Author Topic: Preventing warping of the first layers, anyone solve this problem?  (Read 359 times)

0 Members and 1 Guest are viewing this topic.

Stephane

  • Crew
  • *
  • Posts: 52
  • Gender: Male
  • Respect: +52
Preventing warping of the first layers, anyone solve this problem?
« on: September 14, 2019, 12:27:05 PM »
0
I'm printing a frame bottom, and I have a curious little problem that I can't seem to solve.  See the following picture...

[ Guests cannot view attachments ]

[ Guests cannot view attachments ]

Notice that the very edge of the frame bows outwards.  I tried providing a lot of supports, and the supports appear on both sides of the edge.  The corners are at the correct position (when measured against the other end of the frame), it's the center that bows outwards.

Still, I can't get a straight edge to print.  The other end (the one furthest from the build plate) prints perfectly.

I'm sure someone has seen this problem and found a way to solve it, hoping that the someone is on this forum :)

AlwaysSolutions

  • Crew
  • *
  • Posts: 59
  • Respect: +35
Re: Preventing warping of the first layers, anyone solve this problem?
« Reply #1 on: September 14, 2019, 03:05:10 PM »
0
My problem with parts like that is that the whole thing tends to banana warp away from the underside over the course of several days after curing - have you seen that before or have a fix?  For your specific issue here, my educated guess to your problem is possibly try fewer supports on the actual edge that's warping out.  Just put enough, maybe five or six, to support the first couple layers of that edge, then add the "real" supports on the inward side for the rest for strength.  The resin could be sticking to the supports on top between dips and curing ever so slightly from light for the next layers.  The corners are okay because the resin over there isn't caged in, so to speak.  Keep in mind this is just my guess of what's going on based on my experience with the behaviors of the resins I've observed in other situations.  Worth giving it a go though..

Stephane

  • Crew
  • *
  • Posts: 52
  • Gender: Male
  • Respect: +52
Re: Preventing warping of the first layers, anyone solve this problem?
« Reply #2 on: September 14, 2019, 06:28:28 PM »
0
I've seen the banana warp before, but not on this particular part (to my surprise).  However, even if did warp, I'm glueing it ti the shell.  My solution for long parts that warp is to post cure them with supports still attached, that always works fir me.

Fewer supports would be a good idea, but I don't think that's the problem.  This picture i posted is actually version 2.  The first had far fewer supports and had the exact same problem.  I added the higher number if supports as an attempted fix. 

Lemosteam

  • Crew
  • *
  • Posts: 4333
  • Gender: Male
  • PRR, The Standard Railroad of my World
  • Respect: +1448
    • Designer at Keystone Details
Re: Preventing warping of the first layers, anyone solve this problem?
« Reply #3 on: September 16, 2019, 06:40:57 AM »
0
Have you tried putting less supports in the center?  Maybe those are cure-shrinking at a faster rate than the outer posts?

i.e.:
______________________
||   |    |       |       |    |   ||

OR possibly

______________________
||   |    |     |||     |    |    ||