Printing the main body without support

Dear all,
I am based in Leuven (Belgium) and just launched my project to print a microscope. But, I already meet a problem when trying to print the main body “main_body_LS65-M-BS_brim.stl”.
Our technician told me we need to print it with support (see below screenshot), although it is strongly recommended not to do. The printer machine we have is Prusa I3 MK3S printer, which is supposed to be able to print the piece without support, according to the link: OpenFlexure Microscope - Assembly Instructions
Could you please give some advice on it, is our technician overestimated the difficulties, or we could simply force ‘printing without support’ and let the printer to run? Thank you in advance for your advice!

HI @Liwang. The microscope main body looks as though it should need support. However the mechanism will not work if supports are printed so it has been specifically designed to print without any support.

This is one of mine still on the print bed. You can see there are no supports.

If you have not printed a microscope before it is a good idea to print the just_leg_test.stl

HI William, thanks for sharing and advice. I am going to give a try on the leg. I will keep you updated :man_mechanic:

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It works very well without any supports, I printed two of them on my cheap chinese printer.
Use a slow speed and smaller lauer height if needed.
If the extrusion is thin and the speed is low the the bridges are getting cooled more quickly. :slight_smile:

You can use the smart brim version but be careful when you remove the brim and file the edge before fitting.

The body was designed to be printed in 0.15 layer height. If you use the 0.20 which is commonly used most everywhere, you may have problems. I found I could print with a 0.20 layer height if I simply went with a 0.25 FIRST layer. Open up your slicer and go through this print layer by layer and look for weakness in the bridging and play with layer heights until it goes away.

0.2mm layer height is given in the V7.0.0-alpha instructions and somewhere in the V6.1.5 instructions.
I have always printed at 0.2mm and not found a problem with the microscope body.

Here is what SuperSlicer gives with 0.25 first layer height and 0.20 layer height.

Here is SuperSlicer with the Default settings:

It just looks weak and my guess is the original writer is running into trouble like I did. I solved it with first layer height. Yes, the body should print without supports and if you can’t then you need to investigate your slicer. I’m pretty sure all of the slicers have the ability to display layer by layer and one can head off problems if they know what to look for. I’m just looking to open people’s eyes if they are having trouble printing.


The slicer is clearly getting a little confused by something there with the blue parts in the second version. I don’t understand the magic of slicers to work out the correct direction for the blue bridges.