Support Removal - Before or After Curing


#1

Hi All,

Just curious what others do here. I find that it really depends on the resin. For example, with Tough resin at 0.5mm touch support size, I can cure the parts and peel off supports very easily after curing.

Waiting till after curing means there is less chance that the parts will warp during the curing cycle.

However, for resins like Durable, peeling supports off before curing is VASTLY easier than afterwards. In general, I haven’t had huge issues taking supports off for Standard, Tough, or Rigid after curing, but would be curious to know what people do for other resins such as Durable, Flexible, Elastic, etc.


#2

I tend to remove my supports before post cure unless I worry about the part warping during post cure. Especially with the Form 3, where I have tuned my clear supports to tear off like velcro, it’s vastly easier to remove the supports before they’re hardened in the Form Cure.


#3

Speaking of Formlabs 2.

For elastic resin you should take them out after curing. Tried several time to remove it before and it is much easier afterwards. Also i did a hole once because I pulled the internal supports instead of cutting it. So I reduce the size of the support tip and used scalpel to cut it very close to the model, like shaving the model to cut the support.

For clear resin its depends on the part. It is easier to remove the supports before curing for sure, but for me its depends on the part complexity. If its simple part and very straight forward to remove the support I might do it before or after, depends on how lazy I am :slight_smile:.
For complex parts I normally cure it before removing the support, after curing they are much more brittle and its very help to remove internal support, just bending it a bit and its detach.

For Tough i’m always using it afterwards and always timing the machine so once it finished i’m taking out the parts. The reason is if I left it for the weekend, its just bend on the build platform. They are also bending during the first few weeks. This material is good but not for very accurate parts, its just changing constantly during the first few weeks.


#4

This is interesting to hear.

@CraigBroady do you do this pre-cure regardless of resin type?

I’ve started ripping supports off Durable resin BEFORE post cure, as I find it so much easier for this resin. Ideally I would leave supports on at all times to prevent warping, and for resins like Tough that seems to work OK because the supports peel off easily - but not the case for resins like Durable.

I’ll do some testing myself to compare between resin types and post the results here when I have a chance.


#5

I don’t follow. Pre-cure?


#6

I mean do you typically remove supports before curing for all resin types?


#7

Usually. Typically I’ll only leave supports on for flexible or elastic.


#8

Interesting, OK. I’ve definitely noticed warping in the Form Cure on parts in which I’ve removed supports first. I do a lot of engineering prototypes so warping is highly undesirable.

I’ve done a couple of test prints using Tough, Durable, and Black so far, with Elastic and Rigid remaining to print. Out of the 3 test prints thus far, Durable is the only one which I think I will remove supports first for. Removing supports on reduced touchpoint sizes for Tough & Black post-cure is pretty easy, but more of a pain for Durable.


#9

So I’m not seeing any definitive advice. Lots of good points but I’m still kinda lost.
I’m hoping to dial in real micro here…

  1. Some are saying before and some are saying after Cure.
  2. There’s discussion of brittleness i.e. after cure materials are more brittle.
  3. There is discussion of warping - on this point I have tried lowering the prescribed 60 degree C. to 45C. I learned that I can manipulate my parts after cure, with a heat gun. This was especially helpful when I was making a liquid silicone casting tool and my Form3 prints were quite solid blocks (A&B side of my tool and 3rd part - center core). There was so much residual heat within the tool parts that it did not cool evenly resulting in warped tool parts and bad parting line. So I took a heat gun to the parts, clamped them together in my bench vice and was able to re-adjust the parts to close the parting line.
  4. I have had small parts with a 1.5mm or 2mm wall thickness (injection molded part design) come out warped, even with the supports still attached. Hence the attempt to reduce this by lowering the heat.
  5. The data on the resins suggest they cure over a few weeks if not fully cured when handled right out of the printer. So I assume, if it will cure over a few weeks it is better to under cure it.
  6. NEXT PROBLEM: And this is where the brittle issue comes in - Because I am working on a design for injection molding and I have some really tiny parts < = 1.5mm wall thickness, I am getting broken parts where the support point of connection to my part, at 0.5mm didn’t break away, but the wall of my part broke away with the support. Argggg!
  7. The cost of time and resin for experimentation is killing my bottom line and I’m kinda frustrated as to best practices.
  8. Thoughts?

#10

From my experience, there isn’t really a perfect solution here. I almost always remove supports after curing, unless the geometry makes removing after significantly more difficult or unless the parts are thick enough that I don’t expect warping to occur. There are also certain resins like Elastic and Flexible in which I always remove prior to curing.

For thin walled parts, or parts in which I think will deform, I leave supports on and turn off the heater in the Form Cure entirely. To compensate, I increase the cure time by 3X. I assume the mechanical properties aren’t the same as curing with heat, but I’ve found that this eliminates warping entirely. It would be great to actually know the mechanical properties of these parts, but in most cases they are adequate.

Like you, I also tried dropping temp while curing, or even curing without heat first and then with heat. I’ve found that neither of these help.


#11

While this subject has been cooking here on the forum, I was at my bench (the last hour or so) and worked on my latest print of the same objects, and have been snipping off supports - prior to cure.

The material is more flexible and allows the supports to be “cut” by the snippers, rather than “broken-fractured” as the snipper squeezes through.

I like the idea of turning off the heat all together at this point after supports are take off.

I’ll keep you posted on results.

BTW: using clear resin.


#12

I leave supports on the washed parts if UV cure is done. For Clear parts, I don’t post cure because they become too brittle. GreyPro parts are getting about 5-10 minutes UV cure to stiffen them a little. Supports are removed from GreyPro after post cure to prevent warpage. Some of my model RR parts are ladders with .016" diameter rungs … too tiny for brittle Clear but amazingly tough and flexible in GP after a 10 minute cure.

My supports are 0.10 mm at the tip and pull off easily.