Anti-derailing spoolholder for Prusa Mini

prusaprinters

<p>It is a remix of the original spoolholder that uses printed roller arms and springs to press the spool down.</p><p>To improve the stability of the arm, the profile was divided into two halves, the lower one containing the bushing and separated by a gap of 0.20 mm, the upper one containing the printed spring.</p><p>The rollers have a slight curve to try to overcome the alignment deviations of the spool with respect to the holder.</p><p>The OnShape 3D CAD file for this are available here:<br><a href="https://cad.onshape.com/documents/49bbf8f57065cf313647f15b/w/79f602383b284972660d6f5b/e/ac18d49cb493de29b635015a?renderMode=0&amp;uiState=6168a4756900f101d148eec0">https://cad.onshape.com/documents/49bbf8f57065cf313647f15b/w/79f602383b284972660d6f5b/e/ac18d49cb493de29b635015a?renderMode=0&amp;uiState=6168a4756900f101d148eec0</a></p><h3><strong>Print instructions</strong></h3><p>The tests were carried out with PETG and 15% infill at 230 degrees and a flow rate of 0.98 to avoid stringing and plastic debris.</p><p>Print the gcode twice because it only contains the parts of one rail/base.</p><h3><strong>Assemble</strong></h3><ul><li>Separate the springs from the bushing where the arm pivots with a cutter or knife.</li></ul><figure class="image image-style-align-center image_resized" style="width:46.81%;"><img src="https://media.prusaprinters.org/media/prints/78854/rich_content/c9dffc5e-f522-4811-97a6-bee49c4d8ef6/separar_spring_1.jpeg#%7B%22uuid%22%3A%22710bed47-87da-42cf-a1f9-4316c0bf96e1%22%2C%22w%22%3A1600%2C%22h%22%3A1500%7D"></figure><figure class="image image-style-align-center image_resized" style="width:48.57%;"><img src="https://media.prusaprinters.org/media/prints/78854/rich_content/aa543234-a781-4003-bf9d-f108352cb4b4/separar_spring_2.jpeg#%7B%22uuid%22%3A%22a7af9eb7-7602-45cb-8213-e3abc20ac7f3%22%2C%22w%22%3A991%2C%22h%22%3A1280%7D"></figure><ul><li>For proper adjustment, clean the base hex lock with a cutter.</li></ul><figure class="image image_resized" style="width:50%;"><img src="https://media.prusaprinters.org/media/prints/78854/rich_content/06673e65-e34a-43e3-8648-10ae36e3c6f4/clean_arm_lock.jpeg#%7B%22uuid%22%3A%227bdb585b-791a-4f47-9540-55526493ab5d%22%2C%22w%22%3A978%2C%22h%22%3A1280%7D"></figure><ul><li>For proper adjustment, clean the pin hex lock on the arm with a cutter.</li></ul><figure class="image image_resized" style="width:50%;"><img src="https://media.prusaprinters.org/media/prints/78854/rich_content/cbebf74c-f26e-444a-9fef-3a2ea0d91d48/clean_arm_lock_1.jpeg#%7B%22uuid%22%3A%224496c97c-bc06-463e-b813-399696ebf8df%22%2C%22w%22%3A1280%2C%22h%22%3A747%7D"></figure><ul><li>Insert the arms (L and R) into the base, pressing gently until the pin hexagon is in level with the spring.</li></ul><figure class="image image_resized" style="width:50%;"><img src="https://media.prusaprinters.org/media/prints/78854/rich_content/c55ee891-53ee-456e-a659-da1a1f0bd291/insert_arm_left.jpeg#%7B%22uuid%22%3A%22c805cb70-1c72-4d15-9e50-2bd520168c47%22%2C%22w%22%3A1280%2C%22h%22%3A1165%7D"></figure><figure class="image image_resized" style="width:50%;"><img src="https://media.prusaprinters.org/media/prints/78854/rich_content/acf08b92-839e-4016-9e00-84b14458cc40/level_arm_left.jpeg#%7B%22uuid%22%3A%22cfe782c4-0ecd-45cb-85c3-70b99293ab8e%22%2C%22w%22%3A1014%2C%22h%22%3A1280%7D"></figure><ul><li>At this stage you should have the following materials to assemble a base half: two bearings 608Z, two M3x12, two M3x20, and four M3 nuts, plus the printed parts.</li></ul><figure class="image"><img src="https://media.prusaprinters.org/media/prints/78854/rich_content/c452e759-c96e-40db-9011-c9076a492d6a/need_parts.jpeg#%7B%22uuid%22%3A%22baae33e1-142a-4610-adad-e2d54b040848%22%2C%22w%22%3A1600%2C%22h%22%3A793%7D"></figure><ul><li>On the right side aided by the screws insert the M3x1.9 nuts.</li></ul><figure class="image image_resized" style="width:50%;"><img src="https://media.prusaprinters.org/media/prints/78854/rich_content/40983149-6549-45a7-b51f-b77e3a2b917b/insert_nuts.jpeg#%7B%22uuid%22%3A%22345785ac-6bff-443e-bc6e-212c822dde30%22%2C%22w%22%3A616%2C%22h%22%3A1280%7D"></figure><ul><li>In one of the base halves put the two bearings and rollers.</li></ul><figure class="image image_resized" style="width:75%;"><img src="https://media.prusaprinters.org/media/prints/78854/rich_content/1cf825e8-0ce9-4e7c-8b46-aa757730989a/insert_bearings.jpeg#%7B%22uuid%22%3A%226f957185-87a7-4818-aaeb-53f3042fff7f%22%2C%22w%22%3A1280%2C%22h%22%3A1098%7D"></figure><ul><li>On the left side put the M3x20 screw at the top and the M3x12 screw at the bottom, tighten moderately.</li></ul><figure class="image image_resized" style="width:50%;"><img src="https://media.prusaprinters.org/media/prints/78854/rich_content/c7126df3-caff-4e2f-b0d5-59b2e203e74a/screw_m3.jpeg#%7B%22uuid%22%3A%22aac8036d-962f-40d6-a90b-78e4216367b3%22%2C%22w%22%3A504%2C%22h%22%3A1280%7D"></figure><ul><li>When you finish tightening the screws on both halves, the rail should look like this.</li></ul><figure class="image image_resized" style="width:50%;"><img src="https://media.prusaprinters.org/media/prints/78854/rich_content/9b8969bd-a3d3-4678-84d3-b066c5af83ce/one_rail.jpeg#%7B%22uuid%22%3A%22f3d1d582-454d-48b3-873e-54e3b3cfea2f%22%2C%22w%22%3A726%2C%22h%22%3A1280%7D"></figure><ul><li>Two base halves and four M3x8 screws are required to assemble the rails.</li></ul><figure class="image image_resized" style="width:75%;"><img src="https://media.prusaprinters.org/media/prints/78854/rich_content/955d656e-7b4c-4be7-a63b-530aa8aeaf96/asemble_parantes.jpeg#%7B%22uuid%22%3A%2202366ab5-8278-4674-973a-deda26e48d9b%22%2C%22w%22%3A1600%2C%22h%22%3A864%7D"></figure><ul><li>Screw the four M3x8 as shown in the figure.</li></ul><figure class="image image_resized" style="width:50%;"><img src="https://media.prusaprinters.org/media/prints/78854/rich_content/607af3ec-c37a-4402-a309-0bc987776421/screw_m3_in_rail.jpeg#%7B%22uuid%22%3A%22fc63d897-388d-45ab-9bb3-73f2b0242847%22%2C%22w%22%3A810%2C%22h%22%3A1280%7D"></figure><ul><li>Insert the rails as shown in the figure on both bases. Verify that the rails can be moved to fit the width of the spool.</li></ul><figure class="image image_resized" style="width:50%;"><img src="https://media.prusaprinters.org/media/prints/78854/rich_content/4068d702-2fa7-4d20-8989-d3368311897e/insert_rails.jpeg#%7B%22uuid%22%3A%22d4e46945-9058-48bd-9e1e-23692fb7e38d%22%2C%22w%22%3A1599%2C%22h%22%3A899%7D"></figure><ul><li>Attach the 4 anti-slip pads of approximately 14 x 19 mm.</li></ul><figure class="image image_resized" style="width:75%;"><img src="https://media.prusaprinters.org/media/prints/78854/rich_content/468617bb-2e28-4def-8191-1004a14471e0/ant-slip_pads.jpeg#%7B%22uuid%22%3A%22d55458ad-a29f-47ad-a3b5-fc3964d81b79%22%2C%22w%22%3A885%2C%22h%22%3A1280%7D"></figure><ul><li>The finished spoolholder should look like this.</li></ul><figure class="image"><img src="https://media.prusaprinters.org/media/prints/78854/rich_content/335a0de7-1f70-430f-bb4a-b9242ec7de63/look_complete.jpeg#%7B%22uuid%22%3A%22a4655a41-ef9f-4b26-8be5-f64104eca9ce%22%2C%22w%22%3A1261%2C%22h%22%3A1280%7D"></figure><p>&nbsp;</p>