Beam Intensity and feed rate of different resins

Hello,

I’m doing some experimental work with White V2 and filler materials on my Form2. Since the filler material absorbs some of the lasers light, the resin does not cure completly. Post-curing leads to a hard, stiff part, so increasing the exposure intensity while printing might just do the trick.

Since there is no way to increase the beam intensity or reduce the feed rate manually, I was thinking of fooling the printer. I assume that not all resins are beeing printed with the same beam intensity / feed rate? Putting in an empty cartridge of an different resin would lead the printer to change beam intensity.

If my assumption is right: Which resin requieres the highest beam intensity / lowest feed rate?

I have Black / White / Clear and Castable available.

Greetings and many thanks!

The part is not supposed to be fully cured when it comes off the printer. The resin is intentionally left in a “green” state during printing. Post cure is always required to fully harden the part. If you fool the printer so that it uses a higher exposure for the resin being used for the print, it will cause the PDMS to wear out faster and possibly it will cure the resin to the PDMS hard enough that the printer won’t be able to peel the layer loose and the print will fail.

Based on your description, unless the print is coming off the printer with a soft, floppy consistency, you’re probably good as-is.

If you want to play around with this, though, you can run the printer in Open Mode and tell it the resin is whatever type you want. There’s an resin exposure chart somewhere in this forum that shows what the power levels are for each type of resin.

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Thank you for the quick response.

I am aware that the parts require post curing. What I meant was that my parts (do to the filler material) are jelly like, causing the print to fail.

This chart was exaclty what I was looking for. I did not know that the open mode would allow you to change that setting. So I will digg to find that chart.

Thank you!

unless the print is coming off the printer with a soft, floppy consistency, you’re probably good as-is.

OK, then! You do need a higher exposure level. :slight_smile:

my parts (do to the filler material) are jelly like,

I presume you mean this chart for the Form1?
I guess it should be about the same for the Form2?

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Yep! That’s the chart!

And the resin doesn’t know which printer it’s being printed on. The exposure levels are pretty much the same irrespective of Form1 or Form2.

Also, if you switch out the resin in the cartridge and use a different resin setting then that could have issues when filling the tank–the way it detects the fill level depends on the chemical properties of the resin so it’s possible it could detect inaccurate levels and maybe overfill.

Do you know what the units are, for the Y-axis of that chart?

Are you sure about that ? It seems to me the resin level sensor is just a capacitive sensor and as such it shouldn’t be too sensitive to the type of resin, especially between white, grey and black.

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The sensor doesn’t physically measure the height, I’m not sure exactly but it’s something like it runs an electrical signal through it and from the result it can tell how much resin is in the tank, so the chemical properties will change how that signal gets interpreted.

That’s how capacitive sensors work. They measure the dielectric constant of a material. We have three dielectric values at play here, air, the tank material and the resin. Two of these value are constant within the Form 2 system (air ant tank material), so the sensor only has to measure the resin, it doesn’t really have to detect a narrow range of dielectric value it only has to detect a value that is not exactly air+tank, which is why I think the resin sensor should not be affected by the type of resin that is in the tank.

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Just to clarify - are those exposure times affected by open mode? In other words, do I have to refill a resin tank and trick the Form 2 into thinking it’s printing something it’s not?

I’ve been testing some 3dresyns materials, and they work, but I have to add a bunch of their light blocker, which ups the price. Seems like a waste if I could just turn down the laser power or shorten the exposure.

The cartridge tells the printer what the resin is, and the exposure is set by that. In open mode, you tell the printer what the resin is in order to set the exposure. But you have to add resin by hand. If you want to use a cartridge, you need one that used to have the resin that represents the setting you’d use in open mode for your 3rd party resin. Then you can print in “closed mode” using the cartridge and your 3rd party resin. For example, if you used FL Grey in open mode with your 3rd party resin, you could refill a used/empty FL Grey cartridge with the 3rd party resin and run in not-open mode and the printer wouldn’t know the difference.

Does that answer your question?

It should be noted that FL does not endorse doing this, and they may be less than interested in helping you out if you have a problem.

Thanks for the response!

To further clarify, I asked the people at 3dresyns what resin I should use in PreForm, and the response that I got was, it doesn’t matter. The guy at 3dresyns said that open mode forces a specific limited profile.

In my own testing, I’ve seen that choosing a different resin type in PreForm can dramatically affect actual print time. I don’t know for sure if that’s because of different exposure times, or something like a different peel procedure.

I would just like to know for sure if choosing a different resin type in PeForm while in open mode will in fact change the exposure settings, or if the guy from 3dresyns is correct and open mode forces a fixed exposure profile.

Thats strange Scott - The person I spoke to at 3Dresyns spent a lot of time telling me about the different resin types settings that are available. How different resin settings have different exposure times and speed of laser travel (and therefore more or less total UV energy into an exposed point for a given time - thus affecting the cure)

The resin type settings (He told me to set it to “Clear Version 2”) he gave me for my resin have worked well (in fact significantly better than Formlabs own resins) What I find interesting is the fact that he said their resins would work even better if they had access to those settings (which other printer manufacturers allow) rather than having to work with a handicap (he said the lack of wiper, resin heater and variable settings all made it more difficult to get the best out of the resin on a Form2.

But, saying that - the resins I have tried (ultra hard and tough and ultra hard and flexible) are significantly better than Formlabs own resins, they are cheaper, higher performance and impressive. I guess if they were optimised properly (without the current restrtictions imposed by Formlabs on competitors resins), Then the 3Dresyns would be even more awesome!!

Are you using their resins as shipped? I’ve tried many resin profiles with their UHT resin (including Clear V2). I’ve tried two different batches, one white and one blue. The white I had to mix the color in myself, the blue came pre-mixed. I’ve had two problems, 1) overgrowth - small features and support come out too thick. 2) large prints stick to the PDMS. One large part fused so tightly it was very difficult to remove, and basically ruined a large area in the tank.

Adding their light blocker makes things better, but it’s expensive, and kills much of the savings, and I still can’t get larger prints to work.

Scott - have you contacted 3Dresyns to tell them your problems? Have you asked them what to do?

I did with my prints. I was struggling at first but after chatting to them I got excellent results.

The largest print that I have printed is 183ml in size (according to preform) and other than the very annoying line where the Form2 stops with 3rd party resins after 100ml the print is fantastic.

Scott - They also sent me a copy of their fine tuning instructions. Personally I am happy to fine tune something if I know that in terms of the final physical properties of my printed material are going to be what I want. Those properties are significantly better than materials with a similar product description (physical properties) of Formlabs.

You mentioned cost - I see from the 3Dresyns website that their Lightblocker is €60 for 50ml. That is used (according to their website) in a dose of 1 - 3% - so that is enough for 2 - 7L of resin. It’s not needed most of the time (I found that some of their resins types with the Form2 are perfect out of the bottle.- at other times they needed a little tweak - i have never needed more that 0.6% LB and none of their other additives. So cost for me is less than $10 per litre extra. Yet I end up with significantly better physical performance properties (than FormLabs own resin) and overall it was cheaper than buying Formlabs resin with a similar description.

For example Formlabs “Tough” is $255 per litre (In Europe) but the 3Dresyns “Ultra Hard and Tough” is $86 so even with the shipping cost to the US the 3Dresyns product is considerably cheaper.

Here is the link to their fine tuning instructions: https://www.3dresyns.com/pages/how-to-fine-tune-3dresyns-for-your-printer%20

I did try to contact them through email, and I never got a reply. I have seen their fine tuning instructions, and I am getting OK prints with 3% LB1, with just an occasional tear off stuck to the PDMS.

As for pricing, the price I see in the FormLabs store from the US is $175 for 1L for tough. For 3DResyns it’s about $86 per 1L. And 3% LB1 (30ml), at almost $74 per 50ml, I’ll be generous and say $35 per L added cost. That’s significant compared to the $86 base cost. I’m still saving $50 or so a L, so I’m not going to give up yet.

I just wish I could get better detail (like by turning down the laser power or through a different profile) without adding the LB1.

Just wanted to check in and say that 3DResyns saw this and did get in contact with me.

Basically they said I had too much LB1. I’ve done some more testing with their resins as shipped, and have had a successful test with one of my larger parts (one that was tearing off and getting stuck on the PDMS).

The quality at 0.05mm is pretty good, but I’m still not satisfied with the results at 0.1mm. I’m seeing things overgrown about 7-15% more than FormLabs tough. But the difference is smaller using 0.05, so I’m sticking with that for now. I can work with it, and without LB1 it’s far cheaper.

In my prior test I was comparing to another 3rd party resin. Both 3DResyns and FormLabs look dramatically overgrown in comparison. But it’s not a “tough” resin so it’s probably not a fair comparison.

Anyway, all you formlabs people out there, I still wish I had heater, wiper, and some control over laser exposure in open mode. But it’s not going to stop me from experimenting, particularly when other resins are much cheaper than your own.