From a2fddb98937080ade8eda0e1e5ca43a7fd42f986 Mon Sep 17 00:00:00 2001
From: Rob Hart <hart@g.harvard.edu>
Date: Sat, 15 Jan 2022 01:08:18 +0000
Subject: [PATCH] Update README.md

---
 UrumbotXY/README.md | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/UrumbotXY/README.md b/UrumbotXY/README.md
index 45060a0..2c68059 100644
--- a/UrumbotXY/README.md
+++ b/UrumbotXY/README.md
@@ -79,7 +79,9 @@ Closeup of traces:  Using 1/64" bit and 0.8 mm horizontal separation of paths, a
 
 This machine is close to being able to mill circuitboards.  For the first try, the stiffness of the end effector wrt sideways force seems to be the limiting factor, rather than the xy stiffness.  Next step: a better arrangement of z-stage and full incorporation of the z-motion into the software.
 
-Small-excursion z-axis design:
+### Small-excursion z-axis design:
+
+A cam translates the spindle by flexing the beam a few mm.  Total excursion at the spindle is about +/- 2 mm.
 
 <img src=img/fixed_z.jpg width=50%><br>
 <img src=img/z-cam.jpg width=50%><br>
-- 
GitLab