diff --git a/TeamCode/src/main/assets/tuning/common.js b/TeamCode/src/main/assets/tuning/common.js
index 284537e..af09090 100644
--- a/TeamCode/src/main/assets/tuning/common.js
+++ b/TeamCode/src/main/assets/tuning/common.js
@@ -79,6 +79,26 @@ function fixVels(ts, xs, vs) {
   return numDerivOffline(ts, xs).map((est, i) => inverseOverflow(vs[i + 1], est));
 }
 
+// see https://github.com/FIRST-Tech-Challenge/FtcRobotController/issues/617
+function fixAngVels(vs) {
+  if (vs.length === 0) {
+    return [];
+  }
+
+  let offset = 0;
+  lastV = vs[0];
+  const vsFixed = [lastV];
+  for (let i = 1; i < vs.length; i++) {
+    if (Math.abs(vs[i] - lastV) > Math.PI) {
+      offset -= Math.sign(vs[i] - lastV) * 2 * Math.PI;
+    }
+    vsFixed.push(offset + vs[i]);
+    lastV = vs[i];
+  }
+
+  return vsFixed;
+}
+
 // data comes in pairs
 function newLinearRegressionChart(container, xs, ys, options, onChange) {
   if (xs.length !== ys.length) {
@@ -103,6 +123,7 @@ function newLinearRegressionChart(container, xs, ys, options, onChange) {
   const maxX = xs.reduce((a, b) => Math.max(a, b), 0);
 
   const chartDiv = document.createElement('div');
+  const width = Math.max(0, window.innerWidth - 50);
   Plotly.newPlot(chartDiv, [{
     type: 'scatter',
     mode: 'markers',
@@ -124,10 +145,11 @@ function newLinearRegressionChart(container, xs, ys, options, onChange) {
     dragmode: 'select',
     showlegend: false,
     hovermode: false,
-    width: 600,
+    width,
+    height: width * 9 / 16,
   }, {
-    // 'select2d' left
-    modeBarButtonsToRemove: ['zoom2d', 'pan2d', 'lasso2d', 'zoomIn2d', 'zoomOut2d', 'autoScale2d', 'resetScale2d'],
+    // 'select2d', 'zoom2d', 'pan2d', 'lasso2d', 'zoomIn2d', 'zoomOut2d', 'autoScale2d', 'resetScale2d' left
+    modeBarButtonsToRemove: [],
   });
 
   const results = document.createElement('p');
@@ -161,6 +183,10 @@ function newLinearRegressionChart(container, xs, ys, options, onChange) {
   let pendingSelection = null;
 
   chartDiv.on('plotly_selected', function(eventData) {
+    if (eventData === undefined) {
+      return;
+    }
+
     pendingSelection = eventData;
   });
 
diff --git a/TeamCode/src/main/assets/tuning/dead-wheel-angular-ramp.html b/TeamCode/src/main/assets/tuning/dead-wheel-angular-ramp.html
index 6156955..514bc40 100644
--- a/TeamCode/src/main/assets/tuning/dead-wheel-angular-ramp.html
+++ b/TeamCode/src/main/assets/tuning/dead-wheel-angular-ramp.html
@@ -9,6 +9,10 @@ body {
 }
 
 .content {
+  margin: auto;
+}
+
+header {
   max-width: 600px;
   margin: auto;
 }
@@ -44,28 +48,30 @@ details, a {
   </head>
   <body>
     <div class="content">
-      <h1>RR Dead Wheel Angular Ramp Regression</h1>
-      <details></details>
+      <header>
+        <h1>RR Dead Wheel Angular Ramp Regression</h1>
+        <details></details>
 
-      <div id="download"></div>
+        <div id="download"></div>
 
-      <fieldset>
-        <legend>Feedforward Parameters</legend>
-        <div>
-          kV: <input id="kv" type="text" />
-        </div>
-        <div>
-          kS: <input id="ks" type="text" />
-        </div>
-        <input id="update" type="button" value="update" />
-      </fieldset>
+        <fieldset>
+          <legend>Feedforward Parameters</legend>
+          <div>
+            kV: <input id="kv" type="text" />
+          </div>
+          <div>
+            kS: <input id="ks" type="text" />
+          </div>
+          <input id="update" type="button" value="update" />
+        </fieldset>
 
-      <div id="trackWidthChart">
         <p>
           <button id="latest">Latest</button>
           <input id="browse" type="file" accept="application/json">
         </p>
-      </div>
+      </header>
+
+      <div id="trackWidthChart"></div>
     
       <div id="deadWheelCharts"></div>
     </div>
@@ -73,7 +79,7 @@ details, a {
     <script>
 function loadRegression(data) {
   const [_, angVels] = data.angVels.reduce((acc, vsArg) => {
-    const vs = vsArg.map(v => Math.abs(v));
+    const vs = fixAngVels(vsArg.slice(0, -1)).map(v => Math.abs(v));
     const maxV = vs.reduce((acc, v) => Math.max(acc, v), 0);
     const [accMaxV, _] = acc;
     if (maxV >= accMaxV) {
@@ -86,28 +92,29 @@ function loadRegression(data) {
   data.parEncVels.forEach((vs, i) => {
     const div = document.createElement('div');
     newLinearRegressionChart(div, 
-      angVels.slice(1, angVels.length - 1),
-      fixVels(data.encTimes, data.parEncPositions[i], vs),
-      {title: `Parallel Wheel ${i} Regression`, slope: 'y-position'});
+      angVels.slice(1, -1),
+      fixVels(data.encTimes.slice(0, -1), data.parEncPositions[i].slice(0, -1), vs.slice(0, -1)),
+      {title: `Parallel Wheel ${i} Regression`, slope: 'y-position', noIntercept: true});
     deadWheelCharts.appendChild(div);
   });
   data.perpEncVels.forEach((vs, i) => {
     const div = document.createElement('div');
     newLinearRegressionChart(div, 
-      angVels.slice(1, angVels.length - 1),
-      fixVels(data.encTimes, data.perpEncPositions[i], vs),
-      {title: `Perpendicular Wheel ${i} Regression`, slope: 'x-position'});
+      angVels.slice(1, -1),
+      fixVels(data.encTimes.slice(0, -1), data.perpEncPositions[i].slice(0, -1), vs.slice(0, -1)),
+      {title: `Perpendicular Wheel ${i} Regression`, slope: 'x-position', noIntercept: true});
     deadWheelCharts.appendChild(div);
   });
 
   const setParams = (() => {
-    const appliedVoltages = data.voltages.map((v, i) => 
-      [...data.leftPowers, ...data.rightPowers].reduce((acc, ps) => Math.max(acc, ps[i]), 0) * v);
+    const allPowers = [...data.leftPowers, ...data.rightPowers];
+    const appliedVoltages = data.voltages.slice(0, -1).map((v, i) => 
+      allPowers.reduce((acc, ps) => Math.max(acc, ps[i]), 0) * v);
 
     const setTrackWidthData = newLinearRegressionChart(
       document.getElementById('trackWidthChart'),
       [], [],
-      {title: 'Track Width Regression', slope: 'track width'}
+      {title: 'Track Width Regression', slope: 'track width', noIntercept: true}
     );
 
     return (kV, kS) => setTrackWidthData(angVels, appliedVoltages.map((v, i) => 
@@ -119,6 +126,8 @@ function loadRegression(data) {
   document.getElementById('update').addEventListener('click', () => {
     setParams(parseFloat(kvInput.value), parseFloat(ksInput.value));
   });
+
+  setParams(parseFloat(kvInput.value), parseFloat(ksInput.value));
 }
 
 const latestButton = document.getElementById('latest');
@@ -130,10 +139,12 @@ latestButton.addEventListener('click', function() {
 
         const a = document.createElement('a');
         a.innerText = 'Download';
-        a.href = `/tuning/forward-ramp/${filename}`;
-        a.download = `forward-ramp-${filename}`;
+        a.href = `/tuning/angular-ramp/${filename}`;
+        a.download = `angular-ramp-${filename}`;
 
-        document.getElementById('download').appendChild(a);
+        const download = document.getElementById('download');
+        download.innerHTML = '';
+        download.appendChild(a);
 
         return res.json();
       } else {
@@ -142,7 +153,12 @@ latestButton.addEventListener('click', function() {
       }
     })
     .then(loadRegression)
-    .catch(console.log.bind(console));
+    .catch((e) => {
+      const deadWheelCharts = document.getElementById('deadWheelCharts');
+      deadWheelCharts.innerHTML = '';
+  
+      console.log(e);
+    });
 });
 
 const browseInput = document.getElementById('browse');
diff --git a/TeamCode/src/main/assets/tuning/drive-encoder-angular-ramp.html b/TeamCode/src/main/assets/tuning/drive-encoder-angular-ramp.html
index 816c396..8668fa6 100644
--- a/TeamCode/src/main/assets/tuning/drive-encoder-angular-ramp.html
+++ b/TeamCode/src/main/assets/tuning/drive-encoder-angular-ramp.html
@@ -9,6 +9,10 @@ body {
 }
 
 .content {
+  margin: auto;
+}
+
+header {
   max-width: 600px;
   margin: auto;
 }
@@ -39,48 +43,50 @@ details, a {
   </head>
   <body>
     <div class="content">
-      <h1>RR Drive Encoder Angular Ramp Regression</h1>
-      <details></details>
+      <header>
+        <h1>RR Drive Encoder Angular Ramp Regression</h1>
+        <details></details>
+
+        <div id="download"></div>
 
-      <div id="download"></div>
-      
-      <div id="rampChart">
         <p>
           <button id="latest">Latest</button>
           <input id="browse" type="file" accept="application/json">
         </p>
-      </div>
+      </header>
+      
+      <div id="rampChart"></div>
       <div id="trackWidthChart"></div>
     </div>
 
     <script>
 function loadRegression(data) {
   const leftEncVels = data.leftEncVels.map((vs, i) =>
-        fixVels(data.encTimes, data.leftEncPositions[i], vs));
+        fixVels(data.encTimes.slice(0, -1), data.leftEncPositions[i].slice(0, -1), vs.slice(0, -1)));
   const rightEncVels = data.rightEncVels.map((vs, i) =>
-        fixVels(data.encTimes, data.rightEncPositions[i], vs));
+        fixVels(data.encTimes.slice(0, -1), data.rightEncPositions[i].slice(0, -1), vs.slice(0, -1)));
 
   newLinearRegressionChart(
     document.getElementById('rampChart'),
     [
-      ...leftEncVels.flatMap(vs => vs.map(v => -v)), 
-      ...rightEncVels.flatMap(vs => vs),
+      ...leftEncVels.flatMap(vs => vs.slice(0, -1).map(v => -v)), 
+      ...rightEncVels.flatMap(vs => vs.slice(0, -1)),
     ],
     [
       ...data.leftPowers.flatMap(ps => {
-        const psNew = ps.map((p, i) => -p * data.voltages[i]);
-        return psNew.slice(1, psNew.length - 1);
+        const psNew = ps.slice(0, -1).map((p, i) => -p * data.voltages[i]);
+        return psNew.slice(1, -1);
       }),
       ...data.rightPowers.flatMap(ps => {
-        const psNew = ps.map((p, i) => p * data.voltages[i]);
-        return psNew.slice(1, psNew.length - 1);
+        const psNew = ps.slice(0, -1).map((p, i) => p * data.voltages[i]);
+        return psNew.slice(1, -1);
       }),
     ],
     {title: 'Ramp Regression', slope: 'kV', intercept: 'kS'}
   );
 
   const p = data.angVels.reduce((acc, vsArg) => {
-    const vs = vsArg.map(v => Math.abs(v));
+    const vs = fixAngVels(vsArg).map(v => Math.abs(v));
     const maxV = vs.reduce((acc, v) => Math.max(acc, v), 0);
     const [accMaxV, _] = acc;
     if (maxV >= accMaxV) {
@@ -88,7 +94,7 @@ function loadRegression(data) {
     }
     return acc;
   }, [0, []]);
-  const angVels = p[1].slice(1, p[1].length - 1);
+  const angVels = p[1].slice(1, -1);
 
   newLinearRegressionChart(
     document.getElementById('trackWidthChart'),
@@ -98,7 +104,7 @@ function loadRegression(data) {
         + rightEncVels.reduce((acc, vs) => acc + vs[i], 0) / data.rightEncVels.length)
         * (data.type === 'mecanum' ? 0.5 : 1)
     ),
-    {title: 'Track Width Regression', slope: 'track width'}
+    {title: 'Track Width Regression', slope: 'track width', noIntercept: true}
   );
 }
 
@@ -111,10 +117,12 @@ latestButton.addEventListener('click', function() {
 
         const a = document.createElement('a');
         a.innerText = 'Download';
-        a.href = `/tuning/forward-ramp/${filename}`;
-        a.download = `forward-ramp-${filename}`;
+        a.href = `/tuning/angular-ramp/${filename}`;
+        a.download = `angular-ramp-${filename}`;
 
-        document.getElementById('download').appendChild(a);
+        const download = document.getElementById('download');
+        download.innerHTML = '';
+        download.appendChild(a);
 
         return res.json();
       } else {
diff --git a/TeamCode/src/main/assets/tuning/forward-ramp.html b/TeamCode/src/main/assets/tuning/forward-ramp.html
index 4f75a8b..fb86c02 100644
--- a/TeamCode/src/main/assets/tuning/forward-ramp.html
+++ b/TeamCode/src/main/assets/tuning/forward-ramp.html
@@ -9,6 +9,10 @@ body {
 }
 
 .content {
+  margin: auto;
+}
+
+header {
   max-width: 600px;
   margin: auto;
 }
@@ -39,25 +43,27 @@ details, a {
   </head>
   <body>
     <div class="content">
-      <h1>RR Forward Ramp Regression</h1>
-      <details></details>
+      <header>
+        <h1>RR Forward Ramp Regression</h1>
+        <details></details>
 
-      <div id="download"></div>
+        <div id="download"></div>
 
-      <div id="rampChart">
         <p>
           <button id="latest">Latest</button>
           <input id="browse" type="file" accept="application/json">
         </p>
-      </div>
+      </header>
+
+      <div id="rampChart"></div>
     </div>
 
     <script>
 function loadRegression(data) {
   const forwardEncVels = data.forwardEncVels.flatMap((vs, i) => 
-    fixVels(data.encTimes, data.forwardEncPositions[i], vs));
+    fixVels(data.encTimes.slice(0, -1), data.forwardEncPositions[i].slice(0, -1), vs.slice(0, -1)));
   const appliedVoltages = data.forwardEncVels.flatMap(vs => {
-    const voltages = data.voltages.map((v, i) => 
+    const voltages = data.voltages.slice(0, -1).map((v, i) =>
       data.powers.reduce((acc, ps) => Math.max(acc, ps[i]), 0) * v);
 
     return voltages.slice(1, voltages.length - 1);
@@ -66,7 +72,7 @@ function loadRegression(data) {
   newLinearRegressionChart(
     document.getElementById('rampChart'),
     forwardEncVels, appliedVoltages,
-    {title: 'Ramp Regression', slope: 'kV', intercept: 'kS'}
+    {title: 'Ramp Regression', slope: 'kV', intercept: 'kS', noIntercept: false}
   );
 }
 
@@ -82,7 +88,9 @@ latestButton.addEventListener('click', function() {
         a.href = `/tuning/forward-ramp/${filename}`;
         a.download = `forward-ramp-${filename}`;
 
-        document.getElementById('download').appendChild(a);
+        const download = document.getElementById('download');
+        download.innerHTML = '';
+        download.appendChild(a);
 
         return res.json();
       } else {
