Printing large, solid shapes

[GSJ_NZ]

Hi, I’ve got about 8x fairly large, solid prints to do for a client, and a growing pile of mis-prints!
Has anyone got any tips on how best to orientate and support models this size, and what resin might be best? Should I cut them up into smaller sections?
The models are all roughly L-shaped, and around 63x50mm, and 15-18mm deep. They’re approximately 22-26ml each in volume. I’m printing at 42xy, 30z. The models are not being cast.
I’ve got B9 cherry, Spot-HT and some of their black pigment. I’ve tried all of them so far, and while the Cherry, followed by spot-ht (no pigment) seems to be the most promising with the least warping, I can’t get a complete print. I’m experimenting with the exposure times with the pure spot-HT, but keep getting results like the picture attached. That was using 2800ms exposure. The spot-HT at 1% dilution (by weight) using 1800 and then 2800 exposure was extremely warped before it got to 40% of the print time. Is the pigment causing the extra warping?
All models are going via Pre-form for its suggested support layout, then they’re done in Matrix. Everything goes through Microsoft / Netfabb model repair. I’m using these inverted V-shaped rail supports as they seem to be giving me a better, more accurate base surface on these models than my normal raft of round supports that I use for the smaller jewellery models. They snap off nicely afterwards too. I’ve also tried orientating them vertically, and with various 0.4mm thick raft / base plates at the feet of my supports. I realise 99% of my issues will be with the supports so I’d welcome any other ideas!
Thanks, Gary.

[Jewelermdt]

You might try them at an angle. That way there is not as much load to sag. And maybe do them separate.

[reify]

I think they're just too large to print solid - too much shrinkage. I suggest using MeshMixer to hollow them out and adding a couple drain/vacuum release holes at the bottom (bottom meaning closest to the build platform).

http://www.meshmixer.com/download.html

Not sure what the issue with HT was, never seen this before. You might want to try increasing your Z lift height to 5mm.

If you do make them hollow, you might need to increase your Lift and Sequence Time (aka settle time) on your resin profile page so the resin has time to stop flowing out of the hollow cavity before the exposure starts. I'd try 8000 ms if you're having trouble with the default.

[GSJ_NZ]

Thanks, I hadn't thought about hollowing them out! I'll give this a try.
With the Spot-HT I'm using a new vat so i might not have got the film tension exactly right.