Thread Rating:
  • 0 Vote(s) - 0 Average
Becoming Disillusioned With the Utility of Resin Printed Components
#1
As the subject states, I find my self becoming increasingly disappointed in the utility/usefullness of resin printing. As the FDM crowd are quick to point out i find printed components to be absurdly brittle, with low overall tensile strength (the claimed TS for most strikes me as wishful thinking). Any prolonged exposure to daylight--or even moderately strong higher color temperature artificial light seems to exacerbate this to the point of making resin printed structural components completely unreliable. Time seems to be a factor as well, as though a "self-destruct" clock is set at the end of the printing process.

FWIW I am post-curing in a modified 0.7 ft³ microwave oven fitted with a 30 W 405 nm LED.

I have tried numerous different resins, having best luck with Phrozen's Beige Flex Functional Resin--not cheap @ $54 per litre from Amazon (but it's been unavailable there and elsewhere [typically @ $100/litre] for over 6 months). Has anyone found any other resin that comes close to it's characteristics:

Tensile Stress (Break): 40 MPa
Elongation: 50-60 %
Tensile Modulus: 192 MPa
Hardness: Shore 65D
Heat Deflection Temperature @0.45MPa: 100C

The FDM guys routinely print compliant mechanisms with materials like PETT and Nylon--I don't think that is possible with any SLA resin; but I'd be happy just to print an occasional 2-piece pinned hinge or other hanger/support component that could be trusted to support even 3 or 4 pounds.

Custom peg-board clips are popular with the FDM folks, those that I have printed can barely support 1/10 of their design goal load, and degrade further as they age (a couple weeks seems to be how long resin printed stuff remains usable).

The system does not seem to be especially good at producing even modestly robust mechanical components with more than a 30-day useful life. 

I tried making an IC test clip like this; using Siraya Tech's "Sculpt" resin (one of the better I've used):

[Image: ICTestClip-00.jpg]

I had made the hinged sections 25% or so larger and increased the pivot pin diameter. It still failed miserably, barely surviving assembly and breaking on first use.

Quite disappointing.

Thoughts anyone?
-cliff knight-
[Image: 816-20120803-wide800.jpg]
paladinmicro.com
Reply
#2
(11-15-2020, 01:40 AM)cliffyk Wrote: As the subject states, I find my self becoming increasingly disappointed in the utility/usefullness of resin printing. As the FDM crowd are quick to point out i find printed components to be absurdly brittle, with low overall tensile strength (the claimed TS for most strikes me as wishful thinking). Any prolonged exposure to daylight--or even moderately strong higher color temperature artificial light seems to exacerbate this to the point of making resin printed structural components completely unreliable. Time seems to be a factor as well, as though a "self-destruct" clock is set at the end of the printing process.

FWIW I am post-curing in a modified 0.7 ft³ microwave oven fitted with a 30 W 405 nm LED.

I have tried numerous different resins, having best luck with Phrozen's Beige Flex Functional Resin--not cheap @ $54 per litre from Amazon (but it's been unavailable there and elsewhere [typically @ $100/litre] for over 6 months). Has anyone found any other resin that comes close to it's characteristics:

Tensile Stress (Break): 40 MPa
Elongation: 50-60 %
Tensile Modulus: 192 MPa
Hardness: Shore 65D
Heat Deflection Temperature @0.45MPa: 100C

The FDM guys routinely print compliant mechanisms with materials like PETT and Nylon--I don't think that is possible with any SLA resin; but I'd be happy just to print an occasional 2-piece pinned hinge or other hanger/support component that could be trusted to support even 3 or 4 pounds.

Custom peg-board clips are popular with the FDM folks, those that I have printed can barely support 1/10 of their design goal load, and degrade further as they age (a couple weeks seems to be how long resin printed stuff remains usable).

The system does not seem to be especially good at producing even modestly robust mechanical components with more than a 30-day useful life. 

I tried making an IC test clip like this; using Siraya Tech's "Sculpt" resin (one of the better I've used):

[Image: ICTestClip-00.jpg]

I had made the hinged sections 25% or so larger and increased the pivot pin diameter. It still failed miserably, barely surviving assembly and breaking on first use.

Quite disappointing.

Thoughts anyone?

Hey so I'm realtivy new to 3D printing and primarily use it for tabletop RPG miniatures and terrain.  I've had the same issues when using Elegoo brand resin and Siraya Tech Fast.  What I found is if you mix Siraya Fast with Tenacious at a 4:1 ratio it significantly improves strength. I also did not have to adjust my setting with this mixture.  I know Tenacious is Siraya Techs strongest resin at $65 a bottle!  I know the Blue ($50) is strong as well.  I'd try using mixes with either of the above resins with a Fast or Sculpt.  I hope this helped.
Reply
#3
(02-09-2021, 09:33 AM)pjnyznyk Wrote: Hey so I'm realtivy new to 3D printing and primarily use it for tabletop RPG miniatures and terrain.  I've had the same issues when using Elegoo brand resin and Siraya Tech Fast.  What I found is if you mix Siraya Fast with Tenacious at a 4:1 ratio it significantly improves strength. I also did not have to adjust my setting with this mixture.  I know Tenacious is Siraya Techs strongest resin at $65 a bottle!  I know the Blue ($50) is strong as well.  I'd try using mixes with either of the above resins with a Fast or Sculpt.  I hope this helped.

In the first, because I'm old and spent 13 months of my early adulthood in Vietnam, what are "RPG miniatures"? To me RPG is "Rocket Propelled Grenade".

I got some Phrozen Functional Resin: Beige Flex ($54 for ! kg from Amazon, but apparently no longer available) and had much better results--think I'll stick a crowbar in my wallet and get some Tenacious or maybe some Blue--however "strong" is not my fundamental problem; it's the extremely low elongation at yield that makes the cheap 'ABS-like" resins useless for any but VERY lightly loaded functional components. .

Glass is strong but as a solid block it doesn't bend for shit...
-cliff knight-
[Image: 816-20120803-wide800.jpg]
paladinmicro.com
Reply
#4
(02-09-2021, 10:21 AM)cliffykRole Playing Game.  I print mini characters for a Dungeons and Dragons game I run.  Remember the 80\s and the satanic panic that all us kids were becoming possessed by the devil? That game! Anyway, before springing the money for Tenacious, reach out to Siraya Tech for what you need.  I believe they  provide data sheets detailing strength properties (elongation, shear, etc.) on their resins.  Hope this helps! Wrote:
(02-09-2021, 09:33 AM)pjnyznyk Wrote: Hey so I'm realtivy new to 3D printing and primarily use it for tabletop RPG miniatures and terrain.  I've had the same issues when using Elegoo brand resin and Siraya Tech Fast.  What I found is if you mix Siraya Fast with Tenacious at a 4:1 ratio it significantly improves strength. I also did not have to adjust my setting with this mixture.  I know Tenacious is Siraya Techs strongest resin at $65 a bottle!  I know the Blue ($50) is strong as well.  I'd try using mixes with either of the above resins with a Fast or Sculpt.  I hope this helped.

In the first, because I'm old and spent 13 months of my early adulthood in Vietnam, what are "RPG miniatures"? To me RPG is "Rocket Propelled Grenade".

I got some Phrozen Functional Resin: Beige Flex ($54 for ! kg from Amazon, but apparently no longer available) and had much better results--think I'll stick a crowbar in my wallet and get some Tenacious or maybe some Blue--however "strong" is not my fundamental problem; it's the extremely low elongation at yield that makes the cheap 'ABS-like" resins useless for any but VERY lightly loaded functional components. .

Glass is strong but as a solid block it doesn't bend for shit...
Reply
#5
I have downloaded and scoured everyone of Siraya's data sheets and those available for most other resins (I'm a mechanical engineer so reading spec sheets of materials I might use is 2nd nature). What I've found is that any resin with an elongation at break of < 20% is not suitable for any loaded component. A block of ice would work just as well and likely have a little bit longer service life...
-cliff knight-
[Image: 816-20120803-wide800.jpg]
paladinmicro.com
Reply
#6
(02-11-2021, 08:22 AM)cliffyk Wrote: I have downloaded and scoured everyone of Siraya's data sheets and those available for most other resins (I'm a mechanical engineer so reading spec sheets of materials I might use is 2nd nature). What I've found is that any resin with an elongation at break of < 20% is not suitable for any loaded component. A block of ice would work just as well and likely have a little bit longer service life...

So, would Siraya Blu be suitable? Elongation at break is 25%.
Reply
#7
(02-13-2021, 02:13 PM)jedisct1 Wrote:
(02-11-2021, 08:22 AM)cliffyk Wrote: I have downloaded and scoured everyone of Siraya's data sheets and those available for most other resins (I'm a mechanical engineer so reading spec sheets of materials I might use is 2nd nature). What I've found is that any resin with an elongation at break of < 20% is not suitable for any loaded component. A block of ice would work just as well and likely have a little bit longer service life...

So, would Siraya Blu be suitable? Elongation at break is 25%.

I have not yet used it; I'm having a hard time coughing up the $$, in part because i do not like the colour (blue or clear).

I do have some Siraya Tenacious (claimed 50% EAB) on order (not wild about its colour either but I paint over 1/2 of what I print anyway).

I used a kg of SainSmart Rapid General Purpose resin rated at 28% to 35% and it was OK ("OK" in my vocabulary means "barely adequate).

A stated above, the best I have used so far was the Phrozen Functional Resin: Beige Flex that apparently has been discontinued. It was $40/kg with 50% to 60% elongation at break--based on that experience and my using resins rated 14% to 20%, i think 25% would be just barely adequate ("OK-").

In my experience--just coming up on 1-year, 3.5 LCD screens (my 4th is about 1/2 way through its service life), and 50 to 60 kg of resin--anyone's "water washable" stuff and most (probably ALL) resins touted as "ABS-like" are so brittle as to be useless for making anything but the most lightly loaded components--and then only if you up-size said component to be 10% to 15% larger than if you were machining it from a block of reinforced phenolic resin (itself not an especially robust material). I.e. pretty much useless.

I hope to mix the Tenacious with some of the "ABS-like" garbage I've amassed and come up with something useful... 

I will report back when I've used it a bit...
-cliff knight-
[Image: 816-20120803-wide800.jpg]
paladinmicro.com
Reply
#8
cliffyk Wrote: most (probably ALL) resins touted as "ABS-like" are so brittle as to be useless for making anything but the most lightly loaded components

Most? Perhaps, I have not tried that many of ABS-like resins personally, but from feedback by others I know that many of them are far from perfect. Fortunately, some of them are good enough to be actually useful. For example, I use FUNGDO ABS-Like resin ($32/L including shipping) to print functional parts and it is very durable, unlike some other resins I have tried so far. I have printed many parts with hinges or which have to remain durable under load or snap together regularly, and so far so good. Their "low viscosity ABS-like" resin ($34/L right now, but usually $38/L) is also has good temperature resistance (Glass Transition Temperature 125°C). Both resins stick very well to the bed without too much overexposure, so I can print many parts directly on the bed with reasonable bottom layer compensation around -0.15mm depending on layer height, including gears and other parts, where having an elephant foot would be unacceptable. I calibrated exposure so that I do not need compensation for normal layers (for example, I can print 4.9mm and 5mm cylinders, and 4.9mm one can fit in 5mm hole easily but 5mm cylinder does not fit in it). FUNGDO also has "high toughness ABS-like" resin which is very resistant to breaking, but it costs twice as much as their normal ABS-like resin and has 80°C glass transition temperature and does not stick to the bed as good as their "low viscosity ABS-like" version.

The reason why I got into MSLA printing is because FDM was not good enough to produce some parts I need, they were too brittle or had distorted shape (especially when printing with real ABS, which warps easily and can be very brittle along layers, depending on wall thickness), and actual resolution of FDM printer is not good enough to produce smooth surfaces or fine details such as threads (for example. even though I managed to print some M12 threads with 0.5mm pitch, they needed a lot of postprocessing to actually work with good tolerances and could be successfully printed only in one orientation). But with UV resin, I can print the same parts and use them right away without any postprocessing (except curing and washing, but it is easy with ultrasound bath).

It would be a big disappointment to me if only so called "standard" resins existed which are not durable at all. For example, with ELEGOO resins my experience is not very good, the resin I have tried from them does not stick very well to the bed even with long exposure and some parts can drop to the vat during printing (even the parts I know I can print 100% reliably on the bed with the better resin), and resulting parts are brittle, to the point parts can break during manual cleaning (I prefer to remove most of the resin residue with paper towels before using ultrasound bath) even with wall thickness 2-3mm, or if they are dropped on the floor from small height, or after few uses under light load. The same parts printed with good ABS-like resin can have almost the same rigidy but without being so ridiculously brittle. I'm sure FUNGDO is not the only option and there are good ABS-Like alternatives from other brands, but many of them come at a greater cost (or seemingly similar cost but without including shipping, so actual cost is 1.5-2x higher at checkout), so I have not tried them, and many cheap ABS-like resins are not much better than "standard" resins. But even with FUNGDO resins, the actual cost depends on where you shop... For example, for the same resin, Amazon offers expensive $25 shipping, but on AliExpress shipping is free.

It is worth mentioning that for many parts, FDM printer is still a better choice for various reasons, and ABS filament is significantly cheaper ($12-$14/kg in my country) than ABS-like resin. I still prefer FDM when it will not cause issues for a particular part and when FDM precision is sufficient for it. But even if the price was the same, I would not be able to print everything with resin only, or with filament only. I think of ABS-like resin as of one more useful printing material in my toolbox, with its own pros and cons. "ABS-like" by itself is just a marketing term, and even one manufacturer can have very different resins marked as "ABS-like", with different hardness and different temperature resistances.
Reply
#9
This thread is of great interest to me.  I am new to 3D printing.  We have a couple FDM printers at my office which I've used to print some stuff for personal use.  I'm retiring in a few weeks would like to buy a 3D printer to play with after I retire.  I was planning on purchasing a QIDI X Plus FDM printer but one of the guys in the office has a resin printer at home and swears by it, so I am also looking at an Elegoo Saturn.  I have no interest in printing little action figures and the like, I would be using it to print functional parts.  It sure seems like an FDM printer is a better choice for me; stronger, more flexible parts and easier to use.  Can somebody tell me where I'm wrong in my thinking?

I have the space and the funds to buy both printers, but I don't think I will be printing enough parts to justify having 2 printers and I don't think I want to take the time to become proficient in the use of 2 different printers.  So why should I buy the Saturn or any resin printer?
Reply
#10
(02-04-2022, 07:53 AM)VivaTerlingua Wrote: > It sure seems like an FDM printer is a better choice for me; stronger, more flexible parts and easier to use.  Can somebody tell me where I'm wrong in my thinking?

Printer is just a printer. If you buy flexible resin, you will produce flexible parts. If you buy semi-flexible resin (for example FUNGDO High Toughness) - you will get semi-flexible parts at small thickness or touch and strong parts at sufficiently large thickness. There is also FUNGDO Low Viscosity ABS-like resin, it is slightly more heat resistant than real ABS and has excellent adhesion, I can print much more parts without supports. For example, on this photo you can see example of long thin-walled part which was printed vertically - it had little contact area during printing, just a circle with relatively thin walls at the base (on the right on the photo), and no supports:
[Image: Udef5bace5b3f4430a55c57e4c1c670caJ.jpg]

Also, I was able to repair my soldering iron. Its original nut was made out of ABS and it quickly degraded from heat (became fragile and cracked in multiple places). At first I have tried to replace it with a a nut printed on my FDM printer using high quality ABS filament (very expensive filament comparable by price to this resin), but it degraded even more quickly than original nut (it did not melt, but became fragile and eventually cracked in multiple places, like the original one). But then I printed the nut with Low Viscosity resin:
[Image: U59d423e81e2a4bdbb93260f0846b2151B.jpg]

[Image: U66050baf9bd547f8a06f2b43e7ea803ef.jpg]
At the time of writing, almost five months has passed, no signs of degradation at all despite active usage! I was surprised to discover that this resin is actually better than real ABS.

And of course, precision and quality of resin printing is much better - layers are practically invisible, and more importantly strength is uniform in all directions. FDM printed parts always have layers as their weak spot, and break easily, and produce low quality threads. I'm using FDM printers since 2015 and always had issues with them... They never printed high quality parts for me, not even after many upgrades and tuning. Even with 0.2mm nozzle and 0.05mm layers, quality is very bad - small threads barely functional if printed vertically and non-functional otherwise, parts break easily at layer lines, printing speed is very slow even with standard 0.4mm nozzle, large parts often warp even in closed case on PEI bed and careful leveling and temperature calibration, and so on...

On the other hand, after I purchased my first resin printer, I could print right away after very easy leveling and pouring the resin to the vat. Only things I had to tune was to calibrate exposure and bottom layer tolerance compensation (normal layers do not need any tolerance compensation with the right exposure). For complicated parts, manual support placement is important, since currently there is no software capable of good automatic support placement. But supports are very easy to remove, feels sort of just like removing velcro.

> I have the space and the funds to buy both printers, but I don't think I will be printing enough parts to justify having 2 printers and I don't think I want to take the time to become proficient in the use of 2 different printers.  So why should I buy the Saturn or any resin printer?

Resin printers are more recent and produce higher quality parts, so the question should be why would you even consider FDM printers? They still have some pros which resin printers do not have. For example, FDM printer can print multi-color or even multi-material parts, you can buy 1kg of ABS for about $12 (which is about 960ml of material) but resin will cost at least $30-$35 for 1L. There are some other pros as well, but question is, are any of them important to you? If not, there are no reason to buy FDM printer.

If you have sufficient funds, it is better to buy resin printer and ultrasonic bath. Personally I have 19L ultrasonic bath with 290x260x130mm basket (the basket size is the most important, tank size is larger, but actual useful volume is limited by the basket size). I have two resin printer, Voxelab Proxima 6 with Creality firmware and Elegoo Saturn, the bath is large enough for biggest parts I can print. I print mostly functional parts and actively use both resin printers. I still have FDM printer, but rarely use it. Only reason to use it, if I need to produce a part larger than Saturn can print (my FDM printer cannot print multiple colors or materials, so there are no other reason to use it, except perhaps material cost, but the cost is not an issue for me, part quality is more important, so I use resin printers when possible).

Of course, all of above my personal experience. Perhaps there are others who had better experience with FDM printers than resin printers... But often the cause is bad resin or bad resin printer model, or if somebody needed something only FDM printers can do. All good resin printer models are mentioned at the Chitubox website https://www.chitubox.com/en/download/chi...rmwareList  - if some model is not in the list, it may not support CTB file format and therefore lack features. This is why I had to use CREALITY LD-002H firmware on my Voxelab Proxima 6.

Elegoo Saturn is in the list of officially supported printers by Chitubox, so it is a good choice. I have it and I could use it right away without touching its firmware (but I had to make a small small change in the .gcode settings so fans spin when printing like described here: https://www.reddit.com/r/ElegooSaturn/co...he_fan_is/).
Reply


Forum Jump:


Users browsing this thread: 2 Guest(s)