Warping on 3D prints

[ICH60]

In Feb I started a thread 3D Printing a Early GWR Wagon Body
So a few months have pasted and I giving this update on an issue on the movement of the body. For the fist month I let the painted body sit on the window sill in my kitchen that get the sun till around 2pm to see if any warping happened . All was well. I then took it into my layout shed and it lived in there for another month. It dark most of the time and lit by LED light when I am in there.
I have noticed that the ends, one a lot worse than the other there is now a warp but strangely only on the bottom. I attached a couple of photos to show the movement.
Now it can be flatten by small finger pressure and I if a had put a floor in It probable would have stayed straight.
For information I used Siraya Tech Fast. it was washed in IPA for 10mins and dried off then cured for 10mins, in the ELEGOO separate Washing And Curing Machines
Does any one have any thoughts why this may have happened.

View showing warp at bottom



The view looking at the top.



Ian

 

[Andy_Ross]

It's to do with stress and shrinkage in the resin.
It helps to leave it on the supports for a while and try rotating it to a different angle before you support it.
ALso if it's consistent you can adjust your design to have an opposite curve so the final print ends up flat.

 

[ICH60]

It's to do with stress and shrinkage in the resin.
It helps to leave it on the supports for a while and try rotating it to a different angle before you support it.
ALso if it's consistent you can adjust your design to have an opposite curve so the final print ends up flat.

Andy. Thanks for the pointers

 

[simond]

That warping,

It’s a learning curve…

 

[Bill Bedford]

Resin absorbs IPA, it's best to dry the printed resin at least 24 hours before curing

 

[simond]

Bill,

thanks for that insight. I have (nearly) always been impatient, and occasionally frustrated. A little light has come on.

thank you.
Simon

 

[Andy_Ross]

I ran a business doing bespoke 3d prints and producing mixed laser cut and 3d printed kits. It's something I came across. It's easier to mitigate when you are making multiple repeat parts, you can adjust the print to get good results.

Here are two pictures of a North Eastern signal box kit.
The painted one is an early production sample, see the warping in the end windows?
Compare with a later one with flat parts. I adjusted the supports and rotation of the print and used different slicer settings.
I also separated the door from the window next to it which helped.
It's as much an art as a science.


Close ups are brutal to a model!