<p>I am extending the bed of my TronXY X3 FDM RepRap printer.</p>

<p>I am extending the bed from 220&nbsp;mm x 220&nbsp;mm to 220&nbsp;mm x 300&nbsp;mm.  For now, I will keep the existing bed and add and aluminum sheet on top.  That leaves 40mm on front and back of the original bed.</p>

<p>Right now I only plan on running PLA; but, I do plan on heating the bed.</p>

<p>How thick does the aluminum sheet need to be?</p>

[{'answer_id': 4477, 'author': 'Mikhail Z', 'author_id': 3839, 'author_profile': 'https://3dprinting.stackexchange.com/users/3839', 'pm_score': 3, 'selected': False, 'text': '<p>Main factors that control the process of the print bed selection are</p>\n\n<ul>\n<li>weight: too thick plate increases inertial force, limiting maximum acceleration/jerk (decreased print speed)</li>\n<li>stiffness: too thin plate will warp when heated or bend during calibration (decreased print quality/printer reliability)</li>\n</ul>\n\n<p>For table sizes around 400x400mm I would think of 4mm plate, but it still can warp if heated unevenly.</p>\n\n<p>Sometimes it makes sense to use a sandwich-type table: lower level is MDF, cork panel for heat insulation and thin (1.5-2mm) aluminum heated bed on top.</p>\n'}, {'answer_id': 10186, 'author': 'cmm', 'author_id': 2082, 'author_profile': 'https://3dprinting.stackexchange.com/users/2082', 'pm_score': 2, 'selected': False, 'text': '<p>I build an 18.5&quot; diameter delta printer.  The bed was 3/8&quot; thick 6061 aluminum.  It is plenty stiff, but it takes an hour to heat to 100°C.  When I rebuild it, I\'ll probably drop down to 1/4&quot; and increase the heater from about 250 Watts to 750 Watts.  That should heat the bed in 15 minutes, which is still a long time.  Waiting for the bed to heat for ABS is one of the greatest frustrations with that machine.</p>\n<p>For your machine, how much the 1/8&quot; plate bends will depend a great deal on which aluminum alloy and temper you use.  From <a href="https://www.onlinemetals.com/en/buy/aluminum-sheet?q=%3Aprice-asc%3AThickness%3A0.125%2522%3AAlloy%3A7075%3ATemper%3AT6%3AMaterial%3AAluminum%3AAlloy%3A6061&amp;checkbox=on#" rel="nofollow noreferrer">OnlineMetals.com</a>, 6061-T6 and 7075-T6 are available.  7075 is slightly stiffer, but both should be good enough.  6061 is half the price.</p>\n'}, {'answer_id': 15930, 'author': 'Ek1212', 'author_id': 27400, 'author_profile': 'https://3dprinting.stackexchange.com/users/27400', 'pm_score': 0, 'selected': False, 'text': '<p>I highly recommend aluminium tooling plates. They have a +/- 0.1\xa0mm flatness tolerance on 1 meter. It\'s alloy 5083 offers a great stability. You can purchase such for example at aluminyumburada, which offers <a href="https://www.aluminyumburada.com/aluminum-cut-to-size" rel="nofollow noreferrer">custom cut piecees.</a>. They have a minimum thickness of 5\xa0mm, though the prices get lower the thicker the piece is.</p>\n'}]
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