It seems this cant really be avoided when scrapping of a stuck down model. I was just wondering if this would effect the printing process in anyway if the metal plate was scratched?
Scratches on the metal base are good. I sometimes scratch mine on purpose for better sticking and also use a high grain sanding paper to put bunch of scratches on it.
I thought that deep scratches could effect the silicone layer ? The platform is touching that layer the first layers… Am I wrong?
If the platform touched the silicone layer, then you wouldn’t be able to print anything. If you print at 100 microns for example, then there is a 100 micron gap. You have resin in between the silicone layer and the platform.
Interesting. So thats a relief it doesnt affect the print. I was also thinking of rounding off those sharp edges of the scrapper tool as those are what dig in to the metal.
To echo @Monger_Designs, scratches on the metal base are generally good and can increase adhesion to the build platform. Sharp edges/curls (that may be a result of scratching the metal base with a knife blade), however, are not, and could pose a risk to damaging the silicone layer. It’s important to not the distinction between scratches (even deep scratches) and sharp edges/curls.
For the first few layers, the build platform compresses the resin tank to better squeeze out resin underneath and ensure adhesion. Scratches would generally not come into contact with the silicone in any adverse way––sharp edges / curls could.
When you say the first few layers compresses the resin tank better is it printing thinner layers?
I have some small flat pieces that require a smooth finish, their heights are combines 1/8" but printed in halves directly on the build platform. This gives me absolutely smooth surfaces on the finish sides.
My first run I discovered the machine’s z height was off almost .5mm too thin. The most I can adjust is .4mm before the 50 micron layer starts to fail. Only way I could think of getting this at a perfect height is if I could adjust the speed of the laser and keep the pulse rate the same. This is something I can do on my laser engraver but not on this machine which seems to be at just a few pre-sets and no additional tuning.
I made a step block that had steps at .1", .25" .5" 1", 2" and 5". Printed this at 100 micron layers so I could see the results this year and when I measured the final print the height differences where almost the same from .1 to 5. I took all the differences and averaged them out and used that to fine tune the machine.
My concern is the initial layers because if those are off then maybe the calibration overall will be wrong. If there is a compressed dead zone so to speak then how much is that so I can add it to the models rather than try to compensate in the machine?
Latest adjustment of -.4mm corrected the height of a .1" disk to .0975" with 25 micron layers.
Wondering if my total height will be off if I used any supports.
One of the reasons the use of support structures (and base) is so highly recommended is because of this initial compression behavior. If you’re printing these very small parts and seeing that they are 0.5mm too thin, adding that 0.5mm directly to your model may help. It’s important to note that this early compression helps take care of very small variations within tanks and effects from printing at different layer thicknesses, so the “compressed dead zone” as you’ve referred to it may not remain constant.
If it isn’t constant then how can you maintain accuracy over the entire height of the model between re-prints. Would 2 prints of the same model same orientation be different then?
I’m not sure if I entirely understand your question. The compressed behavior during the first few layers does not impact the rest of the print.
I made a step block and the steps size and actual size as follows:
(note this was printed directly on the build platform)
0.1" - 0.0815"
0.25" - 0.224"
0.5" - 0.475"
1.0" - .980"
2.0" - 1.895"
5.0" - 5.022"
I made a smaller 0.1" test disk that was printed directly on the build platform with the maximum fine tune height adjustment of 0.4mm (anything higher the layers were unstable)
Final 0.1" came out to 0.0975"
Measurements aren’t all that bad given the process. What my only real concern is the minimum thickness I could print flat.
Reason is I am make a mold for challenge coins and other flat items. Standing them on edge or sloped creates build lines that are impossible to clean up. Printing halves flat yields a near perfect surface that will polish up incredibly well. Adhering the 2 halves should be easy with the blue laser pointer I just purchased.
Ultimately should I just pad the model to compensate for this type of print to gain the thickness back OR do a global adjustment with the fine tune.
I am curious if the initial compressed layers is the difference in the models hight or if it is some other variable.
That make sense?
I see. I would recommend padding the model to compensate for the squish. I would recommend against using fine tuning here; it’s use is purely for troubleshooting adherence issues.
I reverted the fine tuning to defaults. I’ll try padding the model so it’s tall enough to fit in my lathe chuck. I did run some out and scaled the thickness up but the details are still slightly shallow and not to the size they should be.
Ok good solution I was told by Flabs was to put your F1 cutters under the support base notch gap and gently pry off. The more scratches you have make it harder to get the model off the platform, so try to avoid using scraper.
Same here, I had failed prints with the Flex before I used sandpaper on the metal platform.