Since there is no unified category for FUSE printers, I write the question here in troubleshotting.
Has anyone tried printing from 100% used powder?
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Welcome to the forums Kostbone.
I have tried and failed several times experimenting with this.
Even the sift gives you a warning if you go below 50% refreshrate, so that should be a major red flag not to go below 50%.
That they market the nylon at 30-50% refreshrate is a complete lie as it will never work,
Nylon 12 nor Nylon 12GF can do that.
What i think alot of ppl is missing is that lets say you have a printer going with 100% new powder,
When that remaining powder goes into the sift, it is concidered recycled powder. You mix at 50% refreshrate and pour that into the hopper of the printer and 50% of that material is now concidered used and thus the quality has started declining. Cause as soon as the fresh powder has been heated up, it looses it integrity and becomes harder for the printer to sinter.
What this means is that after 5-10 prints with a refreshrate of 50% you can basically empty the sift cause the material is basically dead and not going to print good.
Have you sometimes noticed that the cake is stiffer to break apart when extracting the parts?
Well, my belief is that this occurs when the powder goes bad. As i have noticed this behaviour several times when the powders lifespan is coming to an end. Only way is to discard that powder and fill up with new powder, and pretend like it is raining when the cost of material is skyhigh at approx 110 dollar for a kg.
If someone else has opinions/thoughts on this matter, Feel free to jump in the discussion.
Edit: We have both Fuse 1 and Fuse1+ and especially the Fuse1+ the powder has a shorter lifespan than in the Fuse1. I have read some speculations that this is caused by heat leaking into the hopper on the Fuse1+. Not confirmed by Formlabs tho.
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Then I will also join the discussion:
We use the normal PA12 and always print with a refresh rate of 30%. We have experimented with somewhat higher rates, 35% and 40%. However, these have not really produced different results than 30%.
Currently, our sift is set at 33% to somewhat compensate for the used powder portion when brushing the parts off a bit more thoroughly.
We actually push as much powder as possible from the printed build chamber into the sift. Among them is also a accordingly large amount of used powder. Therefore, we have set the specified minimum 30% to 33%.
At this refresh rate, the components are no longer as Tough as at higher refresh rates. Thin components are more brittle and can be broken through more quickly. In most cases, however, we can compensate for this by orienting the parts accordingly in the build space, by building up moving parts such as spring clips or clips along the Z-direction.
Our very first print on the Fuse1+ with PA12 had a 100% rate, of course. Here the parts were extremely resistant. The first test objects had a wall thickness of about 2mm and could hardly be broken with bare hands. Therefore, we want to experiment again with 50% and 55% in the future.
We occasionally have components that we have to dispose of because they have thermally distorted areas. Here, however, I am still undecided whether this is due to the refresh rate. We are currently trying to rule out other causes, such as the build chamber and humidity.
I would not have tried to print with 100% used powder myself, as this is not recommended by Formlabs and other manufacturers without reason. Nevertheless, it is interesting to hear that it has been tried. Many thanks at this point for the report.
The warning for below 50% refresh rate must be due to the PA12GF, as we do not get such a message here with PA12.
Unfortunately, the reports with PA12GF are still very mixed, which is why we will stay with PA12 for now.
Whether the material properties at 30% refresh rate are sufficient for the user, I think everyone must try out for themselves. However, I would call it printable in any case.
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Unfortunately, it is very complex and difficult to achieve a higher fill rate. In order to be able to use 100% of the purchased nylon powder, it is necessary to fill the chamber with at least 30% of the parts, unfortunately, in reality I only manage to fill about 15%. If the parts are in good shape, I can sometimes get to 25%. But that’s the maximum. Once a year I managed even 31%. However, filling the chamber to, for example, 50% is nonsense. I tried it once - not actually printing, but just filling the chamber in the computer, and in order to reach 50%, the parts were in the shape of a cuboid, lying down and of a suitable size that they just fit in the chamber. However, in reality this is never achieved and so I have 85% unused powder that accumulates.
It is a great pity that it is not possible to use 100% of the used nylon powder, for example, on your own parts or test parts. I wouldn’t mind if the strength of the parts was lower, or if the part suffered in terms of surface quality. If I needed to print a part for myself and not for a customer, I wouldn’t mind worse features. When I tried to print 100% used nylon PA12, everything went well, the only problem was that the powder was more difficult to spread. He’s basically stuck. I’ve tried burying it while printing, unfortunately it has to be done every ten minutes or so, and since the prints last all day, it’s nonsense. If I didn’t, I only managed to print for about 2 hours straight.
So I am looking for an alternative to dispose of the used powder. It is also a great pity that the automatic packing is not ideal. It can’t compare to manually comparing parts in the chamber.
Hi everyone.
I’ve only received our Fuse 1 a few days ago and the first print was quite perfect.
but the second and third weren’t. we started to see some structural shift, bad surface finishes.
Not sure if it’s because of my model placement orientation.
On top of that. the first sift machine we received were faulty and leakes powder from the bottom and got replaced.
Some of the powder might be contaminated because a member accidently mix the powder on the floor back into the sift into the used powder.
Our environment is extremely humid and we are not sure how to solve it yet. We are extremely worried it will impact the quality (as it seems our second & third print have clear defects. )
We indeed are discussing with reseller here how to solve it. either we should store used powder and fresh powder in a low humidity box or he suggested for one add some IR lamp in the hopper to help keep it dry.
But as it seems from Andreasemilsson it is better not advised.
i mean my colleagues had a fuse 1 too.
And keeping the powder dry seems to be a big deal. we both agree the assembly tolerances/finishes and the anti-humidity design (if any) are quite poor on both fuse 1 and sift. makes me wonder if it’s really a USD$60000-worth machine (here for us)
I second that… even if you trust the PreForm estimate in powder usage for a job, we have no real idea yet how much powder we are using per job due to this factor that you mention.
Some of our designs are sheaths (for tools etc.) and while trying to run Nylon 12 GF for a year at 50% refresh, what you are mentioning we saw as well. Where the powder internal of the part would be easy to knock out in the sift to then it being like concrete and needing to blast just that loose powder out in the blast cabinet.
I think the sweet spot for us has been going to a 70% refresh for Nylon 12 GF. Yes, with the fixes we may be able to actually go back down to 50%… but the parts themselves defenitly are not as strong and more brittle for our smaller more intricate designs and you start seeing what you bring up. Where the Sift recycled powder flips to being unusable. So I think 70% refresh keeps that recycling going naturally because you obviously are upside down on the Sift ratio at that point so every few jobs we have to do a 0% refresh into a cartridge…and dump that into the trash so the recycled hopper does not overflow.
Lots of wasted material and yes 30-50% refresh is highly false advertising.
The high cost of material for this system is absolutely killing its potential and usage for production running possibilities.
And here it is! I made a vibratory collapsing mechanism to avoid stopping the print by rubbing it badly. I was able to successfully print an entire chamber from 90% recycled powder. I still preferred to use 10% of the new powder. The print was successful, unfortunately the parts suffered from surface defects. I believe that this is due to the fact that the powder degrades by repeated heating. The parts I printed are intended for my use only. I noticed that the degradation is mainly from the underside of the parts, not from the top. I have a lot of used powder. I want to try some more tests when the time comes. I have some of my products where the deformations from the powder used are almost invisible and the shape is very simple and substantial, so I got up to 70% chamber filling, which is amazing. However, if I were to use up all the used powder for these parts, I will never use them in my life 
(approx. 50kg of powder). So I use 2 kilos of powder. I still have to find a use for the rest. I’ll try to get at least an 80/20 or 85/15 ratio of old and new powder with my mechanism.
Now it would like to find out in which company formlabs has the powder made, because there is a big margin. A manufacturer from another company contacted me and offers me the powder for USD 30 per kilo.
I have also been looking for other sources for the powder.
However, here you would need the same PA12. So not only the same polymer, but also the same material color and fineness.
Is there any further information on what kind of powder this should be/which manufacturer?
For that price of powder, I would change most of our components to SLS right away 
That’s exactly the problem. There are two options. First, find a manufacturer that supplies formlabs powder or find a completely compatible powder from another manufacturer. This manufacturer tells me that their powder is completely compatible, that some of their customers use a FUSE printer and print from their powder, however they refuse to tell me who they are.
If the price for powder was up to 50 usd per kilo, I would also use the printer more and not curse so much about wasted powder and failed prints. Mixing original and non-original powder would also be a possible way. Unfortunately, all of these tests would be very expensive, and the price comes at a cost to a good result.
We are quite experimental with our Fuse. For example, a few weeks ago we tried additionally moistening the powder before it goes into the printer. Something that the manufacturer EOS recommends for its powder and machines.
However, we did not notice any significant difference. I would therefore say that humidity does not play as big a role as one might think.
when printing for a longer period of time, you should notice that somewhat coarser, black lumps form on the rear rail, behind the build chamber, when you suck out the printer after printing. these seem to indicate the degree of moisture in the powder. in the tests with moistened powder, we had significantly more of these lumps here. the printing results, however, seemed the same. as soon as we stopped moistening, we probably had fewer lumps again.
a few of these lumps are therefore normal. if you find an extremely large amount on the rear rail after a print, i would take this as an indicator of very high humidity.
we would therefore be quite prepared to carry out other tests as well.
@Kostbone could you give us more information about the manufacturer here? we would like to take a closer look.
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I also like to experiment, so I have a lot of FDM printers from different manufacturers instead of making my life easier by only having one type. My farm is too rich in producers. Of course, it sometimes annoys me personally, because everyone needs a different setup and a different slicer, but it keeps me fit and I’ve also gained a lot of experience from it. For example, I don’t use any uniform printer profiles. When I put something into print, I set all the parameters myself from scratch based on my experience. No default profiles.
I also think humidity doesn’t play that big of a role because the powder dries perfectly with each print. Of course, it may re-moisten before it is used again, but a few cycles together with a dehumidifier are enough, and the powder is free of moisture. The problem will really be with the degradation of the powder by its constant heating and thus the release and release of Lauroctan. I am preparing a second chamber for printing where I will use 90/10 recycled powder. I prepared a set of parts that are just for me and the chamber utilization is an incredible 49%. That doesn’t happen often. However, I won’t use that amount of parts even in two years. We’ll see. I notice that with so much recycling, it is better to print the part vertically rather than diagonally. So now I have all the parts vertical. I am curious about the result.
As for the manufacturer of the powder, I’d rather write it to you outside the Formlabs forum. Contact me, for example, on FB - Black Print page.
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