Good deal.
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Hi again,
The machine is pumping out one great print after another. We have a 100% success rate since we swapped out the white resin for the clear resin. We now have around 10 new 3D printed objects we created over the last 3 days (some were doubled up). We have printed larger and flatter objects than what I pictured earlier in this topic. I reprinted the second form that I pictured and it printed great. When I get time next week, Iâll try the first form I pictured at the top, we just have been busy with a high priority project this week, and I feel very lucky that we have been able to finally use our Form 1 to its full potential. Thanks everyone for your help and suggestions! Here is a pick of one of our new successful prints:
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Thatâs great to hear, Chris. Have you returned to white resin at all? We havenât heard of a great deal of instances of such varied performance with different resins, so weâd like as many details as possible.
A while ago I poured some grey resin into the printer without shaking the bottle. This was a new bottle that was sitting in the dark closet for a good month. I completely forgot to shake it before pouring and then had lots of failures and didnât know why. I then realized what happened. I cleaned my tank, got rid of the resin in the tank then, shook the bottle well and tried to print again. I got nothing but failures.
I changed to a new bottle, shook i well and got nothing but perfect prints.
Since the resin settles, when you donât shake the bottle well before pouring into the tray, you can easily mess up the formula (concentration of pigment vs other components) in the bottle, which may render that bottle useless.
I think this is what may have happened to your bottle of white also. If you go back to it, you will get failed prints. If you get a new bottle of white, you should get successful prints.
The resin warms up because the curing process is exothermic. Itâs not from the laser itself, itâs the chemical reaction that the laser triggers.
The resin warming up should not affect the print at all, because the reaction is contained in such a small area and is very weak. You are right about the chemical reaction that makes that happen though. I once left some madsolid resin to cure in a plastic bag, sitting on top of a fedex padded bag, under the sun and the resin melted through the bag and through the fedex bag. And the cured resin was not just warm. I could barely touch it.
Yea I am sure you guys are right, the chemical reaction causes the most heat. I use casting resins and they get very hot, this would be similar.
I have continued to have successful prints since the last post. I just had a fail today, but I think it might be because my resin tank was wearing out. Anyway, I have been taking close up photos of the prints showing the texture quality of the resin near the end of each print. Even in my clear resin, the surface quality degrades later in the print. Why does this happen, and is it contributing to print failures? Also, has anybody else noticed this effect? Here are some pics, all of these are printed at 100 micron thickness:
This is what the texture looks like through the first 70 or 80% of my prints, depending on how big they are:
This is how the texture looks near the end:
This next print failed after I paused and refilled the resin tank, mid-print. It is interesting to note that the surface texture quality was poor right before I paused it, the pause line is marked in blue dots. The last few layers of the print before I cancelled it seeing the failure, had good surface texture.
Finally, here is a photo of one of our prints, showing what the surface texture change looks like from a normal perspective:
Fantastic documentation â Iâm not personally aware of issues like those youâve pictured, but theyâre certainly a really interesting set of observations. We really appreciate the great photographs as well, as those are really useful for our engineering teams whoâre looking specifically at print process. Iâll make sure that this thread is brought to their attention!
Hi Christopher,
I have noticed similar issues, slight (sometimes pretty bad) degradation of print quality with tall prints or large models. And usually the degradation can be on just one side of the model in form of a bumpy texture, when the other side is very smooth. I donât print a lot of those, so it hasnât been bothering me too much.
There are 2 things that could be causing it I think. One, is the fact that the resin doesnât get mixed enough during the print process and the âpigmentsâ and in case of the clear resin the âuv blockersâ settle a little, and that changes the resinâs ability to block the light effectively, introducing all sorts of weird print quality issues.
Another thing that may be causing it is what I like to call⊠âPDMS Fatigueâ. Basically as you print your hundreds and maybe thousands of layers, the PDMS layerâs ability to inhibit oxygen cure and stay âlubricatedâ diminishes temporarily. So what happens is really hard to visualize and see, but some thin layer then actually may stick to the PDMS and not peel off well, or even peel off on the next peel cycle. They also can shift, wrinkle and warp a little because they stick to the PDMS.
Obviously itâs really hard to observe this happening, but based on your excellent photos, I think that is what may be happening here.
That is why I scrape or âmassageâ the PDMS before each print for a minute or so. Not just to mix the resin around, but also to introduce oxygen back into the PDMS layer and to press resin that may have been saturated into it out a bit.
These are only observations and theories of course. Iâm sure formlabs tech team can do more precise experiments and give us more concrete answers.
@Monger_Designs, it is true that this surface effect I have pictured is dominant on one side of the model wall. So when I have say a cavity in between two walls, one surface will degrade on the outside, and the other surface will degrade on the inside. Here is a photo example, showing how the surface degrades from the same direction on both faces (the print failure was most likely due to a worn resin tray).
As Monger observes, there are a number of factors at play, but weâve been talking internally about some of the problems that youâve highlighted here, and at least part of the issue is the accumulation of very small cured particles in the tank. Over time, those particles can increase in concentration, and eventually adhere to the surface of the part, causing the aberrations that youâre observing. This is especially noticeable in vertical columns and similar shapes.
As you noticed when you refilled the tank, that restored your surface finish, as it reduced the concentration of cured bits (we call emâ floaters). Filtering your resin periodically should do the same. I hope this is helpful. Our engineering teams are aware of the issue, and are working to address it, but I donât have any specific timeline for you. At the moment, fresh resin and care should help your prints always be in tip-top condition.
Sorry to revive an old topic, this is the closest thing i can find to my current print.
My kid is learning about dinosaurs and fossils, so of course daddy needs to print a T-rex head for fun, but fun turned into 2 failed prints. 
The first print, you can see the layers were looking good, for a while, then it started.
I thought i could re-position the dino and try again. The 2nd print lasted longer but still failed.
My resin was clean, tank was clean and cloud free, mirror is clean, and i am stumped.
@Sam_Jacoby was there ever a conclusion to the issue?
Also how do most people filter the resin to get rid of âfloaters?â I hate the idea of dragging a comb across the bottom of my tanks.
After many attempts , mirror cleaning , change of tanks , change of resins, there will be only one answer , the laser is dying, every new attempt to print.
Marcelo, please send us a ticket so we can take a look and help you out.
Jory