LT Tray Woes: Not seeing any of the stated improvements


#1

You’re looking at an LT tray after about 1/2 bottle of standard Formlabs Clear Resin V2. From this usage you can see foggy spots from supports (something I thought LT was designed to reduce/eliminate), gouges in the surface (I’m guessing from the build plate driving stray chunks of failed prints into it, although the wiper is supposed to handle that*), and finally the horizontal streaks which are known to be caused by the wiper motion (I always pour resin into a new tank before installing the wiper, I never let the wiper move while dry).

The huge sharktooth-shaped item is an air bubble between the polyglass and the PDMS/FEP (?) layers above it. This apparently happened during roughly 3 months of storing resin in the tray. This is in my shop so climate control is not an issue.

So in my documented experience, The “LT” moniker refers neither to usage nor storage. What exactly is the improvement then?

  • The wiper does NOT sweep the entire build area after each layer, only up to the edge of the item(s) being printed. This may save a little time per print, but it does NOT move dislocated cured chunks enough to prevent the build plate from driving them into the tray surface on subsequent passes.

#2

It is good practise to filter the resin in the tray after every failed print.

My understanding is that the wiper is there to aerate the resin rather than remove cured resin debris. It certainly doesn’t do a good job of the latter.

Why should you use a LT tray? If they are used carefully they will last for 9-10 litres or more of resin. In my experience failure at lower resin usage comes from operator errors rather than wear.


#3

I’ve been using the same LT tanks for a year and they’re great. Way better than the regular ones imo.


#4

looks like some failed prints that went on to long, along with to much pressure trying to clean, also may / maynot be improper cleaning of tray… I would like to know what steps you took to free failed prints/ cleaning solutions you used or may have used…a little more detail would be great.


#5

The only real reason I ever had prints fail is from too few supports. Usually the build plate doesn’t raise enough to see it until there’s been plenty of time for broken bits to be mashed into the tray surface before anyone can do anything about it.

As for plucking off failed prints, I have never used anything but my fingernail. Yes, I’m not afraid to put a finger into the resin. I’ve lived a good life and I don’t want any more kids. Anyway it’s never marked, much less gouged, the PDMS trays and I saw it acting no differently with the LT.

When I filter the resin afterwards (photo of stack of 125 micron paint filters not enclosed), I use only the spatula that came with the F2 to squeegee the last bits, always dragging never pushing.

I’ve never used cleaning chemicals on them because I have a different tray for each resin type I use.

I’ve had this printer since it came out, so let’s agree to disagree that it’s a rookie mistake on my part. Since FL already replaced one LT tray after the wiper arm (always installed AFTER resin) scratched it into oblivion, and firmware releases have addressed such issues, I find it easier to believe that LT trays took time to get up to speed and the one in this post comes from earlier in that process. In that case, I’m probably just venting, so at best this is a cautionary tale.


#6

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