# Build Plate is not flat **URL:** \ **Category:** Form 2\ **Created:** [September 28, 2016, 1:37pm UTC](https://forum.formlabs.com/t/build-plate-is-not-flat/9800 "2016-09-28T13:37:31Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Rythm1](https://avatars.discourse-cdn.com/v4/letter/r/b9e5f3/32.png) [@Rythm1](https://forum.formlabs.com/u/Rythm1)\ **Post date:** [September 28, 2016, 1:37pm UTC](https://forum.formlabs.com/t/build-plate-is-not-flat/9800/1 "2016-09-28T13:37:31Z")
Hi there, I’ve a pb with the middle of my build plate. I’ve suspect it not to be flat and it fact… it is ! If I print a huge part on the full plate, i’ve 0.5mm of difference between the center and the corners. **Here is the method I used to maesure it :** _White resin, 0.10mm resolution - fine tuning -0.2mm_ (I was desperate with non adhering parts in the middle of my plate.) I’ve print a map of 3mm boxes ![](https://us1.discourse-cdn.com/flex025/uploads/formlabs/original/2X/4/4f1f81ef958f1a703f4034281793390d3b48c5fe.PNG) and I’ve maesured the size of the different boxes. (in mm) ![](https://us1.discourse-cdn.com/flex025/uploads/formlabs/original/2X/1/1907f1dc9b8093749d7469719a2d5b24910c4acc.jpg) We can clearly see the pb 😕 How can I correct that ? How does it happened ? (btw is it normal with a fine tuning at -0.2mm to have 0.5mm heigh less on my part ?) Thank you ! ---
**Author:** ![Zachary\_Brackin](https://avatars.discourse-cdn.com/v4/letter/z/4da419/32.png) [@Zachary\_Brackin](https://forum.formlabs.com/u/Zachary_Brackin)\ **Post date:** [September 28, 2016, 3:41pm UTC](https://forum.formlabs.com/t/build-plate-is-not-flat/9800/2 "2016-09-28T15:41:01Z")
So, one of the things the printer doesn’t do is level the platform to the bottom of the tray, and to overcome this it has a long exposure at the start of the print so that it can cure the unknown thickness. This only affects the support base so it’s not a big deal, but it is an issue if you’re printing directly to the base, in those instances it can help to extend the bottom of the print and then sand it down to the right amount. ---
**Author:** ![CraigBroady](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/craigbroady/32/6106_2.png) [@CraigBroady](https://forum.formlabs.com/u/CraigBroady)\ **Post date:** [September 28, 2016, 3:46pm UTC](https://forum.formlabs.com/t/build-plate-is-not-flat/9800/3 "2016-09-28T15:46:55Z")
Zach’s got it right. What you’re observing is flatness tolerances for across different build platforms and tanks. Support structure rafts eliminate these differences. For the parts that were not adhering near the center, how big were they and did you use supports? ---
**Author:** ![Rythm1](https://avatars.discourse-cdn.com/v4/letter/r/b9e5f3/32.png) [@Rythm1](https://forum.formlabs.com/u/Rythm1)\ **Post date:** [September 29, 2016, 9:18am UTC](https://forum.formlabs.com/t/build-plate-is-not-flat/9800/4 "2016-09-29T09:18:46Z")
Thank you both. In fact I print lot of things without support, directly on the plate. It works well for my project : it needs very little parts, and on the side of the platform it goes really well ! But it not adheres very well on the center, even if it’s really light and little (to answer Craig). So I really wish to have a flat plate. Is it impossible ? I know that support’s base correct that (on I have to be careful because even with base little print fall from the center…) but my goal is to continue to print without. It perfect for me, my parts are design thinking of this way 😉 ---
**Author:** ![billiejean](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/billiejean/32/9236_2.png) [@billiejean](https://forum.formlabs.com/u/billiejean)\ **Post date:** [September 30, 2016, 8:35am UTC](https://forum.formlabs.com/t/build-plate-is-not-flat/9800/5 "2016-09-30T08:35:37Z")
What you are seeing is the Pull/shrink from the Silicone as it starts to capillary up the sides. No way to avoid that with free pouring silicone… The only way to avoid that would to make a part that would be the same size of the tray from polished acrylic of similar material then pour it from the side, but you would still run the risk of loosing the optical clear from any minor imperfections in the acrylic. ---
**Author:** ![aad345](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/aad345/32/5444_2.png) [@aad345](https://forum.formlabs.com/u/aad345)\ **Post date:** [October 8, 2016, 6:22am UTC](https://forum.formlabs.com/t/build-plate-is-not-flat/9800/6 "2016-10-08T06:22:18Z")
For me, the wiper side(right side of the printer) is a lot more compressed than the left side. This is annoying since when I’m trying to print directly on the platform without supports I get a big difference margin (about 3mm) ---
**Author:** ![system](https://us1.discourse-cdn.com/flex025/uploads/formlabs/original/3X/5/b/5bc2bdf993ff27c2e0eecab5010b25626fbb327a.png) [@system](https://forum.formlabs.com/u/system)\ **Post date:** [October 22, 2016, 6:22am UTC](https://forum.formlabs.com/t/build-plate-is-not-flat/9800/7 "2016-10-22T06:22:38Z")
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