ask about drill bit

diff --git a/guide/challenge-bot-questions.org b/guide/challenge-bot-questions.org
index c7ce82a53f270f888dc71d6079dcd663d2b333ef..ab338e64e58c15588036f400530a856add8d66e3 100644 (file)
--- a/guide/challenge-bot-questions.org
+++ b/guide/challenge-bot-questions.org
@@ -12,3 +12,6 @@
        bolt used to hold the arduino?
     3. why did we drill through the arduino, rather than marking holes
        and using the drill to make holes where the marks were?
        bolt used to hold the arduino?
     3. why did we drill through the arduino, rather than marking holes
        and using the drill to make holes where the marks were?

+    4. how does the drill hold onto the drill bit?
+    5. what would happen if the drill bit teeth were not flat on the
+       drill bit?