Wiki source code of Polycarbonate Information Page
Version 12.1 by Eric Nantel on 2023/01/16 14:19
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1.1 | 1 | {{html wiki="false" clean="true"}} |
| 2 | <body bgcolor="#FFFFFF"> | ||
| 3 | <table border="0" cellpadding="0" cellspacing="0" > | ||
| 4 | <tbody><tr> | ||
| 5 | <td valign="top" ><font size="2" face="verdana"><strong>Polycarbonate Information Page<br> | ||
| 6 | <br> | ||
| 7 | Updated <!--webbot bot="Timestamp" startspan s-type="EDITED" s-format="%m/%d/%Y" -->07/30/2007<!--webbot bot="Timestamp" i-checksum="12528" | ||
| 8 | endspan --></strong></font> | ||
| 9 | <p><font size="2" face="verdana"><b>Why Polycarbonate?<br> | ||
| 10 | </b>Some of our robots use Polycarbonate. Why, because it is very strong. The image to the right is of me trying really hard to bend one of the | ||
| 11 | H2 bottom panels. It really hurt holding this long enough for the camera to snap the image. When I let go it returned to its normal flat | ||
| 12 | shape, no worse for the wear. Now Polycarbonate is not indestructible, but it is very tough. A 1/8" thick x 1/4" wide strip can be | ||
| 13 | broken, but it takes several back and forth bends before it finally breaks. </font></p> | ||
| 14 | <p> </p> | ||
| 15 | </td> | ||
| 16 | <td align="center" valign="top " width="320"><img src="./Information on Polycarbonate_files/lexan01s.jpg" border="2" hspace="10" width="320" height="240"><br> | ||
| 17 | <strong><font size="2" face="verdana">Will it Break? No!<br> | ||
| 18 | <br> | ||
| 19 | </font></strong></td> | ||
| 20 | </tr> | ||
| 21 | <tr> | ||
| 22 | <td valign="top" ><font size="2" face="verdana"><b>Laser-cut Lexan properties</b> <br> | ||
| 23 | The cut edge has a black residue which can easily be cleaned with a damp rag or paper towel. It is normal and can't be helped. When the residue | ||
| 24 | is cleaned off, the edge will still be darker than the material. The dark edge is going to be present no matter what color the Lexan is. Most | ||
| 25 | people like the way the cut edge looks, but there are some who would prefer not to have the dark edge. Technically, it would be possible to try | ||
| 26 | to polish the edges, but beware it would be a very labor intensive project, and not worth the trouble in my opinion. <br> | ||
| 27 | <br> | ||
| 28 | <br> | ||
| 29 | </font></td> | ||
| 30 | <td align="center" valign="top" ><img src="./Information on Polycarbonate_files/lexan02.jpg" border="2" hspace="10" width="320" height="240"><br> | ||
| 31 | <font size="2" face="verdana">Figure 1.<br> | ||
| 32 | <br> | ||
| 33 | </font></td> | ||
| 34 | </tr> | ||
| 35 | <tr> | ||
| 36 | <td valign="top" ><font size="2" face="verdana"><b>Lexan protective covering</b> <br> | ||
| 37 | The Lexan pieces have a protective covering that needs to be removed before assembly. When the laser cuts, the covering melts into the cut edge | ||
| 38 | which can make removal difficult. If you gently scrape the cut edge with a metal edge, such as a flat blade screw driver, the covering can | ||
| 39 | easily be separated with a thumb nail. </font></td> | ||
| 40 | <td align="center" valign="top" ><img src="./Information on Polycarbonate_files/lexan04.jpg" border="2" hspace="10" width="320" height="240"><br> | ||
| 41 | <font size="2" face="verdana">Figure 2.<br> | ||
| 42 | <br> | ||
| 43 | </font></td> | ||
| 44 | </tr> | ||
| 45 | <tr> | ||
| 46 | <td valign="top" ><font size="2" face="verdana"><b>Peal and Separate</b><br> | ||
| 47 | Once it is started the covering easily peels off of the pieces. Note, you only want to scrape the edge. If done properly the pieces will not be | ||
| 48 | damaged at all. <br> | ||
| 49 | </font> | ||
| 50 | <p> </p> | ||
| 51 | </td> | ||
| 52 | <td align="center" valign="top" ><img src="./Information on Polycarbonate_files/lexan05.jpg" border="2" hspace="10" width="320" height="240"><br> | ||
| 53 | <font size="2" face="verdana">Figure 3.<br> | ||
| 54 | <br> | ||
| 55 | </font></td> | ||
| 56 | </tr> | ||
| 57 | <tr> | ||
| 58 | <td valign="top" ><font size="2" face="verdana"><b>Stubborn Coverings</b><br> | ||
| 59 | From time to time the coverings can be more difficult to remove. If you have trouble you can gently scrape the cut edge as explained above, then | ||
| 60 | put a piece of Duct Tape over it, then rip it up. This really works pretty well. </font></td> | ||
| 61 | <td align="center" valign="top" ><img src="./Information on Polycarbonate_files/lexan09.jpg" border="2" hspace="10" width="320" height="240"><br> | ||
| 62 | <font size="2" face="verdana">Figure 4.<br> | ||
| 63 | <br> | ||
| 64 | </font></td> | ||
| 65 | </tr> | ||
| 66 | <tr> | ||
| 67 | <td valign="top" ><font size="2" face="verdana"><b>The Finish</b><br> | ||
| 68 | Lexan has a beautiful mirror smooth finish. However, in time it will get tiny surface scratches due to cleaning and normal wear and tear. It | ||
| 69 | isn't really that noticeable, but under the right conditions it can be visible. Note: this step is optional!</font> | ||
| 70 | <p><font size="2" face="verdana">There are some options for modifying the finish.</font></p> | ||
| 71 | <p><font size="2" face="verdana">The Lexan parts can be sand blasted with a fine medium. I especially like the look on the black | ||
| 72 | components. </font></p> | ||
| 73 | <p><font size="2" face="verdana">The parts can be lightly sanded by hand, or with a random orbit sander with extra fine sand paper. This is easy | ||
| 74 | to do, but should be done carefully to avoid removing too much material. The key is to make light even passes with the sander. </font></p> | ||
| 75 | <p><font size="2" face="verdana">The result is a durable charcoal gray appearance that can't be scratched, because it has been pre-scratched in | ||
| 76 | every direction.<br> | ||
| 77 | <br> | ||
| 78 | Lexan can also be painted, but use paint specifically designed for use with Polycarbonate. Your local hobby shop can help with this. There | ||
| 79 | has also been some new developments in the paint industry specifically for plastics. Check out Krylon Fusion. <br> | ||
| 80 | </font></p> | ||
| 81 | </td> | ||
| 82 | <td align="center" valign="top" ><img src="./Information on Polycarbonate_files/lexan03.jpg" border="2" hspace="10" width="320" height="240"><br> | ||
| 83 | <font size="2" face="verdana">Figure 5.<br> | ||
| 84 | <br> | ||
| 85 | </font></td> | ||
| 86 | </tr> | ||
| 87 | <tr> | ||
| 88 | <td valign="top" ><font size="2" face="verdana">Here is an image of our old Pan and Tilt with the random orbit finish.<br> | ||
| 89 | </font></td> | ||
| 90 | <td align="center" valign="top" ><img src="./Information on Polycarbonate_files/lexinf06.jpg" border="2" hspace="10" width="320" height="240"><br> | ||
| 91 | <font size="2" face="verdana">Figure 6.<br> | ||
| 92 | </font></td> | ||
| 93 | </tr> | ||
| 94 | <tr> | ||
| 95 | <td valign="top" ><font size="2" face="verdana"><b>Finishing the holes</b><br> | ||
| 96 | The holes in the panels just need a bit of a push and they just fall out. I am using a 3/32" ball end hex driver here. It works quite well | ||
| 97 | and it's required to build the kits anyway. <br> | ||
| 98 | </font></td> | ||
| 99 | <td align="center" valign="top" ><img src="./Information on Polycarbonate_files/lexan06.jpg" border="2" hspace="10" width="320" height="240"><br> | ||
| 100 | <font size="2" face="verdana">Figure 7.<br> | ||
| 101 | <br> | ||
| 102 | </font></td> | ||
| 103 | </tr> | ||
| 104 | <tr> | ||
| 105 | <td valign="top" ><font size="2" face="verdana"><b>Separating the parts</b><br> | ||
| 106 | Some of the kits have parts nested to simplify packaging and reduce errors. Larger parts can be snapped apart. The smaller parts can be easily | ||
| 107 | separated with a hobby knife. Be careful! Use a large wood backer and work slowly. <br> | ||
| 108 | </font></td> | ||
| 109 | <td align="center" valign="top" ><img src="./Information on Polycarbonate_files/lexan07.jpg" border="2" hspace="10" width="320" height="240"><br> | ||
| 110 | <font size="2" face="verdana">Figure 8.<br> | ||
| 111 | <br> | ||
| 112 | </font></td> | ||
| 113 | </tr> | ||
| 114 | <tr> | ||
| 115 | <td valign="top" ><font size="2" face="verdana"><b>Separating the optional openings</b><br> | ||
| 116 | Some of the kits have optional openings that need to be cut out before assembly. Carefully press a flat Exacto knife into the opening where the | ||
| 117 | part is attached to the main panel. <br> | ||
| 118 | <br> | ||
| 119 | Caution! Do not attempt to snap these optional openings apart. <br> | ||
| 120 | </font></td> | ||
| 121 | <td align="center" valign="top" ><img src="./Information on Polycarbonate_files/lexan08.jpg" border="2" hspace="10" width="320" height="240"><br> | ||
| 122 | <font size="2" face="verdana">Figure 9.<br> | ||
| 123 | <br> | ||
| 124 | </font></td> | ||
| 125 | </tr> | ||
| 126 | <tr> | ||
| 127 | <td valign="top" ><font size="2" face="verdana"><b>Caution!</b><br> | ||
| 128 | Lexan is the same material used in bullet proof glass. It is very strong, but has one important weakness. In the presence of certain chemicals, | ||
| 129 | it will "craze". This means it will crystallize, become brittle, and even shatter. One substance in particular to watch out for is 1, | ||
| 130 | 1, 1 Trichloroethane. This is a solvent, present in some motor cleaners and degreasers, which will crystallize polycarbonate on contact. | ||
| 131 | Trichloroethane is a liquid CFC and has been removed from use, but may still be out there. Some products have switched to its cousin, 1, 1, | ||
| 132 | Difluoroethane. While not as vigorously reactive as the previous chemical, it is still capable of crazing Lexan if allowed to come into contact | ||
| 133 | for too long. Also avoid using Loctite or thread locks on the chassis assembly. They are not necessary and may cause damage to the Lexan.<br> | ||
| 134 | <br> | ||
| 135 | </font></td> | ||
| 136 | <td align="center" valign="top" ></td> | ||
| 137 | </tr> | ||
| 138 | <tr> | ||
| 139 | <td valign="top" ><font size="2" face="verdana"><b>Other Information</b><br> | ||
| 140 | Lexan is a bit on the expensive side compared to foam PVC and acrylic, but the added strength makes it well worth the added cost. It can be | ||
| 141 | drilled and cut easily using standard wood working tools. Use a low speed on the tool and low feed rates to prevent the plastic from melting to | ||
| 142 | the tool. Have fun building your robots, and above all be careful!<br> | ||
| 143 | </font></td> | ||
| 144 | <td align="center" valign="top" ></td> | ||
| 145 | </tr> | ||
| 146 | </tbody></table> | ||
| 147 | </body> | ||
| 148 | {{/html}} |