<p>I'm making a Circuit etching machine (CNC) and I need a good DC motor and drill bit for the spindle. </p>

<p>My machine should be able to <strong>etch</strong>, <strong>drill</strong>, and <strong>cut</strong>:</p>

<ul>
<li><strong>Etching</strong>: take copper off the surface like chemicals or a laser would</li>
<li><strong>Drilling</strong>: drill holes for THT (through-hole) components and possibly 2-sided boards</li>
<li><strong>Cutting</strong>: cut out a piece of the board (cutting a big piece in half or cut a circle out of a big piece)</li>
</ul>

<p>I'd like to have 1 drill bit work with all 3 functions if possible. Having to switch out different bits is OK but a single bit is prefered.</p>

<p>What sort of specifications should my spindle DC motor (rpm, voltage/amperage rating, ...) and drill bit (material, size, angle, ...) have? </p>

[{'answer_id': 10711, 'author': 'cmm', 'author_id': 2082, 'author_profile': 'https://3dprinting.stackexchange.com/users/2082', 'pm_score': 2, 'selected': False, 'text': '<p>There are several sources of PCB "etching" bits.  They tend to be single straight flutes and high angle, very pointy bits.</p>\n\n<p>For the motor, high speed is good.  Look for 30k+ RPM.  The main thing to be concerned about is the amount of runout, or wobble in the tip.  With a tiny tip, you can\'t afford much runout at all.  It will broaden the gap you are cutting and put stress on the bit, probably snapping it.</p>\n\n<p>The key to low runout is very careful alignment of the chuck that holds the tip with the shaft of the motor, and a collet chuck to hold the tool.</p>\n\n<p>The power needs aren\'t high since the speed is high and the cuts are light.  I would think that a 250 watt motor should be way more than sufficient.</p>\n\n<p>The question now asks for drilling and routing, which should work better with the high-speed spindle.  30k is better for the tiny drills than a much slower spindle.  These are hurt by run out.</p>\n\n<p>Usually the drill bits are made of carbide.  For cutting, carbide router or file bits are used.  All drill-bits and router bits and copper cutting bits I have seen for sale have 1/8" or 3mm shank.</p>\n'}, {'answer_id': 10715, 'author': 'Davo', 'author_id': 4922, 'author_profile': 'https://3dprinting.stackexchange.com/users/4922', 'pm_score': 2, 'selected': False, 'text': '<p>At <a href="http://hyrel3d.com" rel="nofollow noreferrer">Hyrel</a>, where I work, we use a 12&nbsp;VDC, 3.5&nbsp;A, 40&nbsp;W spindle tool with 1/4" chuck and 3,000 rpm max (without load) to make prototype circuit boards by machining through the copper layer to make isolation traces.</p>\n'}, {'answer_id': 10904, 'author': 'Greenonline', 'author_id': 4762, 'author_profile': 'https://3dprinting.stackexchange.com/users/4762', 'pm_score': 1, 'selected': False, 'text': '<h3>TL;DR</h3>\n<p>From Davo\'s and cmm\'s answers there seems to be a wide range of drill spindle speeds used (3k-30k rpm). So, just to add to that... 11,000 rpm would appear to be adequate.</p>\n<hr />\n<p>I have been looking into converting a Wilson II 3D printer chassis into a CNC PCB etching machine, recently. In particular, what motor I needed to replace the extruder with.</p>\n<p>A collegue pointed me to an interesting video, <a href="https://www.youtube.com/watch?v=9DhPwtCZ9u4" rel="nofollow noreferrer">PCB making, PCB prototyping – UV solder mask STEP by STEP</a>, produced by Wegstr (no affiliation whatsoever), and their machine uses a 11,000 rpm drill. From the <a href="https://wegstr.com/CNC-Wegstr-(English)" rel="nofollow noreferrer">specification page</a>:</p>\n<blockquote>\n<ul>\n<li>Spindle - Brushless AC motor</li>\n<li>Diameter of spindle - 3.175 mm (0.000737 inch)</li>\n<li>Spindle speed - 11 000 rpm\nElectronic overload protection for the spindle motor</li>\n</ul>\n</blockquote>\n<p>Apparently DC motors suffer from carbon brush wear, so a combination of DC circuitry and brushless AC motor is used for &quot;superior performance and durability&quot;.</p>\n<p>The voltage and current of the spindle motor is unclear/unspecified, but the PSU, that comes with it, outputs 12\xa0V 5\xa0A.</p>\n<p>However, the parts page lists the spindle motor separately, <a href="https://wegstr.com/spindle-11000-rpm" rel="nofollow noreferrer">spindle 11000rpm</a>, with the following specifications:</p>\n<blockquote>\n<ul>\n<li>26V DC power supply</li>\n<li>11000 rpm</li>\n<li>designed for tools with shank diameter 3.175 mm</li>\n<li>fastening tool with the setscrew</li>\n<li>in the rear spindle 4x M4 threaded hole for mounting on a substrate</li>\n<li>power consumption 25W</li>\n<li>brushless construction =&gt; no carbon brush wear =&gt; long life</li>\n<li>low noise</li>\n</ul>\n</blockquote>\n<p>So, given the voltage and power consumption the current rating would seem to be ~1\xa0A.</p>\n<p><a href="https://i.stack.imgur.com/qGv0B.jpg" rel="nofollow noreferrer" title="Spindle Motor 11000 rpm"><img src="https://i.stack.imgur.com/qGv0B.jpg" alt="Spindle Motor 11000 rpm" title="Spindle Motor 11000 rpm" /></a></p>\n'}]
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