Flexible 80a Support Sizes


#1

Hi Form Community-

I’m going to run a handle overgrip with the new Flexible 80a on the Form3 and wondering if anyone has had any experience, success or recommendations on how to align it in Preform and support sizing? The only recommendation per Form is to orient the model a minimum of a 20 degree angle, but nothing else. The part is about 1.5" diameter and 6" long.

Any feedback is welcome.


#2

Sharing my recent experience in case it helps.

For the old Flex v2, I found small parts worked just fine with tiny supports. For example I printed this tire using 0.4mm supports plus two 0.85mm ones where initial contact is made with the first layer of the model, and it came out perfect:

But larger parts are more challenging. This remote control sleeve failed (several times in a variety of orientations) even with a mix of 1.5mm and 2mm supports throughout:

A big issue in my case was the height of the part. The further you get from the build platform, the less rigid your support “substructure” becomes (I’m talking about both the Preform-generated support lattice, and even to some degree the earlier portions of your part upon which the next layer is cured). You get more layer shifting and localized defects. So in this case the suggestion was to reduce the angle of the part, so that the print wouldn’t be so tall (keeping everything tighter toward the platform).

That’s just a small cross-section from my limited experience with an older flavor of Flex.

The newer 80A has substantial improvements, not the least of which was to double the tear strength. You can compare properties in the chart here and also find more specific recommendations on feature size, angles etc.

I haven’t had a chance yet to try the sleeve with the newer formula, and am hopeful it will let me reduce the touchpoint size (along with some great suggestions on orientation improvements from a Formling, such as aligning the part’s major axis roughly along the mixer/peel direction, with the tallest part toward the mixer side so it “pushes” against the peel forces rather than “pulling” with the LPU).

But I imagine the general principle holds that if your part is big and tall, you need to be cautious about reducing touchpoints (and may have to adjust upward). The Preform defaults are a good place to start (although others may have more specific advice based on the dimensions you gave). If your part is small, you can probably get more aggressive and reduce somewhat from the defaults.

Good luck, and would love to see photos of how your overmold comes out (if it’s shareable)!


#3

Flex 80A is a lot easier to print with. I typically use 0.4mm touchpoint size at 1.00 density for all parts.

I usually pick orientation based on minimal support cleanup for all resins. However this is even more important on flexibles because you can’t sand artifacts down as easily as rigid materials.

So I always orient for minimal cleanup first…but there are cases where you have to orient to minimize deformation over support cleanup. This is usually the case for long, thin parts.

Another thing I usually do is orient it such that when it peels you are getting mostly forces in tension on your part instead of tension + lateral forces which deform your entire part and cause issues. More important for tall thin parts.


#4

Thanks for the great input Fellas!! The first pass at it was with much smaller supports (winging it before I got the feedback) and as expected, it failed. Unfortunately had let it run for several hours and this morning was cleaning the mess out of the tray. :joy:

I’m running with 0.5mm touchpoints and a few 0.85mm at specific high tension areas and I’ll let you know how it shakes out. I’ve got two prints, one shallow and one about 6" long, so we’ll see how both react to these changes. I’ll share pictures when they come out.

Talk soon.


#5

Yeah it really depends on part thickness and orientation - specifically, you need to think about how the part may deform during the peel process.

I’ve been lucky enough so far that most of my things have worked at 0.4mm touchpoints.


#6

You likely already did this, but just in case, it’s a good idea to filter the resin before your next attempt (to catch any debris / bits left behind by the failure).


#7

Hi @rkagerer @leonhart88,

I think it would be helpful if you clarify if those advises regarding peel force effects, which are really interesting btw, pertain to a specific printer or not (which Form #?) since they have quite different peeling systems.
He is printing with a Form 3. I also only have a 3 and I just got some F80A to try out.
But I think you guys have both printers, right?
Also, I wonder if Preform take this things into consideration when doing auto-orient :thinking:


#8

My comments pertain to both F2 and F3. Printing in flexibles on the F2 are even harder because, like you say, the peel mechanism is very different and results in a lot of shear forces. This causes parts to deform more and because of hysteresis, may not return to the exact same spot.

Even though peel on the F3 is in tension, because of the way the film peels off, there may be lateral forces along with the mostly tensile forces. It also really depends on your geometry…if you have a very long but angled part, even forces in tension will deform your part during a peel.

I never use the auto orient. I don’t think it’s smart enough to really yield good results across different parts. There are always different variables that you try to optimize for and there’s no way an automatic feature knows exactly what you want.


#9

All I have to add to @leonhart88’s excellent explanation is a picture:

Real-world prints will be a little more complex (you often want to try and tilt in at least two axes) but hopefully that gets across the idea.


#10

Got a good print thanks to the input from the group!! The over grip on the right is 6-inches long and the object on the left is a hexagonal bumper that slides on the 1.5-inch dia tube. I’m pretty happy with the first pass as this and it was a good learning experience. Initial settings were 0.55mm touchpoints at 100% density with about six 0.85mm touches at the top and bottom. I’m not sure if they really contributed to the success but they didn’t hurt it.

I washed for the recommended 20 minutes in relatively clean IPA and then removed the supports. It was pretty easy to pull them off but would recommend going down to 0.50mm or 0.45mm on my next run. I tried doing automatic orientation with Preform and it still gave me a straight up/down orientation, which is counter to what Form recommends. Personally, I don’t give Form high marks for Preform and I spend a lot of time fixing what the software is doing. As you can see from the print, there are some support artifacts between the ribs of the grip which contributed absolutely nothing other than being a booger on the print.

As for my opinions of future prints, I would not go greater than 6-inches on the Form3. It was pretty fascinating watching it peel away from the tray after each burn but the support lattice really flexes hard in tension when the platform pulled upwards and in general, the peel process is uneven and the lattice moves quite a bit until it breaks free. Somehow it manages to reorient itself before the next dive into the bath.

Thanks for all the feedback and I’ll be trying this again in the near future. Still cutting my teeth on the Tough 2000 and learning that one as well.


#11

Glad to see it came out good! Thanks for sharing those specifics.

I’d love if Formlabs provided a “reinforced lattice” option for this resin. Perhaps slightly conical support pillars that are thicker toward the base, or additional lateral buttressing, to try and reduce the flex as you get farther away from the build platform.

Maybe one day a printer will use some kind of optical feedback to find the edges from the last layer and use those to align the next one.


#12

I agree that a reinforced support system for elastic and flexible would be helpful.

Great looking part! I actually would have printed this entirely vertically directly on the build plate. Benefits being that this is the best orientation to minimize deformation and also no supports to clean up after! I am pretty sure flexible 80a would print perfectly fine like this. If it was elastic, it probably would print fine as well if your wall thicknesses weren’t super thin.

Printing at an angle is only to minimize cross sectional area on large parts. If your cross sectional area is small, it doesnt matter at all. Formlabs usually suggests against vertical printing because it’s typically better for most larger parts, but they have lots of examples where they do it (gillette razors, nose swabs) and I do it all the time. It’s important to know why and use that knowledge to your advantage :slightly_smiling_face:

The only potential downside would have been cupping, which you could easily solve with some small drain holes.


#13

Hi guys

Iam having some major printing fails with the flexible 80A resin and need some help.

how would you guys print that object ?? (STL. file rumpf_ attached) size of the object is roughly 50mmx50mm.
my prints are always stuck to the tank after finishing the raft and started with the supports.

thanks for your help

rumpf_offen1.0-27.12.20.stl (858.8 KB)

Print setup



#14

Be sure those thin parts are oriented parallel to the direction of motion of the wiper/mixer. See my photo above (Sep 20) with the ✘ and ✓ icons.

Have you tried angling it some more? At least enough to eliminate the internal supports and turn them into regular ones.

What layer height and printer are you using?

EDIT: I had a quick look at your STL and noticed in the position and orientation you illustrated above there’s likely cupping. You might try an orientation like this instead:

I’ve rotated the part so that it’s in line with the wiper motion (i.e. perpendicular to the wiper itself). I’ve also placed it on supports (using density 1.35) to eliminate the cupping, and tilted it. Then I added a few more manual supports near the start of the print. (If you want to print direct-on-base, which is otherwise fine for your geometry, then you’d need to add a vent hole to your part).

Here’s the file if you want a go:

rumpf_often1.0-27.12.20-edited.form (498.0 KB)

Others may have more time to examine this and improve or refine what I’ve proposed.


#15

Yeah cupping will be the death of you. Also 0.25mm touchpoints are way too small even on the Form 3. If you’re on the Form 2 then they need to be bigger than the F3. I use 0.4mm on the F3.


#16

Thanks for your time and knowledge :pray:t3:

I give it a try and keep you up to date.

Thank you


#17

Yes I am working with the F3,
Okay I will change that.
Thank you :v:t3:


#18

Hey All-

Just wanted to share some discovery with the Flex80A. We’ve been using it a lot over the past few months for production grips and have some pointers:

  • Depending on the type of model and orientation, we’ve actually had great luck printing directly onto the build platform without any supports or rafts. Depends heavily on the model, but we’ve saved ton’s of resin and cleanup by eliminating supports. Prints pop right off with a flat blade Xacto knife (#18 blade).

  • Do need to watch out for cupping, so we placed some .050" relief holes where the tube meets the platform. No cupping issues and haven’t had issues with washing them.

  • We’ve learned that if you print the same part on the same location for about 5-6 times, the print seems to drop off the platform and sticks to the tray. With Flex80, it’s pretty easy to fish it out of the tray, but it seems that the tray loses some of it’s anti-stick properties with Flex80 and simply rips whatever print you have at whatever stage and sticks to the tray. This kind of failure seems to be limited to the Flex and haven’t seen it with other resins. I know that it’s a no-no to print the same thing over and over again, but this is production life. I’ve got a nice pic below that shows the fun. The V2 trays wear far quicker than the projected 600-hours print time with Flex80 even if we rotate the tubes around the build platform (about 250-hours and changing it out tomorrow).

The biggest takeaway from working with Flex80 is that it’s one of the few resins that can be built right on the platform if your model allows for it.


#19

I wonder how the Form 2 tanks compare to the Form 3 ones in terms of wear with this resin.


#20

I’ve used one cartridge of Flex80 and have really enjoyed it. I don’t think I’ve ever printed 5 identical copies in a row, so I can’t confirm your “stick” observation – I did not see it.

In my case, I would occasionally reprogram the resin tray for various different resin types. i.e. I would do 3 or 4 Flex80 prints, then maybe a few Tough prints or black or clear prints, before going back to Flex80.

I’ll order a 2nd cartridge of Flex80 soon. Cartridge 1 had no print failures.