I’m looking to print gaskets and sealing rings using the flexible material. Most of the time these are fairly thin (~3mm diameter) so the autogenerated supports leave a lot of difficult clean-up to do and add imperfections that inhibit sealing. An attempt to print directly on the bed failed to get proper adhesion to the bed.
Here is an example picture of my part. Any recommendations?
Why not turn them on edge and have the support points on the outside edge which is not a sealing surface?
Seeing an image of what the gaskets look like might help you get some answers, there are so many ways to seal stuff that it’s really difficult to advise you 
Good idea. I added a picture to the top post. Thanks!
So I have to confess I have no experience with printing flexible resin, but this part screams “print me without supports” and I personally would still explore this possibility despite the early fails. I’m very interested by your question though because I have a cartridge of flexible ready to go and I expect to have to use it sometime in the next 2 months.
Maybe tweaking the Z offset value by reducing it will help ? For other resins it makes a big difference to how strong the raft/part adheres to the build platform.
If the surface area of the part in contact with the build platform isn’t big enough for the print to adhere correctly, maybe extending this surface area and mark it so that is can be cut off cleanly with an exacto knife ? See pic attached.
Otherwise, @kevinduhe seems to have more experience with Flexible resin and I’m sure the Formlabs staff will also have advices.
Playing the the Z offset should help. If it doesn’t stick well, try to make a thin base(raft) manually in the software to make model stick better to the platform. Once the print is finished you can simply cut it.
Seconding @aad345 suggestion of trying this again flat on the platform. If you’re noticing that this is delaminating, you might reduce the Z offset by 0.2mm at a time until it adheres or up to -1mm.
You’ll likely want to thicken that base a bit as the part will get compressed and there might be a few fractions of a mm of deviation between components of this towards the center of the platform and those on the outside. If needed, you could correct the deviation by making a small jig that holds the part and allows you to sand it flush.
It’s been a little while since I have printed with flex, but I do have several dozen prints under my belt. many of them were long, flat objects such as a watchband. I always printed those flat on the platform with no supports and never had any issue. As @Frew suggests, I did have the Z-offset to -0.2mm
I just tried printing directly on the base with -0.2mm and -0.4mm Z Offset. Unfortunately the part lost adhesion after about the 3rd layer.
It should be safe to iterate down to -1mm. If this is consistently delaminating down to -1mm, you might try adding a raft that increases the cross section of those first layers by a bit.
