I have separated 6 prints from the build platform and each time it’s a difficult, slightly scary, physical, heart pounding event.
I generally spray some IPA at the base to loosen whatever residual goo is hanging about. I then use the spatula and try to get under an edge. Once I’ve got an edge, I know I can get the thing off. But there have been prints that simply will not allow any give until the entire print lets go at once (pretty epic).
I’ve also tried using a larger blade box knife but I do not feel like the razor edge of the knife gives me much advantage over the decrease in safety.
What tips or tricks do you have? Is there any way we can modify the build platform or build structures to make it easier?
I’ve been using the tweezers that came with the printer. On larger pieces I’ll use the spatula too. I use the tweezers to get a corner lifted, then slide in the spatula if needed. I imagine this wouldn’t work if there was a thick piece cured right on the build platform though - I haven’t tried that yet myself.
What I do is I wedge the razor scraper under the part just a little; the razor won’t travel too far because of the handle. Then I leave the razor there and take the spatula and wedge it between the razor scraper and the build platform. Once the spatula is under the part, I remove the razor scraper and the spatula moves under the part a lot more freely. The razor doesn’t have to go under all the way, it just has to go enough under to get the spatula started. For tough parts, a little wiggling around a corner works best. Don’t use too much force or you could injure yourself or damage the part, and once it gets going it doesn’t take too much effort to get the razor under the part.
If you can find a glass razor scraper with a larger handle, it will probably give you a little more leverage. I bought two, one with a really tiny plastic handle (like this one: http://goo.gl/edeyU), and one like I linked to above. The small plastic handle one gave very little leverage and was essentially a waste of money. They also sell razor scrapers with wide blades (http://goo.gl/0z9ud), but I avoided that one because a longer blade means more chance for personal injury, and it wouldn’t be any more useful than the smaller one since the blade won’t go very far under the part anyway.
If you go with the glass razor scraper, be sure to wash off the blade before you use it; I believe most (maybe all) of the blades used in this style of scraper come oiled so they don’t rust (and they do rust quickly). You don’t want this on your build platform or in your resin. After you use it, rinse the tool off in the alcohol bath and wipe it dry, or any resin not rinsed off the tool may cause it to be a little gummy or slippery on your next use. Don’t leave the tool in the alcohol bath or the blade will eventually rust, and it seems it can start rusting in less than a day (this is with 91% isopropyl alcohol, higher purities may not rust it as quickly).
Around here, we do get the occasional stubborn print. I’ve found that the best method is to use the corner of the spatula at an angle nearly parallel to the build platform. I’ll use one hand to brace the platform from the side(remember to keep those fingers off of the metal - the spatula is sharp!) and my dominant hand to apply the corner to the raft of the model.
If the piece doesn’t give within a second or two, I’ll move the corner of the spatula over about a centimeter and try again. I think about it like “probing for sweet spots.” Usually after 3-4 attempts the part will come up easily, since the seal between the platform and the plate has been broken…
@Hirudin: I like your mindset of treating the operation like a slow peel instead of a large pop. I haven’t used the tweezers yet. I’ll give them a try!
@TJ: Great pointer to the glass scraper. I’ll pick one up and give it a try.
@Will: It must get easier with experience. All/most of what I’ve printed so far have been devils to remove. Thanks for the feedback!
I’ve found that holding the left corner of the tray firmly and wedging my hand against the build platform gives me really good leverage to remove the part by scraping away from my body with appropriate force
I’ve scratched the build platform many times already, but they’re mostly surface scratches. They don’t really affect the print quality unless you’re printing something flat against the build platform. Even then it comes out like a surface pattern and doesn’t affect the rest of the print. I’d imagine if they’re deep dents that have any protruding metal, it _might _damage the silicone surface, but then you could probably just sand it down smooth. So far I’ve had no problems with scratches, though.
@Jory - I do place the build platform on the plastic holder as shown but the force required to remove a print is more than the drawing implies. The right hand in the drawing is almost always holding the building platform in place (either the side or the rear of the build platform), not holding the plastic tray as depicted. I recommend Formlabs ask the community for videos of them removing parts from the build platform. It will show just how hard it is but it should also speed up the brainstorming process around how to make it easier.
@Nathan. Good call. We’re working on some videos showing exactly that we’ll get them online in the coming weeks.
We’re also working on improving the way that rafts are printed, so that that kind of force isn’t necessary. The process of ensuring that a print adheres well to the build-platform – and not to the PDMS – is complex, but it’s something we’re aware of and working on. A video will definitely be useful and I’ll let you know when we get it online.
