Help! sectional lifting flexible partials?

[dentalworks]

Hello I've been lurking the forums here for a while and decided to finally post up a recurring issue I'm having with my flexis. I am new to the industry so I've been through a bit of experimentation with my procedure.
My specific issue im looking to cure is the palatal areas always lift about 1.5 mm off of the master model. The thing that has me dumbfounded is if it comes out of the investment fitting perfect then why can't i get it to fit the same on the master?

I'm using all flextstar equipment and materials. I solved quite a few of other issues such as bubbles and heating temps thanks to the info on these boards but this one is to me a make or break detail. Does anyone else have the same issues?

Forgive me if I ask a lot of questions on any terminology or if this has been asked time and again I don't see a search function on the boards. I will post a few pictures for detail

 

[CYNOSURER]

Sounds like you warping it by generating too much heat with finishing... just a guess though. I've been using a yellow DVA butterly disc to cut off the sprue. then a Dedeco green stone (old porcelain tooth trimming wheel 4 inch diameter @ 1/4 inch thick to slowly trim to the bead and reduce thickness. Then a dedeco Black rubber wheel light touch, then red, then white, then pumice, yadda yadda, yadda.

 

[AJEL]

With flex star I have only tried a few but at a LMT course a few years ago, an Older tech(than myself) said he was still pegging his palates & that worked for him.
Pegging the palate means in your refractory U place 2-3 #8 round burr holes about 1/4 deep, during the chill the pegs in theory hold the palate down and avoid the pull toward the inside of the curve. When I started in late 60's it was pretty common to do this with the ancient PMMA like L199, & my first cases in Vulicinite. Try a few & let me know or call CMP I'm sure Elmer or Annie great technicians not sales persons will set U right. hope that helps. I believe AnnieS was a developer of the flexstar mateial so U can't go any higher.