added ikea lack concrete slab stuff; removed keybase txt

input/projects/3d-printing/ikea-lack.md

@@ -12,3 +12,76 @@ flattr: true
 
 **More content coming soon!**
 
+### Concrete slab for noise and vibration dampening
+
+Unfortunately, because the Ikea Lack tables are very lightweight and also hollow, they tend to amplify the sound coming from the 3D printers on them.
+But there is an easy solution to this: vibration dampening by increasing the mass.
+This can be achieved for example by simply creating a large concrete slab.
+In my case, it weighs about 17kg.
+
+First, build a simple wooden frame to contain the wet concrete.
+I've used cheap 40x15x1000mm wood pieces and cut them to 555mm, screwing them together in the corners.
+For the surface below the frame, I've used an old cardboard box.
+I've "sealed" the surfaces of the cardboard and the wood pieces with clear flex-o-tape, to avoid the water wicking out of the concrete too fast, and to be able to remove the pieces easily later-on.
+
+<div class="lightgallery">
+    <a href="img/ikea_lack_concrete_1.jpg">
+        <img src="img/ikea_lack_concrete_1_small.jpg" alt="Simple wooden frame">
+    </a>
+    <a href="img/ikea_lack_concrete_2.jpg">
+        <img src="img/ikea_lack_concrete_2_small.jpg" alt="Screwed together in the corners">
+    </a>
+    <a href="img/ikea_lack_concrete_3.jpg">
+        <img src="img/ikea_lack_concrete_3_small.jpg" alt="Added some tape to seal the surface">
+    </a>
+</div>
+
+Then I've simply hand-mixed about one half of a 35kg bag of cement/sand mixture with 2l of clear tap-water.
+The resulting sludge can then be filled into the frame.
+Apply some vibrations to the edges of the frame using a hammer, and using your hand on top of the concrete, to get most of the bubbles out of the mixture and get it to settle properly.
+You should then use a piece of wood to really get the surface flat.
+
+Also, be careful: avoid contact of the concrete with your skin, it burns after a while!
+
+<div class="lightgallery">
+    <a href="img/ikea_lack_concrete_4.jpg">
+        <img src="img/ikea_lack_concrete_4_small.jpg" alt="Mixing the concrete">
+    </a>
+    <a href="img/ikea_lack_concrete_5.jpg">
+        <img src="img/ikea_lack_concrete_5_small.jpg" alt="Final consistency">
+    </a>
+    <a href="img/ikea_lack_concrete_6.jpg">
+        <img src="img/ikea_lack_concrete_6_small.jpg" alt="Filling the frame">
+    </a>
+    <a href="img/ikea_lack_concrete_7.jpg">
+        <img src="img/ikea_lack_concrete_7_small.jpg" alt="In my first attempt, I just tried to form the surface by hand. It worked, but is not perfect.">
+    </a>
+    <a href="img/ikea_lack_concrete_8.jpg">
+        <img src="img/ikea_lack_concrete_8_small.jpg" alt="Closing it up for 24h">
+    </a>
+    <a href="img/ikea_lack_concrete_9.jpg">
+        <img src="img/ikea_lack_concrete_9_small.jpg" alt="Side-view">
+    </a>
+</div>
+
+After about 24h, the frame can already be removed.
+Because of the large surface area and the low volume of our piece, it get's hard quite quickly.
+And also, we're not using it for large static loads, so we don't have to wait the full 28-days specified by the manufacturer.
+The small parts at the edges where the concrete slightly got under the frame can just be broken off by hand.
+
+<div class="lightgallery">
+    <a href="img/ikea_lack_concrete_10.jpg">
+        <img src="img/ikea_lack_concrete_10_small.jpg" alt="After 24h, one side removed">
+    </a>
+    <a href="img/ikea_lack_concrete_11.jpg">
+        <img src="img/ikea_lack_concrete_11_small.jpg" alt="The small parts at the edge can just be broken off easily by hand">
+    </a>
+    <a href="img/ikea_lack_concrete_12.jpg">
+        <img src="img/ikea_lack_concrete_12_small.jpg" alt="Final result, left view">
+    </a>
+    <a href="img/ikea_lack_concrete_13.jpg">
+        <img src="img/ikea_lack_concrete_13_small.jpg" alt="Final result, right view">
+    </a>
+</div>
+
+And it works perfectly, the noise of the printer is greatly reduced!

static/keybase.txt

@@ -1,65 +0,0 @@
-==================================================================
-https://keybase.io/xythobuz
---------------------------------------------------------------------
-
-I hereby claim:
-
-  * I am an admin of http://xythobuz.de
-  * I am xythobuz (https://keybase.io/xythobuz) on keybase.
-  * I have a public key with fingerprint A37C 346C 471C 1A13 829A  B2E8 4CBB 7193 158A D8D3
-
-To claim this, I am signing this object:
-
-{
-    "body": {
-        "key": {
-            "fingerprint": "a37c346c471c1a13829ab2e84cbb7193158ad8d3",
-            "host": "keybase.io",
-            "key_id": "4cbb7193158ad8d3",
-            "uid": "839b7c380c5f2dbf4df3f78168184d00",
-            "username": "xythobuz"
-        },
-        "service": {
-            "hostname": "xythobuz.de",
-            "protocol": "http:"
-        },
-        "type": "web_service_binding",
-        "version": 1
-    },
-    "ctime": 1411415361,
-    "expire_in": 157680000,
-    "prev": "87286d24c29a7e042552de1384cb16236890e253e18047e69e50115858f14c9e",
-    "seqno": 5,
-    "tag": "signature"
-}
-
-with the aforementioned key, yielding the PGP signature:
-
------BEGIN PGP MESSAGE-----
-Version: GnuPG/MacGPG2 v2.0.22 (Darwin)
-Comment: GPGTools - https://gpgtools.org
-
-owGbwMvMwMUotFZo1qMnX6sZTx/4mMQQolDrWq2UlJ9SqWRVrZSdCqbSMvPSU4sK
-ijLzSpSslBKNzZONTcySTcwNkw0TDY0tjCwTk4xSLUySk5LMDS2NDU0tElMsUoyV
-dJQy8otBOoDGJCUWp+pl5gPFgJz4zBSgKBb1pWAJC2PLJKAVFgbJpmlGKUlpJilp
-xmnmFoZmFoYWJikGBiCFxalFeYm5qUDVFZUlGflJpVVKtTpKQNGyzORUkJtBVqOp
-0EtJBWotKMovyU/OzwFKZJSUFFiB9JVUFoAUlqcmxUONiE/KzEsBehuooSy1qDgz
-P0/JyhCoMrkkE2SmoYkhEJkamxnqKKVWFGQWpcZnglSYmptZGAAByJrUMpBfzI0s
-zFKMTJKBgWSeamBiZGpqlJIKDDSg7w3NjIzNLCwNUo1MjVMNLQxMzFPNLFNNDQyB
-IWJqkWZokmwJcnBxamFevpKVKdCZielAI4sz0/MSS0qLUpVquToZZVgYGLkY2FiZ
-QDHHwMUpAIvPWZ4cDCvSNZWvirwqaG9+f182xkRiW5GIynU+xXuijEvar01y2L4o
-PMTppE9AmXGP+OUnXowXWjZYXud7YeKeu/BOy7T8pgpuXkUvKabHJvnsMg/0+E6u
-aTY+ffvwWlXpomcHw45cOPera6WMcX4W0/c/e1c9Onx32d2f7E5nlNQqI3Uf7/0Q
-MdOgw2V7xQnZvEtfP4WV/zj6IkPuf/k0vfSr1dNDRFxjeCp2rcuYxHBZ3+q52cm3
-MQ76AoYpklINSv9ZTacb2f79PnPuslVc2nsebp0hx8xgb864K6vw1YJLdmvb6l8z
-td9zebjoWL2Bp9nHmtw82bs745RvPwnhmVMV6KLsPmW3/1SvGM21C9a4AAA=
-=ecD9
------END PGP MESSAGE-----
-
-And finally, I am proving ownership of this host by posting or
-appending to this document.
-
-View my publicly-auditable identity here: https://keybase.io/xythobuz
-
-==================================================================
-