How dimensionally stable are the prints?

Hey people!

As someone who uses the Form1 for his job , I always had an eye on the precision of the prints.

To control how dimensionally stable the prints are, I made a little test with some results, that have been pretty surprising.

I always had in mind that the prints are a little too big or too small, so i decided to print Cubes in the size of 10mm each side and place them all over the build plate. (As you can see on the attached wuerfel_form_test…form file  , wuerfel = cube :smiley: )

IMG_8065 nummern.jpg <-- how i printed the cubes

After the print i took my micrometer and tested each side of every single cube. ( Pre-work on the parts : 2 min. washing in Isopropanol 95% , 10 min. dive in fresh Isop. , then 30 min on fresh air to let the Alcohol fly away :wink: )

Surprising was the fact that the cubes in the middle of the plate ,  had the biggest “artifacts” on the surface and they were the ones with the most unregular furface. As you can see on the pictures with the** free space** text, the cubes 5,6,7 have been skewed but only from one side. (left down facing front)

The plates on which the supports stand had different heights as well. mainly the cubes on the opposite side of the hinge had the thinnest tables. 1 + 2

On Image number 8108 you can see a comparsion of the different cubes. 3= near to the hinge, 7 =middle , 1= far far away

All settings have been on Standard 0,1 mm layer thickness

After the Light curing process in our dental UV machine, the results have been pretty similar to the ones before the curing (most + ~0,005)

Maybe some of you can print the cubes on their own machines to see if i am not the only one with these results.

Hope this could help anyone. I will print my things from now on more on the hinge side of the Form 1.

Greetings from Germany  (this explains my english skills  ;-) )

Dustin

wuerfel_form_test_1_0.form

1 Like

Additional Pictures (All shot with an old and dirty EOS 300D and  100mm Macro)

And a Zip with ALL the pictures.

1 Like

https://drive.google.com/file/d/0Bxg40EH685JNVzd3aUVHV0NlUFE/edit?usp=sharing   <-- Zip

Hi Dustin,

Greak test, thank you.

Can i get your mail? ( i live in switzerland and have another few question about your experiance).

Please write me a mail mischareichard (at) gmx (dot) net

thanks, Mischa

Dustin

Thanks for your test. I will try it tonight and should have the results by tomorrow  evening. I have tried to print some cubes as well in the same orientation but they failed.

Please send me your email at - douw dot grobler at telkomsa dot net

Douw

Dustin

Prints came out nicely with a few tiny holes. I will post the results  and more photo’s later in the week.

Ah, very cool.

I can see a difference between your Cubes and mine. the tables look very stable and similar to each other.

Seems to be a problem with our mashine. Hope not ;-/

I´ll send my email adress by this evening.

Bye, Dustin

Hey Dustin from his pic it’s hard to tell. From my experience with three different Form 1’s the front has the thinnest bases the back has the thickest. So in his pic 1 and 4 would be the thinnest which they may well be. Also the difference is less if you print @ 25um and really noticeable @ 100um. Another note is that the thickness of the bases varies from machine to machine this can be adjusted by changing the Z-Offset. The difference in thickness between the front and back on two of my machines seems to be because on both of those machines there is an 0.4deg difference in angle between the tray and the plate.

Here are three pics showing the 0.4deg difference using a digital spirit level. I do not know if this was the intended design but it seems consistent between the machines I have seen. If you type “right triangle 0.4 degrees” into wolfram alpha it’ll draw you a little triangle showing showing about the  rate at which they get thinner.

At last, got some time to give you my results.

I have printed three sets of cubes. 1st at 0.1 , 2nd also at 0.1 and 3rd at 0.05 but have also done the firmware upgrade on my printer. There is not much difference in the surface finish (see 3 Photo’s - Left is 0.1 and right 0.05) but the cubes that was printed on 0.05 after I have done the firmware upgrade was more accurate than the others. Dimensionally they are much closer to 10mm and the imperfections are not as deep as printed on 0.1,  could be the firmware upgrade. The cubes printed closer to the hinge (area 3&4) are 0.1-0.2% bigger/inaccurate than they should be . Area 1&2 gives slightly smaller results -0.23 - -0.33%. Also note that I added an 8th cube on the peel side between  5&7 ( in the mirror image of cube 6 ).

Hope this helps, I know it is confusing but feel free to ask if i am not clear on anything. Attached are all my measurements, i know it is not perfect but helps me to understand my printer better.

Test_summary.docx

Dimentional_test_AmuzingWarthog.xlsx

Thank you Douw,

These are great tests to compare my own printer to. If we get a large enough pool of user data on this sort of thing it will go a long way toward diagnosing our own problems and creating best practices for the Form 1.