{"product_id":"calibration-blocks-for-baseline-accuracy-h2-series","title":"Calibration Blocks for Baseline Accuracy H2 Series","description":"\u003ch2\u003eTL;DR\u003c\/h2\u003e\u003cfigure class=\"table\"\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eTest Phase\u003c\/th\u003e\n\u003cth\u003eMeasurements\u003c\/th\u003e\n\u003cth\u003eAvg (mm)\u003c\/th\u003e\n\u003cth\u003eDeviation from 50 mm\u003c\/th\u003e\n\u003cth\u003e\n\u003cu\u003ePerceived\u003c\/u\u003e Shrinkage in %\u003c\/th\u003e\n\u003cth\u003eConsistency\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eBefore Vision Encoder\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003emix of 49.6x values\u003c\/td\u003e\n\u003ctd\u003e49.680\u003c\/td\u003e\n\u003ctd\u003e−0.320 mm\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong\u003e0.64%\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003elower\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eAfter Vision Encoder\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e8× 49.72, 2× 49.74\u003c\/td\u003e\n\u003ctd\u003e49.724\u003c\/td\u003e\n\u003ctd\u003e−0.276 mm\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong\u003e0.55%\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #E14747\"\u003e\u003cstrong\u003ehigh\u003c\/strong\u003e (0.02 mm spread)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/figure\u003e\u003ch2\u003eTest purpose and setup\u003c\/h2\u003e\u003cp\u003eHere’s a simple but useful little project for anyone who wants to check the baseline dimensional accuracy of their Bambu Lab H2 series printer – completely without the Vision Encoder (at least for now).\u003c\/p\u003e\u003cp\u003eBefore deciding whether I actually \u003ci\u003eneed\u003c\/i\u003e the Vision Encoder upgrade, I wanted to test how well my H2D performs straight out of the box. The printer is already impressively precise, but I wanted to approach this in a slightly more scientific way.\u003c\/p\u003e\u003cp\u003eSo I designed a clean set of \u003cstrong\u003e50×50 mm calibration blocks\u003c\/strong\u003e. One corner is rounded to hide the layer seam so it won’t interfere with measurements. When you're trying to detect deviations as small as 0.1 mm, even a seam can throw off your caliper readings. With the rounded corner, both X and Y axes provide perfectly straight lines for accurate measurement.\u003c\/p\u003e\u003cp\u003eTo get a good spread across the full build plate, the model is printed \u003cstrong\u003efive times\u003c\/strong\u003e:\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003ecenter\u003c\/li\u003e\n\u003cli\u003erear left\u003c\/li\u003e\n\u003cli\u003erear right\u003c\/li\u003e\n\u003cli\u003efront left\u003c\/li\u003e\n\u003cli\u003efront right\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eThis layout should give a solid first impression of how consistent the printer is across its entire printing area.\u003c\/p\u003e\u003cp\u003eAfter printing, I’ll measure all five blocks and see if any of them deviate from the expected 50×50 mm.\u003cbr\u003eIf I do find variations, I’ll order the Vision Encoder and repeat the experiment to see how much the calibration improves the results.\u003c\/p\u003e\u003cp\u003e \u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eFeel free to use these blocks for your own accuracy tests — and share your findings if you want!\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003e \u003c\/p\u003e\u003ch2\u003eBaseline-Test\u003c\/h2\u003e\u003cp\u003eAfter printing and measuring all five calibration blocks, I ended up with an average dimension of \u003cstrong\u003e49.68 × 49.68 mm \u003c\/strong\u003einstead of the intended 50 × 50 mm. This would correspond to a shrinkage of about \u003cstrong\u003e0.32 mm (≈0.64%)\u003c\/strong\u003e. PETG typically shows a shrinkage somewhere in the \u003cstrong\u003e0.2–0.6%\u003c\/strong\u003e range, so my result is slightly above the expected value but still within a reasonable range for an initial baseline test. This gives me a good starting point, and I plan to repeat the experiment after using the Vision Encoder to see how \/ if the dimensional accuracy changes.\u003c\/p\u003e\u003cfigure class=\"image\"\u003e\u003cimg src=\"https:\/\/makerworld.bblmw.com\/makerworld\/model\/DSM00000002060044\/design\/2025-12-05_7749a0cdae07d8.jpeg\"\u003e\u003c\/figure\u003e\u003cp\u003eI’ll now order the Vision Encoder and repeat the test to see if the measurements improve after calibration and a new set of prints.\u003c\/p\u003e\u003ch2\u003eVision-Encoded-Test\u003c\/h2\u003e\u003cp\u003eAfter installing the Vision Encoder and completing the calibration process, I repeated the baseline accuracy test with five new \u003cstrong\u003e50×50 mm calibration blocks\u003c\/strong\u003e. \u003c\/p\u003e\u003cfigure class=\"image\"\u003e\u003cimg src=\"https:\/\/makerworld.bblmw.com\/makerworld\/model\/DSM00000002060044\/design\/2025-12-05_c73f9fa8798e9.jpeg\"\u003e\u003c\/figure\u003e\u003cp\u003eThis time the results were much more consistent: \u003cstrong\u003e8 blocks measured 49.72 × 49.72 mm and 2 blocks measured 49.74 × 49.74 mm\u003c\/strong\u003e. That’s a total variation of only \u003cstrong\u003e0.02 mm\u003c\/strong\u003e, which is a clear improvement compared to the first test.\u003cbr\u003e\u003cbr\u003e\u003cstrong\u003eIn particular, the calibration blocks are now consistent across both the X and Y axes:\u003c\/strong\u003e\u003c\/p\u003e\u003cfigure class=\"image\"\u003e\u003cimg src=\"https:\/\/makerworld.bblmw.com\/makerworld\/model\/DSM00000002060044\/design\/2025-12-05_1bd2e4dc0a264.jpeg\"\u003e\u003c\/figure\u003e\u003cp\u003e \u003c\/p\u003e\u003cp\u003eFrom a neutral perspective, this indicates that the Vision Encoder effectively reduces positional deviation and improves repeatability across the build plate. The average measurement of \u003cstrong\u003e49.724 mm\u003c\/strong\u003e corresponds to a shrinkage of \u003cstrong\u003e0.276 mm\u003c\/strong\u003e, or approximately \u003cstrong\u003e0.55%\u003c\/strong\u003e—slightly lower than the initial \u003cstrong\u003e0.64%\u003c\/strong\u003e baseline. While the printed parts remain a bit under the nominal 50 mm target (which is completely normal for PETG due to material shrinkage), the results are now far more uniform. \u003cstrong\u003eOverall, the calibration delivers a cleaner, more stable, and more reliable dimensional baseline for any future tests.\u003c\/strong\u003e\u003c\/p\u003e\u003ch2\u003eA Quick Note on Perceived Shrinkage (Actual vs. Perceived Shrinkage)\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eThe Vision Encoder and its calibration cannot influence material shrinkage, because shrinkage is caused by the physical behavior of the filament as it cools down — not by the motion accuracy of the printer.\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003e \u003c\/p\u003e\u003cp\u003eMaterial shrinkage depends on:\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003ethe chemical composition of the filament (PETG in this case),\u003c\/li\u003e\n\u003cli\u003eextrusion temperature,\u003c\/li\u003e\n\u003cli\u003ecooling behavior,\u003c\/li\u003e\n\u003cli\u003elayer height,\u003c\/li\u003e\n\u003cli\u003eambient temperature,\u003c\/li\u003e\n\u003cli\u003einfill and wall thickness,\u003c\/li\u003e\n\u003cli\u003eand the thermal contraction during cooling.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eNone of these factors change when you add the Vision Encoder.\u003c\/p\u003e\u003cp\u003e \u003c\/p\u003e\u003cp\u003eThe Vision Encoder only affects \u003cstrong\u003ehow precisely the print head follows the intended X\/Y path\u003c\/strong\u003e. It corrects motion deviations, backlash, small nonlinearities, and positional drift across the build plate.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eSo while the Vision Encoder \u003c\/strong\u003e\u003ci\u003e\u003cstrong\u003ecan\u003c\/strong\u003e\u003c\/i\u003e\u003cstrong\u003e improve dimensional consistency and accuracy of the printer’s movements, it cannot reduce or increase the inherent shrinkage of PETG.\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003e \u003c\/p\u003e\u003cp\u003eThe reason the calculated shrinkage percentages differ (0.64% before vs. 0.55% after) is simply because we express them relative to the \u003ci\u003eintended\u003c\/i\u003e 50 mm dimension. Since the measured averages changed slightly between the two tests, the percentage value changes as well — but this does \u003cstrong\u003enot\u003c\/strong\u003e mean the material suddenly shrank differently. It only reflects the difference in the printed dimensions, not a change in the filament’s physical shrinkage behavior.\u003c\/p\u003e\u003cp\u003e \u003c\/p\u003e\u003cp\u003eIn other words:\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eShrinkage comes from physics.\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eConsistency comes from mechanics.\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eThe results reflect exactly that:\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eShrinkage is still present (normal for PETG) - but measured relative to the intended 50 mm.\u003c\/li\u003e\n\u003cli\u003eBut the \u003cstrong\u003evariation between prints dropped massively\u003c\/strong\u003e, because the motion system is now more repeatable and accurate.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eDesign by De Ka on MakerWorld (license: BY).\u003c\/p\u003e","brand":"Mymadmanlab","offers":[{"title":"Default Title","offer_id":67391421120816,"sku":null,"price":9.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0987\/0809\/5280\/files\/0_7c59bb6f-fc66-4160-baa6-644d2dea7914.png?v=1784750771","url":"https:\/\/mymadmanlab.com\/products\/calibration-blocks-for-baseline-accuracy-h2-series","provider":"Mymadmanlab.com","version":"1.0","type":"link"}