually decreases the holding force of the dried glue from the glue stick, so I only heat up the bed when I'm applying the glue to make it dry faster. You can also heat up the bed when your print is finished because it makes it easier to pry off the glass. Nylon will typically rip cardboard on larger prints, and I haven't tested with hairspray yet.

I doubt the PET tape would prevent a break. The nylon sticks to the glue, which sticks to the glass plate. The thermal contraction of the nylon causes a huge amount of force on the surface of the glass plate toward the center of the part. Putting tape on the glass would only help if the tape ripped or peeled up before the glass broke.

I've been using the blue 1.65mm trimmer line from amazon too. I think that the different brands use the same manufacturer, Desert Extrusion, as a supplier. The trimmer line is virgin nylon. Someone with a 3mm setup should try to find glass filled trimmer line because it has a lower coefficient of thermal expansion. My plate cracked while printing a rectangular part of about 3x5 inches at ~15mm thick.

Warping (and in my case, glass-shattering) is one of the biggest problems with our printers, and it is all about thermal expansion.
Just for reference, here is a short list of plastics and their relative thermal expansions;
http://www.curbellplastics.com/technica ... astics.pdf
Lower numbers mean less warping.

Fiber filled plastics have significantly lower coefficients of thermal expansion (and higher strength), especially carbon fiber. Anyone with a filament extruder should try to get some glass filled resin pellets to test with. I've seen a few suppliers who will send small sample quantities (<25kg) for free.



And Cope413, make sure you don't print too hot because nylon can make some dangerous fumes. I've already printed ~2.75 KG in a small enclosed room over the summer, and I didn't die. As long as the nylon is dry, it doesn't really smell bad. Anything over 250 degrees Celsius should make parts that don't delaminate.

[cope413]

And Cope413, make sure you don't print too hot because nylon can make some dangerous fumes. I've already printed ~2.75 KG in a small enclosed room over the summer, and I didn't die. As long as the nylon is dry, it doesn't really smell bad. Anything over 250 degrees Celsius should make parts that don't delaminate.

Eh, not too worried about the fumes. I've worked with a molding factory for 6-7 years, and they run 100s of lbs of nylon and other plastics at 270-300C every hour, and they have never gotten readings of the fun hydrogen cyanide gas over 1-2ppm. A few ccm of nylon in a well ventilated shop won't get anywhere near worrisome.

I did make myself a dryer - 5g bucket, 25w incandescent bulb, and some rechargeable dessicant - so I'm running it as moisture free as I can. Haven't had even a hint of smell.

I'll check the config.h, didn't think about a max temp setting...

[Generic Default]

I just printed a small cup with trimmer line yesterday. It came out nice, but I know that nylon absorbs water so I filled it up with water to test the permeability. None of the water leaked out of it overnight, but I noticed that the bottom was arched downward so the cup would't sit flat on the table. The sides of the cup didn't warp at all, so it appears that nylon absorbs water differently depending on the print orientation. I microwaved it to get the water out, but that just caused giant tumors to explode out of the base where the water boiled into steam. The sides of the cup didn't show any signs of moisture.

Don't microwave wet nylon because the steam can get hot enough to raise the nylon above its decomposition temperature. I don't know if I just made a bunch of steam or hydrogen cyanide, but I won't be microwaving nylon again.

[cope413]

What is more likely is that you had some gaps in your bottom solid layers and the water got in between the layers. Unless you're burning the filament while extruding, you aren't changing the chemical structure of nylon - so it will absorb water equally.

I'm pretty sure that this trimmer line is nylon 6. If it is, then it can/will absorb about 10% of its weight if left in a moisture rich environment.

You could test this by weighing 100g of the line, leaving it in open air for at least 72 hours (or in your bathroom for a day or 2 to suck up the steam from a shower) and then re-weigh it. It should be close to 110g.

There's more material on the base of a single-walled print - so the base would have more water than the walls - so that part makes sense.

As for microwaving it - you actually should be able to get decent results if needed, but I would set your power level down to 20-30% and cook it 30s at a time.

Microwaves work by exciting water molecules in whatever it is you're microwaving. Most plastics don't absorb the waves at the frequency a standard microwave puts out - I'm not sure if nylon does, but it's not likely. If they don't, then microwaving parts should work if you can evaporate the water out slowly enough to not distort the print.

Full power will boil it quickly and cause the mess you had on the first go-round.

As for HCN, you literally need to burn it or get it to its pyrolysis temp which is somewhere north of 280C in order to produce HCN - so that's not likely in a microwave unless you're being very foolish.

[cope413]

I posted this on a fail thread i started that probably won't get viewed much, so I'll repost it here where it's most relevant...

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.

[Cleveralias]

Wow, cope, thank you very much for taking the time to make this comparison. It's something I've been wanting to check so I'm glad to see your results. I've been using a large amount of silica in a sealed bin but I've never been able to get the RH down below 30%, which seems to agree with your sample 1.

This seems a decent place to share that I finally ordered some low-humidity molecular sieve desiccant from McMaster this week. I threw it in my bin when it arrived Tuesday afternoon and by the time I got home from work yesterday the RH was already down to 19%. So it does seem to be much more effective in low humidity than silica (as it is billed to be). I'm still watching to see how low it can bring the bin over time, but I was encouraged by the early results. I'm hoping this will get things nice and dry and keep me from having to build something more involved, but we'll see.

[Eaglezsoar]

That's one expensive meter that you got there.

[Eaglezsoar]

Wow, cope, thank you very much for taking the time to make this comparison. It's something I've been wanting to check so I'm glad to see your results. I've been using a large amount of silica in a sealed bin but I've never been able to get the RH down below 30%, which seems to agree with your sample 1.

This seems a decent place to share that I finally ordered some low-humidity molecular sieve desiccant from McMaster this week. I threw it in my bin when it arrived Tuesday afternoon and by the time I got home from work yesterday the RH was already down to 19%. So it does seem to be much more effective in low humidity than silica (as it is billed to be). I'm still watching to see how low it can bring the bin over time, but I was encouraged by the early results. I'm hoping this will get things nice and dry and keep me from having to build something more involved, but we'll see.

I looked at the low-humidity molecular sieve desiccant from McMaster, and I am confused on what it is and what to order. Is it a bulk powder or what and how did you figure out
what to order? It sounds like great stuff but I need your help in determining what to order. Also, is this a color change desicant?

[Cleveralias]

Wow, cope, thank you very much for taking the time to make this comparison. It's something I've been wanting to check so I'm glad to see your results. I've been using a large amount of silica in a sealed bin but I've never been able to get the RH down below 30%, which seems to agree with your sample 1.

This seems a decent place to share that I finally ordered some low-humidity molecular sieve desiccant from McMaster this week. I threw it in my bin when it arrived Tuesday afternoon and by the time I got home from work yesterday the RH was already down to 19%. So it does seem to be much more effective in low humidity than silica (as it is billed to be). I'm still watching to see how low it can bring the bin over time, but I was encouraged by the early results. I'm hoping this will get things nice and dry and keep me from having to build something more involved, but we'll see.

I looked at the low-humidity molecular sieve desiccant from McMaster, and I am confused on what it is and what to order. Is it a bulk powder or what and how did you figure out
what to order? It sounds like great stuff but I need your help in determining what to order. Also, is this a color change desicant?

It comes in Tyvek pouches so it's ready to use and you won't have to deal with bulk powder, and there's no color change. I ordered their #1523T63 (http://www.mcmaster.com/#1523T63). It's 5 bags, each good for 1,425ci, and I threw all 5 into my bin, which I think is 30 gallon... Since it seems to be working I'll probably order the next size up next time (1523T64) as that might be a better fit for the container.

[lordbinky]

That's neat stuff. Sadly it's not rechargeable. My RH is typically around 15% in the afternoon and under 40% at night right now, so I may have to look into low humidity desiccants. Ughhh....

[cope413]

It basically comes down to surface area.

What we're talking about here is actually ADsorption, not ABsorption. Desiccants adsorb moisture - that is, they hold the moisture on their surface. Molecular sieves are synthetic and they're designed to have a bunch of pores/cavities/folds in order to greatly increase the adsorptive surface area. I've seen some crazy cool molecular sieves that have adsorptive surface areas of 60-70% of total volume (which, if you're not a chem or physics nerd, is pretty dang impressive).

Anyway, temperature and Rh% both greatly affect adsorption.

Silica is actually really good at room temps and below.

It's not as good in low humidity and elevated temps.

Molecular sieves excel in low humidity and get even better with higher temps.

[cope413]

That's one expensive meter that you got there.

Not too bad...

http://www.globalindustrial.com/p/tools ... QgodgUoArQ

[Eaglezsoar]

It comes in Tyvek pouches so it's ready to use and you won't have to deal with bulk powder, and there's no color change. I ordered their #1523T63 (http://www.mcmaster.com/#1523T63). It's 5 bags, each good for 1,425ci, and I threw all 5 into my bin, which I think is 30 gallon... Since it seems to be working I'll probably order the next size up next time (1523T64) as that might be a better fit for the container.

Thanks for the answer, now I understand what it is and what to order.