Please have a look at my form upload.
I am printing it now.
Please give me your advice as to the orientation and foot print.
Am I trying to print too much in the way of base material?
is the job oriented to the hinge correctly?
I’ll post the results in a couple of hours after the base at least prints. It’s a 12 hour job
vacuumed formed shelf 1.STL, vacuumed formed shelf 2.STL (And 2 more…).form (905.5 KB)
Looks alright and printable. Though, here are my two thoughts:
I would rotate all models 45 degrees on the Z-axis. You want resin tank to peel in the length of each model rather than the width. This so you can build up cured resin which will help keep the model from ripping. When peeling the width of the model it instantly has to peel a very long and unstable part of the model. Hope you understand what I mean. Kind of hard to explain.
I wouldn’t print all parts at once. The further you get towards the peel-motor side, the bigger the peel forces. Furthermore, if one part fails, you either have to keep on printing which will create a blob on the resin tank where your failed part is (which might even ruin the PDMS layer and render your resin tank useless (bye bye €55,-)). Or you’d have to cancel the print which will cancel all models, even the ones which are printing properly. Both ways will cost you resin. So with big parts like these I’d stick to printing one or maybe two at a time.
I have a video but I take it we can’t upload those directly in our replys?
The video shows the thick base layer done and the edge furthest away from the hinge, the leading edge, came unstuck from the build platform about 3/8" back.
Kinda flops down.
But the silicone layer smashes it back up.
Now the supports have started.…
Here is a dropbox link to the video it is a close up of the front edge
Cecil B. DeMille i’m not.
A few shots 6 hours into the build. You can just make out the tear away on the front edge.
Hello Badgerboy,
as Alex V points out long thin areas are better to place parallel to the front edge of the machine, because of the peeling force. It is easier to peel a narrow strip than a broad strip.
There is no perfect orientation for your parts as there hardly ever is but there might be a better compromise. I absolutely understand and am in the same boat when wanting to do as many parts as possible in one shot and also safe as much resin as possible. Unfortunately these desktop machines make it hard due to that separation force between PDMS layer and cured resin (peeling action technology). the way you rotated them would be perfect for keeping large areas as clean as possible. But if you don’t have supports on higher walls you solely rely on the supports holding the part on the very bottom.
This could work but often the part will suffer a failure because of lack of supports throughout.
Is there a side that you’d prefer to be more pristine, because the area that has the attachment points will suffer quality. More so with thinner parts, that rely on supports.
Here is a possibility, which you can try if you want. No guarantees but If I was to make this part, that’s what I’d try.vacuumed formed shelf test rotation.form (457.5 KB)
@Jens_Schnabel’s orientation will probably work!
Note that, though your base has partly peeled off, but keeps printing will end up with the model you want, however, the print will be distorted and will have different dimensions than the original! Don’t know if they’ll be useful then.
Still. How did the print come out, overall?
One more thing, which refers to the hanging off support base.
If that keeps happening you have the option in your software to lower the Building platform, increasing the pressure against the silicone layer, which will fix that problem. (just in case you are not aware of it).
In order to do that you go to HELP up in the preform menu. Scroll down to FINE TUNING (second from the top) and there you’ll find the fine tuning tool. The top option in the window lets you lower or raise the building platform, in a case of constantly hanging off support bases you need to lower your building platform, start by one increment.
If that doesn’t solve it lower it another increment, these increments are in microns. You shouldn’t need more than a maximum of 2 microns. This adjustment will put more pressure on all parts involved, which is the flipside to this fix.However it will fix your hanging off support base problem, if it keeps occurring.
Let us know how things are working out.
I did find areas of uncured resin against the base. Pockets of goo
Also if you run the part under water right after the final rinse of IPA, is turns very cloudy. Oops
Not entirely true… Don’t ask me why. But normally raising the build platform will help stick the base properly against the platform. Unlogical; yes… very… Though I, myself, and others, have had this issue as well. Raising the platform seemed to resolve the issue. Lowering didn’t help at all… I’m still waiting for someone to clear up this mystery… as lowering would seem the most logical solution!
@Badgerboy, The print always turns opaque after you rinse it and you cure the part. It’s not as clear as you see it when printing. You have several ‘hacks’ to make it transparant again. Ranging from excessive sanding or spraying it with clear laquer. I, myself get the best (and instant) results with airbrushing diluted transparant nail polish on the model. It gives you an instant full transparant effect which works better than transparant laquer!
You said you had uncured resin against the base. and pockets of goo. Did these affect the actual print, or was it just residue?
For the result of the prints. I’m very jealous of your finish. you don’t seem to have any irregularities on the flat surface 
… That’s fantastic!
Umm the increments are 100microns and as @Alex_Vermeer mentioned that is definitely the wrong direction. If you look at the base on the prints it is very thin and curling. That is a very clear sign the platform is set too low and needs to be raised. In this case by a lot. I would guess 700microns or more. Just move it up some and print something and measure the thickness of the base. If it is less than 2mm thick then move the platform up some and measure again. Keep doing that till the base is right about 2mm thick. You will get much better results after that. Compression is bad for a lot of reasons and will wreak havoc on your prints. If I ever get around to it I’ll write up some details on why.
Mystery solved! thanks
Thank you for the analysis and advice.
When I return to work next week I will experiment with the information gleaned.
Updates to follow if I come up with anything earth shattering.
Thanks, 100/200microns I meant of course.
Here is my experience - I had plenty of hanging off base supports and the 100 microns down was the key to success maximum 200 microns, fixed it every single time.
Both you guys, Alex and you might be right but I can’t confirm that speaking from my personal experiences and trials and errors. We might be talking different causes.
@Jens_Schnabel that is compleatly possible. Having the platform too far or too close can cause peeling. But when it is too far the base usually is thick and solid in one area of the print. If it is thin everywhere then it’s usually too close.
yes, does make a whole lot of sense in either case.