Evening! Couple of things; first please do read this thread in detail, I document the core issue of warping during formation of the first 2-3cm of the part here:
The orientation approach you have described is common knowledge and probably what Formlabs should be recommending of 30-45 degrees upwards from each axis to avoid steep overhangs (instead of the current guidelines of insufficient 10-15 degree: customer_v2). Pretty much anything remotely square or straight can benefit from this approach and this is probably the best way to go about printing this for the reasons you have stated. I have pretty much fallen in line with orienting flat things like this. I took a closer look at your pictures and notices some things:
This orientation will create pulling forces indicated by red arrows during printing, warping will probably occur with will the middle of the part sinking down. The corners should bend upwards and provide stability. This image below with exaggerated red lines show what I mean, you can see the warping in the image:
Some additional warping observable here:
Furthermore, this image illustrates perhaps the weakest point of Form 4, which is the first part of the corner which first attaches to a supports (a “V” like part) will contain non-straight edges that curl. I think I see this with the top of the model not completely perpendicular to the bottom edge. I discuss this more in my own thread as well:
Curious as too how the pillars at the bottom of the part looks as well, wonder if they are straight.
Of course, I am not going to speak for someone elses experience, and if this is a useable part for someone, that’s great. However, I don’t think you will disagree with me that this model does not achieve the +/- 0.15% or 0.2mm guidelines Formlabs advertises.
Do you have any other suggestions or practices we are not aware of? Unfortunately, seems that supporting is more like triaging on this printer to make sure everything bends together rather than counting on the printer to produce a straight edge. I am pretty sure Friedl also made a thread where he showed some FDM parts off a $500 printer with near perfect straight edges and finish/ accuracy better than anything I have seen from the Form 4 including these pictures, I am sure you can find that on this forum as well.
Also @Friedl_1977 I am going to have to backpedal on my advice on precision model resin, seem that it is not significantly better than another general purpose material after more recent testing…