Printing problem with Mars Pro: solid resin filling in undercuts

[MikeTrice]

Havn't had a chance to try this but I have done a reduced support version. Should be easier to remove supports.

 

Regarding the supports for the version I printed I had to use a craft knife to cut them away before curing. Usually I put the print in hot water and can snap them off easily, but not this time hence trying fewer supports.

 

P.S. My exposure settings might be different on yours due to different strengths of the UV array.

SECR-coach-glazing-brake-3rd 4.stl

[flubrush]

I wasn't quite so quick off the mark as Mike, :-)   but I did get a print done of your file and here is the result.

 

 

 

 

 

Both sides of the part with no attempt to do a final clean-off of the support pimples.   The part is square - the camera lens has imparted a small amount of distortion.    Done on a Phrozen 2018 Shuffle with 0.05mm layer height and Phrozen ABS-like gray resin.     The part has had a scoosh of Halford's primer to make it photographable otherwise you can never get it in focus. :-)

 

 

 

The parts on the plate - vertical orientation and 45 degree rotation.   I had a resin leak on the machine a couple of weeks ago and I don't think I've completely sorted things out since the plate end closer to camera does not print as well as it should    You might note the rounded bottom corner which I think is symptomatic of under-exposure.   So I haven't shown the dodgy one. :-)

 

Jim.

 

Edited November 29, 2020 by flubrush

[njee20]

Can you post a picture of your Chitubox settings (or whatever slicer you’re using). The Pro should be capable of printing that piece faultlessly, those artefacts don’t look good at all. 
 

are you heating  the resin (if it’s somewhere cold)? Could be too viscous. 

[flubrush]

 

With these settings I set the supports using Chitubox's own calculation at 50% then went in and added and subtracted a few to improve matters.  This is now my normal way of working with Chitubox.

 

I have never heated the resin.  The printer sits in an upstairs bedroom and is at whatever temperature the house is.   The house is well insulated so the resin is probably in the 68F - 70F range,  about 20C - 21C

 

Jim.

[MikeTrice]

Last version from me. Redone at 90 degrees and 45 degrees to build plate. Less in the way of supports than previously and now removable in hot water:

 

Hopefully minimum cleanup needed. Settings as before 0.04mm layer thickness 0.8secs per layer AA=8.

SECR-coach-glazing-brake-3rd v5.stl

[Guy Rixon]

Mike has very kindly sent me v6 of the supported model in which the supports are stood off from the part a little more. This makes it easier to wash out any uncured resin, and easier to cut away the support without straining the part and breaking the thin areas.

 

 

Elegoo grey resin, 0.04 mm layers @ 7 seconds (90 second for base layers). I now consider this part solved, and have enough in hand for the first two coaches.

 

Many thanks to all who assisted, and especially to Mike for his detailed support.