Form3 evaluation

I am starting this post as my evaluation of the form3. I have owned a form2 and I am actually on my second form2 and I recently received my Form3. I use the printer for model making and I have probably gone through about 8 liters of clear resin and hundreds of printed parts with the Form2.My first Form2 performed flawlessly, but eventually the optics degraded and I got a hot swap.I have had my new form2 for 5 months and it is working flawlessly. I print exclusively using clear resin and since I print a lot of small highly detailed parts most of my prints are at 50 or 25 microns.

I am not a fanboy of Formlabs, but I have been very happy with my Form2.The number one reason for getting a Form3 was the easier support removal.The most frustrating part about the Form2 and clear resin is removing the supports without chipping the resin.

My Form3 arrived and set up was a breeze.The lack of an on and off button was a bit disappointing.It is quite a bit bigger in size than the Form2.

I performed the optical test and the results were excellent-A little sharper than the form2.

My first print was a small bust that had a lot of detail. I compared the form2 to the form3 and the form3 was a bit sharper than the Form2 and the surface was smoother.I will post pictures after the summary so you can draw your own conclusions.

I think tried printing a larger part and the form3 print failed.I did a print of the form2 and at the exact point where the form3 print failed there was a crack in the Form2 print. I reoriented the print and it printed fine of the form3.

Since I had a print failure I decided to clean the tank.I followed the directions and used the new tool and it was quite easy to clean.I removed a large raft of cured resin for the tank and then filtered the clear resin and refilled the tank.

I then tried to print a box for a friend.he has 2 form3 and the box was failing on his form3.

I printed it using the 1 click print function so preform selected the orientation and supports.The print had really bad print lines on it and despite trying various orientations and supports I still cannot get clean prints.One or more of the sides of the box has defects.

I then made some simple geometric shapes in Rhino6 and did some test prints. What I found was the prints that had few supports printed perfectly.However, the prints that had more supports all had surface detail issues including rippling on the surface of the parts and defects in the wall.

I printed the same parts on the form2 with exactly the same orientation and at the same resolution (25 microns) and every one of them printed perfectly.

I have updated the firmware on the form3 twice and apart from a marginal improvement in the print speed there has been no change in the quality of the prints.

Larger parts take about 30% longer with the form3 and there are more layers in the form3 vs the form2 print even though the parts are orientated exactly the same.

Preform tells you the support touchpoints are not compatible between the form2 and form3 so it redoes them if you use the same model that you had already .However they do look identical.

As far as removing the part from the supports that does seem to be easier than with the form2, but for really delicate parts I still use the cutters

I called my sales rep about the issues and she recommended posting here.I hope some of the formlabs tech team will look at these prints and help me to figure out why they are not printing well.

So at this point my opinion of the Form3 is mixed.Some prints are excellent quality with crisp detail and the clear resin prints are much clearer than with the form 2. However some prints are not good at all and at least based on my experiments it seems the issue is with the supports.

If you are looking for the reliability and consistency of the Form2 you are likely going to be disappointed with the form3.

I have now used almost 500ml of resin just testing the printer and still would not use the Form3 for the parts that I sell. if it cant reliably print basic shapes then it is in no way an improvement over the Form2 and it certainly does not live up to the hype on the website.I really cant understand why this printer has been released if it cant even print a simple geometric design like an open box.

I hope the formlabs engineers will look at my prints and offer some input.

I will be posting photos of all my prints over the next couple of days, but for clarity I wanted to summarize everything first.


This is a small bust.It was pritned in clear resin at 25 micron resolution. The Form3 print is a little smoother and the detail is a little sharper.

Form2 results

Here is the same model printed with the Form3.The resin is clearer after curing than with the form2.This was pritned with the October firmware update installed

Optical test Form3.Really sharp detail.

First failed print on the Form3.It printed OK on the form2 in the same orientation, but there was a crack in the part that matched up with where the print on the form3 failed. I reorientated the part to decrease the surface are of each layer and it printed fine -the print on the right is the second attempt on the Form3.

so for the next test I made some simple open boxes with varying thickness walls and a sphere and a pyramid.

The sphere and one of the pyramids was fine.The second pyramid had a nasty defect on 2 of the walls.

These were printed at 25 microns and using 1 click print to let preform iroent and apply supports

The 3 boxes that I printed all had defects on at least 1 surface.The surfaces had ridges and/or defects in the wall. The orientation of the parts was a bit weird.-They were almost vertical, but again I let preform orient and add supports.These are also

25 micron resolution

So I redid the same prints after the latest firmware update and I angled the prints at about 45 degrees. The prints were better, but again each box had at least one surface with ridges and/or defects.

I then printed the same 3 boxes on the Form2 in the same orientation as the last print on the form3.All 3 boxes were perfect

form3testboxes.form (665.4 KB)

This is the preform file I used for the prints.

I am currently printing the boxes again on the form3 at 100 microns as I read some other resins on the form3 have similar issues

Thanks for posting this. I’d like to repeat one or two of your tests on my equipment.

Would you say the rectangular cube and pyramid showed the most differences between the Form 2 vs Form 3? Could you share the pyramid file?

I didnt print the pyramid on the form2 just the boxes. All of the boxes printed perfectly on the form2. None of them printed perfectly on the form3 . At least one side of the boxes has ridges and/or defects so the surface is not smooth. I will post the .stl of the pyramids later on

form3test3.form (951.5 KB)

Here is the form3 pyramid and sphere preform file

I printed them and posted my results here: Form 3 vs. Form 2 Faceoff!

TLDR: I got some layer shifting on the Form 3 as well.

I notice your most severe shifts are at layers where the supports contact the model, which could be telling. I know it’s not ideal, but you might be able to improve things by doubling the density of your supports. It could also be worth investigating other orientations (I know you tried a couple already).

1 Like

Thanks rkagear,
I did print them with quite a few more supports and got the same result.The layer shifting is related to where the supports meet the models.

I just did a print of the boxes at 100 microns and they were better, but there is still some rippling of the surface.I am guessing layer shifting is less likely at 100 microns because the layers are thicker.

I printed the ring from the other post .It was pretty good except for some layer shifting

here is one on the boxes at 100 microns.Better than 25, but still not a smooth surface.

So I printed the ring

with the holes at 25 microns and got the same ripple effect in the supports that others have noticed

I also reprinted the boxes at different orientation both parallel and perpendicular to the front of the build platform .I still have yet to print a box that doesnt have some defect .

If formlabs says this is due to lack of supports how can they explain this pritn.It would be difficult to add more supports to this model and yet there are still defects in the wall of the box

So at this point I am at a loss.My conclusions are if you want to pritna model with no supports on the main structure it will print fine.If you have a model that needs supports you may have issues.Unlike the form2 preform apparently is not good at orienting or placing supports, but even if you manually orient and apply supports you may still have poor quality prints. Not a good situation at all.

Latest experiment. I tried printing the boxes flat. I positioned them with the closed end directly on the platform and then I added supports. My theory is that the supports are contributing to the layer shifting and the parts I hav e printed with no supports dont show layer shifting.

I was worried about cupping and when I tried to print 3 boxes I got a cupping error, but only on one box which is odd. I was able to prtnt 2 boxes parallel to the build plate with the long axis of the box oriented parallel to the y axis.

here are the results. Much less layer shifting, but a weird pattern on the long sides of of the boxes and a small defect on one short wall of one box.I did get some sagging of the back of the box which was expected due to it being parallel to the build plate.

strange pattern on the long side of the box

defect in wall

sagging on bottom of box

Have you tried printing one upside down, directly on the base (no supports)? i.e. Cap resting on the base.

Sag on the bottom in that orientation is unavoidable and is simply the nature of the beast (SLA in general). The rest - defects and “shifts” in walls - is some kind of a Form 3 specific, as of yet unidentified issue.

Check this thread: Bad prints out of brand New Form 3