On 01/04/2022 at 09:06, Western Star said:

What made you think that tilting the print was necessary?

 

Similarly, what prompted the hole in the wagon floor?

 

regards, Graham

Resin 3D printing is about a battle between the resin sticking to the already printed model and staying stuck to the transparent FEP plastic that forms the bottom of the resin tray. If the cured resin sticks better to the vat than it does to the model then your print fails. A large flat surface area like the bottom of a wagon is quite likely to just stay stuck to the bottom of the printer. By tilting by a few degrees the flat bottom is printed in smaller sections and much more likely to work.

Similarly if you print what is in effect a sealed box then you air pressure can prevent the box from pulling away from the FEP. I added a small hole in the base of the box so that air could get into the sealed box and allow the printer to lift the wagon body off the FEP. I'm not sure if it was strictly necessary but it didn't hurt.

David

17 hours ago, Western Star said:

Good day Dave and thank you for your informative response to my questions.

 

A further question please.  The first photo of the three (tilted) wagons suggests that the raft is not flat or at least the edges are wavy, what is the cause of this distortion?

 

Asking Qs because Son has started 3D printing with an Anycubic Photon Mono using resin from 3D Jake, the learning curve is likely to be steep and reading topics such as yours are helpful.

 

regards, Graham

Hi Graham

The bottom of the raft which is provided by Chitubox has sloped edges so that you can get a scraper under them to lever the part of the bed. There is a tendency for the face of the model pointing towards the bed to be a little wavy. This is because of the resin pulling away from the top of the supports and, occasionally, from uncured resin pooling amongst the supports and not getting washed out enough with IPA after printing before you cure. Designing your parts so that there is a flat or easily sandable surface facing the bed is usually a good idea. There is always a balancing act between too many supports and so too much clean up and not enough supports and a deformed/failed print. I usually err on the side of too many supports and facing having to remove more little legs over just getting a failed print.

hope that helps

David