Printing issues

[tuyere]

Changing your alcohol (especially the clean wash) frequently is a big help, but that gets expensive if you aren't redistilling your solvent like we do.
The two big post-processing QA improvements we figured out that you can do right now, without having to upgrade your equipment significantly or increase your costs, are
1) Adding a quick "third rinse" with brand-new alcohol, just a quick rinse with a lab wash bottle when the parts are still dripping in the basket from the second-stage clean wash; and
2) Forcing alcohol through any internal cavities or holes under pressure, either a hard squeeze with the wash bottle, or with a bigass syringe (50/100ml is good) that you fill from the first-stage wash.
You can also get in implant etc holes with a brush and alcohol, but just blasting a syringe of alcohol through is very effective and thorough, and quick if you have the syringe ready to go. Adds maybe 10-15 seconds to post-processing for each batch, but you get far fewer rewashes, slightly-tacky parts, or rejected parts down the line, and you don't have to be so eagle-eyed looking for resin when you load parts into the UV box.

 

[mmbh]

Yep, great advice. We use three wash bins as well.

 

[Beldent Inc.]

Formlabs Customer Support

Submit a support ticket or use our self-service application

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[sidesh0wb0b]

its your articulator

its so old

get a newer exocad, with newer articulation libraries.

which is your fav articulator model in the exocad library?

 

[CoolHandLuke]

i really don't care, so long as it works.

 

[sidesh0wb0b]

i really don't care, so long as it works.

thats fair lol

 

[harmonylab]

formlabs sucks. slow and inaccurate. went through like 4 of them.

 

[erzdaemon]

Changing your alcohol (especially the clean wash) frequently is a big help, but that gets expensive if you aren't redistilling your solvent like we do.
The two big post-processing QA improvements we figured out that you can do right now, without having to upgrade your equipment significantly or increase your costs, are
1) Adding a quick "third rinse" with brand-new alcohol, just a quick rinse with a lab wash bottle when the parts are still dripping in the basket from the second-stage clean wash; and
2) Forcing alcohol through any internal cavities or holes under pressure, either a hard squeeze with the wash bottle, or with a bigass syringe (50/100ml is good) that you fill from the first-stage wash.
You can also get in implant etc holes with a brush and alcohol, but just blasting a syringe of alcohol through is very effective and thorough, and quick if you have the syringe ready to go. Adds maybe 10-15 seconds to post-processing for each batch, but you get far fewer rewashes, slightly-tacky parts, or rejected parts down the line, and you don't have to be so eagle-eyed looking for resin when you load parts into the UV box.

I also use a big very soft brush like the ones for fence painting (directly in the isopropanol on the whole model all sides),especially in the first and second bath, which helps speeding up cleaning and also to clean out cavaties/interdental areas/around the dies/gingiva pockets/articulator contacts etc.

The first bath is the most important, be thorough with that.

Your second bath will stay clean longer and you can just switch it out with the first one and only make second bath new.

Final clean 5min in SD06 glasses filled with isopropanol in ultrasonic cleaner ~40-44khz, finish with pressurized air to dry.

U can also use pressurized air for problem areas like the analog holes for implant cases ( these are very common to have resin left in, if not cleaned properly, i mainly use the pressurized air after the first rough wash, you can do that into a paper towel)

 

[bigj1972]

I print a test object every so often and the digital micrometer measurements are right on the money. We just use support pins if needed. If we need to articulate large cases we jut use support pins and articulate later.

Right there.. artifact verification. That's how you test for continued printer accuracy.
After that, like the others stated...develop protocols so you don't mess up that accuracy post printing.

 

[tuyere]

RE: ongoing verification, we have a standard battery of two or three parts we print at least once a week for every printer:

• calibration cubes, for verifying X/Y/Z scale factors and detecting distortion; i'm on version 9 of my own 15mm cube design, try to use a cube that's hollow and has a wall thickness comparable to your dental models, solid cubes end up slightly oversized
• a little go/no-go gauge block i designed, for extremely fast and metrology-free checking of print dimensions, intended for technicians to check every job during post-processing without having to pick up calipers or a micrometer
• a high-detail test part that gives overall feedback on print detail, crispness, over/under-exposure, etc. I use the AmeraLabs city for this, it's tiny but manages to cover all the bases reasonably well https://ameralabs.com/blog/town-calibration-part/
• for deeper investigations, I sometimes use a larger diagnostic part that's more comprehensive, i like Siraya Tech's test part https://siraya.tech/pages/siraya-tech-test-model because it covers all the above in a single standardized part

except for the last one, they're small and use very little resin, so they piggyback on production jobs and don't add any extra time to the jobs.

I ask for a full battery of the first 3 diagnostic models every monday from the first job of the day, and I include go/no-go blocks in every 'high-precision' model job, and get the techs to try them on the master gauge i keep in the print lab after washing and post-curing. If the parts are too big, the block won't fit at all; if the parts are too small, they'll fit but only seat half-way into the master gauge. takes 5 seconds to check and I think 2.5ml of resin per block, but it catches issues for critical parts immediately.

 

[tuyere]

I've been puzzling over how to use compressed air to dry/finish cleaning washed prints without having a tech manually spray parts by hand under a fume extractor, it gets good results but is labour-intensive. I designed a drying cabinet that's constantly drawing air through it from the fume hood extractor, so we put baskets of wet parts in there and close the door and they're dry in 60 seconds. great. but sometimes you need to use the air gun, and it's messy. I'm thinking, like, a stationary air knife that we pass wire baskets of parts through, so the parts get the Dyson air-knife treatment, with the alcohol spray and fumes blowing directly into the extractor and out of the building... but I need to figure out the implementation...

 

[tuyere]

Here's that drying cabinet, btw. The idea is that the fume extraction that currently draws from our print post-processing hood is instead ducted through the cabinet, then to the hood. The door latches tight against a gasket, so the extracted air has to flow from one corner of the cabinet to the other, passively drying washed parts in the process. Gonna integrate it into a larger 4040 extrusion post-processing bench I'm currently designing. extrusions and acrylic panels looks very slick, but the design effort required is a hassle.

 

[tuyere]

More about my calibration cubes:
I use a 15mm cube for most purposes, it's a good compromise between being small enough to fit inside full-arch models and being large enough to give useful feedback without a huge fudge-factor. But with many modifications. Probably too many. but it's an effective design, check it:

Put embossed X/Y marks and the printer name, so I can connect scale issues to the correct axis for correction. I added a 'step' at the bottom of the model so I can take true Z-height measurements that don't include the 'elephant foot' distortion of the base layers. Hollowed it out, because you get more accurate results that way and saves on resin- use a wall thickness that matches your hollow model walls. cut it down to 10mm tall because I'm very rarely checking Z-scales. I saw some bowing/bellying of the cube side-walls that added a few microns to measurements, so I added drain holes to break the cavity vacuum, plus internal baffles to keep the side-walls rigid.

Finally, I added four ports on the top of the cube that are sized to mate with the nozzle of a laboratory wash bottle. These make purging the cube interior of resin quick and easy, I just do four quick squirts with the wash bottle during post-processing and it's good.



Let this be a cautionary tale about what happens when a mechanical designer lands in a dental lab.

 

[Car 54]

RE: ongoing verification, we have a standard battery of two or three parts we print at least once a week for every printer:

• calibration cubes, for verifying X/Y/Z scale factors and detecting distortion; i'm on version 9 of my own 15mm cube design, try to use a cube that's hollow and has a wall thickness comparable to your dental models, solid cubes end up slightly oversized
• a little go/no-go gauge block i designed, for extremely fast and metrology-free checking of print dimensions, intended for technicians to check every job during post-processing without having to pick up calipers or a micrometer
• a high-detail test part that gives overall feedback on print detail, crispness, over/under-exposure, etc. I use the AmeraLabs city for this, it's tiny but manages to cover all the bases reasonably well https://ameralabs.com/blog/town-calibration-part/
• for deeper investigations, I sometimes use a larger diagnostic part that's more comprehensive, i like Siraya Tech's test part https://siraya.tech/pages/siraya-tech-test-model because it covers all the above in a single standardized part

except for the last one, they're small and use very little resin, so they piggyback on production jobs and don't add any extra time to the jobs.

I ask for a full battery of the first 3 diagnostic models every monday from the first job of the day, and I include go/no-go blocks in every 'high-precision' model job, and get the techs to try them on the master gauge i keep in the print lab after washing and post-curing. If the parts are too big, the block won't fit at all; if the parts are too small, they'll fit but only seat half-way into the master gauge. takes 5 seconds to check and I think 2.5ml of resin per block, but it catches issues for critical parts immediately.

Thank you for this information and the links.

When I bought my Phrozen Mini 8K, I ran about 4 test samples then decided it was time to spill some resin on the top edge. Luckily, it didn't go on the front of the LED screen, but I thought I'd better take the top off and make sure it wouldn't leak inside. When I took the top off, the ribbon cable that goes to the LCD and a circuit/MOBO board, was so short, that when I tried to put the top back on, pinched the ribbon and broke the connection.

So after about 3-4 back-and-forth emails with Phrozen Taiwan, got the new ribbon about a month later. I finally got myself motivated to replace it and finished it tonight. It's printing wonderfully, but now I also need to get back to re-educating myself on using Chitubox (there is more information and YouTube videos with them) and in calibrating it to start printing non-removable die models, my thought was what do I use for a reference calibration?

It looks like your links will help to provide that? Or is there a better link for something a little bigger, or could you sell me the stl of your 15mm cube? I have the micrometers that came with my S1 sinter furnace for measuring the calibration discs, so I'm covered there. I just need a cube, or a link to a stl file to help me with my settings for models.

Is the cube in this link you provided a good reference? Is it a certain dimension size?

Siraya Tech Test Model

Siraya Tech Test Model V5 Download here. Introduction:We developed the Siraya Tech test model V5 to be a quick and easy way for the user to determine exposure value for resolution, accuracy, and printability. It is built on previous works from Peopoly, Photonster’s XP2, and many inputs from our...

siraya.tech

 

[sidesh0wb0b]

More about my calibration cubes:
I use a 15mm cube for most purposes, it's a good compromise between being small enough to fit inside full-arch models and being large enough to give useful feedback without a huge fudge-factor. But with many modifications. Probably too many. but it's an effective design, check it:
View attachment 44167
Put embossed X/Y marks and the printer name, so I can connect scale issues to the correct axis for correction. I added a 'step' at the bottom of the model so I can take true Z-height measurements that don't include the 'elephant foot' distortion of the base layers. Hollowed it out, because you get more accurate results that way and saves on resin- use a wall thickness that matches your hollow model walls. cut it down to 10mm tall because I'm very rarely checking Z-scales. I saw some bowing/bellying of the cube side-walls that added a few microns to measurements, so I added drain holes to break the cavity vacuum, plus internal baffles to keep the side-walls rigid.

Finally, I added four ports on the top of the cube that are sized to mate with the nozzle of a laboratory wash bottle. These make purging the cube interior of resin quick and easy, I just do four quick squirts with the wash bottle during post-processing and it's good.
View attachment 44168


Let this be a cautionary tale about what happens when a mechanical designer lands in a dental lab.

i love all this! thank you for the details about what your up to!
and thats a great idea for drying. we all need more "hands off" tasks being sorted by technology. hand drying prints is noisy, messy, and time consuming. sticking them in a box to dry for a few minutes seems like a no brainer!

 

[tuyere]

i love all this! thank you for the details about what your up to!
and thats a great idea for drying. we all need more "hands off" tasks being sorted by technology. hand drying prints is noisy, messy, and time consuming. sticking them in a box to dry for a few minutes seems like a no brainer!

Thanks. I used to do product / process design for an industrial design firm that specialized in small projects for small manufacturing businesses, so it's hard not to carry that over to the lab, where very labour-intensive processes are tolerated a lot more than they are in other industries- print post-processing is virtually identically-tedious for a one-tech lab or a 100-tech lab, that's pretty unusual compared to other manufacturing.

 

[Car 54]

Thank you for this information and the links.

When I bought my Phrozen Mini 8K, I ran about 4 test samples then decided it was time to spill some resin on the top edge. Luckily, it didn't go on the front of the LED screen, but I thought I'd better take the top off and make sure it wouldn't leak inside. When I took the top off, the ribbon cable that goes to the LCD and a circuit/MOBO board, was so short, that when I tried to put the top back on, pinched the ribbon and broke the connection.

So after about 3-4 back-and-forth emails with Phrozen Taiwan, got the new ribbon about a month later. I finally got myself motivated to replace it and finished it tonight. It's printing wonderfully, but now I also need to get back to re-educating myself on using Chitubox (there is more information and YouTube videos with them) and in calibrating it to start printing non-removable die models, my thought was what do I use for a reference calibration?

It looks like your links will help to provide that? Or is there a better link for something a little bigger, or could you sell me the stl of your 15mm cube? I have the micrometers that came with my S1 sinter furnace for measuring the calibration discs, so I'm covered there. I just need a cube, or a link to a stl file to help me with my settings for models.

Is the cube in this link you provided a good reference? Is it a certain dimension size?

Siraya Tech Test Model

Siraya Tech Test Model V5 Download here. Introduction:We developed the Siraya Tech test model V5 to be a quick and easy way for the user to determine exposure value for resolution, accuracy, and printability. It is built on previous works from Peopoly, Photonster’s XP2, and many inputs from our...

siraya.tech

@tuyere I did figure it out, that yes, the line under the box for 10 mm, was for the box itself. With how close I am now, I should be good as far as printing opposings and for prep, solid contacts, don't you think?

 

[tuyere]

Missed your questions, sorry - I wouldn't use that latticed cube from the siraya test part to check your scale factor, it's too compressible and is printed at a weird angle so the faces don't align with the axes we care about. It's more of a 'torture test', a delicate part that will show defects readily if your exposure settings aren't dialled in. Also gives you something neat to play with afterwards, those little lattice cubes end up all over the lab after a while, people seem to like them.
I'd be happy to sell you my own designs, but I'm not set up for that at the moment. I'll put something together. In the meantime, grab any generic calibration cube from a hobbyist site like Thingiverse: https://www.thingiverse.com/search?q=calibration+cube&page=1&sort=popular You don't need to print a 20mm cube 20mm high, that's a lot of material, I would scale the part in the z-axis only down to 0.75, 0.5 or so, so you get a faster print.

Also: the other features on that diagnostic part give you useful information, you can check the 10mm line to make sure it's actually 10mm- do this while the part is on the plate, it'll curl when removed and ruin the measurement (that's why cubes are nice, they don't distort after printing). Look at the fine features under a microscope, it looks to me like you might be overexposing, the very fine engraved crosses seem to be filled in. Hard to tell from the picture.
For general exposure and print setting checks, the Ameralabs city is very good, but it has nothing to check the scale with. Typically I couple the city with a calibration cube, and that covers all the bases reasonably well.

 

[Car 54]

Missed your questions, sorry - I wouldn't use that latticed cube from the siraya test part to check your scale factor, it's too compressible and is printed at a weird angle so the faces don't align with the axes we care about. It's more of a 'torture test', a delicate part that will show defects readily if your exposure settings aren't dialled in. Also gives you something neat to play with afterwards, those little lattice cubes end up all over the lab after a while, people seem to like them.
I'd be happy to sell you my own designs, but I'm not set up for that at the moment. I'll put something together. In the meantime, grab any generic calibration cube from a hobbyist site like Thingiverse: https://www.thingiverse.com/search?q=calibration+cube&page=1&sort=popular You don't need to print a 20mm cube 20mm high, that's a lot of material, I would scale the part in the z-axis only down to 0.75, 0.5 or so, so you get a faster print.

Also: the other features on that diagnostic part give you useful information, you can check the 10mm line to make sure it's actually 10mm- do this while the part is on the plate, it'll curl when removed and ruin the measurement (that's why cubes are nice, they don't distort after printing). Look at the fine features under a microscope, it looks to me like you might be overexposing, the very fine engraved crosses seem to be filled in. Hard to tell from the picture.
For general exposure and print setting checks, the Ameralabs city is very good, but it has nothing to check the scale with. Typically I couple the city with a calibration cube, and that covers all the bases reasonably well.

Thank you, as with you, it's always a thoughtful and informative reply, wherever you are posting, including here...I really appreciate it
edit: I just downloaded the 20mm cube, I'll give it a try. I have plenty of resin to experiment with

 

[Car 54]

@tuyere no worries about trying to figure out your calibration cube for my purchasing it, with what you provided, and a little more clicking and ticking, I'll get there. If not, I'll post back