Is it normal for thin sword blades to warp right after curing?

The curling you are seeing is almost certainly a result of internal stresses generated during the UV cure process, which causes polymer shrinkage. Because the blade is thin and long, these stresses aren't evenly distributed across the surface, leading to warping before the material has fully stabilized. Rotation is definitely one of your best options. If you can set up a simple rotation mechanism or manually flip the model halfway through the cure time, you distribute the curing pressure equally, preventing the stress from concentrating on one side. If you can't rotate it, propping it up so the weight and the light exposure are balanced will help a lot. Try balancing it on two supports rather than letting it hang or rest on just one end. Regarding geometry in the slicer, increasing the thickness slightly isn't the only answer. Because the stress is highest where the surface area is greatest, introducing a slight taper or even a gentle curve into the sword profile in the model itself can actually help dissipate the curing tension. If you angle the print during setup, making sure the longest surface is not perfectly parallel to the light, it often changes how the stress settles. If you haven't already, try increasing the exposure time in the slicer, even if it seems overkill. Sometimes a slightly longer, more gradual exposure can allow the resin to settle and gain structural integrity before the stresses pull it out of shape. But honestly, the physical setup and rotation are usually the most effective fixes for long thin parts.

My issue is a little diffrent since I mostly print smaller stuff, not big models like that warrior. I have been seeing parts peel off the build plate and that's what I'm realy struggling with lately. I am wondering if the temp setting on the printer itself has a big impact on adhesion, even if the print looks good. I've read that different resin needs specific plate temperatures, and I am not sure if mine is set correctly for this specific stuff.

That warping is a pain becuase the stress builds up fast. When I print large, thin pieces like a broadsword, I always incorporate a 15-minute pause during the printing cycle on the side of the part where it is attached to the support structure. This gives the resin time to slightly solidify and reduces that immediate internal tension before the whole part is complete. You should try that approach on your next print. Sometimes the material just needs a moment to stabilize before the print finishes and the full load settles.

I often find that before we even consider the mechanical aspects of rotation or geometry, the surface preparation of the initial print itself determines how successfully it will cure without warping. Specifically, I've observed that if the contact points between the print and the build plate are overly porous or oily, the curing process is severely hampered right from the start, leading to localized stress points later on. My experiance shows that even a microscopic layer of residue on the resin is enugh to create these uneven cure dynamics, which I belive contributes to the instability. Are you ensuring your supports are cleaned with an isopropyl solution before the initial immersion?

I've noticed that the distance from your UV lamp really matters. If the light is too intense or too close, the resin cures unevenly right on the surface before the bulk of the piece is set, wich totally sets up more stress. Try backing the lamp up a bit to get a more consistent dose of light across the whole shape. Also, make sure the light source is even on the whole sword; if one side is getting more direct light than the other, it's gonna warp up anyway. I've had better results using a light box that diffuses the beam.

Update: tried the mid-print pause idea on the next run and the new sword came off the plate way flatter, still curing it now but no banana so far. That said the blade still bends a little once it sits in the sun on my shelf for a day. Is that just the resin relaxing over time or should I try a longer cure at lower strength?