Mike - exciting times for you :) Please let us know what kind of positional precision you see after you’ve printed a few!
it is not that the parts have visible warps, but i make a lot of axi symmetrical parts and the diameters become slightly conical, no matter how you place the part.
i did some test to rule out calibration issue with the axis’s, so i guess it is something happening when the part is cleansed in the alchohol, but i am not sure.
Yes using some UV light to cure the parts can be recommended, i found a cheap UV Box used to cure nail polish, and it does the job just fine. 15minutes in the box and you get rid of the slimy surface on the parts.
tried for 1 hour with a part printed with transparent resin, and it turned yellow, and became very hard and brittle.
So you shouldnt cure them for too long.
@Aaron Moncur,
For the parts we print, failure is very very VERY rare. For one, people with failed prints (in the threads I’ve participated in, at least) are when you print very large parts. But, even when I printed a very large custom case for an arduino+LCD screen setup (about 5"X4"X3") I did not have any failure.
It is just my opinion, as I have no objective evidence to prove as such, is that many of these large prints failing are due to these “sculpture”-like designs which are significantly different than mechanical parts. That’s why my giant arduino case printed OK and the other guys are having some issues – but that’s just what I think.
For the accuracy, we’re hitting ±0.1mm quite frequently with the Form1. Note, this is for a well developed model. At my employer, we spend significant amounts of time designing parts for injection molding and have tons of design rules to ensure the best dimensional stability. It is not as simple as "shell"ing a model, IMHO.
That being said, we occasionally do have features which are small by up to 0.3mm – typically on a diameter of a feature. This makes some sense because one wall can be at -0.15 and the other side of the diameter can be at +0.15. So if you have Ø10±0.3.
With some software, you can un-shrink the 3D and print it so it shrinks IF you knew what the stroke is. As my parts are just for proof-of-concept, I’m not that particular yet.
David,
±0.1mm is great, and even the occasional ±0.3mm wouldn’t be horrible on some parts. That is encouraging. Thanks for sharing. Also glad to hear you’re having great success with reliability. I imagine many of my parts will be on the higher end of the size spectrum, pushing the size limits of the Form 1. However, as you’ve mentioned, they’ll be pretty mechanical in nature, not many organic shapes coming from my work. Hopefully you’re right and that will yield reliable prints. Thanks again for sharing.
The peal operation is much different in the Form1 than in the B9creator. The Form1 actually pulls the part straight off the silicone rubber tank. The B9 slides it off. This is a big difference in forces and directions. The Form1 is a tensile test the B9 a shear test. Most of my failures, which are frequent for large prints are due to fracture of the support columns. Once a support fractures you are almost assured a failed part. The clear resin is the worst. I have had much better luck with the Gray. I believe the pigment provides some structural benefit like fillers in other filled resins. The other issue with the clear is it is very hard to find and remove all debris after a failed print. Small also fail often if they have open volumes with thin wall surrounding them. The prints that have closed volumes nearly always have some type of failure on the side away from the hinge. If the part is sufficiently vented the failures go away. I believe this is do to the fluid flow forces created as the part is pulled off the build platform. Like pulling a suction cup off a window the part deforms due to the inability of the resin to flow under the part to fill the gap. When it deforms too much the part cracks. When the build platform comes back up the resin now washes some of the cracked bits out creating a hole and debris that inhibits proper layer formation. I have resorted to printing the side walls with no bottoms. Printing bottoms separately and bonding them in place or adding vent holes that are filled after printing. Also I break up large prints into smaller parts that print reliably and assemble them.
@ron, I had the opposite experience it the gray resin. I wasted 2 bottles of it with about a 25% success rate. With the clear, I have had an 80+% rate. It could have been due to a defective printer, Formlabs replaced it, but the clear worked good in that printer.
In addition to the Formlabs, I have a Bits from Bytes 3D Touch. It has never been very dimensionally accurate and it is an all around pain to work with. The Formlabs is far easier to use but has a high failure rate especially on large useful parts. It’s great for small figurines.