Noob questions, The Machine

[fredk]

...
The application dictates the tools.

That about says it all.

Ardvark, I understand your dislike of ABS. Its stinky and somewhat hard to work with. For your applications, it offers no benefit.

For many of my applications I need the following: chemical resistance to salt water and its constituents, reasonable strength, some pliability, the ability to easily bond to itself and other similar materials, the ability to be or become water tight at no or very low pressure.

The first and last eliminate a number of materials. ABS hits all the marks and works very well. For the few people I know 3d printing parts, it is the go to material. I know of one individual who has recently printed and built a ball valve assembly using ABS.

For some idea of the applications, have a look at this thread. http://reefcentral.com/forums/showth...2547305&page=5 The page I linked to shows the ball valve assemblies. Page 8 shows a generic filter that is used to hold a wide variety or media.

The big downside to ABS is that it produces noxious fumes while printing. I live in an apartment so that is a large concern to me.

Polycrbonate meets many of the requirements, but I'm not sure how water tight it can be printed or made. PETG sounds like an awesome material, but I have no idea if it comes off the printer water tight. Its chemical resistance means vapor polishing is impossible.

I'm thrilled to hear you have a salt water tank Todd. You know what I'm looking for.

Thank you both for your comments they have been very helpful.

[Todd-67]

The big downside to ABS is that it produces noxious fumes while printing. I live in an apartment so that is a large concern to me.


I'm thrilled to hear you have a salt water tank Todd. You know what I'm looking for.

The fumes are way overblown when you have an enclosed printer.

Funny you're a member of ree central as well..... I will have to check that thread out. I only hang out there in the winter. That is when I have time. The printing stuff is an everyday professional thing.

[fredk]

The fumes are way overblown when you have an enclosed printer.

Having grown up on a farm through the '70s and '80s I watched a lot of the older guys handling chemicals without protection and doing maintenance/trouble shooting with bare hands. Lots of them ended up with not so good outcomes. I'm cautious when it comes to anything potentially noxious.

Funny you're a member of ree central as well..... I will have to check that thread out. I only hang out there in the winter. That is when I have time. The printing stuff is an everyday professional thing.

I've been a member of RC for a very long time. Lots of interesting stuff going on there.

It's cool that you are printing professionally. My impression is that most people at the moment are doing fun stuff, so don't pay as much attention to material properties. I see a lot of potential for customized fittings for many tank plumbing and filter needs, but the materials have to hold up over time.

I wonder if RC could benefit from a dedicated 3D printing thread in the DIY area. It is an ideal application of the technology.

[fredk]

Done. Ordered the Black Widow. In the end I decided I did not want to deal with the up front fiddling with the Tarantula to get it more stable for printing.

Its only money...

Thanks all for your help.

[curious aardvark]

polycarbonate is probably the hardest material to print with I've yet come across. Even the guys at polymaker who gave me the pc plus - can't tell me how to print it lol
The sheet of buildtak they gave me - did stick to the pc, permamently. I mentioned this to them and they said: yes that happens. And it's shrinkage makes abs look positively stable.

You will need not only a high temp all metal hotend but a sealed heated building chamber and some kind of magic print surface that even the people who make the filament can't advise on.

todd - I said use pet-g, personally I like pla - but if it doesn't work in salt water - then use pet-g.

fred - whether or not a 3d printed part is water tight is largely down to the way it's printed. Anything that isn't watertight can be painted with varnish, or any of the propriatary 3d print smoothing compounds around.
pet-g has much better layer bonding than abs, prints on an unenclosed machine and isn't much more expensive than abs. It also has a lot less shrinkage, which helps reduce micro gaps in the structure.

The fumes from abs are not as much of the problem as it's shrinkage and all the acetone you end up breathing in.
Yes people use it, I suspect many of them do so beacuse they haven't bothered to look seriously at the alternatives. The materials advances in 3d printing filaments in the last few years is just astonishing.

Another material you might want to look at is ninjatek's Armadillo. It's a rigid supertough material, that apparently prints easily. Handling it you'd think you were holding some kind of hardened nylon. I believe they said it was polyurethane.
Pretty impressive stuff.
I haven't tried it yet - but had along talk to the ninjatek guys and handled a few prints. The only thing that impressed me more this year materials wise, was a fibreglass composite from an italian company (maybe spanish). That was as light and strong as traditional fibreglass and printed - again - on an unenclosed machine.

Then you have innofil's new Pro 1 - easily the best material I've printed with for ease of use.
Lots of different applications depending on how hot and how fast you print it. Also food contact safe.

Like i said, I did spend 6 months exclusively using abs - it will teach you an awful lot about how to calibrate your printer and how not to get frustrated when yet another print fails. But as an end use material I was never impressed, and it's just been left way behind by the new guys on the block.

[wirlybird]

Keep a close eye on ebay for the guy selling the returned Flashforge Creator Pros. I got some very good deals on like new printers that just needed a little adjustment to get them going. Even with shipping I paid less than half of new. It is a small gamble but worth it I think.

If someone were to drop one of those in my lap for $800 I wouldn't say no, but that's way above my budget. I missed out by a day on a used Flashforge Creator Pro for $550. At that price I would probably have given up on the larger bed for now.


I have no design experience, so I have no idea how slicing and gluing might affect structural integrity on a part.

I'm of half a mind to go back to the original plan and buy the base Tevo Tarantula kit for $330 CAD and play with that to really understand what my needs are. I would imagine there is quite a learning curve for 3d modeling and printer setup to get whats in my head to turn into a real usable part.

I normally like to buy once and, other than minor mods, be done with it. There is not much technical info on these low end printers, so even when I buy one with an 'all metal' head, it is not clear what that really means or if I can work with higher temperature parts. Everyone seems to have all metal hot ends these days, but I imagine that they are not all created equal.

Materials is a whole other can of worms. I've been looking into PETG for the last couple of days. It looks to hit all the marks with a bonus of no/little toxic fumes while printing. The one downside is for some things I would want to bond to PVC, ABS, or acrylic. There are lots of good bonding options for poly-carbonate and ABS, but only one for PETG.

Hmm, buy a cheap printer (that works) and loads of different materials? Or maybe a lottery ticket...

[wirlybird]

I agree completely with Todd. ABS has a learning curve but with study and diligence it is easy to print and makes really nice prints. PETG is a good alternative but has its downfalls also. It is more flexible than ABS and on thin parts this will become more prevalent.
PLA is great for a lot of things and good to get started with. However, it is "brittle" and forget heat. I made drain covers for my kitchen sink and the hot water is enough to start to soften the PLA slightly. It will in time degrade around water also. I am testing this in the sink!! It works fine for this application but I know it won't last.

I haven't used nylon yet but it does require high temps and it is also extremely hygroscopic being that it can saturate in under 24 hours so storage is critical.

Curious Ardvark is expressing his opinion which he is entitled to, as am I, but I would take it as just that. I disagree with him more often than not.

ABS is not hard to print if you know what you are doing. A lot of people do it. The industrial high end companies like stratasys customers go through a lot of ABS. :-) I use it almost exclusively as it is very durable for snap fits and impact resistance if you have your settings correct and you can print other materials if you have a dual head machine for dissolvable supports. It also post processes well. Brittle ABS prints are results of improper extrusion/heat parameters and infill/shell settings.

In your initial posts you mentioned mentioned you wanted to print parts for use where heat is involved for your smoker and you also mentioned the use of Polycarbonite. Heat is best handled with a semi crystalline structure material as they don't creep and loose strength with heat at their glass transitional zone. That would be nylon. PC and ABS are amorphous and while way better than PLA at temps are not the material of choice because of degrading strength properties and creep. Both PC and Nylon require high temp metal hot ends. PLA is horrible in heat situations even though your temps that you listed are well below where it should be a problem the part probably will not last long.

Absolutely DO NOT use an item printed in PLA in a salt water tank. PLA degrades in a few ways. Moisture is the base then you have chemicals such as chlorine which is high in saltwater. Heat and bacteria are the other enemies which your tank requires to be sustained. I have salt water reef tanks as well. The constant flow of water in the tank with the dissolved abrasive salt will not be good. I know this because before HIPS came out I used PLA as a disolvable support structure for ABS prints. See the video below on how it's done. I have a unit very similar to this one.

https://www.youtube.com/watch?v=uWYn5wJ72zY

PLA is great for a lot of applications and it is easy for noobies. I print almost exclusively for prototype parts for consumer retail goods as I am a mechanical engineer so it just isn't for me most of the time. No one polymer is. There are so many different ones for a reason. The application dictates the tools.

[Todd-67]

It will in time degrade around water also. I am testing this in the sink!! It works fine for this application but I know it won't last.

I haven't used nylon yet but it does require high temps and it is also extremely hygroscopic being that it can saturate in under 24 hours so storage is critical.

PLA won't degrade for a long time in water alone. It needs bacteria and heat such as in a landfill (or fish tank) along with the moisture. Detergents and chemicals design to breakdown organics such as drain cleaner (lye). heat and adgitation speed up the process just like in the video I use a heated ultrasonic parts cleaner with a water/lye mix. PVA will melt in straight water. Heat and agitation will speed that process up as well. Alternatively to the ultrasonic cleaner you could use a fish tank heater in water with a pump to create a strong current for pretty cheap that I would think would work almost as well.

[wirlybird]

PLA won't degrade for a long time in water alone. It needs bacteria and heat such as in a landfill (or fish tank) along with the moisture. Detergents and chemicals design to breakdown organics such as drain cleaner (lye). heat and adgitation speed up the process just like in the video I use a heated ultrasonic parts cleaner with a water/lye mix. PVA will melt in straight water. Heat and agitation will speed that process up as well. Alternatively to the ultrasonic cleaner you could use a fish tank heater in water with a pump to create a strong current for pretty cheap that I would think would work almost as well.

Interesting. I guess I was a little vague! I am interested to see how it hold up as a drain screen in normal day to day usage in a kitchen sink. Not the most scientific study! I actually made these to fill in the drain hole. Ever set a colander in the sink to have it tip when the feet go in the drain. So these just make the bottom of the sink level by covering/filling the drain.

[curious aardvark]

pla is not brittle.
Hit it with a hammer and it doesn't shatter, it usually dents.

What it is, is harder and stiffer than abs. But print it thin and it flexes at least as well as abs.

A lot of a 3d prints properties are down to how the thing is printed. I probably design my pla stuff to the capabilities of the material better than most. But right from the first pla print I've had absolutely none of the supposed issues people claim for it.

Abs on the other hand was just a hassle from the first day to the last.
I don't have an enclosed printer - so abs was never going to be fun.

If you have an enclosed printer and you like acetone - give it a go.

Just be aware there are alternatives that don't have any of the built in hassle of abs.