Form Labs Durable Resin
There are multiple different reviews of this resin on the Internet and I’ve decided to take a moderately different approach. As people who have followed me will know by now, I am not an industrial user. I spend, what seems at times like obscene amounts of money on my personal hobbies… such as 3D-Printing. But, I am a home user and I have been through multiple different levels of cheap, moderately cheap, and insanely expensive printers and their accessories.
So, yes, I have a Form 2 printer at home. I’ve also bought the Form Wash, but as you can see from the picture above, I tend to use the buckets included with the printer.
And for people reading me for the first time. I’m not like other reviewers. I do this for free and so far, no one has even offered to give me anything for free for the purpose of reviews or bribes. When I like something, I write about it.
What I’m up to
Well, my little girl, who maybe isn’t so little anymore as she’s about to be an adult next month, she told me “Pappa, I want to learn robots!” and, being the level headed and never over-indulging father that I am, I decided she needed a nearly industrial robotic arm to learn with.
The problem is, it can be quite expensive and at times nearly impossible to get the parts required to build such a robot in Norway. From printing enormous parts and adding NEMA 23 motors to a design, you have to save a buck where you can.
Well, I decided that for gears, I would contact Form Labs and ask them if they had any materials which they’d recommend for printing the gears I needed. This would save me at least $50 in parts and maybe another $80 in shipping and customs. So, I rushed to their online chat.
ALL BUSINESSES SHOULD BE LIKE THIS!!!
Ok… let’s get straight to the point. I have never in my whole life had such an incredibly productive conversation either professionally or personally than I’ve had with Form Labs. The gentleman who greeted me in the chat was professional, friendly, wrote excellent English, and might have been one of the most knowledgeable people regarding their companies products ever. He listened attentively to my needs, what I wanted to accomplish and then he answered with a “That’s unusual, I’m not entirely sure. I think Durable Resin will work best for you, but I think you should order some samples and also talk with another specialist here at Form and I’m sure we’ll get it right.”
Well, I was pretty sure I’d end up spending $600 on Rigid 10K resin… which I’ll write a short review on soon. But, I requested samples of Durable and Rigid 10K resin from the website. I am not a big industrial customer and I didn’t want to bother them with my hobby project… and yet.
The next day I received a phone call from a sales solution specialist at Form Labs in Berlin. She was AMAZING. (I’m not dropping names as I haven’t asked permission). She again listened to my needs and she agreed with her colleague that I should look at Durable if I want to print gears. The detail isn’t the highest and it’s not the most rigid material, but for the 5mm pitch transmission pulleys I hoped to print… it was probably what I wanted.
She also sent me a sample of Rigid 10K and… I’m trying to convince myself not to buy a Form 3L (this year) and throw away all my other printers. I’ll write about that later.
In comes my heros
Again, I didn’t ask for permission, so I won’t use names. But my local Form Labs dealer in Oslo, Norway who, surprisingly enough I have a very good relationship with (they get possibly more of my salary than my wife does), when I was talking with them told me
“A customer just returned a fresh package of Durable resin because somewhere in shipping, it must have been beaten up and it started leaking in the bag. You want it?”
And that’s where the printing began. I looked at the package and it was a sealed package of Durable Resin with some resin leaking in the bag. So, I bought a fresh tray, ran home (drove, I’m too lazy to run) and immediately cleaned it up and popped it into the printer… and yes… I printed.
What did he print?
I immediately printed a huge T5 belt gear for the robotic arm. “Try the resin on something small first” one might suggest. And “Don’t waste so much expensive resin on something like that”. Or “Don’t you know resin and SLA sucks for functional parts?”
I say FORGET THAT
I printed an enormous belt gear and it used A LOT of resin. But I was smart! I hollowed the gear out, stuck a few holes in it and I let it rip.
What did he get?
I got an enormous gear that was a NIGHTMARE to wash. I mean seriously. I was about to go get the Form Wash out of storage and head to the 3D printer store to get 10l of isopropyl alcohol at the bargain price of like $150 in Norway (there are weird taxes on it).
But I washed it and I rinsed it and then I stuck it in my home made curing station and… it was almost perfect but… it was sticky. So I broke out the citrus cleaner and went at it… and it was sticky.. and there was that kinda mushy “he should have washed it better” feeling.
The package arrives
Well, I received the package and I opened it up and it was lovely. But I couldn’t help thinking “What did I do wrong?” and “Where did I fail?”
See, the Form Labs print was just so amazingly beautiful that I couldn’t figure out how come my print was so bad.
So I rushed to the 3D printer store. And talked with them (while also sticking my gear into their Form Cure for a while). And they told me that their experiences with the Durable Resin were far more similar to the sample than my print.
BEFORE WE GO TOO FAR
It sounds like I’m unhappy with my gear. I LOVE my gear. I am very happy with it. In fact, it’s on the robot and it’s sitting under about 10KG of weight and it is working FLAWLESSLY. Compared to the Form Labs high temp resin, it’s a much much better suited for this purpose.
Back to the story
They told me that using a Form 3 (as the sample did) could have something to do with it. But they were convinced that it’s more likely that I didn’t wash it properly and since the part was hollow, it didn’t clean the inside of the part from all the resin as well as I may have liked it to.
The Form 3 is actually quite a big upgrade from the Form 2 from what I’ve seen. I only have a Form 2 here and at work, but when I visit the printer store, I definitely see that the Form 2 does a better job.
Washing is almost everything
I printed more parts where durable was important. The item above is a spacer which I printed to avoid spending a pile of money on metal spacers and shipping.
I dropped the part into a basket of alcohol which needs to be changed soon as it’s getting dirty. I scrubbed it with a toothbrush and my gloves and scrubbed some more and left it in the alcohol for two hours.
Then a scrubbed a little more and popped it into a nice clean vat of alcohol for a few hours.
When it came out, it was clear to me… no really, it was clear as in, it was practically transparent. It was a tremendous improvement.
Unlike the FormLabs High Temp resin I normally use which you can clean pretty easily with gentle washing in alcohol, the same true for FormLabs Pro Resin, the durable resin is… well durable. It really just does not want to come away from the cured resin. It takes a lot of work.
Avoiding an ultrasonic cleaner
I think a lot of people have found when printing with DLP or LCD printers, the only reasonable way to clean a print is with an ultrasonic cleaner.
Well, I’m not going that way. Isopropyl alcohol is flammable and worse, it’s easily nebulized into a somewhat combustible vapor. It is NOT safe to use IPA in an ultrasonic cleaner and every time I watch videos where they do this, I want to jump through the screen and smack the people doing it. IT IS NOT SAFE and it is a really bad idea.
There are other cleaning solutions which are pretty good, and I’m tempted to talk with a chemist I work together with and ask him to find the right solution for me. But for now, I’ll either get my Form Wash and spend the money on the rapidly evaporating IPA or I’ll keep scrubbing and waiting.
Did the results continue?
I’m not able to consistently reproduce the results on the durable resin, but I will keep trying.
Resolution
I’m printing using Form’s new “adaptive layer height” feature which I think is amazing. But the truth is that I think that durable resin really needs the full treatment.
My belief is that Durable Resin is probably the resin which benefits the most from being printed on the Form 3. Compared with High Temp which prints pretty much perfectly every single time and cleans up nicely, the interlayer updates between the Form 2 and the Form 3 causes less distortion between layers. The Form 3 uses a more flexible build platform which peels away from the prints between each layer. The Form 2 starts by sliding to the side, then pulls and I have a very strange feeling this causes microscopic bubbles to form in the print. I did look under the microscope, but I can’t magnify more than 200x using optics. So I haven’t see that. I think it’s much finer than that.
But overall, I think by printing on the Form 2 with adaptive layers, either my layers are too big or too small. I need to find the Goldilocks zone.
Why keep using it if it’s not perfect?
Who said it wasn’t perfect?
Ok… it’s not perfect. I’m in the immortal hunt for the perfect PA12 SLS replacement. The durable resin certainly wins the gold medal on that. But it’s not rigid enough for my liking. The sample I received from Form Labs was more rigid than any of my prints which leads me to think of something else.
Maybe heat helps too
The recommended post processing curing procedure for Durable Resin is to bombard it with 405nm UV light for 60 minutes while also cooking the print at 60 degrees.
I’m pretty sure that the cooking is pretty important with Durable. Even though I waited several days between doing it and I didn’t clean the big gear enough, I saw noticeable improvements when using the Form Cure.
The part became somewhat bendy and less rigid when it was cooked. That lasted until it cooled down. I think that the heating assists with a glassing effect.
So could it be perfect?
It’s pretty amazing stuff. It’s strong. It supports the robot beautifully. The gears are working perfectly. The screws are holding with no additional reinforcement even though I clearly (and intentionally) over-tightened one of them.
I could easily print a replacement for this using polycarbonate on an Ultimaker S5 I’m borrowing right now. I won’t.
I think durable resin was probably the almost perfect material for this print. Once it cleaned and cooked and it came together in the end, it was really a great material.
I printed smaller and functional parts for use on the robot. The gear pictured above is fully tested when attached to a 4nm NEMA 23 motor and this gear is strong and it will last for years.
The resin actually printed thin walls very well. I didn’t really expect that from the durable resin. I expected it to struggle with anything smaller than 1mm. It instead rose to the occasion like a true champion.
I am now printing a scale model of a prototype for a robotic mining bore that I’m entering in a competition next week. So soon I’ll have used the full liter of durable resin… and I’m happy.
Will I buy it again?
I honestly believe that this is maybe the best utility resin I’ve some across. While I love printing FDM polycarbonate, there are a lot of problems that come with that. I think that for any application where I need a material which is REALLY … well durable. Anywhere I need parts which simply WILL NOT BREAK, durable is my new choice. I believe it’s extremely likely I’ll have bought a package of durable resin in the next week or two because I think it’s the most functional resin I’ve encountered in the sense that it’s not too soft, not too hard. It can print quality parts for more than just prototypes.
I would have to revisit this in a year and let you know more, but I believe that this is maybe the best material I’ve encountered for making items like gears, bushings, spacers, nylon washer replacements, etc… I think it printed very well in scale which I was skeptical of. I think Durable Resin will replace my use of polycarbonate when producing machines… so long as I can make them fit on my tiny little Form 2. The one exception is when I need rigid components. And in my next article about Form Labs, you’ll learn why I will likely go bankrupt in the next year or two.
