@sean I'll just show you how to use the ng-knob module instead of customising our gauge since it seems that is what you really want to use.
Use this for your usermodule file. This loads the ng-knob and d3 libraries (you dont need to load angular as our app already loads it) and tells the user module it needs to include the ui.knob module.
define(['angular', 'require',
'https://cdnjs.cloudflare.com/ajax/libs/ng-knob/0.1.3/ng-knob.js',
'https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.10/d3.min.js'], function(angular, require) {
'use strict';
var userModule = angular.module('userModule', ['maUiApp', 'ui.knob']);
return userModule;
}); // define
You don't really need to define and use a controller as you can just use the <ui-knob> directive in your pages.
e.g. Put a point value on the gauge and set some options -
<div class="ma-designer-root" id="8167524e-1ad3-414d-9b65-d872f1317b4d" style="width: 1366px; height: 768px; position: relative;">
<ui-knob id="2666c64f-0a4f-4041-82ee-1f132d82728e" value="myPoint.value" options="{size:300}" style="position: absolute; left: 220px; top: 80px;"></ui-knob>
<ma-get-point-value id="82a89bb2-cf03-49d2-a001-f9abf219c5fb" style="position: absolute; left: 28px; top: 159px;" point-xid="voltage" point="myPoint"></ma-get-point-value>
</div>