Anycubic Photon

[peteski]

Better than SWs parts...

If you don't mind removing all the supports then yes, the print quality and surface quality appear much better than any of the Shapeways FUD/FXD (or whatever the current name is).  The material also is also much stronger, more flexible and less brittle.

[bnsfdash8]

I've been working on some C&O "deco" boxcar ends for a friend. This was a my first time using the Anycubic grey and I'm pretty happy with the results, but I'll have to work on the step lines.

[Chris333]

Print it flat, just add extra supports and group them heavy in the corners so it doesn't rip off during printing.

[Mark W]

Print it flat, just add extra supports and group them heavy in the corners so it doesn't rip off during printing.

Second this.  At this point, I print everything flat and just increase supports.  I found that a support every 2.5mm (with an extra support between the two 2.5mm gaps in corners and ends) works well enough for N Scale sized parts.

[bnsfdash8]

Thanks guys. I just started a print with the ends laid flat. Fingers crossed I have enough supports.

[narrowminded]

Second this.  At this point, I print everything flat and just increase supports.  I found that a support every 2.5mm (with an extra support between the two 2.5mm gaps in corners and ends) works well enough for N Scale sized parts.

... and then what diameter do you like for the "top" and then the "mid" supports? 

Many times the part you're linking to with the support dictates what you can use but I'm finding a "top", the face engaging the part, does OK at a max of .6mm and is what I will use when the face is broad and available for that size.  Also a mid support at that size for stability when space allows, which is most of the time.  I have used "top" sizes of .5 and less, down to .2 (reluctantly) when it was about 70% to 90% of the finer detail face it was supporting.  I try not to have the support engagement overhanging the edge of a finished detail.  Near to the edge, OK.  Overhanging, avoid.

I'm often at 2mm off the build plate figuring it's the minimum to get at the with the scraper to remove from the build plate and I've quit using a raft when the supports are all attached to a face that will be out of sight on the finished part as many will break off the part while stripping from the plate.  If I need them to stay attached or together such as smaller delicate support to delicate features, then I will use a raft with the "skate" edge to hold it all together coming off the plate and then raising the support height, maybe to 3mm or even 4mm if needed for room to get in to snip the supports cleanly. 

There are still judgement calls needed when placing the supports but in general I haven't had any parts fail to stay attached to the build plate but have lost a few individual small, delicate support attachments at the part end, not the plate end, especially when the part was located at the outer perimeter of the build plate.  I attribute that to the resin viscosity and the displaced volume during layer cycles increasing the further from center that the part is located, therefore the velocity of that resin passing around the supports increasing all of the way to the outer edges.  When I lost supports like that it was almost a pattern around center where it happened which led me to the conclusion I just outlined.  This was especially evident when printing my .015" links and pins hanging vertically.  I would estimate that the failures started to occur in the last third of the plate heading away from center.  Choice is increase support size or if that's not an option, don't fill that area with parts.  There is no option to slow down the z axis cycle speed to reduce the passing resin velocity.

[narrowminded]

I've been working on some C&O "deco" boxcar ends for a friend. This was a my first time using the Anycubic grey and I'm pretty happy with the results, but I'll have to work on the step lines.

You should be able to get a very nice print of that part printing flat as has been advised.   Ain't it cool?!

[bnsfdash8]

Flat is way to go.

[CNscale]

Knowing nothing about 3D printing (but following these threads to learn all I can) please forgive me if this is a dumb question: If you're printing flat and the back side of the part (like that boxcar door) doesn't have any detail, why do you need any supports? Why can't you just print it directly on the build plate?

[narrowminded]

Knowing nothing about 3D printing (but following these threads to learn all I can) please forgive me if this is a dumb question: If you're printing flat and the back side of the part (like that boxcar door) doesn't have any detail, why do you need any supports? Why can't you just print it directly on the build plate?

I have done that.  My town monument was printed that way.  That and the concrete tunnel portal that showed up in a few pics of the tippers and code 40 track bed are the only things I have printed that way as everything else had dimensions that mattered.

The reason for the supports is legitimate and even critical in most cases.  The base layers are cured at extra time (4x+) to assure a good attachment to the plate and as such they also tend to cure extra resin beyond the defined perimeter.  Call it mushrooming at the base layers that are set to bake longer.

The second reason is to do with the build plate squareness to the developing screen and really, to establish a true zero that's independent of the physical setup, assuring Z axis dimension accuracy.   The build plate in mine has a slight crown from the factory.  A very nice casting, I think, but that method also left a slight crown, no surprise.  And then to adjust the plate squareness to the rest of the involved pieces it's possible and even likely that as careful as you do the base physical squaring that it's not absolutely, to the last tenth, perfectly square.  Between the crown in the build plate and the likelihood that the squaring wasn't absolutely perfect, the supports and over curing of the first few layers assure that when the part starts to develop it's starting from a  fully corrected, perfectly square base line.

So, with that in mind, when I printed the monument right on the build plate all came out satisfactory for the application but I'm sure the height wasn't perfect to the last few thousandths and I had to file away the "flash" overhanging from the first few layers that were mushroomed out around the bottom perimeter.  On that part it was OK as the dimension was not critical and it was easy to file with that dimension also not critical.  If it had been, those could have been rejects.  Also, from one position on the build plate to another the parts wouldn't be identical height whereas with the supports correcting all of the variables, they are.  It's about accuracy and the supports set that base line "zero" perfectly.  Hope that helps.

[sirenwerks]

So would it be possible to do other, more conventional car ends, doors or are the stop lines going to be an issue with those small tube structures?

[Kentuckian]

Bnsfdash8, can you help a brother out? Since Intermountain punted on their deco end boxcar, I would be in for a pair of these.

[PiperguyUMD]

Now we're talkin! I think I'm finally getting the hang of this. I think this shell is on par with, or exceeds the one I have from shapeways in almost every aspect - except for mounting holes. I know some of you guys are getting some pretty clean small diameter openings, but the I can't seem to make it happen. This shell had .012 holes or larger for hand rail stanchions, grab irons, plumbing etc, but the best I can muster are the tiny dimples seen in the photos. It's not the end of the world though, I don't mind drilling them out. Measuring and marking them from scratch is a pain.
 

[SSW7771]

I jumped on this bandwagon and got myself a Photon after seeing all the awesomeness here. I have not a few prints so far, mainly from models I have found on Thingiverse. I did print, paint and install these transformers for my layout. I guess I need to start working on my own models...

[narrowminded]

I know some of you guys are getting some pretty clean small diameter openings, but the I can't seem to make it happen. This shell had .012 holes or larger for hand rail stanchions, grab irons, plumbing etc, but the best I can muster are the tiny dimples seen in the photos. It's not the end of the world though, I don't mind drilling them out.

That looks pretty excellent!

As far as holes go, those small ones are tough.  The resin likes to linger in them and gets partially cured so fills them in.  As you said, drilling them out isn't hard as long as you have the dimple to start them. 

Now, with that said, I've found that the problem is aggravated by the wall thickness, thicker being worse, and fairly logical.  What I'm doing is calling out a larger diameter hole for almost anything, especially under .020".  Very thin wall (.012"?) and a diameter around .008" I would probably start by adding .006", .003" per side.  Thicker wall add more, a little bigger hole, add maybe a little less, but I have used in various examples all of the way up to .010" over.  Example: I have a .030" wall that I want an .018" hole in, allowing .003" clearance for a .015" pin, printing with that hole vertical.  My drawing calls out a .025" hole and it generally comes out OK, right around the desired .018", but a few holes may still take a small amount while checking the hole with a drill.  It's easy though and the holes have always been placed right where I wanted them.  Work with this and you'll get it closer but for small holes it will probably always be best to check them individually unless you can accept a really loose fit.     Meanwhile, really nice shell!