B9 Bonanza!

[Bexley]

Latest print. Came out mostly okay. The fuselage halves are about 4" long, for reference.





Except some spots where the layers didn't quite attach to each other:

[Chuck Doan]

Bexley, what is the material like? Brittle, or soft or?

[Bexley]

It's... both? It sands nicely. It has a little bit of flex to it, but it'll snap if I try to bend it much, like urethane resin. I'm still waiting on my UV cure lamp so I can post-cure them fully, that might change things. But like most 3d printing UV curing resins (at least, those that at I've had any experience with) it's not going to stand up to heavy use/abuse.

[Bexley]

[Bill Gill]

Yowzah! neat stuff.

[Bexley]

It appears the "delamination" was due to a lack of supports. Somehow I missed those areas when setting up the print. One of the areas did have supports, but needed more. Pretty rookie mistake, and I feel kinda dumb. But at least, it was operator error and not something hard to diagnose.

[artizen]

That is going to look so cool with wings and paint!

[finescalerr]

Is the "delamination" the area that appears to have a herringbone pattern or is that intentional? -- Russ

[Bill Gill]

Russ, I think the delamination might be the area in the green circle, but I'm also curious about the patterning that to me looks like woodgrain, one sample area marked by the arrowhead. Is that what you referrred to as 'herringbone'.
Anyway, Bexley, is that texture on purpose? Seems like it is.

[mabloodhound]

The delamination is in the big picture, lower right side panel with curved lamination.
Nice results from that printer.

[Bexley]

"Delamination"

[Bexley]

The patterning is from the layering. The sides are gently tapered, so it's more pronounced than in other areas.

[finescalerr]

Thanks for pointing that out, Bill. The piece looked so good to me late last night I didn't even notice the delamination. Maybe I thought it was intentional but how am I supposed to know what I think?

So what about the layering pattern? Would you have to sand it off? Is it fine enough that primer and paint would hide it completely? Would another attempt at printing eliminate both imperfections?

Russ

[Bexley]

The delamination was my fault, I needed to add supports there. Essentially, the only thing holding that spot in position as the vat slid away to release the layer was where the layer attached to the rest of the model, so tas the vat pulled away that section was a bit loose.

The layering/texture just needs a light sanding. Mr. Surfacer might even be enough to fill it in, but I don't have any on hand at the moment. It's not that much worse in person than what I see at work on the very expensive machine.

I had my first failure last night. The PDMS (silicone release layer) gave out. Surprisingly, some of the parts still came out (pics later) but the area right over the worn bit was all wobbly and disfigured. This is the one real disadvantage of the B9 (though, as far as I know, all other printers in this price range have the same issue): the curing of the resin on the silicone wears out the silicone. This can be alleviated by placing models in different areas, so that the same spots aren't getting repeatedly worn, but eventually, the layer needs to be replaced. It's a simple procedure, especially with their most recent vat design, but it's another expense. I bought a second vat, though, so that I'll always be able to have one ready to go in case of a PDMS failure. The upcoming software update will supposedly double the life of the PDMS (instead of returning the vat to the same position after every layer, it offsets to a slightly different position each time, so that the same spots on the PDMS aren't getting hit every layer.

[Bexley]

Wrecked PDMS- the clouding is from repeated exposures. The ripped up area in the upper left is what caused the print to fail. Replacing it is pretty simple, the coating is a silicone called Sylgard 184. Place the vat on a level surface, pour 66 ml of mixed silicone into the raised side of the vat. The raised side has a lip, so most of the silicone stays in that half, but a small amount will work it's way over the lip as it levels itself, forming the dropoff point required to release suction. (Older style vats required damming one side, pouring it in, moving it around, etc. Much easier now.)




Failed print.