I’m actually printing Elastic 50A with a need for some accuracy. Its a print with thin walls (about 1.5mm) in a form of a cup, the bottom is perfect in dimensions but the edges on top are too wide.
I used the following process :
20min cleaning in TPM with support
Let it dry for 10 min then remove supports
10 min in IPA batch
Drying with compressed air
30 min curing at 70° in a jar of room temp water (after 10 min of preheating the Form Cure L)
It seems, from my understanding from reading many topic on the forum, that my problems may come from IPA absorption which would deform my part.
So for my next test I’ll try to lower the cleaning time in IPA as much as possible but I wonder, does Elastic also absorb TPM ?
If so I may reduce both cleaning times ( I was thinking around 5 min in TPM then only a quick in-out in IPA) and then letting it dry about 3 days.
I read your blog + 2 of your posts on this forum before posting mine.
I sadly do not have a dehydrator at work for this project, and since it is due for monday I’m a little short to order one.
Letting it dry for more than 48h would do the trick ?
Also from your testing does Elastic 50 absorb TPM the same way as it does absorb IPA ?
You just need enough drying…so either a dehydrator, air drying with enough time, or forced air drying with a fan, etc.
The main thing is that it takes time, and just dry to the touch is not good enough. 48 hours air or fan drying will probably be adequate but you should take some measurements to check.
I haven’t tried TPM because we mostly use IPA but I would imagine it’s similar.
If your parts are larger than they should be it’s almost certainly solvent absorption.
Your best bet for now is to air dry it for >48 hours. If you have a portable fan, put it next to it to add convection and then 48 hours is probably enough (could be even shorter but not sure).
Well I printed another batch to test and right of the printer the parts are already too large …
So I am printing 2 new sets :
One at 97.5% and one at 90%.
I’ve never seen parts come off the printer in their green state grossly inaccurate. They’ve always been surprisingly good considering how wobbly the material is during printing.
If this is happening, it may not be very well oriented, supported, or there could be other factors at play (eg. cupping) but I’m just spitballing here.
Maybe not enough support on the higher end of the cup yes.
Sorry I can’t really show you much more because of our IT policy, can’t even sent an image to a cloud, let alone a file…
The print at 97.5% is perfect for the small part (70x15x30mm)
A tad bit too large for the big one (90x30x50mm). For this one a 95% would have been perfect, the 90% is a bit small but may work streched a bit.
It was my first complex part in elastic, the previous one have always be small plug so it was a way easier design.
Thin wall with tight tolerances is definitely not why elastic was made but if I can make something usable that is good enough for us.
Yeah, cups for Elastic resin can contribute a LOT to issues. I would say they exacerbate any cupping issues you might see with rigid resins.
I’ve done thin walled Elastic parts before with surprising accuracy so it can definitely come down to the setup and/or fine tuning. Glad to hear you got it working though!
