Feedback Wanted on Working SLS/SLM 3D Printer December 18, 2014 01:30PM |
Registered: 9 years ago Posts: 12 |
Re: Feedback Wanted on Working SLS/SLM 3D Printer December 24, 2014 09:25AM |
Registered: 10 years ago Posts: 8 |
Re: Feedback Wanted on Working SLS/SLM 3D Printer December 24, 2014 09:49AM |
Registered: 9 years ago Posts: 12 |
Re: Feedback Wanted on Working SLS/SLM 3D Printer December 24, 2014 10:13AM |
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Re: Feedback Wanted on Working SLS/SLM 3D Printer December 24, 2014 11:24AM |
Registered: 9 years ago Posts: 12 |
Re: Feedback Wanted on Working SLS/SLM 3D Printer December 31, 2014 06:06PM |
Registered: 9 years ago Posts: 52 |
That would be great. It would be fantastic to have a opensource SLS machine, or information on sintering, the little tricks what works and what doesn't and such. Right now I think it's a matter of getting more research and development published, documented and tested before more members venture into this area. It's a high bar atm, as it seems there's no one who yet has SLS machine that makes good nylon parts.Quote
Joshua Dickerson
If it means anything, we intend to contribute our findings to the opensource community as time goes on. Thanks again for your feedback and good luck on your project.
Re: Feedback Wanted on Working SLS/SLM 3D Printer January 04, 2015 01:21PM |
Registered: 9 years ago Posts: 127 |
Re: Feedback Wanted on Working SLS/SLM 3D Printer January 06, 2015 12:31PM |
Registered: 9 years ago Posts: 12 |
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TTN
That would be great. It would be fantastic to have a opensource SLS machine, or information on sintering, the little tricks what works and what doesn't and such. Right now I think it's a matter of getting more research and development published, documented and tested before more members venture into this area. It's a high bar atm, as it seems there's no one who yet has SLS machine that makes good nylon parts.
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Ezrec
Suggestion: Get a fuser unit from an old laser printer, affix it to the leading edge of the powder wiper, and run the fuser unit as you do the powder wipe.
If you get the fuser temp correct, that should 'relax' the rasterized nylon enough so that the edjest curl down before the powder is applied.
Re: Feedback Wanted on Working SLS/SLM 3D Printer April 04, 2015 05:10AM |
Registered: 9 years ago Posts: 210 |
Re: Feedback Wanted on Working SLS/SLM 3D Printer April 06, 2015 10:09PM |
Registered: 9 years ago Posts: 12 |
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Dejay
Nice project! I'd love to build my own SLS printer.
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Dejay
About the melting vs sintering and print quality, isn't sintering better to avoid "globs" of molten droplets? I've read about this here.
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Dejay
Does the print need to adhere to the print bed or can they just start in the middle of the powder? I'm asking because I would think that not having to worry about use blue tape or print surface adherence etc would be awesome.
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Dejay
One of the must have features a powder printer would have to have is a "cleanup mode". So after you pulled out your printed object the powder is moved back to the feeder from the build platform smiling smiley
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Dejay
Good luck with your project!
Re: Feedback Wanted on Working SLS/SLM 3D Printer April 07, 2015 12:38AM |
Registered: 9 years ago Posts: 210 |
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Joshua Dickerson
So far we haven't been able to notice a difference, but we also are just barely getting the surface heater unit up and running. We were delayed by applying to a bunch of startup accelerators. When we start seeing the results from the upgrade, we'll followup with you and let you know.
Re: Feedback Wanted on Working SLS/SLM 3D Printer May 13, 2015 01:59PM |
Registered: 9 years ago Posts: 12 |
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Dejay
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Joshua Dickerson
So far we haven't been able to notice a difference, but we also are just barely getting the surface heater unit up and running. We were delayed by applying to a bunch of startup accelerators. When we start seeing the results from the upgrade, we'll followup with you and let you know.
Ah the damn paperwork
I'd bet controlling the surface temperature precisely and tuning the laser power so that you don't melt but just sinter without globs is the key to precise prints. The best results by far the in a low cost SLS printer I've seen is from the sintratec printer. They seem to use a 500W surface heater that you can see reacting very quickly to keep the surface just at the right temperature. They also only use 2.3W 445nm laser diode (only dark powder of course). But I'm just curious about this and don't have any experience with lasers.
Re: Feedback Wanted on Working SLS/SLM 3D Printer May 13, 2015 02:23PM |
Registered: 9 years ago Posts: 210 |
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Joshua Dickerson
we were rejected by every single startup accelerator we applied to (which is nearly all of them.)
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Joshua Dickerson
Yes, you're right. We incorporated all those factors into the printer's kinematics equations which takes the physics of the process into account, so that it all happens automatically. We just plug in the DSC constants, among other things we get from the PA650 datasheet and it just works. Sintratec's pulled off our initial approach, which was to use a visible laser diode on dyed nylon powder (nylon doesn't absorb much in the visible region otherwise.) We quickly decided that we didn't want to limit ourselves to just colors that would absorb the laser's wavelength, so we decided to use a CO2 laser. It's proven to be an order of magnitude harder than we ever imagined.
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Joshua Dickerson
We also got our printer to support both selective laser sintering and selective laser melting. It appears SLS makes the characteristic airy white prints people are used to from shapeways. We're not getting globs of any kind in selective laser melting mode, but we noticed that the layered structure is more apparent because the contrast between the white powder and the off-white fully melted nylon. The selective laser melting prints are also many times stronger than our SLS prints. By strong we mean we really tried hard to delaminate and break our prints and they all survived. I was even able to stand on top of one of our gyroid prints with one foot. We're doing experiments to see if we can combine the best of SLS and SLM into a single print, but we're not sure if someone's already patented the process.
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Joshua Dickerson
Here is a picture of our most recent print, fresh out of the powder.
[www.flickr.com]
This picture shows a comparison of a typical print before the surface heater (on the left) and the print we got with the surface heater (on the right of course).
[www.flickr.com]
Re: Feedback Wanted on Working SLS/SLM 3D Printer May 13, 2015 06:07PM |
Registered: 9 years ago Posts: 12 |
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Dejay
Sorry to hear! Convincing people you are an entrepreneur when you're really more of a tinkerer is always a tough sell. Been there myself. You have to pretend and masquerade with the right kind of costume... e.g. business suit and lingo... Plus they always want to see patents lol.
Maybe you could try a kickstarter / indiegogo. The business presentation and due diligence that you can actually pull of the production is just as important there as well but if your product is good and people want it they don't care about smell Making your project open source might help with adding confidence in the project. And also help getting more people involved.
Better quality videos (video quality and audio and storytelling) would definitely help too.
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Dejay
For me the color option isn't really that big of a deal, you can always spray paint stuff if you want (and need to for the perfect finish (see a guide) anyway). For me price and low maintenance is much more important. If you could make it more affordable for home use that would be much more worth to me than the color. Maybe you can later upgrade to a new kind of IR diode that allows for more colors etc. Of course some say that powder based 3D printing will never be good for home use and I am a hobbyist so might not be your desired target audience.
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Dejay
Interesting. I guess the first solution that comes to mind would be to change the intensity / speed of the laser for the outside surfaces and the inside / infill. "Can't we have both?"
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Dejay
Links fixed. The accuracy still seems to be somewhat lacking? Does the gantry have limited repeatability or is this dependent on the heat? Or maybe the powder spreader? I have no experience with SLS I'm just curious
I wish you all the best luck with your project!
Re: Feedback Wanted on Working SLS/SLM 3D Printer May 13, 2015 06:39PM |
Registered: 9 years ago Posts: 210 |
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Joshua Dickerson
Actually we anticipate a lot of hobbyists will want our printer-we're just having a difficult time keeping the final cost under $4K. It's starting to look more like nearly $5K. Unfortunately, nylon appears to be nearly transparent in all the wavelengths available by semiconductor diode lasers (even the IR ones). We also went the CO2 route because we found a way to do full colored prints. By full color, we mean each individual voxel of an object can be a different color. So you could make a Mario figurine for instance without having to paint on his eyes or mustache, or anything else for that matter. It will be our subsequent product release if we even make it to market with this one.
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Joshua Dickerson
Thanks! Great eye! There are a few things you're seeing. One is the fact that we made the new print in medium/low resolution so that it would be a fair comparison to the baseline object we printed without the surface heater. Another is long term drift of the scanner galvos, which is a problem with the type of feedback sensor they use. Another is the fact that we had to enlarge the mirrors to accommodate the needs of the scanner topology we're using and the driver boards that were shipped with them weren't designed for that. If we tune the galvo amps aggressively enough to improve repeatability, it oscillates on the next power up destroying the mirror/galvo -so we have to detune the control loops a bit. All of these compound to reduce accuracy and precision. The most obvious solution is to use a high-inertia galvo amp board, which we'll be incorporating soon. We have a few ideas for combating long term drift too, so we'll let you know how that pans out over the next 3 weeks.
Re: Feedback Wanted on Working SLS/SLM 3D Printer May 14, 2015 12:53AM |
Registered: 9 years ago Posts: 12 |
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Dejay
Hehe you could also just have said that it's part of the model
This sounds really interesting. Thanks for sharing some insight.
Re: Feedback Wanted on Working SLS/SLM 3D Printer July 13, 2015 01:22PM |
Registered: 9 years ago Posts: 12 |
Re: Feedback Wanted on Working SLS/SLM 3D Printer August 09, 2015 10:53AM |
Registered: 9 years ago Posts: 127 |
Re: Feedback Wanted on Working SLS/SLM 3D Printer August 09, 2015 03:27PM |
Registered: 9 years ago Posts: 12 |
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Ezrec
So, from your IndieGoGo update, it seems that you now have a commercial backer - congratulations!
Re: Feedback Wanted on Working SLS/SLM 3D Printer August 09, 2015 03:32PM |
Registered: 9 years ago Posts: 210 |
Re: Feedback Wanted on Working SLS/SLM 3D Printer August 09, 2015 08:06PM |
Registered: 9 years ago Posts: 12 |
Re: Feedback Wanted on Working SLS/SLM 3D Printer December 18, 2016 02:37AM |
Registered: 9 years ago Posts: 52 |
Re: Feedback Wanted on Working SLS/SLM 3D Printer December 18, 2016 02:52AM |
Registered: 9 years ago Posts: 12 |